Topographic optic disc analysis by Heidelberg retinal tomography in ocular Behcet's disease.

PubMed

Berker, Nilufer; Elgin, Ufuk; Ozdal, Pinar; Batman, Aygen; Soykan, Emel; Ozkan, Seyhan S

2007-09-01

To compare the topographic characteristics of the optic discs in patients with severe and mild ocular Behçet's disease by using Heidelberg retinal tomographaphy (HRT). This prospective study included 47 eyes of 47 patients with ocular BD who were being followed-up at the Uveitis Clinic of the Ankara Ulucanlar Eye Research Hospital, Ankara, Turkey. The patients were divided into two groups. Group 1 consisted of 21 eyes with mild uveitis, and group 2 consisted of 26 eyes with severe uveitis. All patients underwent topographic optic disc analysis by HRT II, and the quantitative optic disc parameters of both groups were compared by non-parametric Mann-Whitney U test. The mean cup volume, rim volume, cup area, disc area and cup depth in group 1 were found to be statistically significantly greater than those in group 2 (p<0.0001, p = 0.03, p = 0.021, p = 0.01 and p = 0.017, respectively), while the difference between the mean cup-to-disc ratios in group 1 and group 2 were found to be statistically insignificant (p = 0.148). A relationship was found between the severity of ocular BD and optic disc topography determined by HRT. In eyes with smaller optic discs, uveitis was observed to have a more severe course with more frequent relapses than those with larger discs.

Pattern visual evoked potentials in eyes with disc swelling due to cat scratch disease-associated neuroretinitis.

PubMed

Chai, Yuzhu; Yamamoto, Shuichi; Hirayama, Atsuko; Yotsukura, Jiro; Yamazaki, Hiroko

2005-01-01

To evaluate optic nerve function by pattern visual evoked potentials (VEPs) in eyes with optic disc swelling due to neuroretinitis associated with cat scratch disease (CSD). Four eyes of four patients with marked optic disc swelling resembling optic neuritis but diagnosed serologically as CSD received systemic steroid treatment. VEPs elicited by black and white checkerboard stimuli created on a TV monitor were recorded before the treatment. The visual acuity (VA) in the affected eyes was decreased to 20/50 in two eyes and finger counting in two eyes at their initial visits. Ophthalmoscopic examination revealed neuroretinitis characterized by severe optic disc swelling, chorioretinal exudates, and macular edema in all eyes. Anti-Bartonella henselae serum antibody was markedly elevated in all patients confirming the diagnosis of CSD. The P100 of the transient VEPs was only mildly reduced without a delay in the implicit times in three eyes and only slightly delayed in the other eye. The steady-state VEPs were mildly reduced in two eyes and phase-reversed in other two eyes. The VA fully recovered after systemic steroid treatment in all patients. Although all examined patients showed marked swelling of the optic disc and visual decrease, the pattern VEPs were not affected as severely as in idiopathic optic neuritis. However, the degree of change of the pattern VEPs varied among patients.

Optic disc coloboma in two nigerian siblings: Case report and review of literature.

PubMed

Babalola, Y O; Olawoye, O O; Idam, P O

2017-11-01

We report two cases of bilateral asymmetric optic disc coloboma (ODC) in siblings. The index patient is a 9-year-old Nigerian girl with severe cognitive deficit who presented with a poor vision of 3 years' duration. She had a history of childhood febrile convulsions and delayed developmental milestones. Her visual acuity could not be assessed because she had a cognitive deficit and expressive aphasia. Ocular examination revealed a very large excavated right optic disc with only a strip of remnant neuro-retinal rim superiorly, and a smaller left optic disc with inferior disc excavation, superior wedge of the pink neuro-retinal rim as well as a temporal optic disc pit. No systemic features of syndromes associated with ODCs and intellectual disability were present in both patients. The younger sibling an 8-year-old girl later presented to the eye clinic with a 5-month history of poor vision in the left eye. Ocular examination revealed visual acuity of 6/6 in the right eye and counting fingers in the left eye. Dilated binocular indirect ophthalmoscopy revealed a right large excavated colobomatous disc and a left small disc with infero-temporal disc coloboma.

Glaucoma management in patients with osteo-odonto-keratoprosthesis (OOKP): the Singapore OOKP Study.

PubMed

Kumar, Rajesh S; Tan, Donald T H; Por, Yong-Ming; Oen, Francis T; Hoh, Sek-Tien; Parthasarathy, Anand; Aung, Tin

2009-01-01

To report diagnostic modalities and treatment options for glaucoma in eyes with osteo-odonto keratoprosthesis (OOKP). Eyes that underwent OOKP were evaluated for glaucoma at the time of the first postoperative visit, then at 1 and 3 months after the procedure, and thereafter every 6 months. All eyes underwent stereo-biomicroscopic optic nerve head (ONH) assessment, kinetic (Goldmann perimetry) and automated static visual field testing, ONH photography, Heidelberg retina tomograph, scanning laser polarimetery (GDx), and optical coherence tomography. Treatment of glaucoma was also reviewed. Average follow-up period was 19.1 (range: 5 to 31) months. Of the 15 eyes that underwent OOKP, 5 eyes had preexisting glaucoma. None of the other 10 eyes developed glaucoma after OOKP. ONH photography and visual field testing were the most reliable methods to assess status of the disease, whereas Heidelberg retina tomograph and optical coherence tomography could be performed with reasonable reproducibility and quality; GDx imaging was poor. All patients with glaucoma were treated with oral acetazolamide 500 mg twice a day. Transscleral cyclophotocoagulation was performed in 3 eyes at stage 2 of OOKP surgery. Progression of glaucoma was noted in 2 eyes on the basis of optic disc photographs and automated perimetry. Visual field testing and optic disc assessment with optic disc photographs seem to be effective methods to monitor eyes with OOKP for glaucoma. Treatment strategies include oral medications to lower intraocular pressure and cyclophotocoagulation.

Choroidal thickness in Chinese patients with non-arteritic anterior ischemic optic neuropathy.

PubMed

Jiang, Libin; Chen, Lanlan; Qiu, Xiujuan; Jiang, Ran; Wang, Yaxing; Xu, Liang; Lai, Timothy Y Y

2016-08-31

Non-arteritic anterior ischemic optic neuropathy (NA-AION) is one of the most common types of ischemic optic neuropathy. Several recent studies suggested that abnormalities of choroidal thickness might be associated with NA-AION. The main objective of this case-control study was to evaluate whether choroidal thickness is an ocular risk factor for the development of NA-AION by evaluating the peripapillary and subfoveal choroidal thicknesses in affected Chinese patients. Forty-four Chinese patients with unilateral NA-AION were recruited and compared with 60 eyes of 60 normal age and refractive-error matched control subjects. Peripapillary and subfoveal choroidal thicknesses were measured by enhanced depth imaging optical coherence tomography. Choroidal thicknesses of eyes with NA-AION and unaffected fellow eyes were compared with normal controls. Choroidal thicknesses of NA-AION eyes with or without optic disc edema were also compared. The correlation between choroidal thickness and retinal nerve fiber layer (RNFL) thickness, logMAR best-corrected visual acuity (BCVA), and the mean deviation (MD) of Humphrey static perimetry in NA-AION eyes were analyzed. The peripapillary choroidal thicknesses at the nasal, nasal inferior and temporal inferior segments in NA-AION eyes with optic disc edema were significantly thicker compared with that of normal subjects (P < 0.05). There was no significant difference in the choroidal thicknesses between the unaffected fellow eyes of NA-AION patients and normal eyes of healthy controls; or between the NA-AION eyes with resolved optic disc edema and normal eyes (all P > 0.05). No significant correlation between choroidal thickness and RNFL thickness, logMAR BCVA and perimetry MD was found in eyes affected by NA-AION (all P > 0.05). Increase in peripapillary choroid thickness in some segments was found in NA-ION eyes with optic disc edema. However, our findings do not support the hypothesis that choroidal thickness is abnormal in Chinese patients with NA-AION compared with normal subjects with similar age and refractive error status.

Ocular characteristics associated with the location of focal lamina cribrosa defects in open-angle glaucoma patients.

PubMed

Park, H-Yl; Hwang, Y S; Park, C K

2017-04-01

PurposeTo investigate the clinical characteristics according to the location of focal lamina cribrosa (LC) defects and its associated ocular features.Patients and methodsA total of 139 open-angle glaucoma patients underwent Spectralis optical coherence tomography (OCT) with enhanced depth imaging. Alterations in the contour of the LC were investigated to find focal LC defects. The location of the visible LC defect from the neural canal wall (far-peripheral and mid-peripheral) and clock-hour position (superotemporal, temporal and inferotemporal) were classified. Disc ovality ratio and disc-foveal angle were measured from disc and retinal nerve fiber layer (RNFL) photographs. The disc tilt degree was measured using a Heidelberg Retina Tomograph (HRT) III system. The en face OCT image of the disc scans was registered to the disc and RNFL photographs, to determine whether the focal LC defects corresponded spatially to the glaucomatous damage location.ResultsEyes with far-peripheral LC defects were significantly myopic and had a higher disc ovality ratio. The disc tilt degree obtained by HRT revealed significant temporal disc tilt in eyes with temporal LC defects (P<0.001). Eyes with inferotemporal LC defects had a significantly larger disc-foveal angle (P=0.027). The inferotemporal LC defects corresponded to the location of glaucomatous damage in 81.6%; however, only 46.2% of eyes with a superotemporal LC defect and 3.2% of eyes with a temporal LC defect corresponded spatially with the glaucomatous damage location.ConclusionsThe clinical characteristics and association with glaucomatous damage location were different according to the location of focal LC defect.

Mfsd2a Is a Transporter for the Essential ω-3 Fatty Acid Docosahexaenoic Acid (DHA) in Eye and Is Important for Photoreceptor Cell Development.

PubMed

Wong, Bernice H; Chan, Jia Pei; Cazenave-Gassiot, Amaury; Poh, Rebecca W; Foo, Juat Chin; Galam, Dwight L A; Ghosh, Sujoy; Nguyen, Long N; Barathi, Veluchamy A; Yeo, Sia W; Luu, Chi D; Wenk, Markus R; Silver, David L

2016-05-13

Eye photoreceptor membrane discs in outer rod segments are highly enriched in the visual pigment rhodopsin and the ω-3 fatty acid docosahexaenoic acid (DHA). The eye acquires DHA from blood, but transporters for DHA uptake across the blood-retinal barrier or retinal pigment epithelium have not been identified. Mfsd2a is a newly described sodium-dependent lysophosphatidylcholine (LPC) symporter expressed at the blood-brain barrier that transports LPCs containing DHA and other long-chain fatty acids. LPC transport via Mfsd2a has been shown to be necessary for human brain growth. Here we demonstrate that Mfsd2a is highly expressed in retinal pigment epithelium in embryonic eye, before the development of photoreceptors, and is the primary site of Mfsd2a expression in the eye. Eyes from whole body Mfsd2a-deficient (KO) mice, but not endothelium-specific Mfsd2a-deficient mice, were DHA-deficient and had significantly reduced LPC/DHA transport in vivo Fluorescein angiography indicated normal blood-retinal barrier function. Histological and electron microscopic analysis indicated that Mfsd2a KO mice exhibited a specific reduction in outer rod segment length, disorganized outer rod segment discs, and mislocalization of and reduction in rhodopsin early in postnatal development without loss of photoreceptors. Minor photoreceptor cell loss occurred in adult Mfsd2a KO mice, but electroretinography indicated visual function was normal. The developing eyes of Mfsd2a KO mice had activated microglia and up-regulation of lipogenic and cholesterogenic genes, likely adaptations to loss of LPC transport. These findings identify LPC transport via Mfsd2a as an important pathway for DHA uptake in eye and for development of photoreceptor membrane discs. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

The Optic Nerve Head in Primary Open-Angle Glaucoma Eyes With High Myopia: Characteristics and Association With Visual Field Defects.

PubMed

Chen, Li-Wei; Lan, Yu-Wen; Hsieh, Jui-Wen

2016-06-01

To evaluate the morphologic characteristics of optic neuropathy and its association with visual field (VF) defects in primary open-angle glaucoma (POAG) eyes with high myopia. In this cross-sectional study, we reviewed data from 375 Taiwanese patients (375 eyes) of POAG, ages 20 to 60 years. Optic disc photographs were used for planimetric measurements of morphologic variables. The myopic refraction was divided into high myopia (<-6.0 D) and nonhigh myopia (moderate myopia to hyperopia). The optic disc area was classified as moderate (1.59 to 2.85 mm), large, and small. Differences in characteristics between groups, correlations with the disc area, and factors associated with VF defects were determined. Of the 142 highly myopic eyes, 33 (23%) had a large disc, 26 (18%) had a small disc, and 55 (39%) had a tilted disc. Large discs had a higher cup-to-disc (C/D) area ratio and a higher tilt ratio; small discs had a smaller rim area and a lower tilt ratio (all P<0.05). Characteristics associated with high myopia included a smaller rim area, a higher C/D area ratio, and a lower tilt ratio (all P<0.001). In logistic regression, the refraction, the C/D area ratio, the rim area, and the tilt ratio (all P<0.05) were associated with VF defects. In Taiwanese individuals with POAG, our study found that tilted, large, or small discs were prevalent in highly myopic eyes. Of these characteristics, only the disc tilt and high myopia by itself were associated with the severity of glaucomatous optic neuropathy.

Retinitis pigmentosa inversa with unilateral high myopia with fellow eye optic disc pitting.

PubMed

Sheth, Saumil; Rush, Ryan; Narayanan, Raja

2011-01-01

To report a possible rare association of bilateral retinitis pigmentosa inversa (RPI) with unilateral high myopia with fellow eye optic disc pitting. A 55-year-old man with a history of reduced vision in the right eye since childhood presented with gradually decreasing vision in the left eye. On examination, a -23.00 diopter refractive error and diffuse chorioretinal atrophy consistent with pathologic myopia was found in the right eye. An optic disc pit with posterior pole pigmentary alterations thought to be consequent to a previous neurosensory detachment was found in the left eye. Though the retinal arteriolar attenuation seen in both eyes with an inconsistent history of night blindness since childhood pointed towards the possibility of a concurrently existing rod or rod-cone dystrophy, the posterior pole pigmentary alterations characteristic of RPI were clearly masked by the above pathologies. Optical coherence tomography demonstrated prominent foveal atrophy and an optic disc pit in the left eye. Electroretinography (ERG) demonstrated moderately attenuated amplitudes with prolonged implicit times of rod and cone responses bilaterally. The patient was diagnosed with bilateral RPI and anisometropic amblyopia in the right eye. This report documents a unique constellation of findings which include bilateral RPI and unilateral high myopia with an optic disc pit in the fellow eye. An ERG confirmation of a dystrophic etiology should be sought in suspicious cases, especially when findings are masked by the concurrent presence of other pathologies.

Optic nerve involvement in a borderline lepromatous leprosy patient on multidrug therapy.

PubMed

Prabha, Neel; Mahajan, Vikram K; Sharma, Surinder K; Sharma, Vikas; Chauhan, Pushpinder S; Mehta, Karaninder S; Abhinav, C; Khatri, Gaytri; Chander, Bal; Tuli, Rajiv

2013-12-01

Amidst the plethora of ocular complications of leprosy, involvement of the posterior segment or optic nerve is extremely rare. The mechanism of optic neuritis in leprosy is poorly understood. A 47 year-old man presented with a single lesion suggestive of mid-borderline (BB) leprosy over left periorbital region; the histology showed borderline lepromatous (BL) leprosy with a BI of 3+. After initial improvement with WHO MDT-MB and prednisolone (40 mg/d) he developed sudden and painless diminished vision in the left eye, about 3 weeks later. His visual acuity was 6/9 in the left and 6/6 in the right eye, and there was left optic disc edema, hyperemia and blurred disc margins. Treatment with prednisolone (60 mg/d) along with WHO MDT-MB continued. A month later he returned with painless diminished vision in the other eye as well. Visual acuity was 6/6 in the right and 6/12 in the left eye, and there was right optic disc edema and left optic disc atrophy. CT of the head and MRI of the brain were normal. Inflammatory edema of the orbital connective tissue or other surrounding structures, or direct infiltration of vasa nervosa with resultant vascular occlusion leading to optic nerve ischemia, seems the most plausible explanation of optic nerve involvement in this case.

The Drosophila T-box transcription factor Midline functions within the Notch–Delta signaling pathway to specify sensory organ precursor cell fates and regulates cell survival within the eye imaginal disc

PubMed Central

Das, Sudeshna; Chen, Q. Brent; Saucier, Joseph D.; Drescher, Brandon; Zong, Yan; Morgan, Sarah; Forstall, John; Meriwether, Andrew; Toranzo, Randy; Leal, Sandra M.

2014-01-01

We report that the T-box transcription factor Midline (Mid), an evolutionary conserved homolog of the vertebrate Tbx20 protein, functions within the Notch–Delta signaling pathway essential for specifying the fates of sensory organ precursor cells. This complements an established history of research showing that Mid regulates the cell-fate specification of diverse cell types within the developing heart, epidermis and central nervous system. Tbx20 has been detected in diverse neuronal and epithelial cells of embryonic eye tissues in both mice and humans. However, the mechanisms by which either Mid or Tbx20 function to regulate cell-fate specification or other critical aspects of eye development including cell survival have not yet been elucidated. We have also gathered preliminary evidence suggesting that Mid may play an indirect, but vital role in selecting SOP cells within the third-instar larval eye disc by regulating the expression of the proneural gene atonal. During subsequent pupal stages, Mid specifies SOP cell fates as a member of the Notch–Delta signaling hierarchy and is essential for maintaining cell viability within by inhibiting apoptotic pathways. We present several new hypotheses that seek to understand the role of Mid in regulating developmental processes downstream of the Notch receptor that are critical for specifying unique cell fates, patterning the adult eye and maintaining cellular homeostasis during eye disc morphogenesis. PMID:23962751

Comparative experiments for in vivo fibroplasia and biological stability of four porous polymers intended for use in the Seoul-type keratoprosthesis

PubMed Central

Kim, M K; Lee, J L; Wee, W R; Lee, J H

2002-01-01

Aims: To evaluate in vivo fibroplasia and biological stability of porous polymers intended for use in the Seoul-type keratoprosthesis (S-KPro). Methods: Four porous polymers (polypropylene, two kinds of polyethylene terephthalate (PE70 and PE50), and polyurethane) were investigated. Discs of polymers were inserted into the corneal stroma of rabbits for a 2 and 5 month period. Corneal oedema and neovascularisation were evaluated. The fibroplasia and collagen deposition were examined under light and transmission electron microscopy. S-KPros, whose skirt was made of four types of polymer, were implanted into the rabbits' eyes. The retention time and complications were evaluated. Results: Neovascularisation and corneal oedema were found in all of the disc inserted eyes, but the corneal oedema subsided within 2 months in most of the eyes. The mean number of fibroblasts increased significantly in polypropylene and PE50 disc inserted eyes compared with polyurethane disc inserted eyes. Plentiful collagen deposition was also found in both polypropylene and PE50 disc inserted eyes. Mean retention time in the polypropylene SK-Pro implanted eyes was longer than that of the other eyes (20.7 weeks). The PE70 skirt induced corneal melting around the prosthesis. Conclusion: Polypropylene encourages fibroblast ingrowth and shows good biological stability when used as a skirt material in S-KPro. PMID:12084755

Automated determination of cup-to-disc ratio for classification of glaucomatous and normal eyes on stereo retinal fundus images

NASA Astrophysics Data System (ADS)

Muramatsu, Chisako; Nakagawa, Toshiaki; Sawada, Akira; Hatanaka, Yuji; Yamamoto, Tetsuya; Fujita, Hiroshi

2011-09-01

Early diagnosis of glaucoma, which is the second leading cause of blindness in the world, can halt or slow the progression of the disease. We propose an automated method for analyzing the optic disc and measuring the cup-to-disc ratio (CDR) on stereo retinal fundus images to improve ophthalmologists' diagnostic efficiency and potentially reduce the variation on the CDR measurement. The method was developed using 80 retinal fundus image pairs, including 25 glaucomatous, and 55 nonglaucomatous eyes, obtained at our institution. A disc region was segmented using the active contour method with the brightness and edge information. The segmentation of a cup region was performed using a depth map of the optic disc, which was reconstructed on the basis of the stereo disparity. The CDRs were measured and compared with those determined using the manual segmentation results by an expert ophthalmologist. The method was applied to a new database which consisted of 98 stereo image pairs including 60 and 30 pairs with and without signs of glaucoma, respectively. Using the CDRs, an area under the receiver operating characteristic curve of 0.90 was obtained for classification of the glaucomatous and nonglaucomatous eyes. The result indicates potential usefulness of the automated determination of CDRs for the diagnosis of glaucoma.

Eyes with Suspicious Appearance of the Optic Disc and Normal Intraocular Pressure: Using Clinical and Epidemiological Characteristics to Differentiate Those with and without Glaucoma.

PubMed

Dias, Diego T; Ushida, Michele; Sousa, Marina C; Dorairaj, Syril; Biteli, Luis G; Leite, Mauro T; Paranhos, Augusto; Prata, Tiago S

2016-01-01

Among all glaucoma suspects, eyes with optic nerve head features suspicious or suggestive of early glaucoma are probably those that offer the greatest challenge for clinicians. In contrast with the robust longitudinal data published on ocular hypertension, there is no specific management guideline for these patients. Therefore, evaluating eyes with suspicious optic disc appearance and normal intraocular pressure (IOP), we sought to investigate potential differences in clinical and epidemiological characteristics to differentiate those with normal-tension glaucoma (NTG) from those with presumed large physiological optic disc cups (pLPC). In this observational case-control study, we consecutively enrolled individuals with pLPC and NTG. All eyes had vertical cup-to-disc ratio (VCDR)≥0.6 and untreated IOP<21 mmHg. Glaucomatous eyes had reproducible visual field defects. Eyes with pLPC required normal visual fields and ≥30 months of follow-up with no evidence of glaucomatous neuropathy. Clinical and epidemiological parameters were compared between groups. Eighty-four individuals with pLPC and 40 NTG patients were included. Regarding our main results, NTG patients were significantly older and with a higher prevalence of Japanese descendants (p<0.01). Not only did pLPC eyes have smaller mean VCDR, but also larger optic discs (p≤0.04). There were no significant differences for gender, central corneal thickness, and spherical equivalent (p≥0.38). Significant odds ratios (OR) were found for race (OR = 2.42; for Japanese ancestry), age (OR = 1.05), VCDR (OR = 5.03), and disc size (OR = 0.04; p≤0.04). In conclusion, in patients with suspicious optic disc and normal IOP, those with older age, Japanese ancestry, smaller optic discs, and larger VCDR are more likely to have NTG, and therefore, deserve deeper investigation and closer monitoring.

Long-term outcomes of pars plana vitrectomy without internal limiting membrane peeling for optic disc pit maculopathy.

PubMed

Avci, R; Yilmaz, S; Inan, U U; Kaderli, B; Kurt, M; Yalcinbayir, O; Yildiz, M; Yucel, A

2013-12-01

To evaluate the results of surgical treatment of maculopathy secondary to congenital optic pit anomaly with pars plana vitrectomy (PPV), endolaser to the temporal edge of the optic disc and C3F8 tamponade without internal limiting membrane (ILM) peeling. Thirteen eyes of 12 patients with serous macular detachment and/or macular retinoschisis secondary to congenital optic disc pit (ODP) were included in the study. All eyes underwent PPV, posterior hyaloid removal, endolaser photocoagulation on the temporal margin of the optic disc and 12% C3F8 gas tamponade. Anatomic success and functional outcome determined retrospectively by optical coherence tomography and measurement of best corrected visual acuity (BCVA), respectively were the main outcome parameters. Two lines or more improvement in BCVA was obtained in 11 eyes and 6 of these eyes had 20/40 or better BCVA at the final visit. Subretinal or intraretinal fluid was completely resorbed postoperatively in 12 eyes but a little intraretinal fluid persisted in one eye at the 16-month follow-up. Better visual improvement was observed in patients treated by earlier surgical intervention. PPV, C3F8 gas tamponade and endolaser to the optic disc margin without ILM peeling may yield favourable results in the treatment of ODP maculopathy.

The Drosophila T-box transcription factor Midline functions within the Notch-Delta signaling pathway to specify sensory organ precursor cell fates and regulates cell survival within the eye imaginal disc.

PubMed

Das, Sudeshna; Chen, Q Brent; Saucier, Joseph D; Drescher, Brandon; Zong, Yan; Morgan, Sarah; Forstall, John; Meriwether, Andrew; Toranzo, Randy; Leal, Sandra M

2013-01-01

We report that the T-box transcription factor Midline (Mid), an evolutionary conserved homolog of the vertebrate Tbx20 protein, functions within the Notch-Delta signaling pathway essential for specifying the fates of sensory organ precursor (SOP) cells. These findings complement an established history of research showing that Mid regulates the cell-fate specification of diverse cell types within the developing heart, epidermis and central nervous system. Tbx20 has been detected in unique neuronal and epithelial cells of embryonic eye tissues in both mice and humans. However, the mechanisms by which either Mid or Tbx20 function to regulate cell-fate specification or other critical aspects of eye development including cell survival have not yet been elucidated. We have also gathered preliminary evidence suggesting that Mid may play an indirect, but vital role in selecting SOP cells within the third-instar larval eye disc by regulating the expression of the proneural gene atonal. During subsequent pupal stages, Mid specifies SOP cell fates as a member of the Notch-Delta signaling hierarchy and is essential for maintaining cell viability by inhibiting apoptotic pathways. We present several new hypotheses that seek to understand the role of Mid in regulating developmental processes downstream of the Notch receptor that are critical for specifying unique cell fates, patterning the adult eye and maintaining cellular homeostasis during eye disc morphogenesis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

5D imaging via light sheet microscopy reveals cell dynamics during the eye-antenna disc primordium formation in Drosophila

NASA Astrophysics Data System (ADS)

Huang, Yu Shan; Ku, Hui Yu; Tsai, Yun Chi; Chang, Chin Hao; Pao, Sih Hua; Sun, Y. Henry; Chiou, Arthur

2017-03-01

5D images of engrailed (en) and eye gone (eyg) gene expressions during the course of the eye-antenna disc primordium (EADP) formation of Drosophila embryos from embryonic stages 13 through 16 were recorded via light sheet microscopy and analyzed to reveal the cell dynamics involved in the development of the EADP. Detailed analysis of the time-lapsed images revealed the process of EADP formation and its invagination trajectory, which involved an inversion of the EADP anterior-posterior axis relative to the body. Furthermore, analysis of the en-expression pattern in the EADP provided strong evidence that the EADP is derived from one of the en-expressing head segments.

Glaucoma-induced optic disc morphometric changes and glaucoma diagnostic ability of Heidelberg Retina Tomograph II in highly myopic eyes.

PubMed

Mayama, Chihiro; Tsutsumi, Tae; Saito, Hitomi; Asaoka, Ryo; Tomidokoro, Atsuo; Iwase, Aiko; Otani, Shinichiro; Miyata, Kazunori; Araie, Makoto

2014-01-01

This study was performed to first investigate the morphological differences in the optic nerve head between highly myopic non-glaucomatous controls and highly myopic glaucomatous eyes in comparison with the differences between emmetropic non-glaucomatous controls and emmetropic glaucomatous eyes using confocal scanning laser ophthalmoscopy. Further, the ability of the apparatus in glaucoma diagnosis in highly myopic eyes was compared with that in emmetropic eyes. Healthy subjects and age-matched patients with early-stage open-angle glaucoma were divided into two groups: emmetropic eyes (-1.0 to +1.0 diopters) and highly myopic eyes (-12.0 to -5.0 diopters).The participants were comprised of 65 emmetropic normal eyes, 59 emmetropic glaucomatous eyes, 62 highly myopic normal eyes, and 68 highly myopic glaucomatous eyes and eyes with pathologic myopia were carefully excluded. Confocal scanning laser tomographic parameters were compared among all subjects after adjustment for age and disc area. The ROC curves and sensitivity and specificity for glaucoma detection using several clinical methods were then compared between the emmetropic and highly myopic eyes. Rim area, cup/disc area ratio, mean cup depth, and cup shape measure of glaucoma eyes are significantly different from those of normal eyes in both highly myopic eyes and emmetropic eyes. Methodological overestimation of retinal nerve fiber layer cross sectional area due to optic disc tilting was suggested in the highly myopic eyes. The diagnostic performance of glaucoma using several discriminant methods significantly deteriorated in the highly myopic eyes. In the highly myopic glaucomatous eyes, confocal scanning laser tomographic parameters were significantly different from that of non-glaucomatous highly myopic eyes but diagnostic performance of glaucoma was deteriorated than that in emmetropic eyes. These findings demonstrate the utility and limitations of the apparatus in diagnosing glaucoma in highly myopic patients.

Dependence of optic disc parameters on disc area according to Heidelberg Retina Tomograph: Part II.

NASA Astrophysics Data System (ADS)

Machekhin, V.; Manaenkova, G.; Bondarenko, O.

2007-05-01

With the help of Heidelberg Retina Tomograph (HRT-II) optic disc parameters in 211 eyes of 115 healthy patients with refraction Em +/- 3,0 D and 96 eyes of 72 patients with myopia 3,5-14,0 D without any signs of glaucoma were studied. Analysis of optic disc parameters were carried out in 5 groups of patients according to disc area: less than 1,5 mm2, 1,5- 2,5 mm2, 2,5-3,0 mm2, 3,0-3,5 mm2 and more than 3,5 mm2. An accurate depending on disc area was revealed for all optic disc parameters in all sectors, which was manifested by increasing cup disc and rim disc (area and volume) and other parameters. We consider it is necessary to use the proper tables for right interpretation of received data for early diagnosis of glaucoma.

Optomotor-blind negatively regulates Drosophila eye development by blocking Jak/STAT signaling.

PubMed

Tsai, Yu-Chen; Grimm, Stefan; Chao, Ju-Lan; Wang, Shih-Chin; Hofmeyer, Kerstin; Shen, Jie; Eichinger, Fred; Michalopoulou, Theoni; Yao, Chi-Kuang; Chang, Chih-Hsuan; Lin, Shih-Han; Sun, Y Henry; Pflugfelder, Gert O

2015-01-01

Organ formation requires a delicate balance of positive and negative regulators. In Drosophila eye development, wingless (wg) is expressed at the lateral margins of the eye disc and serves to block retinal development. The T-box gene optomotor-blind (omb) is expressed in a similar pattern and is regulated by Wg. Omb mediates part of Wg activity in blocking eye development. Omb exerts its function primarily by blocking cell proliferation. These effects occur predominantly in the ventral margin. Our results suggest that the primary effect of Omb is the blocking of Jak/STAT signaling by repressing transcription of upd which encodes the Jak receptor ligand Unpaired.

Does Optic Nerve Head Size Variation Affect Circumpapillary Retinal Nerve Fiber Layer Thickness Measurement by Optical Coherence Tomography?

PubMed Central

Huang, David; Chopra, Vikas; Lu, Ake Tzu-Hui; Tan, Ou; Francis, Brian; Varma, Rohit

2012-01-01

Purpose. To determine the relationship between retinal nerve fiber layer (RNFL) thickness, optic disc size, and image magnification. Methods. The cohort consisted of 196 normal eyes of 101 participants in the Advanced Imaging for Glaucoma Study (AIGS), a multicenter, prospective, longitudinal study to develop advanced imaging technologies for glaucoma diagnosis. Scanning laser tomography was used to measure disc size. Optical coherence tomography (OCT) was used to perform circumpapillary RNFL thickness measurements using the standard fixed 3.46-mm nominal scan diameter. A theoretical model of magnification effects was developed to relate RNFL thickness (overall average) with axial length and magnification. Results. Multivariate regression showed no significant correlation between RNFL thickness and optic disc area (95% confidence interval [CI] = −0.9 to 4.1 μm/mm2, P = 0.21). Linear regression showed that RNFL thickness depended significantly on axial length (slope = −3.1 μm/mm, 95% CI = −4.9 to −1.3, P = 0.001) and age (slope = −0.3 μm/y, 95% CI = −0.5 to −0.2, P = 0.0002). The slope values agreed closely with the values predicted by the magnification model. Conclusions. There is no significant association between RNFL thickness and optic disc area. Previous publications that showed such an association may have been biased by the effect of axial length on fundus image magnification and, therefore, both measured RNFL thickness and apparent disc area. The true diameter of the circumpapillary OCT scan is larger for a longer eye (more myopic eye), leading to a thinner RNFL measurement. Adjustment of measured RNFL thickness by axial length, in addition to age, may lead to a tighter normative range and improve the detection of RNFL thinning due to glaucoma. PMID:22743319

Role of Retinal Nerve Fiber Layer Thickness and Optic Disk Measurement by OCT on Early Diagnosis of Glaucoma.

PubMed

Hua, Zanmei; Fang, Qiuyun; Sha, Xiangyin; Yang, Ruiming; Hong, Zuopeng

2015-03-01

Glaucoma is an eye disease that can lead to irreversible optic nerve damage and cause blindness. Optical coherence tomography (OCT) allows an early diagnosis of glaucoma by the measurements of the retinal nerve fiber and optic disc parameters. A retrospective study was designed to analyze the effects of the measurement of the retinal nerve fiber layer (RNFL) thickness and the optic disc tomography by spectral-domain OCT on the early diagnosis of suspected glaucoma and primary open angle glaucoma (POAG). This was a clinical case-control study. The RNFL thickness around the optic disc and optic disk tomographic parameters of the control (n = 51, 98 eyes), suspected glaucoma (n = 81, 146 eyes), and POAG groups (n = 55, 106 eyes) were measured by OCT. The parameters included superior, inferior, nasal and temporal mean RNFL thickness, disc area (DA), cup area (CA), rim area (RA), disc volume (DV), cup volume (CV), rim volume (RV), cup/disc area ratio (CA/DA), rim/disc area ratio (RA/DA), cup/disc volume ratio (CV/DV) and rim/disc volume ratio (RV/DV). Superior, nasal, and mean RNFL parameters, DA, CA,RA, DV, CV, CA/DA, RA/DA, CV/DV and RV/DV significantly differed among three groups by single-factorial ANOVA. Inferior and temporal RNFL thickness significantly differed between the control and POAG groups. No significant difference was observed in RV among three groups. In the POAG group, the maximum area under the ROC curve (AROC) of mean RNFL thickness was 0.845. The maximum AROC of optic disk parameters was RA/DA (0.998), followed by CA/DA (0.997). The AROC of CA, RA, CV, and DV were all > 0.900. OCT may serve as a useful diagnostic modality in distinguishing suspected glaucoma from POAG.

Doped sesquioxide ceramic for eye-safe solid state laser materials

NASA Astrophysics Data System (ADS)

Kim, Woohong; Baker, Colin; Florea, Catalin; Frantz, Jesse; Villalobos, Guillermo; Shaw, Brandon; Bowman, Steve; O'Connor, Shawn; Sadowski, Bryan; Hunt, Michael; Aggalwar, Ishwar; Sanghera, Jasbinder

2013-03-01

In this paper, we present our recent results in the development of Ho3+ doped sesquioxides for eye-safe solid state lasers. We have synthesized optical quality Lu2O3 nanopowders doped with concentrations of 0.1, 1.0, 2.0, and 5% Ho3+. The powders were synthesized by a co-precipitation method beginning with nitrates of holmium and lutetium. The nanopowders were hot pressed into optical quality ceramic discs. The optical transmission of the ceramic discs is excellent, nearly approaching the theoretical limit. The optical, spectral and morphological properties as well as the lasing performance from highly transparent ceramics are presented.

Photographic Reading Center of the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT): Methods and Baseline Results

PubMed Central

Fischer, William S.; Wall, Michael; McDermott, Michael P.; Kupersmith, Mark J.; Feldon, Steven E.

2015-01-01

Purpose. To describe the methods used by the Photographic Reading Center (PRC) of the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT) and to report baseline assessments of papilledema severity in participants. Methods. Stereoscopic digital images centered on the optic disc and the macula were collected using certified personnel and photographic equipment. Certification of the camera system included standardization and calibration using a model eye. Lay readers assessed disc photos of all eyes using the Frisén grade and performed quantitative measurements of papilledema. Frisén grades by PRC were compared with site investigator clinical grades. Spearman rank correlations were used to quantify associations among disc features and selected clinical variables. Results. Frisén grades according to the PRC and site investigator's grades, matched exactly in 48% of the study eyes and 42% of the fellow eyes and within one grade in 94% of the study eyes and 92% of the fellow eyes. Frisén grade was strongly correlated (r > 0.65, P < 0.0001) with quantitative measures of disc area. Cerebrospinal fluid pressure was weakly associated with Frisén grade and disc area determinations (r ≤ 0.31). Neither Frisén grade nor any fundus feature was associated with perimetric mean deviation. Conclusions. In a prospective clinical trial, lay readers agreed reasonably well with physicians in assessing Frisén grade. Standardization of camera systems enhanced consistency of photographic quality across study sites. Images were affected more by sensors with poor dynamic range than by poor resolution. Frisén grade is highly correlated with quantitative assessment of disc area. (ClinicalTrials.gov number, NCT01003639.) PMID:26024112

Photographic Reading Center of the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT): Methods and Baseline Results.

PubMed

Fischer, William S; Wall, Michael; McDermott, Michael P; Kupersmith, Mark J; Feldon, Steven E

2015-05-01

To describe the methods used by the Photographic Reading Center (PRC) of the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT) and to report baseline assessments of papilledema severity in participants. Stereoscopic digital images centered on the optic disc and the macula were collected using certified personnel and photographic equipment. Certification of the camera system included standardization and calibration using a model eye. Lay readers assessed disc photos of all eyes using the Frisén grade and performed quantitative measurements of papilledema. Frisén grades by PRC were compared with site investigator clinical grades. Spearman rank correlations were used to quantify associations among disc features and selected clinical variables. Frisén grades according to the PRC and site investigator's grades, matched exactly in 48% of the study eyes and 42% of the fellow eyes and within one grade in 94% of the study eyes and 92% of the fellow eyes. Frisén grade was strongly correlated (r > 0.65, P < 0.0001) with quantitative measures of disc area. Cerebrospinal fluid pressure was weakly associated with Frisén grade and disc area determinations (r ≤ 0.31). Neither Frisén grade nor any fundus feature was associated with perimetric mean deviation. In a prospective clinical trial, lay readers agreed reasonably well with physicians in assessing Frisén grade. Standardization of camera systems enhanced consistency of photographic quality across study sites. Images were affected more by sensors with poor dynamic range than by poor resolution. Frisén grade is highly correlated with quantitative assessment of disc area. (ClinicalTrials.gov number, NCT01003639.).

High-resolution imaging of the retinal nerve fiber layer in normal eyes using adaptive optics scanning laser ophthalmoscopy.

PubMed

Takayama, Kohei; Ooto, Sotaro; Hangai, Masanori; Arakawa, Naoko; Oshima, Susumu; Shibata, Naohisa; Hanebuchi, Masaaki; Inoue, Takashi; Yoshimura, Nagahisa

2012-01-01

To conduct high-resolution imaging of the retinal nerve fiber layer (RNFL) in normal eyes using adaptive optics scanning laser ophthalmoscopy (AO-SLO). AO-SLO images were obtained in 20 normal eyes at multiple locations in the posterior polar area and a circular path with a 3-4-mm diameter around the optic disc. For each eye, images focused on the RNFL were recorded and a montage of AO-SLO images was created. AO-SLO images for all eyes showed many hyperreflective bundles in the RNFL. Hyperreflective bundles above or below the fovea were seen in an arch from the temporal periphery on either side of a horizontal dividing line to the optic disc. The dark lines among the hyperreflective bundles were narrower around the optic disc compared with those in the temporal raphe. The hyperreflective bundles corresponded with the direction of the striations on SLO red-free images. The resolution and contrast of the bundles were much higher in AO-SLO images than in red-free fundus photography or SLO red-free images. The mean hyperreflective bundle width around the optic disc had a double-humped shape; the bundles at the temporal and nasal sides of the optic disc were narrower than those above and below the optic disc (P<0.001). RNFL thickness obtained by optical coherence tomography correlated with the hyperreflective bundle widths on AO-SLO (P<0.001) AO-SLO revealed hyperreflective bundles and dark lines in the RNFL, believed to be retinal nerve fiber bundles and Müller cell septa. The widths of the nerve fiber bundles appear to be proportional to the RNFL thickness at equivalent distances from the optic disc.

Spectral Domain Optical Coherence Tomography in Glaucoma: Qualitative and Quantitative Analysis of the Optic Nerve Head and Retinal Nerve Fiber Layer (An AOS Thesis)

PubMed Central

Chen, Teresa C.

2009-01-01

Purpose: To demonstrate that video-rate spectral domain optical coherence tomography (SDOCT) can qualitatively and quantitatively evaluate optic nerve head (ONH) and retinal nerve fiber layer (RNFL) glaucomatous structural changes. To correlate quantitative SDOCT parameters with disc photography and visual fields. Methods: SDOCT images from 4 glaucoma eyes (4 patients) with varying stages of open-angle glaucoma (ie, early, moderate, late) were qualitatively contrasted with 2 age-matched normal eyes (2 patients). Of 61 other consecutive patients recruited in an institutional setting, 53 eyes (33 patients) met inclusion/exclusion criteria for quantitative studies. Images were obtained using two experimental SDOCT systems, one utilizing a superluminescent diode and the other a titanium:sapphire laser source, with axial resolutions of about 6 μm and 3 μm, respectively. Results: Classic glaucomatous ONH and RNFL structural changes were seen in SDOCT images. An SDOCT reference plane 139 μm above the retinal pigment epithelium yielded cup-disc ratios that best correlated with masked physician disc photography cup-disc ratio assessments. The minimum distance band, a novel SDOCT neuroretinal rim parameter, showed good correlation with physician cup-disc ratio assessments, visual field mean deviation, and pattern standard deviation (P values range, .0003–.024). RNFL and retinal thickness maps correlated well with disc photography and visual field testing. Conclusions: To our knowledge, this thesis presents the first comprehensive qualitative and quantitative evaluation of SDOCT images of the ONH and RNFL in glaucoma. This pilot study provides basis for developing more automated quantitative SDOCT-specific glaucoma algorithms needed for future prospective multicenter national trials. PMID:20126502

Optomotor-Blind Negatively Regulates Drosophila Eye Development by Blocking Jak/STAT Signaling

PubMed Central

Tsai, Yu-Chen; Grimm, Stefan; Chao, Ju-Lan; Wang, Shih-Chin; Hofmeyer, Kerstin; Shen, Jie; Eichinger, Fred; Michalopoulou, Theoni; Yao, Chi-Kuang; Chang, Chih-Hsuan; Lin, Shih-Han; Sun, Y. Henry; Pflugfelder, Gert O.

2015-01-01

Organ formation requires a delicate balance of positive and negative regulators. In Drosophila eye development, wingless (wg) is expressed at the lateral margins of the eye disc and serves to block retinal development. The T-box gene optomotor-blind (omb) is expressed in a similar pattern and is regulated by Wg. Omb mediates part of Wg activity in blocking eye development. Omb exerts its function primarily by blocking cell proliferation. These effects occur predominantly in the ventral margin. Our results suggest that the primary effect of Omb is the blocking of Jak/STAT signaling by repressing transcription of upd which encodes the Jak receptor ligand Unpaired. PMID:25781970

Observation of neovascularization of the disc associated with proliferative diabetic retinopathy using OCT angiography.

PubMed

Akiyama, Hideo; Li, Danjie; Shimoda, Yukitoshi; Matsumoto, Hidetaka; Kishi, Shoji

2018-05-01

To describe the relationship between the vitreous and the neovascularization of the disc (NVD) using swept source optical coherence tomography (SS-OCT) and OCT angiography (OCTA). Retrospective. We examined 17 eyes of 11 consecutive patients diagnosed as NVD associated with proliferative diabetic retinopathy (PDR). The location of the NVD feeder or collector vessels were examined by using RTVue XR Avanti. To determine the condition of the posterior vitreous detachment (PVD) and the proliferative tissue of the NVD, we performed 12 mm horizontal and vertical scans through the disc using SS-OCT. OCT images of all 17 cases indicated there was no PVD on the optic disc. OCTA showed that the locations of the newly formed vessels from the optic disc were overwhelmingly outside the physiological cupping (95%). No cases exhibited formation of neovascularization inside the physiological cupping. OCT images revealed all 17 eyes had proliferative tissues located under the posterior wall of the vitreous, with 12 out of 17 eyes exhibiting additional invasion of the proliferative tissue into the vitreous through the posterior wall. Epiretinal membrane or a thickened posterior wall of the vitreous was present in 10 out of the 17 eyes. NVD associated with PDR arises from outside the physiological cupping and grows along the posterior wall of the vitreous. The absence of PVD on the optic disc is essential to the growth of NVD.

Correlation between corneal thickness and optic disc morphology in normal tension glaucoma using modern technical analysis.

PubMed

Coman, Laurenţiu; Costescu, Monica; Alecu, Mihail; Coman, Oana Andreia

2014-01-01

The purpose of this study was to evaluate the relationship between central corneal thickness (CCT) and optic disc morphology in normal tension glaucoma (NTG). Patients with NTG underwent eye examination, optic disc imaging with Heildelberg Retina Tomograph II (HRT II) and ultrasound corneal pachymetry. The morphological parameters of the optic discs were used to classify the eyes into four groups: generalized enlargement (GE) type, myopic glaucomatous (MY) type, focal ischemic (FI) type and senile sclerotic (SS) type. A correlation between CCT and optic disc morphology obtained by HRT II was calculated. Multiple comparison and post hoc tests were performed in order to determine the significance of the differences between the four groups. The strongest correlation was between CCT and the parameters of optic disc imaging obtained at HRT II in the GE type of optic disc.

Laser speckle flowgraphy for differentiating between nonarteritic ischemic optic neuropathy and anterior optic neuritis.

PubMed

Maekubo, Tomoyuki; Chuman, Hideki; Nao-I, Nobuhisa

2013-07-01

The aim of this study was to investigate the usefulness of laser speckle flowgraphy (LSFG) for the differentiation of acute nonarteritic ischemic optic neuropathy (NAION) from anterior optic neuritis (ON). To investigate blood flow in the optic disc under normal conditions, NAION, and anterior ON, we compared the tissue blood flow of the right eye with that of the left eye in the control group, and that of the affected eye with that of the unaffected eye in the NAION and anterior ON groups. In the normal control group, the tissue blood flow did not significantly differ between the right and left eyes. In the NAION group, all 6 patients had decreased optic disc blood flow in the NAION eye when compared with the unaffected eye. By contrast, in the anterior ON group, all 6 patients had increased optic disc blood flow in the anterior ON eye when compared with the unaffected eye. In the NAION group, the mean blur rate (MBR) of the affected eyes was 29.5 % lower than that of the unaffected eyes. In the anterior ON group, the MBR of the affected eyes was 15.9 % higher than that of the unaffected eyes. LSFG could be useful in differentiating between NAION and anterior ON. In addition, this imaging technique saves time and is noninvasive.

Longitudinal analysis of progression in glaucoma using spectral-domain optical coherence tomography.

PubMed

Wessel, Julia M; Horn, Folkert K; Tornow, Ralf P; Schmid, Matthias; Mardin, Christian Y; Kruse, Friedrich E; Juenemann, Anselm G; Laemmer, Robert

2013-05-01

To compare the longitudinal loss of RNFL thickness measurements by SD-OCT in healthy individuals and glaucoma patients with or without progression concerning optic disc morphology. A total of 62 eyes, comprising 38 glaucomatous eyes with open angle glaucoma and 24 healthy controls, were included in the study (Erlangen Glaucoma Registry, NTC00494923). All patients were investigated annually over a period of 3 years by Spectralis SD-OCT measuring peripapillary RNFL thickness. By masked comparative analysis of photographs, the eyes were classified into nonprogressive and progressive glaucoma cases. Longitudinal loss of RNFL thickness was compared with morphological changes of optic disc morphology. Mixed model analysis of annual OCT scans revealed an estimated annual decrease of the RNFL thickness by 2.12 μm in glaucoma eyes with progression, whereas glaucoma eyes without progression in optic disc morphology lost 1.18 μm per year in RNFL thickness (P = 0.002). The rate of change in healthy eyes was 0.60 μm and thereby also significantly lower than in glaucoma eyes with progression (P < 0.001). The intrasession variability of three successive measurements without head repositioning was 1.5 ± 0.7 μm. The loss of mean RNFL thickness exceeded the intrasession variability in 60% of nonprogressive eyes, and in 85% of progressive eyes after 3 years. LONGITUDINAL MEASUREMENTS OF RNFL THICKNESS USING SD-OCT SHOW A MORE PRONOUNCED REDUCTION OF RNFL THICKNESS IN PATIENTS WITH PROGRESSION COMPARED WITH PATIENTS WITHOUT PROGRESSION IN GLAUCOMATOUS OPTIC DISC CHANGES. (www.clinicaltrials.gov number, NTC00494923.).

Differences in Optical Coherence Tomography Assessment of Bruch Membrane Opening Compared to Stereoscopic Photography for Estimating Cup-to-Disc Ratio.

PubMed

Mwanza, Jean-Claude; Huang, Linda Y; Budenz, Donald L; Shi, Wei; Huang, Gintien; Lee, Richard K

2017-12-01

To compare the vertical and horizontal cup-to-disc ratio (VCDR, HCDR) by an updated optical coherence tomography (OCT) Bruch membrane opening (BMO) algorithm and stereoscopic optic disc photograph readings by glaucoma specialists. Reliability analysis. A total of 195 eyes (116 glaucoma and 79 glaucoma suspect) of 99 patients with stereoscopic photographs and OCT scans of the optic discs taken during the same visit were compared. Optic disc photographs were read by 2 masked glaucoma specialists for VCDR and HCDR estimation. Intraclass correlation coefficient (ICC) and Bland-Altman plots were used to assess the agreement between photograph reading and OCT in estimating CDR. OCT images computed significantly larger VCDR and HCDR than photograph reading before and after stratifying eyes based on disc size (P < .001). The difference in CDR estimates between the 2 methods was equal to or greater than 0.2 in 29% and 35% of the eyes for VCDR and HCDR, respectively, with a mean difference of 0.3 in each case. The ICCs between the readers and OCT ranged between 0.50 and 0.63. The size of disagreement in VCDR correlated weakly with cup area in eyes with medium (r 2  = 0.10, P = .008) and large (r 2  = 0.09, P = .007) discs. OCT and photograph reading by clinicians agree poorly in CDR assessment. The difference in VCDR between the 2 methods was depended on cup area in medium and large discs. These differences should be considered when making conclusions regarding CDRs in clinical practice. Copyright © 2017 Elsevier Inc. All rights reserved.

Optic disc size and other parameters from optical coherence tomography in Vietnamese-Americans.

PubMed

Peng, Pai-Huei; Fu, Sheena; Nguyen, Ngoc; Porco, Travis; Lin, Shan C

2011-08-01

To investigate the optic disc parameters by optical coherence tomography (OCT) in Vietnamese with various types of glaucoma. Medical charts of Vietnamese and White patients within a single practice were reviewed. Disc and rim areas by OCT were compared among nonglaucoma controls, different types of glaucoma, and glaucoma suspect. The association of these parameters with demographic and ocular features was evaluated. Data from 1416 Vietnamese and 57 White patients were included. A larger mean disc area was observed in eyes with primary angle-closure glaucoma than in eyes with primary angle-closure and primary angle-closure suspect (both P<0.001). There was no association between disc size with central corneal thickness (P=0.051) and sex (P=0.155). Vietnamese patients with glaucoma and glaucoma suspicion had larger discs than diagnosis-matched Whites (P=0.043 and 0.021, respectively). Vietnamese patients with glaucoma seem to have larger optic discs than White patients. Central corneal thickness had no association with disc area in this study population.

Influence of optic disc leakage on objective optic nerve head assessment in patients with uveitis.

PubMed

Heinz, Carsten; Kogelboom, Katy; Heiligenhaus, Arnd

2016-02-01

Secondary glaucoma is a common complication in patients with uveitis. Heidelberg Retina Tomography (HRT) and retinal nerve fiber layer (RNFL) thickness on optical coherence tomography (OCT) are widely used for examining optic nerve head changes. We evaluated these parameters in patients with uveitis and secondary glaucoma and with inflammatory papillary leakage on fluorescein angiography. Prospective single-center analysis of patients with uveitis, evaluating the impact of optic disc leakage on objective optic disc imaging parameters. Overall, 96 eyes of 59 patients were included. Papillary leakage was found in 42 eyes (43.8 %), and secondary glaucoma was found in 41 eyes (42.7 %). Glaucoma and papillary leakage were present in 12 (29 %) eyes with leakage and in 29 (54 %) eyes without leakage (p = 0.023). Neuroretinal rim area (p = 0.004), rim volume on HRT (p = 0.004), and RNFL thickness on OCT (p = 0.0008) were significantly increased in eyes with papillary leakage, while RNFL on HRT was unchanged (p = 0.255). When only eyes with normal IOP were examined, all objective parameters on OCT and HRT were significantly increased, whereas in eyes with secondary glaucoma, there was only a trend in the same direction, which did not reach significance. A comparison of eyes with secondary glaucoma and optic disc leakage to normal eyes with no glaucoma or leakage revealed no difference in any of the parameters. The objective parameters of optic nerve head imaging tools are significantly influenced by papillary leakage. In patients with secondary glaucoma and papillary leakage, these techniques are unable to detect and monitor glaucomatous damage.

The relationship between central corneal thickness and optic disc size in patients with primary open-angle glaucoma in a hospital-based population.

PubMed

Terai, Naim; Spoerl, Eberhard; Pillunat, Lutz E; Kuhlisch, Eberhard; Schmidt, Eckart; Boehm, Andreas G

2011-09-01

To investigate the relationship between central corneal thickness (CCT) and optic disc size in patients with primary open-angle glaucoma (POAG) in a hospital-based population. Data for the right eyes of 1435 White patients with POAG were included in a retrospective hospital-based study. All eyes underwent optic nerve head imaging using Heidelberg Retina Tomograph II (HRT II; Heidelberg Engineering, Heidelberg, Germany) and CCT measurement by ultrasound corneal pachymetry. Eyes with prior intraocular or corneal surgery were excluded. Low-quality HRT II images were also excluded. The impact of age, gender, CCT, intraocular pressure, cylindrical and spherical refractive error as independent factors on optic disc size was investigated in a multiple linear regression analysis. The data for 1104 right eyes qualified for participation in the study. The median age of these patients was 65 years. The median CCT was 547 μm (25th-75th percentile 522-575 μm). The median optic disc size was 2.21 mm(2) (25th-75th percentile 1.89-2.60 mm(2)). Multiple linear regression analysis revealed that age (p = 0.001), CCT (p = 0.001) and spherical equivalent (p = 0.049) were correlated to disc size according to the following formula: disc area = -0.004 × age - 0.001 × CCT - 0.014 × spherical equivalent +3.290. R(2) of the whole model was 0.021. Univariate regression analysis between age and disc area provided R(2) = 0.008 with p = 0.002. Univariate regression analysis between disc area and CCT provided R(2) = 0.005 with p = 0.02. In this retrospective hospital-based study we could not detect a clinically relevant correlation between optic disc size and CCT. The correlation between CCT and disc size and between age and disc size were statistically significant, but the R(2) values were very low. The results of the study are biased because of its hospital-based design, so the results of the study need to be confirmed in a large population-based study. © 2009 The Authors. Journal compilation © 2009 Acta Ophthalmol.

Myopic Maculopathy and Optic Disc Changes in Highly Myopic Young Asian Eyes and Impact on Visual Acuity.

PubMed

Koh, Victor; Tan, Colin; Tan, Pei Ting; Tan, Marcus; Balla, Vinay; Nah, Gerard; Cheng, Ching-Yu; Ohno-Matsui, Kyoko; Tan, Mellisa M H; Yang, Adeline; Zhao, Paul; Wong, Tien Yin; Saw, Seang-Mei

2016-04-01

To determine the prevalence and risk factors of myopic maculopathy and specific optic disc and macular changes in highly myopic eyes of young Asian adults and their impact on visual acuity. Prospective cross-sectional study. In total, 593 highly myopic (spherical equivalent refraction [SER] less than -6.00 diopters [D]) and 156 emmetropic (SER between -1.00 and +1.00 D) male participants from a population-based survey were included. All participants underwent standardized medical interviews, ophthalmic examination, and color fundus photographs. These photographs were graded systematically to determine the presence of optic disc and macular lesions. Myopic maculopathy was classified based on the International Classification of Myopic Maculopathy. The mean age was 21.1 ± 1.2 years. The mean SER for the highly myopic and emmetropic group was -8.87 ± 2.11 D and 0.40 ± 0.39 D, respectively (P < .001). Compared to emmetropic eyes, highly myopic eyes were significantly more likely to have optic disc tilt, peripapillary atrophy (PPA), posterior staphyloma, chorioretinal atrophy, and myopic maculopathy (all P < .001). The main findings included PPA (98.3%), disc tilt (22.0%), posterior staphyloma (32.0%), and chorioretinal atrophy (8.3%). Myopic maculopathy was present in 8.3% of highly myopic eyes and was associated with older age (odds ratio [OR] 1.66; 95% CI: 1.22, 2.26), reduced choroidal thickness (OR 0.99; 95% CI: 0.98, 0.99), and increased axial length (AL) (OR 1.52; 95% CI: 1.06, 2.19). The presence of disc tilt, posterior staphyloma, and chorioretinal atrophy were associated with reduced visual acuity. Our study showed that myopia-related changes of the optic disc and macula were common in highly myopic eyes even at a young age. The risk factors for myopic maculopathy include increased age, longer AL, and reduced choroidal thickness. Some of these changes were associated with reduced central visual function. Copyright © 2016 Elsevier Inc. All rights reserved.

An Endovascular Cannulation Needle with an Internal Wire for the Fragmentation of Thrombi in Retinal Vein Occlusion

PubMed Central

Asami, Tetsu; Kaneko, Hiroki; Miyake, Kensaku; Ota, Ichiro; Miyake, Goichiro; Kato, Seiichi; Yasuda, Shunsuke; Iwase, Takeshi; Ito, Yasuki; Terasaki, Hiroko

2016-01-01

Purpose We report a newly developed device to fragment thrombi in retinal vein occlusion. Methods The new instrument consists of a 23-gauge (G) pipe and a 37-G needle with an internal wire. A total of 40 porcine eyes were used; 20 eyes for experiments in the branch retinal vein (BRV group) and 20 eyes for experiments in the central retinal vein (CRV group). We placed 25-G 3-port trocars, and core vitrectomy was performed. Another 23-G scleral incision was performed for insertion of the needle. The needle pierced the retinal vein at a distance of three- to four- or one-disc diameters from the optic disc (BRV or CRV group, respectively), and the internal wire was advanced toward the disc. The success rates of needle piercing and cannulation of the internal wire were recorded in each group. In the CRV group, the cannulation was deemed successful when the tip reached inside the optic disc. Real-time optical coherence tomography imaging also was performed using the Zeiss Rescan 700 device in porcine eyes. Histologic examination of the retinal vessel inserted with the internal wire was performed. Results The success rates of needle piercing into the BRV and CRV were 85% and 95%, respectively. The success rates of cannulation of the internal wire into the BRV and CRV were 85% and 0%, respectively. The process of cannulation was recorded successfully with the Rescan 700. Histologic examination showed no damages to the endothelial cell layer. Conclusions The needle and internal wire intended to be used for recanalization of BRV occlusion were successfully pierced and cannulated into the BRV. Translational Relevance This newly developed device could become a treatment modality for retinal vein occlusion to fragment thrombi that present treatment methods cannot reach and remove directly. PMID:27730009

Genetic analysis of fibroblast growth factor signaling in the Drosophila eye.

PubMed

Mukherjee, T; Choi, I; Banerjee, Utpal

2012-01-01

The development of eyes in Drosophila involves intricate epithelial reorganization events for accurate positioning of cells and proper formation and organization of ommatidial clusters. We demonstrate that Branchless (Bnl), the fibroblast growth factor ligand, regulates restructuring events in the eye disc primordium from as early as the emergence of clusters from a morphogenetic front to the cellular movements during pupal eye development. Breathless (Btl) functions as the fibroblast growth factor receptor to mediate Bnl signal, and together they regulate expression of DE-cadherin, Crumbs, and Actin. In addition, in the eye Bnl regulates the temporal onset and extent of retinal basal glial cell migration by activating Btl in the glia. We hypothesized that the Bnl functions in the eye are Hedgehog dependent and represent novel aspects of Bnl signaling not explored previously.

Determination of cup-to-disc ratio of optical nerve head for diagnosis of glaucoma on stereo retinal fundus image pairs

NASA Astrophysics Data System (ADS)

Muramatsu, Chisako; Nakagawa, Toshiaki; Sawada, Akira; Hatanaka, Yuji; Hara, Takeshi; Yamamoto, Tetsuya; Fujita, Hiroshi

2009-02-01

A large cup-to-disc (C/D) ratio, which is the ratio of the diameter of the depression (cup) to that of the optical nerve head (ONH, disc), can be one of the important signs for diagnosis of glaucoma. Eighty eyes, including 25 eyes with the signs of glaucoma, were imaged by a stereo retinal fundus camera. An ophthalmologist provided the outlines of cup and disc on a regular monitor and on the stereo display. The depth image of the ONH was created by determining the corresponding pixels in a pair of images based on the correlation coefficient in localized regions. The areas of the disc and cup were determined by use of the red component in one of the color images and by use of the depth image, respectively. The C/D ratio was determined based on the largest vertical lengths in the cup and disc areas, which was then compared with that by the ophthalmologist. The disc areas determined by the computerized method agreed relatively well with those determined by the ophthalmologist, whereas the agreement for the cup areas was somewhat lower. When C/D ratios were employed for distinction between the glaucomatous and non-glaucomatous eyes, the area under the receiver operating characteristic curve (AUC) was 0.83. The computerized analysis of ONH can be useful for diagnosis of glaucoma.

Application of the ISNT rules on retinal nerve fibre layer thickness and neuroretinal rim area in healthy myopic eyes.

PubMed

Qiu, Kunliang; Wang, Geng; Lu, Xuehui; Zhang, Riping; Sun, Lixia; Zhang, Mingzhi

2018-03-01

We determined the applicability of inferior > superior > nasal > temporal (ISNT) rules on retinal nerve fibre layer (RNFL) thickness and rim area and evaluated the impact of various ocular factors on the performance of the ISNT rules in healthy myopic eyes. A total of 138 eyes from 138 healthy myopic subjects were included in this cross-sectional observational study. The peripapillary RNFL and optic disc in each eye were imaged with Cirrus HD optical coherence tomography (OCT) and Heidelberg Retina Tomograph II (HRT2), respectively. The performance of the inferior > superior (IS), inferior > superior > nasal > temporal (IST) and ISNT rules on RNFL thickness and rim area was determined and compared between low-to-moderate myopia and high myopia. The effects of ocular factors [including axial length, disc area, disc tilt, disc torsion, disc-fovea angle (DFA) and retina artery angle] on the performance of ISNT rules were evaluated with logistic regression analysis. The mean axial length and refractive error were 25.57 ± 1.09 mm (range, 22.52-28.77 mm) and -5.12 ± 2.30 D [range, -9.63 to -0.50 dioptres (D)], respectively. Sixty-three per cent of the healthy eyes were compliant with the ISNT rule on rim area, while ISNT rule on RNFL thickness was followed in only 11.6% of the included eyes. For rim area, smaller disc area was significantly associated with increased compliance of the IS rule (odds ratio: 0.46, p = 0.039), IST rule (odds ratio: 0.46, p = 0.037) and ISNT rule (odds ratio: 0.44, p = 0.030). For RNFL thickness, greater DFA was significantly associated with increased compliance of the IS and IST rules (odds ratio: 1.30, p < 0.001; odds ratio: 1.19, p = 0.006, respectively). In healthy myopic subjects, 88.4% and 37% of eyes did not comply with the ISNT rule on RNFL thickness and rim area, respectively. Due to significant low compliance in healthy eyes, the ISNT rule and its variants have limited potential utility in diagnosing glaucoma in myopic subjects. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Progress in Electron Beam Mastering of 100 Gbit/inch2 Density Disc

NASA Astrophysics Data System (ADS)

Takeda, Minoru; Furuki, Motohiro; Yamamoto, Masanobu; Shinoda, Masataka; Saito, Kimihiro; Aki, Yuichi; Kawase, Hiroshi; Koizumi, Mitsuru; Miyokawa, Toshiaki; Mutou, Masao; Handa, Nobuo

2004-07-01

We developed an electron beam recorder (EBR) capable of recording master discs under atmospheric conditions using a novel differential pumping head. Using the EBR and optimized fabrication process for Si-etched discs with reactive ion etching (RIE), a bottom signal jitter of 9.6% was obtained from a 36 Gbit/inch2 density disc, readout using a near-field optical pickup with an effective numerical aperture (NA) of 1.85 and a wavelength of 405 nm. We also obtained the eye patterns from a 70 Gbit/inch2 density disc readout using an optical pickup with a 2.05 NA and the same wavelength, and showed almost the same modulation ratio as the simulation value. Moreover, the capability of producing pit patterns corresponding to a 104 Gbit/inch2 density is demonstrated.

Covalent Binding of Antibodies to Cellulose Paper Discs and Their Applications in Naked-eye Colorimetric Immunoassays.

PubMed

Peng, Yanfen; Gelder, Victor Van; Amaladoss, Anburaj; Patel, Kadamb Haribhai

2016-10-21

This report presents two methods for the covalent immobilization of capture antibodies on cellulose filter paper grade No. 1 (medium-flow filter paper) discs and grade No. 113 (fast-flow filter paper) discs. These cellulose paper discs were grafted with amine functional groups through a silane coupling technique before the antibodies were immobilized on them. Periodate oxidation and glutaraldehyde cross-linking methods were used to graft capture antibodies on the cellulose paper discs. In order to ensure the maximum binding capacity of the capture antibodies to their targets after immobilization, the effects of various concentrations of sodium periodate, glutaraldehyde, and capture antibodies on the surface of the paper discs were investigated. The antibodies that were coated on the amine-functionalized cellulose paper discs through a glutaraldehyde cross-linking agent showed enhanced binding activity to the target when compared to the periodate oxidation method. IgG (in mouse reference serum) was used as a reference target in this study to test the application of covalently immobilized antibodies through glutaraldehyde. A new paper-based, enzyme-linked immunosorbent assay (ELISA) was successfully developed and validated for the detection of IgG. This method does not require equipment, and it can detect 100 ng/ml of IgG. The fast-flow filter paper was more sensitive than the medium-flow filter paper. The incubation period of this assay was short and required small sample volumes. This naked-eye, colorimetric immunoassay can be extended to detect other targets that are identified with conventional ELISA.

Isolation and expression of scabrous, a gene regulating neurogenesis in Drosophila.

PubMed

Mlodzik, M; Baker, N E; Rubin, G M

1990-11-01

Mutations in the Drosophila scabrous (sca) gene affect eye and bristle development, leading to irregular spacing of ommatidia and bristle duplications in the adult fly. We have cloned the sca gene by P-element tagging. The sca transcription unit is 12 kb and consists of four exons that are joined in a 3.2-kb mRNA. In an enhancer trap screen we have isolated several P[lacZ] insertions close to the sca transcription start site. We have examined the expression pattern of sca by in situ hybridization to sca transcripts, by beta-galactosidase localization in the P[lacZ] lines, and by immunocytochemistry with an anti-sca antiserum. During embryogenesis, sca is expressed in a dynamic pattern associated with neural development. During imaginal development, sca is mainly expressed in the R8 photoreceptor precursor cells in the eye imaginal disc and in sensory organ precursor cells in other discs. In the wing disc, sca expression is coextensive with the anlagen for bristles and is controlled by genes of the achaete-scute complex. Based on its loss-of-function phenotype, expression pattern, and the predicted structure of its product, a secreted peptide with homology to the fibrinogen gene family, we propose that sca encodes a signal involved in lateral inhibition within individual domains of the developing nervous system.

Reference Standard Test and the Diagnostic Ability of Spectral Domain Optical Coherence Tomography in Glaucoma.

PubMed

Rao, Harsha L; Yadav, Ravi K; Addepalli, Uday K; Begum, Viquar U; Senthil, Sirisha; Choudhari, Nikhil S; Garudadri, Chandra S

2015-08-01

To evaluate the relationship between the reference standard used to diagnose glaucoma and the diagnostic ability of spectral domain optical coherence tomograph (SDOCT). In a cross-sectional study, 280 eyes of 175 consecutive subjects, referred to a tertiary eye care center for glaucoma evaluation, underwent optic disc photography, visual field (VF) examination, and SDOCT examination. The cohort was divided into glaucoma and control groups based on 3 reference standards for glaucoma diagnosis: first based on the optic disc classification (179 glaucoma and 101 control eyes), second on VF classification (glaucoma hemifield test outside normal limits and pattern SD with P-value of <5%, 130 glaucoma and 150 control eyes), and third on the presence of both glaucomatous optic disc and glaucomatous VF (125 glaucoma and 155 control eyes). Relationship between the reference standards and the diagnostic parameters of SDOCT were evaluated using areas under the receiver operating characteristic curve, sensitivity, and specificity. Areas under the receiver operating characteristic curve and sensitivities of most of the SDOCT parameters obtained with the 3 reference standards (ranging from 0.74 to 0.88 and 72% to 88%, respectively) were comparable (P>0.05). However, specificities of SDOCT parameters were significantly greater (P<0.05) with optic disc classification as reference standard (74% to 88%) compared with VF classification as reference standard (57% to 74%). Diagnostic parameters of SDOCT that was significantly affected by reference standard was the specificity, which was greater with optic disc classification as the reference standard. This has to be considered when comparing the diagnostic ability of SDOCT across studies.

Automated boundary detection of the optic disc and layer segmentation of the peripapillary retina in volumetric structural and angiographic optical coherence tomography.

PubMed

Zang, Pengxiao; Gao, Simon S; Hwang, Thomas S; Flaxel, Christina J; Wilson, David J; Morrison, John C; Huang, David; Li, Dengwang; Jia, Yali

2017-03-01

To improve optic disc boundary detection and peripapillary retinal layer segmentation, we propose an automated approach for structural and angiographic optical coherence tomography. The algorithm was performed on radial cross-sectional B-scans. The disc boundary was detected by searching for the position of Bruch's membrane opening, and retinal layer boundaries were detected using a dynamic programming-based graph search algorithm on each B-scan without the disc region. A comparison of the disc boundary using our method with that determined by manual delineation showed good accuracy, with an average Dice similarity coefficient ≥0.90 in healthy eyes and eyes with diabetic retinopathy and glaucoma. The layer segmentation accuracy in the same cases was on average less than one pixel (3.13 μm).

Automated boundary detection of the optic disc and layer segmentation of the peripapillary retina in volumetric structural and angiographic optical coherence tomography

PubMed Central

Zang, Pengxiao; Gao, Simon S.; Hwang, Thomas S.; Flaxel, Christina J.; Wilson, David J.; Morrison, John C.; Huang, David; Li, Dengwang; Jia, Yali

2017-01-01

To improve optic disc boundary detection and peripapillary retinal layer segmentation, we propose an automated approach for structural and angiographic optical coherence tomography. The algorithm was performed on radial cross-sectional B-scans. The disc boundary was detected by searching for the position of Bruch’s membrane opening, and retinal layer boundaries were detected using a dynamic programming-based graph search algorithm on each B-scan without the disc region. A comparison of the disc boundary using our method with that determined by manual delineation showed good accuracy, with an average Dice similarity coefficient ≥0.90 in healthy eyes and eyes with diabetic retinopathy and glaucoma. The layer segmentation accuracy in the same cases was on average less than one pixel (3.13 μm). PMID:28663830

Characteristics of choroidal neovascularization in the complications of age-related macular degeneration prevention trial.

PubMed

Maguire, Maureen G; Alexander, Judith; Fine, Stuart L

2008-09-01

To describe the characteristics of incident choroidal neovascularization (CNV) in observed and treated eyes in the Complications of Age-related Macular Degeneration Prevention Trial (CAPT). Cross-sectional descriptive study within a multicenter, randomized clinical trial. Patients who developed CNV during CAPT follow-up. Inclusion criteria for CAPT specified bilateral large drusen (>or=10 drusen at least 125 micro), visual acuity >or=20/40 in each eye, and age >or=50. Exclusion criteria included CNV and geographic atrophy >1 Macular Photocoagulation Study (MPS) disc area or within 500 micro of the foveal center. One eye of each person was selected randomly for low-intensity laser treatment and the contralateral eye was observed. Fluorescein angiography was performed at baseline, annually for >or=5 years, and whenever there were symptoms of CNV. Trained readers at the CAPT Photograph Reading Center assessed color stereo photographs and angiogram negatives to identify CNV. Choroidal neovascularization was classified by type (predominantly classic CNV, minimally classic CNV, occult only CNV, or scar), location, and area. Visual acuity was measured by certified examiners. Symmetry of characteristics between eyes of bilaterally affected patients was examined. Choroidal neovascularization developed in 282 eyes of 225 patients. At the time of detection, 192 (68%) of the lesions were occult only, 153 (54%) were subfoveal, and 157 (56%) were or=20/40 in 123 (69%) of 179 eyes with visual acuity measured at the time of detection. Choroidal neovascularization developed in both eyes in 57 patients (25%) during CAPT follow-up. Lesions in eyes of bilaterally affected patients were no more similar to each other than affected eyes in 2 different patients. When patients are monitored closely, many CNV lesions can be detected outside of the fovea and when they are relatively small. Early detection may lead to improved long-term visual acuity.

Bar represses dPax2 and decapentaplegic to regulate cell fate and morphogenetic cell death in Drosophila eye.

PubMed

Kang, Jongkyun; Yeom, Eunbyul; Lim, Janghoo; Choi, Kwang-Wook

2014-01-01

The coordinated regulation of cell fate and cell survival is crucial for normal pattern formation in developing organisms. In Drosophila compound eye development, crystalline arrays of hexagonal ommatidia are established by precise assembly of diverse cell types, including the photoreceptor cells, cone cells and interommatidial (IOM) pigment cells. The molecular basis for controlling the number of cone and IOM pigment cells during ommatidial pattern formation is not well understood. Here we present evidence that BarH1 and BarH2 homeobox genes are essential for eye patterning by inhibiting excess cone cell differentiation and promoting programmed death of IOM cells. Specifically, we show that loss of Bar from the undifferentiated retinal precursor cells leads to ectopic expression of Prospero and dPax2, two transcription factors essential for cone cell specification, resulting in excess cone cell differentiation. We also show that loss of Bar causes ectopic expression of the TGFβ homolog Decapentaplegic (Dpp) posterior to the morphogenetic furrow in the larval eye imaginal disc. The ectopic Dpp expression is not responsible for the formation of excess cone cells in Bar loss-of-function mutant eyes. Instead, it causes reduction in IOM cell death in the pupal stage by antagonizing the function of pro-apoptotic gene reaper. Taken together, this study suggests a novel regulatory mechanism in the control of developmental cell death in which the repression of Dpp by Bar in larval eye disc is essential for IOM cell death in pupal retina.

The Location of the Deepest Point of the Eyeball Determines the Optic Disc Configuration.

PubMed

Kim, Yong Chan; Jung, Younhea; Park, Hae-Young Lopilly; Park, Chan Kee

2017-07-19

Tilted and rotated appearances are hallmarks of the myopic optic disc. As the eyeball grows axially, the posterior pole elongates not only globally but in a localized manner as well. In this process, the optic disc is pulled towards the deepest point of the elongated eyeball, which might result in a change in optic disc configuration. Thus, we hypothesized that analyzing the variation of posterior pole contour can play a major role in understanding optic disc configuration in myopic subjects. By analyzing consecutive images of swept source OCT coronal sections at the posterior pole, the deepest interface between Bruch's membrane and the choroid could be identified as the deepest point of the eyeball (DPE). The location and the properties of the DPE differed significantly between the 125 eyes of non-glaucomatous myopic group and the 40 eyes of non-glaucomatous emmetropic group classified based on 24 mm axial length. The results suggested that the larger disc to DPE angle and the larger disc to DPE depth strongly predicts the optic disc torsion degree and the optic disc tilt. Our findings suggest that identifying the posterior pole profile plays a major role in understanding the optic disc alterations found in myopic subjects.

Agreement of glaucoma specialists and experienced optometrists in gonioscopy and optic disc evaluation

PubMed Central

Kumar, Addepalli U.; Jonnadula, Ganesh B.; Garudadri, Chandrasekhar; Rao, Harsha L.; Senthil, Sirisha; Papas, Eric B.; Sankaridurg, Padmaja; Khanna, Rohit C.

2013-01-01

Purpose To compare the diagnostic performance of glaucoma specialists and experienced optometrists in gonioscopy and optic disc assessment. Methods This study was done to validate the diagnostic performance of two experienced optometrists for using their skills of detecting glaucoma using gonioscopy and optic disc assessment in a major epidemiological study, the L V Prasad Eye Institute Glaucoma Epidemiology and Molecular Genetics Study (LVPEI-GLEAMS). Gonioscopic findings for 150 eyes were categorized as 0, 1 and 2 for open angle, primary angle closure suspect (PACS) and primary angle closure (PAC) respectively. Optic disc findings for 200 eyes were categorized as 0, 1 and 2 for normal, suspects and glaucomatous respectively. Weighted kappa (κ) and diagnostic accuracy parameters were calculated. Two optometrists (#1 and #2) participated in the study. Results Agreement between glaucoma specialists and optometrist for interpretation of gonioscopy to discriminate PACS and PAC from open angles and for interpretation of optic disc to discriminate glaucomatous and suspicious discs from normal, the kappa (κ) was 0.92 and 0.84 and 0.90 and 0.89 for optometrists #1 and #2 respectively. Sensitivities and specificities were above 90% for gonioscopy. Optic disc evaluation had specificities greater than 95% to discriminate normal from glaucomatous discs while the sensitivities were 83% and 93% for optometrists #1 and #2 respectively. Conclusion Agreement between optometrists and glaucoma specialists, in diagnostic performance of gonioscopy and optic assessment was excellent with high sensitivity and specificity. Hence, we conclude that the experienced optometrists can detect glaucoma accurately in the LVPEI-GLEAMS.

Genetic Analysis of Fibroblast Growth Factor Signaling in the Drosophila Eye

PubMed Central

Mukherjee, T.; Choi, I.; Banerjee, Utpal

2012-01-01

The development of eyes in Drosophila involves intricate epithelial reorganization events for accurate positioning of cells and proper formation and organization of ommatidial clusters. We demonstrate that Branchless (Bnl), the fibroblast growth factor ligand, regulates restructuring events in the eye disc primordium from as early as the emergence of clusters from a morphogenetic front to the cellular movements during pupal eye development. Breathless (Btl) functions as the fibroblast growth factor receptor to mediate Bnl signal, and together they regulate expression of DE-cadherin, Crumbs, and Actin. In addition, in the eye Bnl regulates the temporal onset and extent of retinal basal glial cell migration by activating Btl in the glia. We hypothesized that the Bnl functions in the eye are Hedgehog dependent and represent novel aspects of Bnl signaling not explored previously. PMID:22384378

Optical Coherence Tomography Angiography in Optic Disc Swelling.

PubMed

Fard, Masoud Aghsaei; Jalili, Jalil; Sahraiyan, Alireza; Khojasteh, Hassan; Hejazi, Marjane; Ritch, Robert; Subramanian, Prem S

2018-05-04

To compare optical coherence tomography angiography (OCT-A) of peripapillary total vasculature and capillaries in patients with optic disc swelling. Cross-sectional study. Twenty nine eyes with acute nonarteritic anterior ischemic optic neuropathy (NAION), 44 eyes with papilledema, 8 eyes with acute optic neuritis, and 48 eyes of normal subjects were imaged using OCT-A. Peripapillary total vasculature information was recorded using a commercial vessel density map. Customized image analysis with major vessel removal was also used to measure whole-image capillary density and peripapillary capillary density (PCD). Mixed models showed that the peripapillary total vasculature density values were significantly lower in NAION eyes, followed by papilledema eyes and control eyes, using commercial software (P < .0001 for all comparisons). The customized software also showed significantly lower PCD of NAION eyes compared with papilledema eyes (all P < .001), but did not show significant differences between papilledema and control subjects. Our software showed significantly lower whole image and PCD in eyes with optic neuritis than papilledema. There was no significant difference between NAION and optic neuritis using our software. The area under the receiver operating curves for discriminating NAION from papilledema eyes and optic neuritis from papilledema eyes was highest for whole-image capillary density (0.94 and 0.80, respectively) with our software, followed by peripapillary total vasculature (0.9 and 0.74, respectively ) with commercial software. OCT-A is helpful to distinguish NAION and papillitis from papilledema. Whole-image capillary density had the greatest diagnostic accuracy for differentiating disc swelling. Copyright © 2018 Elsevier Inc. All rights reserved.

Parapapillary Gamma Zone and Progression of Myopia in School Children: The Beijing Children Eye Study.

PubMed

Guo, Yin; Liu, Li Juan; Tang, Ping; Feng, Yi; Lv, Yan Yun; Wu, Min; Xu, Liang; Jonas, Jost B

2018-03-01

To assess the development and enlargement of the parapapillary gamma zone in school children. This school-based prospective longitudinal study included Chinese children attending grade 1 in 2011 and returning for yearly follow-up examinations until 2016. These examinations consisted of a comprehensive ocular examination with biometry and color fundus photographs. The parents underwent a standardized interview. The parapapillary gamma zone was defined as the area with visible sclera at the temporal optic disc margin, and the optic disc itself was measured on fundus photographs. The study included 294 children (mean age in 2016, 11.4 ± 0.5 years [range, 10-13 years]; mean axial length, 24.1 ± 1.1 mm [range, 21.13-27.29 mm]). In multivariate analysis, larger increases in the gamma zone area during the study period were correlated (coefficient of determination for bivariate analysis [r2], r2 = 0.69) with larger increases in the vertical-to-horizontal disc diameter ratios (P < 0.001; standardized regression coefficient beta [beta], 0.53; nonstandardized regression coefficient B [B], 4.05; 95% confidence intervals [CI], 3.37-4.73), larger axial elongation (P < 0.001; beta, 0.32; B, 0.37; 95% CI, 0.26-0.47), a larger vertical disc diameter at baseline (P < 0.001; beta, 0.22; B, 0.98; 95% CI, 0.62-1.33), a larger gamma zone area at baseline (P < 0.001; beta, 0.14; B, 0.41; 95% CI, 0.17-0.64), and more time spent indoors studying (P = 0.015; beta, 0.10; B, 0.09; 95% CI, 0.02-0.17). The development and enlargement of the gamma zone in the temporal parapapillary region were associated with an optic disc rotation around the vertical disc axis as indicated by an increasing vertical-to-horizontal disc diameter ratio. These morphologic findings fit with the notion of a backward pull of the temporal peripapillary sclera through the optic nerve dura mater in axially elongated eyes.

Prediction of functional loss in glaucoma from progressive optic disc damage.

PubMed

Medeiros, Felipe A; Alencar, Luciana M; Zangwill, Linda M; Bowd, Christopher; Sample, Pamela A; Weinreb, Robert N

2009-10-01

To evaluate the ability of progressive optic disc damage detected by assessment of longitudinal stereophotographs to predict future development of functional loss in those with suspected glaucoma. The study included 639 eyes of 407 patients with suspected glaucoma followed up for an average of 8.0 years with annual standard automated perimetry visual field and optic disc stereophotographs. All patients had normal and reliable standard automated perimetry results at baseline. Conversion to glaucoma was defined as development of 3 consecutive abnormal visual fields during follow-up. Presence of progressive optic disc damage was evaluated by grading longitudinally acquired simultaneous stereophotographs. Other predictive factors included age, intraocular pressure, central corneal thickness, pattern standard deviation, and baseline stereophotograph grading. Hazard ratios for predicting visual field loss were obtained by extended Cox models, with optic disc progression as a time-dependent covariate. Predictive accuracy was evaluated using a modified R(2) index. Progressive optic disc damage had a hazard ratio of 25.8 (95% confidence interval, 16.0-41.7) and was the most important risk factor for development of visual field loss with an R(2) of 79%. The R(2)s for other predictive factors ranged from 6% to 26%. Presence of progressive optic disc damage on stereophotographs was a highly predictive factor for future development of functional loss in glaucoma. These findings suggest the importance of careful monitoring of the optic disc appearance and a potential role for longitudinal assessment of the optic disc as an end point in clinical trials and as a reference for evaluation of diagnostic tests in glaucoma.

Toxocara optic neuropathy: clinical features and ocular findings.

PubMed

Choi, Kwang-Dong; Choi, Jae-Hwan; Choi, Seo-Young; Jung, Jae Ho

2018-01-01

We evaluated thirteen eyes of twelve patients diagnosed clinically and serologically with Toxocara optic neuropathy. Eleven patients had unilateral involvement and one patient had bilateral optic neuropathy. Eight patients (66.7%) had a possible infection source to Toxocara. Six patients (50%) had painless acute optic neuropathy. Ten eyes had asymmetric, sectorial optic disc edema with peripapillary infiltration and three eyes had diffuse optic disc edema. Eosinophilia was noted in five patients (41.7%) and optic nerve enhancement was observed in eight of eleven eyes (72.7%) with available orbit magnetic resonance imaging (MRI). Mean visual acuity significantly improved following treatment [mean logarithmic of the minimum angle of resolution (logMAR) 0.94±0.56 at baseline and 0.47±0.59 at the final ( P =0.02)]. Asymmetric optic disc edema with a peripapillary lesion and a history of raw meat ingestion were important clues for diagnosing Toxocara optic neuropathy. Additionally, Toxocara IgG enzyme-linked immunosorbent assay (ELISA) test and evaluating eosinophil may be helpful for diagnosis.

Toxocara optic neuropathy: clinical features and ocular findings

PubMed Central

Choi, Kwang-Dong; Choi, Jae-Hwan; Choi, Seo-Young; Jung, Jae Ho

2018-01-01

We evaluated thirteen eyes of twelve patients diagnosed clinically and serologically with Toxocara optic neuropathy. Eleven patients had unilateral involvement and one patient had bilateral optic neuropathy. Eight patients (66.7%) had a possible infection source to Toxocara. Six patients (50%) had painless acute optic neuropathy. Ten eyes had asymmetric, sectorial optic disc edema with peripapillary infiltration and three eyes had diffuse optic disc edema. Eosinophilia was noted in five patients (41.7%) and optic nerve enhancement was observed in eight of eleven eyes (72.7%) with available orbit magnetic resonance imaging (MRI). Mean visual acuity significantly improved following treatment [mean logarithmic of the minimum angle of resolution (logMAR) 0.94±0.56 at baseline and 0.47±0.59 at the final (P=0.02)]. Asymmetric optic disc edema with a peripapillary lesion and a history of raw meat ingestion were important clues for diagnosing Toxocara optic neuropathy. Additionally, Toxocara IgG enzyme-linked immunosorbent assay (ELISA) test and evaluating eosinophil may be helpful for diagnosis. PMID:29600190

Hypodense regions (holes) in the retinal nerve fiber layer in frequency-domain OCT scans of glaucoma patients and suspects.

PubMed

Xin, Daiyan; Talamini, Christine L; Raza, Ali S; de Moraes, Carlos Gustavo V; Greenstein, Vivienne C; Liebmann, Jeffrey M; Ritch, Robert; Hood, Donald C

2011-09-09

To better understand hypodense regions (holes) that appear in the retinal nerve fiber layer (RNFL) of frequency-domain optical coherence tomography (fdOCT) scans of patients with glaucoma and glaucoma suspects. Peripapillary circle (1.7-mm radius) and cube optic disc fdOCT scans were obtained on 208 eyes from 110 patients (57.4 ± 13.2 years) with glaucomatous optic neuropathy (GON) and 45 eyes of 45 controls (48.0 ± 12.6 years) with normal results of fundus examination. Holes in the RNFL were identified independently by two observers on the circle scans. Holes were found in 33 (16%) eyes of 28 (25%) patients; they were not found in any of the control eyes. Twenty-four eyes had more than one hole. Although some holes were relatively large, others were small. In general, the holes were located adjacent to blood vessels; only three eyes had isolated holes that were not adjacent to a vessel. The holes tended to be in the regions that are thickest in healthy controls and were associated with arcuate defects in patients. Holes were not seen in the center of the temporal disc region. They were more common in the superior (25 eyes) than in the inferior (15 eyes) disc. Of the 30 eyes with holes with reliable visual fields, seven were glaucoma suspect eyes with normal visual fields. The holes in the RNFL seen in patients with GON were probably due to a local loss of RNFL fibers and can occur in the eyes of glaucoma suspects with normal visual fields.

The wing and the eye: a parsimonious theory for scaling and growth control?

PubMed

Romanova-Michaelides, Maria; Aguilar-Hidalgo, Daniel; Jülicher, Frank; Gonzalez-Gaitan, Marcos

2015-01-01

How a developing organ grows and patterns to its final shape is an important question in developmental biology. Studies of growth and patterning in the Drosophila wing imaginal disc have identified a key player, the morphogen Decapentaplegic (Dpp). These studies provided insights into our understanding of growth control and scaling: expansion of the Dpp gradient correlated with the growth of the tissue. A recent report on growth of a Drosophila organ other than the wing, the eye imaginal disc, prompts a reconsideration of our models of growth control. Despite striking differences between the two, the Dpp gradient scales with the target tissues of both organs and the growth of both the wing and the eye is controlled by Dpp. The goal of this review is to discuss whether a parsimonious model of scaling and growth control can explain the relationship between the Dpp gradient and growth in these two different developmental systems. © 2015 Wiley Periodicals, Inc.

The Advanced Glaucoma Intervention Study (AGIS): 10. Variability among academic glaucoma subspecialists in assessing optic disc notching.

PubMed

Gaasterland, D E; Blackwell, B; Dally, L G; Caprioli, J; Katz, L J; Ederer, F

2001-01-01

An analysis of data from the Advanced Glaucoma Intervention Study (AGIS) has found eyes reported to have partial optic disc rim notching (not to the edge) at baseline to have less risk of subsequent visual field loss than eyes with no notching. Because this is counterintuitive and because classification of notching had not been defined in the AGIS protocol, we have assessed AGIS ophthalmologists interobserver and intraobserver agreement on notching. Fourteen glaucoma subspecialists classified notching in 26 pairs of stereoscopic disc photographs of eyes with mild to severe glaucomatous optic neuropathy. They classified images as showing either no notching, notching not to the edge, or notching to the edge. Several hours later, 10 of them classified the same images a second time. In an analysis of interobserver agreement, of 26 stereoscopic images, a plurality of ophthalmologists classified notching as absent in 9 (35%), as present but not to the edge in 7 (27%), and as present and not to the edge in 10 (38%). All 14 ophthalmologists (100%) agreed on the classification of 7 (27%) of the images, and 13 of the 14 ophthalmologists (93%) agreed on the classification of 4 additional images (15%). Of these 11 images with at least 93% agreement, notching was reported as absent in 3 (27%) and to the edge in 8 (73%). In the remaining 15 images, there was substantial disagreement about whether notching was present and, if so, whether it was to the edge. In an analysis of intraobserver agreement, none of the 10 ophthalmologists who completed the viewing a second time classified all eyes exactly the same as the first time, though 5 ophthalmologists made 4 or fewer reclassifications. Overall, 80% of the original classifications were reproduced on second reading. Of the initial classifications that were not reproduced, slightly more than half were first classified as having notching not to the edge. Without definitions or examples of optic disc rim notching, the glaucoma subspecialists had relatively high intraobserver agreement but were likely to disagree with each other in characterizing the degree of disc rim notching. We recommend development of a standard photographic classification of disc rim notching. The classification should be tested for inter- and intra-observer agreement.

The Advanced Glaucoma Intervention Study (AGIS): 10. Variability among academic glaucoma subspecialists in assessing optic disc notching.

PubMed Central

Gaasterland, D E; Blackwell, B; Dally, L G; Caprioli, J; Katz, L J; Ederer, F

2001-01-01

PURPOSE: An analysis of data from the Advanced Glaucoma Intervention Study (AGIS) has found eyes reported to have partial optic disc rim notching (not to the edge) at baseline to have less risk of subsequent visual field loss than eyes with no notching. Because this is counterintuitive and because classification of notching had not been defined in the AGIS protocol, we have assessed AGIS ophthalmologists interobserver and intraobserver agreement on notching. METHODS: Fourteen glaucoma subspecialists classified notching in 26 pairs of stereoscopic disc photographs of eyes with mild to severe glaucomatous optic neuropathy. They classified images as showing either no notching, notching not to the edge, or notching to the edge. Several hours later, 10 of them classified the same images a second time. RESULTS: In an analysis of interobserver agreement, of 26 stereoscopic images, a plurality of ophthalmologists classified notching as absent in 9 (35%), as present but not to the edge in 7 (27%), and as present and not to the edge in 10 (38%). All 14 ophthalmologists (100%) agreed on the classification of 7 (27%) of the images, and 13 of the 14 ophthalmologists (93%) agreed on the classification of 4 additional images (15%). Of these 11 images with at least 93% agreement, notching was reported as absent in 3 (27%) and to the edge in 8 (73%). In the remaining 15 images, there was substantial disagreement about whether notching was present and, if so, whether it was to the edge. In an analysis of intraobserver agreement, none of the 10 ophthalmologists who completed the viewing a second time classified all eyes exactly the same as the first time, though 5 ophthalmologists made 4 or fewer reclassifications. Overall, 80% of the original classifications were reproduced on second reading. Of the initial classifications that were not reproduced, slightly more than half were first classified as having notching not to the edge. CONCLUSION: Without definitions or examples of optic disc rim notching, the glaucoma subspecialists had relatively high intraobserver agreement but were likely to disagree with each other in characterizing the degree of disc rim notching. We recommend development of a standard photographic classification of disc rim notching. The classification should be tested for inter- and intra-observer agreement. PMID:11797305

Differences between Non-arteritic Anterior Ischemic Optic Neuropathy and Open Angle Glaucoma with Altitudinal Visual Field Defect.

PubMed

Han, Sangyoun; Jung, Jong Jin; Kim, Ungsoo Samuel

2015-12-01

To investigate the differences in retinal nerve fiber layer (RNFL) change and optic nerve head parameters between non-arteritic anterior ischemic optic neuropathy (NAION) and open angle glaucoma (OAG) with altitudinal visual field defect. Seventeen NAION patients and 26 OAG patients were enrolled prospectively. The standard visual field indices (mean deviation, pattern standard deviation) were obtained from the Humphrey visual field test and differences between the two groups were analyzed. Cirrus HD-OCT parameters were used, including optic disc head analysis, average RNFL thickness, and RNFL thickness of each quadrant. The mean deviation and pattern standard deviation were not significantly different between the groups. In the affected eye, although the disc area was similar between the two groups (2.00 ± 0.32 and 1.99 ± 0.33 mm(2), p = 0.586), the rim area of the OAG group was smaller than that of the NAION group (1.26 ± 0.56 and 0.61 ± 0.15 mm(2), respectively, p < 0.001). RNFL asymmetry was not different between the two groups (p = 0.265), but the inferior RNFL thickness of both the affected and unaffected eyes were less in the OAG group than in the NAION group. In the analysis of optic disc morphology, both affected and unaffected eyes showed significant differences between two groups. To differentiate NAION from OAG in eyes with altitudinal visual field defects, optic disc head analysis of not only the affected eye, but also the unaffected eye, by using spectral domain optical coherence tomography may be helpful.

Beta-Zone parapapillary atrophy and the velocity of glaucoma progression.

PubMed

Teng, Christopher C; De Moraes, Carlos Gustavo V; Prata, Tiago S; Tello, Celso; Ritch, Robert; Liebmann, Jeffrey M

2010-05-01

Beta-Zone parapapillary atrophy (PPA) occurs more commonly in eyes with glaucoma. Rates of glaucomatous visual field (VF) progression in eyes with and without beta-zone PPA at the time of baseline assessment were compared. Retrospective, comparative study. Two hundred forty-five patients from the New York Glaucoma Progression Study. Subjects with glaucomatous optic neuropathy and repeatable VF loss were assessed for eligibility. Eyes with a Heidelberg Retina Tomograph II (HRT) examination, at least 5 visual field tests after the HRT in either eye, optic disc photographs, and <6 diopters of myopia were enrolled. beta-Zone PPA was defined as a region of chorioretinal atrophy with visible sclera and choroidal vessels adjacent to the optic disc. Global rates of VF progression were determined by automated pointwise linear regression analysis. Univariate analysis included age, gender, ethnicity, central corneal thickness (CCT), refractive error, baseline mean deviation, baseline intraocular pressure (IOP), mean IOP, IOP fluctuation, disc area, rim area, rim area-to-disc area ratio, beta-zone PPA area, beta-zone PPA area-to-disc area ratio, and presence or absence of beta-zone PPA. The relationship between beta-zone PPA and the rate and risk of glaucoma progression. Two hundred forty-five eyes of 245 patients (mean age, 69.6+/-12.3 years) were enrolled. The mean follow-up was 4.9+/-1.4 years and the mean number of VFs after HRT was 9.3+/-2.7. beta-Zone PPA was present in 146 eyes (65%). Eyes with beta-zone PPA progressed more rapidly (-0.84+/-0.8 dB/year) than eyes without it (-0.51+/-0.6 dB/year; P<0.01). Multivariate regression showed significant influence of mean IOP (hazard ratio [HR], 1.11; P<0.01), IOP fluctuation (HR, 1.17; P = 0.02), and presence of beta-zone PPA (HR, 2.59; P<0.01) on VF progression. Moderate (0.5-1.5 dB/year; P = 0.01) and fast (>1.5 dB/year; P = 0.08) global rates of progression occurred more commonly in eyes with beta-zone PPA than in eyes without it. Thinner CCT (<525 microm) had a weak but significant correlation with presence of beta-zone PPA (kappa = 0.13). Eyes with beta-zone PPA are at increased risk for glaucoma progression and warrant close clinical surveillance. Copyright 2010 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Normal versus High Tension Glaucoma: A Comparison of Functional and Structural Defects

PubMed Central

Thonginnetra, Oraorn; Greenstein, Vivienne C.; Chu, David; Liebmann, Jeffrey M.; Ritch, Robert; Hood, Donald C.

2009-01-01

Purpose To compare visual field defects obtained with both multifocal visual evoked potential (mfVEP) and Humphrey visual field (HVF) techniques to topographic optic disc measurements in patients with normal tension glaucoma (NTG) and high tension glaucoma (HTG). Methods We studied 32 patients with NTG and 32 with HTG. All patients had reliable 24-2 HVFs with a mean deviation (MD) of −10 dB or better, a glaucomatous optic disc and an abnormal HVF in at least one eye. Multifocal VEPs were obtained from each eye and probability plots created. The mfVEP and HVF probability plots were divided into a central 10-degree (radius) and an outer arcuate subfield in both superior and inferior hemifields. Cluster analyses and counts of abnormal points were performed in each subfield. Optic disc images were obtained with the Heidelberg Retina Tomograph III (HRT III). Eleven stereometric parameters were calculated. Moorfields regression analysis (MRA) and the glaucoma probability score (GPS) were performed. Results There were no significant differences in MD and PSD values between NTG and HTG eyes. However, NTG eyes had a higher percentage of abnormal test points and clusters of abnormal points in the central subfields on both mfVEP and HVF than HTG eyes. For HRT III, there were no significant differences in the 11 stereometric parameters or in the MRA and GPS analyses of the optic disc images. Conclusions The visual field data suggest more localized and central defects for NTG than HTG. PMID:19223786

Dominant Drop mutants are gain-of-function alleles of the muscle segment homeobox gene (msh) whose overexpression leads to the arrest of eye development.

PubMed

Mozer, B A

2001-05-15

Dominant Drop (Dr) mutations are nearly eyeless and have additional recessive phenotypes including lethality and patterning defects in eye and sensory bristles due to cis-regulatory lesions in the cell cycle regulator string (stg). Genetic analysis demonstrates that the dominant small eye phenotype is the result of separate gain-of-function mutations in the closely linked muscle segment homeobox (msh) gene, encoding a homeodomain transcription factor required for patterning of muscle and nervous system. Reversion of the Dr(Mio) allele was coincident with the generation of lethal loss-of-function mutations in msh in cis, suggesting that the dominant eye phenotype is the result of ectopic expression. Molecular genetic analysis revealed that two dominant Dr alleles contain lesions upstream of the msh transcription start site. In the Dr(Mio) mutant, a 3S18 retrotransposon insertion is the target of second-site mutations (P-element insertions or deletions) which suppress the dominant eye phenotype following reversion. The pattern of 3S18 expression and the absence of msh in eye imaginal discs suggest that transcriptional activation of the msh promoter accounts for ectopic expression. Dr dominant mutations arrest eye development by blocking the progression of the morphogenetic furrow leading to photoreceptor cell loss via apoptosis. Gal4-mediated ubiquitous expression of msh in third-instar larvae was sufficient to arrest the morphogenetic furrow in the eye imaginal disc and resulted in lethality prior to eclosion. Dominant mutations in the human msx2 gene, one of the vertebrate homologs of msh, are associated with craniosynostosis, a disease affecting cranial development. The Dr mutations are the first example of gain-of-function mutations in the msh/msx gene family identified in a genetically tractible model organism and may serve as a useful tool to identify additional genes that regulate this class of homeodomain proteins. Copyright 2001 Academic Press.

Neurophthalmological conditions mimicking glaucomatous optic neuropathy: analysis of the most common causes of misdiagnosis.

PubMed

Dias, Diego Torres; Ushida, Michele; Battistella, Roberto; Dorairaj, Syril; Prata, Tiago Santos

2017-01-10

To analyze the most common neurophthalmological conditions that may mimic glaucomatous optic neuropathy and to determine which most often lead to misdiagnosis when evaluated by a glaucoma specialist. We reviewed the charts of consecutive patients with optic neuropathies caused by neurophthalmological conditions screened in a single Eye Clinic within a period of 24 months. Within these enrolled patients, we selected the eyes whose fundoscopic appearance could resemble glaucoma based in pre-defined criteria (vertical cup-to-disc ratio ≥0.6, asymmetry of the cup-to-disc ratio ≥0.2 between eyes, presence of localized retinal nerve fiber layer and/or neuroretinal rim defects, and disc haemorrhages). Then, color fundus photographs and Humphrey Visual Field tests (HVF) of these eyes were mixed with tests from 21 consecutive glaucomatous patients (42 eyes with normal tension glaucoma). These images were mixed randomly and a masked glaucoma specialist was asked to distinguish if each set of exams was from a patient with glaucoma or with a neurophthalmologic condition. Among the 101 eyes (68 patients) enrolled with neurophthalmological diseases, 16 (15.8%) were classified as conditions that could mimic glaucoma. The most common diagnoses were ischemic optic neuropathy (25%), compressive optic neuropathy (18.7%) and hereditary optic neuropathy (18.7%). Based on the analysis of fundus photographs and HVF tests, 25% of these were misdiagnosed as glaucoma (two ischemic optic neuropathies and two congenital optic disc anomalies). Conversely, 11.9% of the glaucomatous neuropathies were misdiagnosed as neurophthalmological disorders. Overall, the glaucoma specialist correctly diagnosed 84.5% of the eyes. Some neurophthalmological disorders can mimic glaucoma. In our study, isquemic and compressive optic neuropathies were the ones that most often did so. Almost one quarter of the eyes were misdiagnosed when evaluated by a glaucoma specialist, which can lead to inadequate management and influence the prognosis of these patients.

Peripapillary Retinoschisis in Glaucomatous Eyes

PubMed Central

Lee, Eun Ji; Kim, Tae-Woo; Kim, Mijin; Choi, Yun Jeong

2014-01-01

Purpose To investigate the structural and clinical characteristics of peripapillary retinoschisis observed in glaucomatous eyes using spectral-domain optical coherence tomography (SD-OCT). Methods Circumpapillary retinal nerve fiber layer (cpRNFL) and macular cross-hair SD-OCT scans and infrared fundus images of the glaucoma patients from the Investigating Glaucoma Progression Study (IGPS) and healthy volunteers were reviewed. Optic disc images obtained using enhanced depth imaging (EDI) SD-OCT were also evaluated. The structural characteristics and clinical course of the retinoschisis associated with glaucoma were investigated. Results Twenty-five retinoschisis areas were found in 22 of the 372 patients (5.9%) included in the IGPS, and in 1 area in 1 of 187 healthy control subjects (0.5%). In the 22 glaucomatous eyes with retinoschisis, the schisis was attached to the optic disc and overlapped with the retinal nerve fiber layer (RNFL) defect. The RNFL was the layer most commonly affected by the retinoschisis, either alone or together with other deeper layers. Acquired optic disc pit was identified in 8 eyes on disc photography and/or B-scan images obtained by EDI SD-OCT. Spontaneous resolution of this condition was observed in nine eyes. No retinal detachment or macular involvement of the retinoschisis was observed in any of the eyes. Multivariate analysis showed a significant influence of a higher intraocular pressure at SD-OCT scanning on the presence of retinoschisis (Odds ratio  = 1.418, P = 0.001). Conclusions The present study investigated 22 cases of peripapillary retinoschisis in glaucomatous eyes. The retinoschisis was attached to the optic nerve and topographically correlated with RNFL defect. It often resolved spontaneously without causing severe visual disturbance. Care should be taken not to overestimate the RNFL thickness in eyes with retinoschisis, and also not to misinterpret the resolution of retinoschisis as a rapid glaucomatous RNFL deterioration. PMID:24587238

Optic nerve head cupping in glaucomatous and non-glaucomatous optic neuropathy.

PubMed

Fard, Masoud Aghsaei; Moghimi, Sasan; Sahraian, Alireza; Ritch, Robert

2018-05-23

Enlargement of optic disc cupping is seen both in glaucoma and in neurological disorders. We used enhanced depth imaging with spectral-domain optical coherence tomography to differentiate glaucoma from non-glaucomatous optic neuropathy. The optic discs were scanned in this prospective comparative study, and the lamina cribrosa (LC) thickness and anterior laminar depth (ALD) in the central, superior and inferior optic nerve head, and peripapillary choroidal thicknesses, were measured. There were 31 eyes of 31 patients with severe glaucoma and 33 eyes of 19 patients with non-glaucomatous cupping. Eyes of 29 healthy controls were also enrolled. There was no significant difference in the cup-to-disc ratio and in the average peripapillary nerve fibre layer thickness between the glaucoma and non-glaucomatous cupping groups (p>0.99). The average peripapillary choroidal thickness was thinner in glaucoma eyes than in the control eyes after adjusting for age and axial length. Glaucomatous and non-glaucomatous eyes had greater ALD and thinner LC than the control eyes (p<0.001 for both). ALDs of glaucoma eyes were deeper than non-glaucomatous eyes (p=0.01 for central ALD) when age, axial length and peripapillary choroidal thickness were included in the linear mixed model. Prelaminar thickness and LC thickness of glaucoma eyes were not different from non-glaucomatous eyes after adjusting. Deeper ALD was observed in glaucoma than non-glaucomatous cupping after adjusting for choroidal thickness. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Comparing multifocal VEP and standard automated perimetry in high-risk ocular hypertension and early glaucoma.

PubMed

Fortune, Brad; Demirel, Shaban; Zhang, Xian; Hood, Donald C; Patterson, Emily; Jamil, Annisa; Mansberger, Steven L; Cioffi, George A; Johnson, Chris A

2007-03-01

To compare the diagnostic performance of multifocal visual evoked potential (mfVEP) and standard automated perimetry (SAP), in eyes with high-risk ocular hypertension or early glaucoma. Both eyes of 185 individuals with high-risk ocular hypertension or early glaucoma were evaluated. Subjects ranged in age from 37 to 87 (mean +/- SD: 61 +/- 11 years). Pattern-reversal mfVEPs were obtained by using VERIS (Electro-Diagnostic Imaging, San Mateo, CA) with a four-electrode array and were analyzed with custom software. SAP visual fields (SITA-standard; Carl Zeiss Meditec, Inc., Dublin, CA) were obtained within 22.3 +/- 27.0 days of the mfVEP. Stereo disc photographs and Heidelberg Retina Tomograph (HRT) images were obtained during one visit, which was within 24.8 +/- 50.4 days of the mfVEP and 33.1 +/- 62.9 days of the SAP visual field. Abnormalities on the mfVEP were defined by using a variety of cluster criteria: SAP with pattern standard deviation (PSD) P

High-density near-field optical disc recording using phase change media and polycarbonate substrate

NASA Astrophysics Data System (ADS)

Shinoda, Masataka; Saito, Kimihiro; Ishimoto, Tsutomu; Kondo, Takao; Nakaoki, Ariyoshi; Furuki, Motohiro; Takeda, Minoru; Akiyama, Yuji; Shimouma, Takashi; Yamamoto, Masanobu

2004-09-01

We developed a high density near field optical recording disc system with a solid immersion lens and two laser sources. In order to realize the near field optical recording, we used a phase change recording media and a molded polycarbonate substrate. The near field optical pick-up consists of a solid immersion lens with numerical aperture of 1.84. The clear eye pattern of 90.2 GB capacity (160nm track pitch and 62 nm per bit) was observed. The jitter using a limit equalizer was 10.0 % without cross-talk. The bit error rate using an adaptive PRML with 8 taps was 3.7e-6 without cross-talk. We confirmed that the near field optical disc system is a promising technology for a next generation high density optical disc system.

The drosophila T-box transcription factor midline functions within Insulin/Akt and c-Jun-N terminal kinase stress-reactive signaling pathways to regulate interommatial bristle formation and cell survival

PubMed Central

Chen, Q. Brent; Das, Sudeshna; Visic, Petra; Buford, Kendrick D.; Zong, Yan; Buti, Wisam; Odom, Kelly R.; Lee, Hannah; Leal, Sandra M.

2015-01-01

We recently reported that the T-box transcription factor midline (mid) functions within the Notch-Delta signaling pathway to specify sensory organ precursor (SOP) cell fates in early-staged pupal eye imaginal discs and to suppress apoptosis (Das et al.). From genetic and allelic modifier screens, we now report that mid interacts with genes downstream of the insulin receptor(InR)/Akt, c-Jun-N-terminal kinase (JNK) and Notch signaling pathways to regulate interommatidial bristle (IOB) formation and cell survival. One of the most significant mid-interacting genes identified from the modifier screen is dFOXO, a transcription factor exhibiting a nucleocytoplasmic subcellular distribution pattern. In common with dFOXO, we show that Mid exhibits a nucleocytoplasmic distribution pattern within WT third-instar larval (3°L) tissue homogenates. Because dFOXO is a stress-responsive factor, we assayed the effects of either oxidative or metabolic stress responses on modifying the mid mutant phenotype which is characterized by a 50% loss of IOBs within the adult compound eye. While metabolic starvation stress does not affect the mid mutant phenotype, either 1 mM paraquat or 20% coconut oil, oxidative stress inducers, partially suppresses the mid mutant phenotype resulting in a significant recovery of IOBs. Another significant mid-interacting gene we identified is groucho (gro). Mid and Gro are predicted to act as corepressors of the enhancer-of-split gene complex downstream of Notch. Immunolabeling WT and dFOXO null 3°L eye-antennal imaginal discs with anti-Mid and anti-Engrailed (En) antibodies indicate that dFOXO is required to activate Mid and En expression within photoreceptor neurons of the eye disc. Taken together, these studies show that Mid and dFOXO serve as critical effectors of cell fate specification and survival within integrated Notch, InR/dAkt, and JNK signaling pathways during 3°L and pupal eye imaginal disc development. PMID:25748605

Age-related change and sex difference over 60s in disc-fovea angle in Japanese population: the Nagahama Study.

PubMed

Miyata, Manabu; Yoshikawa, Munemitsu; Ohtsuki, Hiroshi; Muraoka, Yuki; Hata, Masayuki; Yokota, Satoshi; Fujimoto, Masahiro; Miyake, Masahiro; Tabara, Yasuharu; Matsuda, Fumihiko; Yoshimura, Nagahisa

2018-01-25

To analyse the disc-fovea angle (DFA) by age group and to compare sex differences in each age group in a large cohort population. This community-based cross-sectional cohort study included 9682 eyes of 9682 volunteers (aged 30-75 years). We measured the DFA, which is the angle between a horizontal line and a line connecting the fovea with the centroid of an optic disc on fundus photographs of the right eye. We manually marked the fovea and surrounded the optic disc. The centroid of an optic disc and the DFA was automatically calculated using originally developed software. We compared the DFA between age groups in 10-year increments and investigated sex differences of DFA in each age group. Overall mean DFA was 6.32 ± 3.53°. The DFA of older subjects was significantly larger than that of younger subjects (p < 0.001). The DFA of women was larger than that of men in their 60s and 70s (p < 0.001 for both), but not in subjects in their 30s, 40s and 50s. Larger DFA in women than in men in their 60s and 70s suggests the possibility that age-related excyclo-shift occurs more easily in postmenopausal women compared to men of the same age. © 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Optic disc pit with sectorial retinitis pigmentosa.

PubMed

Balikoglu-Yilmaz, Melike; Taskapili, Muhittin; Yilmaz, Tolga; Teke, Mehmet Yasin

2013-01-01

Sectorial retinitis pigmentosa (RP) and optic disc pit (ODP) are rare clinical conditions. We present a 40-year-old woman with a history of mild night blindness and decreased vision in the right eye for about 5 years. Fundus examination revealed retinal pigmentary changes in the superior and inferotemporal sectors covering the macula and reduced arterial calibre and ODP at the temporal edge of the optic disc. In addition, fundus autofluorescence, spectral-domain optical coherence tomography, fluorescein angiography, and multifocal electroretinogram scans confirmed these clinical findings. Visual acuity was decreased due to an atrophic-appearing foveal lesion. No intervention was suggested because of the poor visual potential. To the best of our knowledge, the present study is the first to describe coexistent optic disc pit and sectorial RP in the superior and inferotemporal sectors covering the macula in the same eye with figures.

Optic nerve and retinal features in uveitis associated with juvenile systemic granulomatous disease (Blau syndrome).

PubMed

Carreño, Ester; Guly, Catherine M; Chilov, Michael; Hinchcliffe, Annie; Arostegui, Juan I; Lee, Richard W J; Dick, Andrew D; Ramanan, Athimalaipet V

2015-05-01

To determine whether patients with juvenile systemic granulomatous disease (JSGD) (Blau syndrome) and uveitis have a characteristic ocular phenotype. Clinical and imaging data were collected retrospectively from patients attending the Regional Combined Paediatric Rheumatology and Ocular Inflammatory Service, Bristol Eye Hospital. General demographic information, laterality of the uveitis, age at onset, anatomical classification and course of the uveitis, clinical phenotype and specific NOD2 mutation were recorded for each patient. Seventeen eyes from nine patients (five males; four females) were included in the study. Mean age at the disease onset was 15 months, range 1-84 months. Eight patients had bilateral uveitis. Anterior uveitis was present in five eyes, intermediate uveitis in two eyes, and there were 10 eyes with panuveitis, manifesting as multifocal choroiditis. Appearance of optic disc included indistinct disc margins in six eyes, optic nerve head pallor in six eyes, optic disc vessel sheathing in four eyes, and there was peripapillary hypo/hyperpigmentation in 13 eyes accompanied with characteristic peripapillary nodular excrescences. Among NOD2 mutations, the p.R334W was the most commonly detected (n: four cases), and three patients carried novel variants, the p.E338D and p.D390V variants in one patient, and the p.H520Y and p.Q809K variants in two different patients. Chronic bilateral panuveitis and a nodular peripapillary appearance in childhood onset uveitis are characteristic features of JSGD, which support the need for an appropriate genetic NOD2 analysis. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Are All Retinal Nerve Fiber Layer Defects on Optic Coherence Tomography Glaucomatous?

PubMed Central

Gür Güngör, Sirel; Ahmet, Akman

2017-01-01

Objectives: In this study, we investigated the patients who were referred to our clinic with a prediagnosis of glaucoma based on retinal nerve fiber layer (RNFL) defects on optic coherence tomography (OCT) but were determined to have nonglaucomatous RNLF defects upon detailed examination. Materials and Methods: The ophthalmic examination notes, OCT images, Heidelberg retinal tomography (HRT) II and fundus photographs of 357 patients were retrospectively evaluated. Final diagnoses of these patients were investigated. Results: Of the 357 patients, 216 (60.5%) were diagnosed as open angle glaucoma, 33 (9.2%) as low-tension glaucoma, 39 (10.9%) as pre-perimetric glaucoma. The ophthalmic examinations of 14 patients (3.9%) were normal and there were no RNFL defects in OCT examinations after dilatation. In 39 patients (10.9%), the ophthalmic and optic disc examinations were completely normal and no etiologic factor explaining RNFL defects was found. Twenty-two eyes of 16 patients (4.5%) were included in this study (the mean age was 53.8±11.5 years; 9 men and 7 women). After detailed questioning of the medical history and systemic and neurologic examinations, a diagnosis of ischemic optic neuropathy was made in 11 eyes (10 patients) (2.8%), optic neuritis in 3 eyes (2 patients) (0.6%), optic disc drusen in 4 eyes (2 patients) (0.6%), pseudotumor cerebri in 2 eyes (1 patient) (0.3%), and cerebral palsy in 2 eyes (1 patient) (0.3%). Conclusion: Decrease in RNFL thickness on OCT images alone may be misleading in glaucoma examination. In cases where optic disc cupping is not evident, diagnosis should not be based on OCT RNFL examinations alone, and the patient’s medical history, detailed ophthalmic examination, OCT optic disc parameters, HRT, and visual field tests should all be carefully evaluated together. PMID:29109895

Variability of vertical cup to disc ratio measurement and the effects of glaucoma 5-year risk estimation in untreated ocular hypertensive eyes.

PubMed

Chan, Poemen Pui Man; Chiu, Vivian S M; Wong, Mandy O I

2018-06-01

To compare the vertical cup to disc ratio (VCDR) measurements obtained with optical coherence tomography (OCT), Heidelberg retina tomography (HRT) and stereophotography of the optic nerve head (ONH) in patients with ocular hypertension (OHT), and their corresponding estimated 5-year risk for development of glaucoma. ONH images of patients with OHT were taken by fundus camera (stereoscopic images), OCT and HRT. Optic disc stereophotographs were evaluated with a stereo-viewer by two glaucoma specialists (SP1 and SP2) and the VCDR was measured with the ImageJ software. VCDR measurements obtained with stereophotography, OCT and HRT were used to calculate the estimated 5-year risk. One hundred and forty eyes of 75 patients with OHT were included. The VCDR values measured by OCT, HRT, SP1 and SP2 were 0.60±0.14, 0.53±0.23, 0.44±0.13 and 0.49±0.10, respectively. The corresponding 5-year risk for development of glaucoma was 19.54%±16.60%, 18.13%±16.96%, 15.64%±14.35% and 16.70%±14.49%, respectively. Different degrees of proportional biases were observed in VCDR measurements obtained with stereophotography, OCT and HRT. The maximum difference of VCDR measurement was 0.64, while the maximum difference of the corresponding 5-year risk was 24.02%. The disagreement in VCDR measured by OCT, HRT and stereophotography in untreated OHT eyes extends to their 5-year risk estimation of glaucoma development. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Microstructure of the optic disc pit in open-angle glaucoma.

PubMed

Choi, Yun Jeong; Lee, Eun Ji; Kim, Bo Hyuk; Kim, Tae-Woo

2014-11-01

To investigate the structural and clinical characteristics of the optic disc pit (ODP) in primary open-angle glaucoma (POAG) via enhanced depth imaging (EDI) spectral-domain optical coherence tomography (SD-OCT). Prospective, observational case series. Seventy POAG eyes clinically diagnosed with an ODP via stereo disc photography. Optic discs were scanned using EDI SD-OCT. Serial horizontal and vertical B-scan images covering the optic discs were obtained from each eye. The structural characteristics of the ODP were investigated via 3-dimensional images constructed from the serial B-scans, focusing on the presence of alterations in the contour of the lamina cribrosa (LC) or prelaminar tissue (PLT), in conjunction with associated clinical characteristics. The structural characteristics of the ODP and associated clinical characteristics. In the EDI SD-OCT images, the ODP was viewed as an isolated alteration of the LC (n = 14, 20.0%) or PLT (n = 16, 22.9%) or an alteration of both the LC and PLT (n = 40, 57.1%). Alterations of the LC were located at the mid-periphery near the LC insertion (n = 17) or far periphery adjacent to the LC insertion (n = 37), and the depth of alteration was deep (n = 23), involving nearly full-thickness LC, or shallow (n = 31), with partially visible LC at the base. Fifty-four eyes (77.1%) exhibited parafoveal visual field (VF) defect within 10 degrees of fixation, and in 98.1% of these eyes (53/54) it was spatially associated with the location of ODP. The parafoveal VF defect was more prevalent in eyes with LC alteration than those without (83.3% vs. 56.2%, P = 0.023) and in eyes with deep LC defect than those with shallow defect (95.7% vs. 74.2%, P = 0.036). Disc hemorrhage (32.4% vs. 0.0%, P = 0.008) and peripapillary retinoschisis (18.9 vs. 0.0%, P = 0.055) were more strongly associated with LC alterations located at the far periphery than at the mid-periphery. Enhanced depth imaging SD-OCT facilitated visualization of the varied structure of the ODP, which presented as alteration of the LC or PLT or both. The clinical significance of differing characteristics of ODP microstructure remains to be determined. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Optic Nerve Head Development in Healthy Infants and Children Using Handheld Spectral-Domain Optical Coherence Tomography.

PubMed

Patel, Aarti; Purohit, Ravi; Lee, Helena; Sheth, Viral; Maconachie, Gail; Papageorgiou, Eleni; McLean, Rebecca J; Gottlob, Irene; Proudlock, Frank A

2016-10-01

To determine feasibility of optic nerve head (ONH) imaging and to characterize ONH development in full-term infants without sedation using handheld spectral-domain optical coherence tomography (SD OCT). Prospective cross-sectional study. Three hundred fifty-two children aged between 1 day and 13 years. All participants were imaged using handheld SD OCT without sedation during a single scan session. The percentage of successful scans was calculated. Interexaminer reproducibility and differences between right and left eyes were assessed using intraclass correlation coefficients (ICCs). Images were analyzed using ImageJ software. The developmental trajectories over time for ONH parameters were calculated using fractional polynomial modelling. Disc and cup diameter (expressed as distance in micrometers and visual angle in degrees), cup depth, Bruch's membrane opening-minimum rim width (BMO-MRW), retinal thickness, and retinal nerve fiber layer (RNFL; 1700 μm and 6° from the disc center). On average, 70% of participants were imaged successfully. Interexaminer reliability was excellent (ICC, >0.89) for diametric and retinal thickness parameters. Right and left eyes were similar for diametric measurements (ICC, >0.79), but more variable for nasal BMO-MRW, RNFL, and retinal thickness. The mean disc and cup diameter increase by 30% and 40%, respectively, between birth and 13 years of age when expressed as a distance measure, but remained constant (at 5°-5.5° and 2°, respectively) when expressed as a visual angle with reference to the eye nodal point. The peripapillary temporal RNFL demonstrated a marked initial decrease of nearly 35% between birth and approximately 18 months of age. This was followed by a slow increase up to 12 years of age when measured at 1700 μm from the disc center, although there was little change when measured at 6° from the disc center. We demonstrated feasibility of handheld SD OCT imaging of the ONH in full-term infants and children without anaesthesia or sedation. This is the first in vivo handheld SD OCT study to describe the development of ONH parameters during the critical early years of visual maturation. Our results provide a normative database for use in routine practice and further studies of ONH pathologic features. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Heidelberg retina tomograph measurements of the optic disc and parapapillary retina for detecting glaucoma analyzed by machine learning classifiers.

PubMed

Zangwill, Linda M; Chan, Kwokleung; Bowd, Christopher; Hao, Jicuang; Lee, Te-Won; Weinreb, Robert N; Sejnowski, Terrence J; Goldbaum, Michael H

2004-09-01

To determine whether topographical measurements of the parapapillary region analyzed by machine learning classifiers can detect early to moderate glaucoma better than similarly processed measurements obtained within the disc margin and to improve methods for optimization of machine learning classifier feature selection. One eye of each of 95 patients with early to moderate glaucomatous visual field damage and of each of 135 normal subjects older than 40 years participating in the longitudinal Diagnostic Innovations in Glaucoma Study (DIGS) were included. Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, Dossenheim, Germany) mean height contour was measured in 36 equal sectors, both along the disc margin and in the parapapillary region (at a mean contour line radius of 1.7 mm). Each sector was evaluated individually and in combination with other sectors. Gaussian support vector machine (SVM) learning classifiers were used to interpret HRT sector measurements along the disc margin and in the parapapillary region, to differentiate between eyes with normal and glaucomatous visual fields and to compare the results with global and regional HRT parameter measurements. The area under the receiver operating characteristic (ROC) curve was used to measure diagnostic performance of the HRT parameters and to evaluate the cross-validation strategies and forward selection and backward elimination optimization techniques that were used to generate the reduced feature sets. The area under the ROC curve for mean height contour of the 36 sectors along the disc margin was larger than that for the mean height contour in the parapapillary region (0.97 and 0.85, respectively). Of the 36 individual sectors along the disc margin, those in the inferior region between 240 degrees and 300 degrees, had the largest area under the ROC curve (0.85-0.91). With SVM Gaussian techniques, the regional parameters showed the best ability to discriminate between normal eyes and eyes with glaucomatous visual field damage, followed by the global parameters, mean height contour measures along the disc margin, and mean height contour measures in the parapapillary region. The area under the ROC curve was 0.98, 0.94, 0.93, and 0.85, respectively. Cross-validation and optimization techniques demonstrated that good discrimination (99% of peak area under the ROC curve) can be obtained with a reduced number of HRT parameters. Mean height contour measurements along the disc margin discriminated between normal and glaucomatous eyes better than measurements obtained in the parapapillary region. Copyright Association for Research in Vision and Ophthalmology

Heidelberg Retina Tomograph Measurements of the Optic Disc and Parapapillary Retina for Detecting Glaucoma Analyzed by Machine Learning Classifiers

PubMed Central

Zangwill, Linda M.; Chan, Kwokleung; Bowd, Christopher; Hao, Jicuang; Lee, Te-Won; Weinreb, Robert N.; Sejnowski, Terrence J.; Goldbaum, Michael H.

2010-01-01

Purpose To determine whether topographical measurements of the parapapillary region analyzed by machine learning classifiers can detect early to moderate glaucoma better than similarly processed measurements obtained within the disc margin and to improve methods for optimization of machine learning classifier feature selection. Methods One eye of each of 95 patients with early to moderate glaucomatous visual field damage and of each of 135 normal subjects older than 40 years participating in the longitudinal Diagnostic Innovations in Glaucoma Study (DIGS) were included. Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, Dossenheim, Germany) mean height contour was measured in 36 equal sectors, both along the disc margin and in the parapapillary region (at a mean contour line radius of 1.7 mm). Each sector was evaluated individually and in combination with other sectors. Gaussian support vector machine (SVM) learning classifiers were used to interpret HRT sector measurements along the disc margin and in the parapapillary region, to differentiate between eyes with normal and glaucomatous visual fields and to compare the results with global and regional HRT parameter measurements. The area under the receiver operating characteristic (ROC) curve was used to measure diagnostic performance of the HRT parameters and to evaluate the cross-validation strategies and forward selection and backward elimination optimization techniques that were used to generate the reduced feature sets. Results The area under the ROC curve for mean height contour of the 36 sectors along the disc margin was larger than that for the mean height contour in the parapapillary region (0.97 and 0.85, respectively). Of the 36 individual sectors along the disc margin, those in the inferior region between 240° and 300°, had the largest area under the ROC curve (0.85–0.91). With SVM Gaussian techniques, the regional parameters showed the best ability to discriminate between normal eyes and eyes with glaucomatous visual field damage, followed by the global parameters, mean height contour measures along the disc margin, and mean height contour measures in the parapapillary region. The area under the ROC curve was 0.98, 0.94, 0.93, and 0.85, respectively. Cross-validation and optimization techniques demonstrated that good discrimination (99% of peak area under the ROC curve) can be obtained with a reduced number of HRT parameters. Conclusions Mean height contour measurements along the disc margin discriminated between normal and glaucomatous eyes better than measurements obtained in the parapapillary region. PMID:15326133

High-Density Near-Field Readout over 50 GB Capacity Using Solid Immersion Lens with High Refractive Index

NASA Astrophysics Data System (ADS)

Shinoda, Masataka; Saito, Kimihiro; Kondo, Takao; Ishimoto, Tsutomu; Nakaoki, Ariyoshi

2003-02-01

We have investigated high-density near-field readout using a solid immersion lens with a high refractive index. By using a glass material with a high refractive index of 2.08, we developed an optical pick-up with the effective numerical aperture of 1.8. We could observe a clear eye pattern for a 50 GB capacity disc in 120 mm diameter. We confirmed that the near-field readout system is promising method of realizing a high-density optical disc system.

High-Density Near-Field Optical Disc Recording

NASA Astrophysics Data System (ADS)

Shinoda, Masataka; Saito, Kimihiro; Ishimoto, Tsutomu; Kondo, Takao; Nakaoki, Ariyoshi; Ide, Naoki; Furuki, Motohiro; Takeda, Minoru; Akiyama, Yuji; Shimouma, Takashi; Yamamoto, Masanobu

2005-05-01

We developed a high-density near-field optical recording disc system using a solid immersion lens. The near-field optical pick-up consists of a solid immersion lens with a numerical aperture of 1.84. The laser wavelength for recording is 405 nm. In order to realize the near-field optical recording disc, we used a phase-change recording media and a molded polycarbonate substrate. A clear eye pattern of 112 GB capacity with 160 nm track pitch and 50 nm bit length was observed. The equivalent areal density is 80.6 Gbit/in2. The bottom bit error rate of 3 tracks-write was 4.5× 10-5. The readout power margin and the recording power margin were ± 30.4% and ± 11.2%, respectively.

Photoreceptor disc shedding in the living human eye

PubMed Central

Kocaoglu, Omer P.; Liu, Zhuolin; Zhang, Furu; Kurokawa, Kazuhiro; Jonnal, Ravi S.; Miller, Donald T.

2016-01-01

Cone photoreceptors undergo a daily cycle of renewal and shedding of membranous discs in their outer segments (OS), the portion responsible for light capture. These physiological processes are fundamental to maintaining photoreceptor health, and their dysfunction is associated with numerous retinal diseases. While both processes have been extensively studied in animal models and postmortem eyes, little is known about them in the living eye, in particular human. In this study, we report discovery of the optical signature associated with disc shedding using a method based on adaptive optics optical coherence tomography (AO-OCT) in conjunction with post-processing methods to track and monitor individual cone cells in 4D. The optical signature of disc shedding is characterized by an abrupt transient loss in the cone outer segment tip (COST) reflection followed by its return that is axially displaced anteriorly. Using this signature, we measured the temporal and spatial properties of shedding events in three normal subjects. Average duration of the shedding event was 8.8 ± 13.4 minutes, and average length loss of the OS was 2.1 μm (7.0% of OS length). Prevalence of cone shedding was highest in the morning (14.3%) followed by the afternoon (5.7%) and evening (4.0%), with load distributed across the imaged patch. To the best of our knowledge these are the first images of photoreceptor disc shedding in the living retina. PMID:27895995

Competition among gene regulatory networks imposes order within the eye-antennal disc of Drosophila

PubMed Central

Weasner, Bonnie M.; Kumar, Justin P.

2013-01-01

The eye-antennal disc of Drosophila gives rise to numerous adult tissues, including the compound eyes, ocelli, antennae, maxillary palps and surrounding head capsule. The fate of each tissue is governed by the activity of unique gene regulatory networks (GRNs). The fate of the eye, for example, is controlled by a set of fourteen interlocking genes called the retinal determination (RD) network. Mutations within network members lead to replacement of the eyes with head capsule. Several studies have suggested that in these instances all retinal progenitor and precursor cells are eliminated via apoptosis and as a result the surrounding head capsule proliferates to compensate for retinal tissue loss. This model implies that the sole responsibility of the RD network is to promote the fate of the eye. We have re-analyzed eyes absent mutant discs and propose an alternative model. Our data suggests that in addition to promoting an eye fate the RD network simultaneously functions to actively repress GRNs that are responsible for directing antennal and head capsule fates. Compromising the RD network leads to the inappropriate expression of several head capsule selector genes such as cut, Lim1 and wingless. Instead of undergoing apoptosis, a population of mutant retinal progenitors and precursor cells adopt a head capsule fate. This transformation is accompanied by an adjustment of cell proliferation rates such that just enough head capsule is generated to produce an intact adult head. We propose that GRNs simultaneously promote primary fates, inhibit alternative fates and establish cell proliferation states. PMID:23222441

Optic Disc Pit with Sectorial Retinitis Pigmentosa

PubMed Central

Taskapili, Muhittin; Yilmaz, Tolga; Teke, Mehmet Yasin

2013-01-01

Sectorial retinitis pigmentosa (RP) and optic disc pit (ODP) are rare clinical conditions. We present a 40-year-old woman with a history of mild night blindness and decreased vision in the right eye for about 5 years. Fundus examination revealed retinal pigmentary changes in the superior and inferotemporal sectors covering the macula and reduced arterial calibre and ODP at the temporal edge of the optic disc. In addition, fundus autofluorescence, spectral-domain optical coherence tomography, fluorescein angiography, and multifocal electroretinogram scans confirmed these clinical findings. Visual acuity was decreased due to an atrophic-appearing foveal lesion. No intervention was suggested because of the poor visual potential. To the best of our knowledge, the present study is the first to describe coexistent optic disc pit and sectorial RP in the superior and inferotemporal sectors covering the macula in the same eye with figures. PMID:23781365

Regression Analysis of Optical Coherence Tomography Disc Variables for Glaucoma Diagnosis.

PubMed

Richter, Grace M; Zhang, Xinbo; Tan, Ou; Francis, Brian A; Chopra, Vikas; Greenfield, David S; Varma, Rohit; Schuman, Joel S; Huang, David

2016-08-01

To report diagnostic accuracy of optical coherence tomography (OCT) disc variables using both time-domain (TD) and Fourier-domain (FD) OCT, and to improve the use of OCT disc variable measurements for glaucoma diagnosis through regression analyses that adjust for optic disc size and axial length-based magnification error. Observational, cross-sectional. In total, 180 normal eyes of 112 participants and 180 eyes of 138 participants with perimetric glaucoma from the Advanced Imaging for Glaucoma Study. Diagnostic variables evaluated from TD-OCT and FD-OCT were: disc area, rim area, rim volume, optic nerve head volume, vertical cup-to-disc ratio (CDR), and horizontal CDR. These were compared with overall retinal nerve fiber layer thickness and ganglion cell complex. Regression analyses were performed that corrected for optic disc size and axial length. Area-under-receiver-operating curves (AUROC) were used to assess diagnostic accuracy before and after the adjustments. An index based on multiple logistic regression that combined optic disc variables with axial length was also explored with the aim of improving diagnostic accuracy of disc variables. Comparison of diagnostic accuracy of disc variables, as measured by AUROC. The unadjusted disc variables with the highest diagnostic accuracies were: rim volume for TD-OCT (AUROC=0.864) and vertical CDR (AUROC=0.874) for FD-OCT. Magnification correction significantly worsened diagnostic accuracy for rim variables, and while optic disc size adjustments partially restored diagnostic accuracy, the adjusted AUROCs were still lower. Axial length adjustments to disc variables in the form of multiple logistic regression indices led to a slight but insignificant improvement in diagnostic accuracy. Our various regression approaches were not able to significantly improve disc-based OCT glaucoma diagnosis. However, disc rim area and vertical CDR had very high diagnostic accuracy, and these disc variables can serve to complement additional OCT measurements for diagnosis of glaucoma.

Association of Bruch's membrane opening and optic disc morphology to axial length and visual field defects in eyes with primary open-angle glaucoma.

PubMed

Nakanishi, Hideo; Suda, Kenji; Yoshikawa, Munemitsu; Akagi, Tadamichi; Kameda, Takanori; Ikeda, Hanako Ohashi; Yokota, Satoshi; Kurimoto, Yasuo; Tsujikawa, Akitaka

2018-03-01

To examine the morphology of Bruch's membrane opening (BMO), optic disc, and peripapillary atrophy (PPA) by scanning laser ophthalmoscopy (SLO) and spectral-domain optical coherence tomography (SD-OCT), and to determine their association with the axial length and visual field defects. This was a cross-sectional study of 94 eyes of 56 subjects; 77 eyes were diagnosed with primary open-angle glaucoma and 17 eyes as normal. The margins of the optic disc were determined in the SLO images, and that of the BMO in the SD-OCT images. The ovality and area of the BMO and the optic disc were measured. The beta and gamma-PPA areas were also measured. The association of each parameter with the axial length and the mean deviation (MD) of the visual field tests was determined by generalized estimating equations (GEEs). The optic disc ovality was associated with the axial length and the MD (β = -0.47, P = 7.6 × 10 -4 and β = 0.12, P = 0.040). The BMO ovality was not significantly associated with the axial length and the MD. The BMO area was associated with the axial length (β = 0.30, P = 0.029). A larger BMO area was associated with a thinner BMO-based neuroretinal rim width (BMO-MRW) after adjustments for the MD (β = -0.30, P = 2.1 × 10 -4 ). The beta- and gamma-PPA areas were associated with the axial length (β = 0.50, P = 7.4 × 10 -5 and β = 0.62, P = 4.2 × 10 -6 ). The optic disc ovality was associated with both the axial length and MD, whereas BMO ovality was not. Attention should be paid to the influence of the axial length-related enlargement of the BMO.

Bilateral Glaucomatous Optic Neuropathy Caused by Eye Rubbing.

PubMed

Savastano, Alfonso; Savastano, Maria Cristina; Carlomusto, Laura; Savastano, Silvio

2015-01-01

In this report, we describe a particular condition of a 52-year-old man who showed advanced bilateral glaucomatous-like optic disc damage, even though the intraocular pressure resulted normal during all examinations performed. Visual field test, steady-state pattern electroretinogram, retinal nerve fiber layer and retinal tomographic evaluations were performed to evaluate the optic disc damage. Over a 4-year observational period, his visual acuity decreased to 12/20 in the right eye and counting fingers in the left eye. Visual fields were severely compromised, and intraocular pressure values were not superior to 14 mm Hg during routine examinations. An accurate anamnesis and the suspicion of this disease represent a crucial aspect to establish the correct diagnosis. In fact, our patient strongly rubbed his eyes for more than 10 h per day. Recurrent and continuous eye rubbing can induce progressive optic neuropathy, causing severe visual field damage similar to the pathology of advanced glaucoma.

Refraction and the axial length of the eyeball in patients with the optic disc drusen.

PubMed

Obuchowska, Iwona; Mariak, Zofia

2009-01-01

The aim of the study was to demonstrate the relationship between the optic disc drusen (ODD) and the axial length of the eyeball as well as refractive error. We examined prospectively 40 patients with ODD, 18 men and 22 women, age range from 34 to 69 years. All subjects underwent full ophthalmic examination, visual field testing and color-coded duplex sonography of the ocular vessels. Refraction was determined with an autorefractometer (Topcon RM-8000B) and further refined subjectively. Spherical equivalent refraction was calculated as the spherical dioptre plus one half of the cylindrical dioptre. Axial lengths were measured with a Sonomed ultrasound scanner model E-Z Scan AB5500. Clinical signs were observed in 65% of the eyes with drusen, among them, 38% had symptoms of visual acuity loss and all had visual fields defects. There were 21 eyes (18 eyes with and 3 without drusen), with a recorded refractive error. Significant differences in hyperopia were observed between the eyes with and without drusen (p = 0.048). The rate of occurrence of myopia did not differ significantly between affected and unaffected eyes (p = 0.06). The mean spherical equivalent refraction and axial dimensions of the eye differed significantly among the groups of eyes with and without drusen (p < 0.05). Significant differences in mean values of peak-systolic and end-diastolic velocities (p < 0.001) as well as in the resistivity index (p = 0.047) were observed between eyes with and without drusen. The optic disc drusen are often associated with shorter and hyperopic eyes. This anatomical conditions and vascular factors may contribute to pathogenesis of drusen.

Long Term Ex Vivo Culture and Live Imaging of Drosophila Larval Imaginal Discs.

PubMed

Tsao, Chia-Kang; Ku, Hui-Yu; Lee, Yuan-Ming; Huang, Yu-Fen; Sun, Yi Henry

Continuous imaging of live tissues provides clear temporal sequence of biological events. The Drosophila imaginal discs have been popular experimental subjects for the study of a wide variety of biological phenomena, but long term culture that allows normal development has not been satisfactory. Here we report a culture method that can sustain normal development for 18 hours and allows live imaging. The method is validated in multiple discs and for cell proliferation, differentiation and migration. However, it does not support disc growth and cannot support cell proliferation for more than 7 to 12 hr. We monitored the cellular behavior of retinal basal glia in the developing eye disc and found that distinct glia type has distinct properties of proliferation and migration. The live imaging provided direct proof that wrapping glia differentiated from existing glia after migrating to the anterior front, and unexpectedly found that they undergo endoreplication before wrapping axons, and their nuclei migrate up and down along the axons. UV-induced specific labeling of a single carpet glia also showed that the two carpet glia membrane do not overlap and suggests a tiling or repulsion mechanism between the two cells. These findings demonstrated the usefulness of an ex vivo culture method and live imaging.

Retinoschisis and neurosensory detachment in advanced focal glaucoma.

PubMed

Arranz-Márquez, E; Jarrín Hernández, E; Pastor, A; García Gil de Bernabé, J

2017-10-01

A 71-year-old woman with normotensive primary open-angle glaucoma presented with an asymptomatic temporal peripapillary retinoschisis, associated with serous retinal detachment in the eye with the more advanced glaucoma. It was located at the inferior pole of the optic disc, in the proximity of a glaucomatous focal disc defect. Although congenital optic pits are strongly related with juxta-papillary retinoschisis, retinoschisis can also arise from acquired defects in the proximity of glaucomatous optic discs. As symptoms depend on the extent of the retinoschisis, the prevalence of this complication could be greater than that reported in glaucomatous eyes. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

Neuro-Ophthalmology at a Tertiary Eye Care Centre in India.

PubMed

Dhiman, Rebika; Singh, Digvijay; Gantayala, Shiva P; Ganesan, Vaitheeswaran L; Sharma, Pradeep; Saxena, Rohit

2017-11-09

Neuro-ophthalmology as a specialty is underdeveloped in India. The aim of our study was to determine the spectrum and profile of patients presenting to a tertiary eye care center with neuro-ophthalmic disorders. A retrospective hospital-based study was conducted, and records of all patients seen at the neuro-ophthalmology clinic of Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India, over a 1-year period were retrieved and evaluated. Of a total of 30,111 patients referred to various specialty clinics in a span of 1 year, 1597 (5%) were referred for neuro-ophthalmology evaluation. The mean patient age was 30.8 ± 19.5 years, with a male dominance (M:F = 2.02:1). Among these patients, optic nerve disorders were noted in 63.8% (n = 1,020), cranial nerve palsy in 7% (n = 114), cortical visual impairment in 6.5% (n = 105), and others (eye/optic nerve hypophasia, blepharospasm, and optic disc drusen) in 6% (n = 95). Among the patients with optic nerve disorders, optic neuropathy without disc edema/(traumatic optic neuropathy, hereditary, tumor-related, retrobulbar neuritis, toxic, and idiopathic) was noted in 42.8% (n = 685) and optic neuropathy with disc edema (ischemic optic neuropathy, papilledema, post-papilledema optic atrophy, papillitis, neuroretinitis, and inflammatory optic neuropathy) in 20.9% (n = 335). Sixteen percent of patients (n = 263) were incorrect referrals. The neuro-ophthalmic clinic constitutes a significant referral unit in a tertiary eye care center in India. Traumatic and ischemic optic neuropathies are the most common diagnoses. Neuro-ophthalmology requires further development as a subspecialty in India to better serve the nation's population.

Comparison of different methods of inter-eye asymmetry of rim area and disc area analysis

PubMed Central

Fansi, A A K; Boisjoly, H; Chagnon, M; Harasymowycz, P J

2011-01-01

Purpose To describe different methods of inter-eye asymmetry of rim area (RA) to disc area (DA) asymmetry ratio (RADAAR) analysis. Methods This was an observational, descriptive, and cross-sectional study. Both the eyes of all participants underwent confocal scanning laser ophthalmoscopy (Heidelberg retina tomograph (HRT 3)), frequency-doubling technology perimetry (FDT), and complete ophthalmological examination. Based on ophthalmological clinical examination and FDT results of the worse eye, subjects were classified as either normal, possible glaucoma, and probable glaucoma or definitive glaucoma. RADAAR values were calculated based on stereometric HRT 3 values using different mathematical formulae. RADAAR-1 was calculated as a relative difference of rim and DAs between the eyes. RADAAR-2 was calculated by subtracting the value of rim to DA ratio of the smaller disc from the value of rim to DA ratio of the larger disc. RADAAR-3 was calculated by dividing the previous two values. Statistical analyses included ANOVA as well as Student t-tests. Results Data of 334 participants were analysed, 78 of which were classified as definitive glaucoma. RADAAR-1 values were significantly different between the four different groups of diagnosis (F=5.82; P<0.001). The 1st and 99th percentile limits of normality for RADAAR-1, RADAAR-2, and RADAAR-3 in normal group were, respectively, −10.64 and 8.4; −0.32 and 0.22; and 0.58 and 1.32. Conclusions RADAAR-1 seems to best distinguish between the diagnostic groups. Knowledge of RADAAR distribution in various diagnostic groups may aid in clinical diagnosis of asymmetric glaucomatous damage. PMID:21921945

Combined use of Doppler OCT and en face OCT functions for discrimination of an aneurysm in the lamina cribrosa from a disc hemorrhage.

PubMed

Holló, Gábor

2015-12-01

In addition to retinal nerve fiber layer thickness measurements, the recently introduced AngioVue optical coherence tomography (OCT) offers corresponding layer-by-layer Doppler OCT and en face OCT functions, for simultaneous evaluation of perfusion and structure of the optic nerve head. We investigated the clinical usefulness of combined use of Doppler and en face Fourier-domain OCT functions of the AngioVue Fourier-domain OCT for discrimination of a disc hemorrhage and a disc hemorrhage-like atypical vessel structure located deep in the lamina cribrosa. We present our findings with AngioVue OCT on a disc hemorrhage and a spatially related retinal nerve fiber layer bundle defect in a glaucomatous eye (case 1). Both alterations were detected on en face OCT images without any Doppler OCT signal. We also report on an aneurysm suggestive for a disc hemorrhage on clinical examination and disc photography in a treated ocular hypertensive eye (case 2). The aneurysm was within the lamina cribrosa tissue at the border of the cup and the neuroretinal rim. This vascular structure produced strong Doppler signals but no structurally detectable signs on the en face OCT images. Combined evaluation of corresponding Doppler OCT and en face OCT images enables ophthalmologists to easily separate true disc hemorrhages from disc hemorrhage-like deep vascular structures. This is of clinical significance in preventing unnecessary intensification of pressure-lowering treatment in glaucoma.

Spontaneous Resolution of Long-Standing Macular Detachment due to Optic Disc Pit with Significant Visual Improvement.

PubMed

Parikakis, Efstratios A; Chatziralli, Irini P; Peponis, Vasileios G; Karagiannis, Dimitrios; Stratos, Aimilianos; Tsiotra, Vasileia A; Mitropoulos, Panagiotis G

2014-01-01

To report a case of spontaneous resolution of a long-standing serous macular detachment associated with an optic disc pit, leading to significant visual improvement. A 63-year-old female presented with a 6-month history of blurred vision and micropsia in her left eye. Her best-corrected visual acuity was 6/24 in the left eye, and fundoscopy revealed serous macular detachment associated with optic disc pit, which was confirmed by optical coherence tomography (OCT). The patient was offered vitrectomy as a treatment alternative, but she preferred to be reviewed conservatively. Three years after initial presentation, neither macular detachment nor subretinal fluid was evident in OCT, while the inner segment/outer segment (IS/OS) junction line was intact. Her visual acuity was improved from 6/24 to 6/12 in her left eye, remaining stable at the 6-month follow-up after resolution. We present a case of spontaneous resolution of a long-standing macular detachment associated with an optic disc pit with significant visual improvement, postulating that the integrity of the IS/OS junction line may be a prognostic factor for final visual acuity and suggesting OCT as an indicator of visual prognosis and the probable necessity of a surgical management.

Effect of moderate intraocular pressure changes on topographic measurements with confocal scanning laser tomography in patients with glaucoma.

PubMed

Nicolela, Marcelo T; Soares, Adael S; Carrillo, Monica M; Chauhan, Balwantray C; LeBlanc, Raymond P; Artes, Paul H

2006-05-01

To evaluate optic disc topography changes after intraocular pressure (IOP) modulation in patients with glaucoma. Twenty-three patients with glaucoma were studied. Three mean optic disc topography images were obtained with the Heidelberg Retina Tomograph II at baseline and weeks 1, 2, 4, and 8 (visits 1, 2, 3, 4, and 5, respectively). Topical medications were discontinued in the study eye after visit 1 and resumed after visit 4 but maintained in the contralateral control eye. Central corneal thickness was measured at the last visit. Topographic changes were determined by stereometric parameters (rim area and mean cup depth) and at discrete topographic locations using the Topographic Change Analysis program (from the Heidelberg Retina Tomograph II). In the study eyes, IOP increased significantly (5.4 mm Hg at visit 4; P<.001) after withdrawal of topical medications but returned to baseline levels after resuming medications; no statistically significant topographic changes, however, were observed. Moreover, no relationship between change in IOP and stereometric parameters was observed. Central corneal thickness was not associated with changes in optic disc topography induced by IOP modulation. In patients with glaucoma, significant but relatively moderate IOP increases and decreases on the order of 5 mm Hg did not appear to have an effect on optic disc topography.

Discus: investigating subjective judgment of optic disc damage.

PubMed

Denniss, Jonathan; Echendu, Damian; Henson, David B; Artes, Paul H

2011-01-01

To describe a software package (Discus) for investigating clinicians' subjective assessment of optic disc damage [diagnostic accuracy in detecting visual field (VF) damage, decision criteria, and agreement with a panel of experts] and to provide reference data from a group of expert observers. Optic disc images were selected from patients with manifest or suspected glaucoma or ocular hypertension who attended the Manchester Royal Eye Hospital. Eighty images came from eyes without evidence of VF loss in at least four consecutive tests (VF negatives), and 20 images from eyes with repeatable VF loss (VF positives). Software was written to display these images in randomized order, for up to 60 s. Expert observers (n = 12) rated optic disc damage on a 5-point scale (definitely healthy, probably healthy, not sure, probably damaged, and definitely damaged). Optic disc damage as determined by the expert observers predicted VF loss with less than perfect accuracy (mean area under receiver-operating characteristic curve, 0.78; range, 0.72 to 0.85). When the responses were combined across the panel of experts, the area under receiver-operating characteristic curve reached 0.87, corresponding to a sensitivity of ∼60% at 90% specificity. Although the observers' performances were similar, there were large differences between the criteria they adopted (p < 0.001), even though all observers had been given identical instructions. Discus provides a simple and rapid means for assessing important aspects of optic disc interpretation. The data from the panel of expert observers provide a reference against which students, trainees, and clinicians may compare themselves. The program and the analyses described in this article are freely accessible from http://www.discusproject.blogspot.com/.

Plaque radiotherapy for choroidal melanoma encircling the optic disc (circumpapillary choroidal melanoma).

PubMed

Sagoo, Mandeep S; Shields, Carol L; Mashayekhi, Arman; Freire, Jorge; Emrich, Jacqueline; Reiff, Jay; Komarnicky, Lydia; Shields, Jerry A

2007-09-01

To report results of plaque radiotherapy for choroidal melanoma that completely encircles the optic disc (circumpapillary melanoma). Retrospective medical record review over a 31-year period of 37 consecutive patients. The main outcome measures were treatment complications, long-term visual acuity, enucleation, tumor recurrence, metastasis, and death. The median patient age at treatment was 69 years (range, 20-86 years). The presenting complaint was visual loss in 19 eyes (51%), photopsia in 5 (14%), and visual field loss in 3 (8%). All tumors touched and encircled the optic disc for 360 degrees . The quadrantic location of the main tumor epicenter was superior in 8 eyes (22%), nasal in 10 (27%), inferior in 9 (24%), and temporal in 10 (27%). The median tumor basal diameter was 11 mm (range, 4.8-20 mm) and median tumor thickness was 3.6 mm (range, 1.8-14.8 mm). The optic disc was obscured to some extent by overhanging tumor in 19 cases (52%). The most commonly used isotope for plaque radiotherapy was iodine 125 (n = 34 cases; 92%), and a notched plaque design was used in 34 cases (92%). Planned adjunctive treatment included transpupillary thermotherapy in 17 cases (49%) and argon laser photocoagulation in 6 of 35 cases (17%) with follow-up. Of the 28 eyes with more than 5 months' follow-up (mean, 52 months; median, 46 months; range, 5-234 months), treatment complications included nonproliferative and proliferative retinopathy in 11 (39%) and 7 eyes (25%); maculopathy in 7 (25%); papillopathy in 9 eyes (32%); neovascular glaucoma in 5 (18%); and vitreous hemorrhage in 13 (46%). Pars plana vitrectomy was required in only 2 of 13 eyes (15%) with persistent vitreous hemorrhage. Long-term visual acuity of 20/200 or worse was observed in 13 eyes (62%), and 12 eyes (57%) lost more than 5 Snellen visual acuity lines, excluding 7 cases (25%) in which enucleation was necessary. Recurrence was noted in 4 cases (14%), of which 3 were treated with enucleation and 1 with transpupillary thermotherapy. Systemic metastasis occurred in 1 patient (4%) and there were no melanoma-specific deaths during the study period. Custom-designed plaque radiotherapy is a potential treatment for selected patients with circumpapillary choroidal melanoma. We found satisfactory local tumor control, and globe retention was achieved in 75% of eyes with more than 5 months' follow-up.

Combining morphometric features and convolutional networks fusion for glaucoma diagnosis

NASA Astrophysics Data System (ADS)

Perdomo, Oscar; Arevalo, John; González, Fabio A.

2017-11-01

Glaucoma is an eye condition that leads to loss of vision and blindness. Ophthalmoscopy exam evaluates the shape, color and proportion between the optic disc and physiologic cup, but the lack of agreement among experts is still the main diagnosis problem. The application of deep convolutional neural networks combined with automatic extraction of features such as: the cup-to-disc distance in the four quadrants, the perimeter, area, eccentricity, the major radio, the minor radio in optic disc and cup, in addition to all the ratios among the previous parameters may help with a better automatic grading of glaucoma. This paper presents a strategy to merge morphological features and deep convolutional neural networks as a novel methodology to support the glaucoma diagnosis in eye fundus images.

Persistence of the primary vitreous in association with the morning glory disc anomaly.

PubMed

Brown, G C; Gonder, J; Levin, A

1984-01-01

Two patients with the morning glory disc anomaly are reported. In one, fibrovascular stalk passed forward into the vitreous cavity, while in the second a persistent hyaloid artery extended anteriorly from a tuft of fibrous tissue to the posterior lens capsule. These cases suggest that in some eyes the morning glory disc anomaly occurs as a variant of persistent hyperplastic primary vitreous (PHPV).

Cat-scratch disease: ocular manifestations and treatment outcome.

PubMed

Habot-Wilner, Zohar; Trivizki, Omer; Goldstein, Michaella; Kesler, Anat; Shulman, Shiri; Horowitz, Josepha; Amer, Radgonde; David, Ran; Ben-Arie-Weintrob, Yael; Bakshi, Erez; Almog, Yehoshua; Sartani, Gil; Vishnevskia-Dai, Vicktoria; Kramer, Michal; Bar, Asaf; Kehat, Rinat; Ephros, Moshe; Giladi, Michael

2018-03-05

To characterize cat-scratch disease (CSD) ocular manifestations and visual outcome and evaluate the effect of systemic antibiotics and corticosteroids on final visual acuity (VA). Multicentre retrospective cohort study. Medical records of 86 patients with ocular disease (107 eyes) of 3222 patients identified in a national CSD surveillance study were reviewed. Mean age was 35.1 ± 14.2 years. Median follow-up was 20 weeks (range 1-806 weeks). Of 94/107 (88%) eyes with swollen disc, 60 (64%) had neuroretinitis at presentation, 14 (15%) developed neuroretinitis during follow-up, and 20 (21%) were diagnosed with inflammatory disc oedema. Optic nerve head lesion, uveitis, optic neuropathy and retinal vessel occlusion were found in 43 (40%), 38 (36%), 34 (33%) and 8 (7%) eyes, respectively. Good VA (better than 20/40), moderate vision loss (20/40-20/200) and severe vision loss (worse than 20/200) were found in 26/79 (33%), 35/79 (44%) and 18/79 (23%) eyes at baseline and in 63/79 (80%), 11/79 (14%) and 5/79 (6%) eyes at final follow-up, respectively (p < 0.001). Significant VA improvement (defined as improvement of ≥3 Snellen lines at final follow-up compared to baseline) occurred in 12/24 (50%) eyes treated with antibiotics compared with 14/16 (88%) eyes treated with antibiotics and corticosteroids (p = 0.02). Multivariate logistic regression was suggestive of the same association (odds ratio 7.0; 95% CI 1.3-37.7; p = 0.024). Optic nerve head lesion is a common and unique manifestation of ocular CSD. Most patients improved and had final good VA. Combined antibiotics and corticosteroid treatment was associated with a better visual outcome. © 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Cupping reversal in pediatric glaucoma--evaluation of the retinal nerve fiber layer and visual field.

PubMed

Ely, Amanda L; El-Dairi, Mays A; Freedman, Sharon F

2014-11-01

To identify optic nerve head (ONH) cupping reversal and associated optical coherence tomography (OCT) and Humphrey visual field changes in pediatric glaucoma. Retrospective observational case series. Sequential surgical cases of juvenile open-angle glaucoma (OAG) or primary congenital glaucoma (PCG) with sustained postoperative intraocular pressure (IOP) reduction. Group 1 had preoperative and postoperative ONH photographs and OCT; Group 2 had preoperative clinical ONH assessment and postoperative imaging. Cupping evaluation was confirmed by masked glaucoma and neuro-ophthalmology specialists. Of 80 cases, 9 eyes (9 children) met criteria for Group 1; 24 eyes (19 children) met criteria for Group 2. Group 1: Five of 9 eyes (56%) demonstrated cupping reversal, with preoperative vs postoperative mean IOP 34.2 ± 6.6 mm Hg vs 10.6 ± 4.1 mm Hg (P < .00001) and mean average retinal nerve fiber layer (RNFL) 71.0 ± 30 μm vs 62.8 ± 24 μm (P = .4), respectively. RNFL was stable in 4 of 5 eyes (all juvenile OAG), but thinned (Δ = -41 μm) in 1 eye with PCG. Humphrey visual fields (reliable in 2 of 3 eyes) showed no significant change. Group 2: Fourteen of 24 PCG eyes (58%) demonstrated cupping reversal, with preoperative vs postoperative mean IOP 36.1 ± 8.9 mm Hg vs 13.3 ± 2.1 mm Hg (P < .00001). Two eyes had thin RNFL postoperatively despite healthy-appearing ONH. Postoperative RNFL showed statistically significant linear correlation with preoperative (but not postoperative) cup-to-disc ratio. Limitations include small numbers, few reliable Humphrey visual fields, and absent preoperative imaging (Group 2). Some eyes with IOP reduction and ONH cupping reversal show continued RNFL thinning postoperatively. The preoperative ONH cup-to-disc ratio predicted the postoperative RNFL better than the postoperative "reversed and smaller" cup-to-disc ratio. Cupping reversal in pediatric glaucoma may not predict improved ONH health and deserves further study. Copyright © 2014 Elsevier Inc. All rights reserved.

Fast localization of optic disc and fovea in retinal images for eye disease screening

NASA Astrophysics Data System (ADS)

Yu, H.; Barriga, S.; Agurto, C.; Echegaray, S.; Pattichis, M.; Zamora, G.; Bauman, W.; Soliz, P.

2011-03-01

Optic disc (OD) and fovea locations are two important anatomical landmarks in automated analysis of retinal disease in color fundus photographs. This paper presents a new, fast, fully automatic optic disc and fovea localization algorithm developed for diabetic retinopathy (DR) screening. The optic disc localization methodology comprises of two steps. First, the OD location is identified using template matching and directional matched filter. To reduce false positives due to bright areas of pathology, we exploit vessel characteristics inside the optic disc. The location of the fovea is estimated as the point of lowest matched filter response within a search area determined by the optic disc location. Second, optic disc segmentation is performed. Based on the detected optic disc location, a fast hybrid level-set algorithm which combines the region information and edge gradient to drive the curve evolution is used to segment the optic disc boundary. Extensive evaluation was performed on 1200 images (Messidor) composed of 540 images of healthy retinas, 431 images with DR but no risk of macular edema (ME), and 229 images with DR and risk of ME. The OD location methodology obtained 98.3% success rate, while fovea location achieved 95% success rate. The average mean absolute distance (MAD) between the OD segmentation algorithm and "gold standard" is 10.5% of estimated OD radius. Qualitatively, 97% of the images achieved Excellent to Fair performance for OD segmentation. The segmentation algorithm performs well even on blurred images.

Retinal displacement toward optic disc after internal limiting membrane peeling for idiopathic macular hole.

PubMed

Ishida, Masahiro; Ichikawa, Yoshikazu; Higashida, Rieko; Tsutsumi, Yorihisa; Ishikawa, Atsushi; Imamura, Yutaka

2014-05-01

To examine the retinal displacement following successful macular hole (MH) surgery with internal limiting membrane (ILM) peeling and gas tamponade, and to determine the correlation between the extent of displacement and the basal MH size. Retrospective, interventional, observational case series. The medical records of consecutive patients with an idiopathic MH that had undergone vitrectomy with ILM peeling and gas tamponade were studied. The distances between the optic disc and the intersection of 2 retinal vessels located nasal or temporal to the fovea were measured manually preoperatively (A), and 2 weeks and 1, 3, 6, and 12 months postoperatively (B), on the fundus autofluorescence or near-infrared images. The basal and minimum diameters of the MHs were measured in the spectral-domain optical coherence tomographic images. The correlations between the ratio of the retinal displacement (A - B/A) and basal diameters of the MHs were determined. Twenty-one eyes of 21 patients (9 men, mean age: 64.6 ± 8.4 years) were studied. Ten eyes (47.6%) had stage 2 MH, 9 eyes (42.9%) had stage 3 MH, and 2 eyes (9.5%) had stage 4 MH. The temporal retinal vessels were displaced 260.8 ± 145.8 μm toward the optic disc at 2 weeks postoperatively, which was significantly greater than the 91.1 ± 89.7 μm of the nasal retinal vessels (paired t test, P < .001). The ratio of retinal displacement in the temporal field at 2 weeks was significantly correlated with the basal diameter of the MH (Spearman's rank correlation coeffieient = -0.476, P = .033. The greater displacement of the temporal retina than the nasal retina toward the optic disc postoperatively suggests that the temporal retina is more flexible and can be retracted toward the optic disc during the MH closure. Copyright © 2014 Elsevier Inc. All rights reserved.

Optic nerve lesion following neuroborreliosis: a case report.

PubMed

Burkhard, C; Gleichmann, M; Wilhelm, H

2001-01-01

Neuroborreliosis may cause various neuro-ophthalmological complications. We describe a case with a bilateral optic neuropathy. A 58-year-old female developed facial paresis six weeks after an insect bite. One week later she developed bilateral optic disc swelling with haemorrhages and nerve fibre bundle defects in the lower visual field of the left eye. In CSF and serum, raised IgM and IgG titres to Borrelia burgdorferi were found. Systemic antibiotic treatment led to improvement of the vision and facial paresis, but not all visual field defects resolved, probably due to ischemic lesions of the optic disc. In optic nerve lesions due to neuroborreliosis it is difficult to distinguish between inflammatory and ischemic lesions. This patient demonstrated features of an ischemic optic nerve lesion.

Correlation between retinal nerve fibre layer thickness and optic nerve head size: an optical coherence tomography study.

PubMed

Savini, G; Zanini, M; Carelli, V; Sadun, A A; Ross-Cisneros, F N; Barboni, P

2005-04-01

To investigate the correlation between retinal nerve fibre layer (RNFL) thickness and optic nerve head (ONH) size in normal white subjects by means of optical coherence tomography (OCT). 54 eyes of 54 healthy subjects aged between 15 and 54 underwent peripapillary RNFL thickness measurement by a series of three circular scans with a 3.4 mm diameter (Stratus OCT, RNFL Thickness 3.4 acquisition protocol). ONH analysis was performed by means of six radial scans centred on the optic disc (Stratus OCT, Fast Optic Disc acquisition protocol). The mean RNFL values were correlated with the data obtained by ONH analysis. The superior, nasal, and inferior quadrant RNFL thickness showed a significant correlation with the optic disc area (R = 0.3822, p = 0.0043), (R = 0.3024, p = 0.026), (R = 0.4048, p = 0.0024) and the horizontal disc diameter (R = 0.2971, p = 0.0291), (R = 0.2752, p = 0.044), (R = 0.3970, p = 0.003). The superior and inferior quadrant RNFL thickness was also positively correlated with the vertical disc diameter (R = 0.3774, p = 0.0049), (R = 0.2793, p = 0.0408). A significant correlation was observed between the 360 degrees average RNFL thickness and the optic disc area and the vertical and horizontal disc diameters of the ONH (R = 0.4985, p = 0.0001), (R = 0.4454, p = 0.0007), (R = 0.4301, p = 0.0012). RNFL thickness measurements obtained by Stratus OCT increased significantly with an increase in optic disc size. It is not clear if eyes with large ONHs show a thicker RNFL as a result of an increased amount of nerve fibres or to the shorter distance between the circular scan and the optic disc edge.

Fulminant Ocular Toxoplasmosis: The Hazards of Corticosteroid Monotherapy.

PubMed

Oray, Merih; Ozdal, Pinar Cakar; Cebeci, Zafer; Kir, Nur; Tugal-Tutkun, Ilknur

2016-12-01

To describe fulminant toxoplasma retinochoroiditis induced by corticosteroid monotherapy. Clinical records of nine patients were reviewed. All patients (five female, four male; aged 15-64 years) had been misdiagnosed as unilateral non-infectious uveitis and given systemic and/or local corticosteroid injections elsewhere. Mean disease duration before referral was 105.6 ± 71 (45-240) days. Visual acuity at presentation was <20/200 in six eyes. Average lesion size was 6.6 disc areas in eight eyes and all four quadrants were involved in one. Toxoplasma DNA was detected in eight tested eyes. Mean duration of anti-toxoplasmic therapy was 92.5 ± 37.1 days. Three eyes developed rhegmatogenous retinal detachment. Four patients underwent pars plana vitrectomy. Final visual acuity was <20/200 in five eyes. Iatrogenic immunosuppression due to initial misdiagnosis may lead to an aggressive course and serious complications of ocular toxoplasmosis, a potentially self-limiting infection.

Comparison of Automated Analysis of Cirrus HD-OCT™ Spectral Domain Optical Coherence Tomography with Stereo Photos of the Optic Disc

PubMed Central

Sharma, Ashish; Oakley, Jonathan D.; Schiffman, Joyce C.; Budenz, Donald L.; Anderson, Douglas R.

2010-01-01

OBJECTIVE To evaluate a new automated analysis of optic disc images obtained by spectral domain optical coherence tomography (SD-OCT). Areas of the optic disc, cup, and neural rim in SD-OCT images were compared with these areas from stereoscopic photographs, to represent the current traditional optic nerve evaluation. The repeatability of measurements by each method was determined and compared. DESIGN Evaluation of diagnostic technology. PARTICIPANTS 119 healthy eyes, 23 eyes with glaucoma, and 7 suspect eyes METHODS Optic disc and cup margins were traced from stereoscopic photographs by three individuals independently. Optic disc margins and rim widths were determined automatically in SD-OCT. A subset of photographs was examined and traced a second time, and duplicate SD-OCT images were also analyzed. MAIN OUTCOME MEASUREMENTS Agreement among photograph readers, between duplicate readings, and between SD-OCT and photographs were quantified by the intraclass correlation coefficient (ICC), by the root mean square (RMS), and the standard deviation (SD) of the differences. RESULTS Optic disc areas tended to be slightly larger when judged in photographs than by SD-OCT, while cup areas were similar. Cup and optic disc areas showed good correlation (0.8) between average photographic reading and SD-OCT, but only fair correlation of rim areas (0.4). The SD-OCT was highly reproducible (ICC of 0.96 to 0.99). Each reader was also consistent with himself on duplicate readings of 21 photographs (ICC 0.80 to 0.88 for rim area, 0.95 to 0.98 for all other measurements), but reproducibility was not as good as SD-OCT. Measurements derived from SD-OCT did not differ from photographic readings more than the readings of photographs by different readers differed from each other. CONCLUSIONS Designation of the cup and optic disc boundaries by an automated analysis of SD-OCT was within the range of variable designations by different readers from color stereoscopic photographs, but use of different landmarks typically made the designation of the optic disc size somewhat smaller in the automated analysis. There was better repeatability among measurements from SD-OCT than from among readers of photographs. The repeatability of automated measurement of SD-OCT images is promising for use both in diagnosis and in monitoring of progression. PMID:21397334

Comparison of optical coherence tomography and fundus photography for measuring the optic disc size.

PubMed

Neubauer, Aljoscha S; Krieglstein, Tina R; Chryssafis, Christos; Thiel, Martin; Kampik, Anselm

2006-01-01

To assess the agreement and repeatability of optic nerve head (ONH) size measurements by optical coherence tomography (OCT) as compared to conventional planimetry of fundus photographs in normal eyes. For comparison with planimetry the absolute size of the ONH of 25 eyes from 25 normal subjects were measured by both OCT and digital fundus photography (Zeiss FF camera 450). Repeatability of automated Stratus OCT measurements were investigated by repeatedly measuring the optic disc in five normal subjects. Mean disc size was 1763 +/- 186 vertically and 1632 +/- 160 microm horizontally on planimetry. On OCT, values of 1772 +/- 317 microm vertically (p = 0.82) and a significantly smaller horizontal diameter of 1492 +/- 302 microm (p = 0.04) were obtained. The 95% limits of agreement were (-546 microm; +527 microm) for vertical and (-502 microm; +782 microm) for horizontal planimetric compared to OCT measurements. In some cases large discrepancies existed. Repeatability of automatic measurements of the optic disc by OCT was moderately good with intra-class correlation coefficients (ICC) of 0.78 horizontally and 0.83 vertically. The coefficient of repeatability indicating instrument precision was 80 microm for horizontal and 168 microm for vertical measurements. OCT can be used to determine optic disc margins in moderate agreement with planimetry in normal subjects. However, in some cases significant disagreement with photographic assessment may occur making manual inspection advisable. Automatic disc detection by OCT is moderately repeatable.

Flexibly deployed Pax genes in eye development at the early evolution of animals demonstrated by studies on a hydrozoan jellyfish.

PubMed

Suga, Hiroshi; Tschopp, Patrick; Graziussi, Daria F; Stierwald, Michael; Schmid, Volker; Gehring, Walter J

2010-08-10

Pax transcription factors are involved in a variety of developmental processes in bilaterians, including eye development, a role typically assigned to Pax-6. Although no true Pax-6 gene has been found in nonbilateral animals, some jellyfish have eyes with complex structures. In the cubozoan jellyfish Tripedalia, Pax-B, an ortholog of vertebrate Pax-2/5/8, had been proposed as a regulator of eye development. Here we have isolated three Pax genes (Pax-A, Pax-B, and Pax-E) from Cladonema radiatum, a hydrozoan jellyfish with elaborate eyes. Cladonema Pax-A is strongly expressed in the retina, whereas Pax-B and Pax-E are highly expressed in the manubrium, the feeding and reproductive organ. Misexpression of Cladonema Pax-A induces ectopic eyes in Drosophila imaginal discs, whereas Pax-B and Pax-E do not. Furthermore, Cladonema Pax-A paired domain protein directly binds to the 5' upstream region of eye-specific Cladonema opsin genes, whereas Pax-B does not. Our data suggest that Pax-A, but not Pax-B or Pax-E, is involved in eye development and/or maintenance in Cladonema. Phylogenetic analysis indicates that Pax-6, Pax-B, and Pax-A belong to different Pax subfamilies, which diverged at the latest before the Cnidaria-Bilateria separation. We argue that our data, showing the involvement of Pax genes in hydrozoan eye development as in bilaterians, supports the monophyletic evolutionary origin of all animal eyes. We then propose that during the early evolution of animals, distinct classes of Pax genes, which may have played redundant roles at that time, were flexibly deployed for eye development in different animal lineages.

Effect of recording duration on the diagnostic performance of multifocal visual-evoked potentials in high-risk ocular hypertension and early glaucoma.

PubMed

Fortune, Brad; Zhang, Xian; Hood, Donald C; Demirel, Shaban; Patterson, Emily; Jamil, Annisa; Mansberger, Steven L; Cioffi, George A; Johnson, Chris A

2008-01-01

To evaluate the effect on diagnostic performance of reducing multifocal visual-evoked potential (mfVEP) recording duration from 16 to 8 minutes per eye. Both eyes of 185 individuals with high-risk ocular hypertension or early glaucoma were studied. Two 8-minute mfVEP recordings were obtained for each eye in an ABBA order using VERIS. The first recording for each eye was compared against single run (1-Run) mfVEP normative data; the average of both recordings for each eye was compared against 2-Run normative data. Visual fields (VFs) were obtained by standard automated perimetry (SAP) within 22.3+/-27.0 days of the mfVEP. Stereo disc photographs and Heidelberg Retina Tomograph images were obtained together, within 24.8+/-50.4 days of the mfVEP and 33.1+/-62.9 days of SAP. Masked experts graded disc photographs as either glaucomatous optic neuropathy or normal. The overall Moorfields Regression Analysis result from the Heidelberg Retina Tomograph was used as a separate diagnostic classification. Thus, 4 diagnostic standards were applied in total, 2 based on optic disc structure alone and 2 others based on disc structure and SAP. Agreement between the 1-Run and 2-Run mfVEP was 90%. Diagnostic performance of the 1-Run mfVEP was similar to that of the 2-Run mfVEP for all 4 diagnostic standards. Sensitivity was slightly higher for the 2-Run mfVEP, whereas specificity was slightly higher for the 1-Run mfVEP. If higher sensitivity is sought, the 2-Run mfVEP will provide better discrimination between groups of eyes with relatively high signal-to-noise ratio (eg, early glaucoma or high-risk suspects). But if higher specificity is a more important goal, the 1-Run mfVEP provides adequate sensitivity and requires only half the test time. Considered alongside prior studies, the present results suggest that the 1-Run mfVEP is an efficient way to confirm (or refute) the extent of VF loss in patients with moderate or advanced glaucoma, particularly in those with unreliable VFs, including malingering or other "functional" forms of VF loss.

Nonarteritic anterior ischemic optic neuropathy following pars plana vitrectomy for macular hole treatment: case report.

PubMed

Cunha, Leonardo Provetti; Cunha, Luciana Virgínia Ferreira Costa; Costa, Carolina Ferreira; Monteiro, Mário Luiz Ribeiro

2016-01-01

Herein, we report a case of nonarteritic anterior ischemic optic neuropathy (NAION) following uneventful pars plana vitrectomy for macular hole treatment. A 56-year-old previously healthy woman presented with a full-thickness macular hole in right eye (OD) and small cup-to-disc ratios in both eyes. Five days after surgery, she noticed sudden painless loss of vision in OD and was found to have an afferent pupillary defect and intraocular pressure of 29 mmHg. Fundus examination showed right optic disc edema and the resolution of a macular hole with an inferior altitudinal visual field defect. Erythrocyte sedimentation rate, C-reactive protein levels, and general physical examination findings were normal. She was treated with hypotensive eyedrops and oral prednisone, resulting in mild visual improvement and a pale optic disc. A combination of face-down position and increased intraocular pressure due to a small optic disc cup were considered as potential mechanisms underlying NAION in the present case. Vitreoretinal surgeons should be aware of NAION as a potentially serious complication and be able to recognize associated risk factors and clinical findings.

Could Buerger's disease cause nonarteritic anterior ischemic optic neuropathy?: a rare case report.

PubMed

Korkmaz, Anil; Karti, Omer; Top Karti, Dilek; Yüksel, Bora; Zengin, Mehmet Ozgur; Kusbeci, Tuncay

2018-04-05

We present an interesting case with nonarteritic anterior ischemic optic neuropathy (NAION) accompanied by Buerger's disease. A 43-year-old man was referred to our neuro-ophthalmology clinic with a complaint of visual deterioration in the left eye that started 5 days ago. He suffered from Buerger's disease, and he had acute pain in the right lower limb below the knee. His best corrected visual acuity was 10/10 in the right eye and 2/10 in the left eye by Snellen chart. There was a relative afferent pupil defect in the left eye. The right optic disc was normal on fundus examination, and blurring, hemorrhagic swelling was found at the left optic disc. Inferior altitudinal visual field defect was observed in the left eye. Neurological examination was normal. Computed tomography angiography scan revealed occlusion in the right posterior tibial artery. Brain imaging and laboratory tests such as blood analyses, genetic screening, coagulation, and lipid panels were unremarkable. NAION may occur in patients with Buerger's disease, but it is extremely rare. Therefore, clinicians should be aware of this rare association.

Measurement of retinal nerve fiber layer thickness in eyes with optic disc swelling by using scanning laser polarimetry and optical coherence tomography.

PubMed

Hata, Masayuki; Miyamoto, Kazuaki; Oishi, Akio; Kimura, Yugo; Nakagawa, Satoko; Horii, Takahiro; Yoshimura, Nagahisa

2014-01-01

The retinal nerve fiber layer thickness (RNFLT) in patients with optic disc swelling of different etiologies was compared using scanning laser polarimetry (SLP) and spectral-domain optical coherence tomography (OCT). Forty-seven patients with optic disc swelling participated in the cross-sectional study. Both GDx SLP (enhanced corneal compensation) and Spectralis spectral-domain OCT measurements of RNFLT were made in 19 eyes with papilledema (PE), ten eyes with optic neuritis (ON), and 18 eyes with nonarteritic anterior ischemic optic neuropathy (NAION) at the neuro-ophthalmology clinic at Kyoto University Hospital. Differences in SLP (SLP-RNFLT) and OCT (OCT-RNFLT) measurements among different etiologies were investigated. No statistical differences in average OCT-RNFLT among PE, ON, and NAION patients were noted. Average SLP-RNFLT in NAION patients was smaller than in PE (P<0.01) or ON (P=0.02) patients. When RNFLT in each retinal quadrant was compared, no difference among etiologies was noted on OCT, but on SLP, the superior quadrant was thinner in NAION than in PE (P<0.001) or ON (P=0.001) patients. Compared with age-adjusted normative data of SLP-RNFLT, average SLP-RNFLT in PE (P<0.01) and ON (P<0.01) patients was greater. Superior SLP-RNFLT in NAION patients was smaller (P=0.026). The ratio of average SLP-RNFLT to average OCT-RNFLT was smaller in NAION than in PE (P=0.001) patients. In the setting of RNFL thickening, despite increased light retardance in PE and ON eyes, SLP revealed that NAION eyes have less retardance, possibly associated with ischemic axonal loss.

Measurement of retinal nerve fiber layer thickness in eyes with optic disc swelling by using scanning laser polarimetry and optical coherence tomography

PubMed Central

Hata, Masayuki; Miyamoto, Kazuaki; Oishi, Akio; Kimura, Yugo; Nakagawa, Satoko; Horii, Takahiro; Yoshimura, Nagahisa

2014-01-01

Background The retinal nerve fiber layer thickness (RNFLT) in patients with optic disc swelling of different etiologies was compared using scanning laser polarimetry (SLP) and spectral-domain optical coherence tomography (OCT). Methods Forty-seven patients with optic disc swelling participated in the cross-sectional study. Both GDx SLP (enhanced corneal compensation) and Spectralis spectral-domain OCT measurements of RNFLT were made in 19 eyes with papilledema (PE), ten eyes with optic neuritis (ON), and 18 eyes with nonarteritic anterior ischemic optic neuropathy (NAION) at the neuro-ophthalmology clinic at Kyoto University Hospital. Differences in SLP (SLP-RNFLT) and OCT (OCT-RNFLT) measurements among different etiologies were investigated. Results No statistical differences in average OCT-RNFLT among PE, ON, and NAION patients were noted. Average SLP-RNFLT in NAION patients was smaller than in PE (P<0.01) or ON (P=0.02) patients. When RNFLT in each retinal quadrant was compared, no difference among etiologies was noted on OCT, but on SLP, the superior quadrant was thinner in NAION than in PE (P<0.001) or ON (P=0.001) patients. Compared with age-adjusted normative data of SLP-RNFLT, average SLP-RNFLT in PE (P<0.01) and ON (P<0.01) patients was greater. Superior SLP-RNFLT in NAION patients was smaller (P=0.026). The ratio of average SLP-RNFLT to average OCT-RNFLT was smaller in NAION than in PE (P=0.001) patients. Conclusion In the setting of RNFL thickening, despite increased light retardance in PE and ON eyes, SLP revealed that NAION eyes have less retardance, possibly associated with ischemic axonal loss. PMID:24379653

Progression of asymptomatic optic disc swelling to non-arteritic anterior ischaemic optic neuropathy.

PubMed

Subramanian, Prem S; Gordon, Lynn K; Bonelli, Laura; Arnold, Anthony C

2017-05-01

The time of onset of optic disc swelling in non-arteritic anterior ischaemic optic neuropathy (NAION) is not known, and it is commonly assumed to arise simultaneously with vision loss. Our goal is to report the presence and persistence of optic disc swelling without initial vision loss and its subsequent evolution to typical, symptomatic NAION. Clinical case series of patients with optic disc swelling and normal visual acuity and visual fields at initial presentation who progressed to have vision loss typical of NAION. All subjects underwent automated perimetry, disc photography and optic coherence tomography and/or fluorescein angiography to evaluate optic nerve function and perfusion. Four patients were found to have sectoral or diffuse optic disc swelling without visual acuity or visual field loss; the fellow eye of all four had either current or prior NAION or a 'disc at risk' configuration. Over several weeks of clinical surveillance, each patient experienced sudden onset of visual field and/or visual acuity loss typical for NAION. Current treatment options for NAION once vision loss occurs are limited and may not alter the natural history of the disorder. Subjects with NAION may have disc swelling for 2-10 weeks prior to the occurrence of visual loss, and with the development of new therapeutic agents, treatment at the time of observed disc swelling could prevent vision loss from NAION. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

A hierarchical cluster analysis of normal-tension glaucoma using spectral-domain optical coherence tomography parameters.

PubMed

Bae, Hyoung Won; Ji, Yongwoo; Lee, Hye Sun; Lee, Naeun; Hong, Samin; Seong, Gong Je; Sung, Kyung Rim; Kim, Chan Yun

2015-01-01

Normal-tension glaucoma (NTG) is a heterogenous disease, and there is still controversy about subclassifications of this disorder. On the basis of spectral-domain optical coherence tomography (SD-OCT), we subdivided NTG with hierarchical cluster analysis using optic nerve head (ONH) parameters and retinal nerve fiber layer (RNFL) thicknesses. A total of 200 eyes of 200 NTG patients between March 2011 and June 2012 underwent SD-OCT scans to measure ONH parameters and RNFL thicknesses. We classified NTG into homogenous subgroups based on these variables using a hierarchical cluster analysis, and compared clusters to evaluate diverse NTG characteristics. Three clusters were found after hierarchical cluster analysis. Cluster 1 (62 eyes) had the thickest RNFL and widest rim area, and showed early glaucoma features. Cluster 2 (60 eyes) was characterized by the largest cup/disc ratio and cup volume, and showed advanced glaucomatous damage. Cluster 3 (78 eyes) had small disc areas in SD-OCT and were comprised of patients with significantly younger age, longer axial length, and greater myopia than the other 2 groups. A hierarchical cluster analysis of SD-OCT scans divided NTG patients into 3 groups based upon ONH parameters and RNFL thicknesses. It is anticipated that the small disc area group comprised of younger and more myopic patients may show unique features unlike the other 2 groups.

[Case of pediatric chronic myeloid leukemia with bilateral visual loss onset].

PubMed

Hara, Yusuke; Kamura, Yumi; Oikawa, Aki; Shichino, Hiroyuki; Mugishima, Hideo; Goto, Hiroshi

2010-05-01

Chronic myeloid leukemia (CML) during childhood is rare, and only been a few cases showed visual disturbances as an initial symptom. We report a pediatric CML case diagnosed by bilateral visual loss. An 11-year-old boy complained of visual loss in both eyes. His best corrected visual acuity was 0.5 in the right eye and 0.2 in the left. Fundus examination showed disc swelling, dilated and tortuous retinal veins and multiple elevated retinal lesions with hemorrhages of various size from one-forth to four disc diameters in both eyes. He was diagnosed as having CML by leucocytosis and systematic work-up including Philadelphia chromosome-positive, BCR-ABL kinase domain in peripheral blood and bone marrow. The ocular findings improved after treatment with hydroxyurea, leukocytaphresis and imatinib. His best corrected visual acuity improved to 0.7 in both eyes. Recent leukemia therapy including imatinib is effective not only for ocular lesions but also to induce hematological remission in childhood CML.

Deducing material quality in cast and hot-forged steels by new bending test

NASA Astrophysics Data System (ADS)

Valberg, Henry; Langøy, Morten; Nedreberg, Mette; Helvig, Torgeir

2017-10-01

A special bend test has been developed and applied for the purpose of characterization and comparison of the material ductility in crankpin steel discs manufactured by casting, or casting subsequently followed by hot open-die forging (ODF) or closed-die forging (CDF). The bending test specimen consists of a small rectangular plate of material with a round hole cut out in the middle. The "eye-shape" specimens were cut out from various positions either near to the surface of, or from the interior of the discs. The test method revealed differences in ductility for the investigated materials, and for different depth positions inside the discs. The roughening of the specimen surface on the top-side of the specimen bend also varied dependent on the processing method for the material. Current results show that this test method is useful for evaluation of material quality in differently processed material. Experimental bend test results are presented for differently processed variants of the same material, i.e., crankpin discs either made by solely casting or casting subsequently followed by hot working either by ODF or CDF.

Sma- and Mad-related protein 7 (Smad7) is required for embryonic eye development in the mouse.

PubMed

Zhang, Rui; Huang, Heng; Cao, Peijuan; Wang, Zhenzhen; Chen, Yan; Pan, Yi

2013-04-12

Smad7 is an intracellular inhibitory protein that antagonizes the signaling of TGF-β family members. Deletion of Smad7 in the mouse leads to an abnormality in heart development. However, whether Smad7 has a functional role in the development of other organs has been elusive. Here we present evidence that Smad7 imparts a role to eye development in the mouse. Smad7 is expressed in both the lens and retina in the developing embryonic eye. Depletion of Smad7 caused various degrees of coloboma and microphthalmia with alterations in cell apoptosis and proliferation in eyes. Smad7 was implicated in lens differentiation but was not required for the induction of the lens placode. The development of the periocular mesenchyme was retarded with the down-regulation of Bmp7 and Pitx2 in mutant mice. Retinal spatial patterning was affected by Smad7 deletion and was accompanied by altered bone morphogenetic protein (BMP) signaling. At late gestation stages, TGF-β signaling was up-regulated in the differentiating retina. Smad7 mutant mice displayed an expanded optic disc with increasing of sonic hedgehog (SHH) signaling. Furthermore, loss of Smad7 led to a temporal change in retinal neurogenesis. In conclusion, our study suggests that Smad7 is essential for eye development. In addition, our data indicate that alterations in the signaling of BMP, TGF-β, and SHH likely underlie the defects in eye development caused by Smad7 deletion.

A Comparison of Functional and Structural Measures for Identifying Progression of Glaucoma

PubMed Central

Xin, Daiyan; Greenstein, Vivienne C.; Ritch, Robert; Liebmann, Jeffrey M.; De Moraes, Carlos Gustavo

2011-01-01

Purpose. To compare glaucoma progression by functional and structural tests. Methods. The authors prospectively studied 33 glaucoma patients (55 eyes); 20 eyes (15 patients) had disc hemorrhage, and 35 eyes (18 patients) had exfoliation glaucoma. The following tests were performed at two baseline and three follow-up examinations: frequency doubling perimetry (FDT), 24-2 Humphrey visual fields (HVF), multifocal visual evoked potentials (mfVEP), and optical coherence tomography (OCT). To identify progression, the baseline measurements were averaged and compared to those obtained at the final examination. Stereophotographs of the optic disc were obtained at baseline and compared with those at the final examination. Results. Patients were followed up for 21.1 ± 1.8 months. For HVF there were significant changes in mean deviation (MD) in eight (14.5%) eyes but in pattern standard deviation (P/SD) in only two (3.6%) eyes. For FDT, there were significant changes in MD in 13 (23.6%) eyes. Five eyes showed changes in MD for HVF and FDT. For mfVEP, there was an increase in abnormal points in nine (16.4%) eyes. Six of these eyes did not show significant HVF or FDT changes. For OCT, RNFL average thickness values were significantly decreased in nine (16.4%) eyes. Nine (16.4%) eyes showed progression on stereophotography; four of these eyes did not show significant changes on OCT and functional tests. Conclusions. Each test showed evidence of progression in some eyes. However, agreement among tests and stereophotography regarding which eyes showed progression was poor, illustrating the importance of following up patients with a combination of functional and structural tests. PMID:20847115

[Nonarteritic ischemic optic neuropathy animal model and its treatment applications].

PubMed

Chuman, Hideki

2014-04-01

Nonarteritic ischemic optic neuropathy (NAION) is one of the most common acute unilaterally onset optic nerve diseases. One management problem in terms of NAION is the difficulty of differential diagnosis between NAION and anterior optic neuritis (ON). A second problem is that there is no established treatment for the acute stage of NAION. A third problem is that there is no preventive treatment for a subsequent attack on the fellow eye, estimated to occur in 15 to 25% of patients with NAION. For differentiation of acute NAION from anterior optic neuritis, we investigated the usefulness of laser speckle flowgraphy (LSFG). In the normal control group, the tissue blood flow did not significantly differ between the right and left eyes. In the NAION group, all 6 patients had 29.5% decreased mean blur rate (MBR), which correlates to optic disc blood flow, of the NAION eye compared with the unaffected eye. In the anterior ON group, all 6 cases had 15.9% increased MBR of the anterior ON eye compared with the unaffected eye. Thus, LSFG showed a difference of the underlying pathophysiology between NAION and anterior ON despite showing disc swelling in both groups and could be useful for differentiating both groups. For the treatment of acute stage of NAION, we tried to reproduce the rodent model of NAION (rNAION) developed by Bernstein and colleagues. To induce rNAION, after the administration of rose bengal(RB) (2.5 mM) into the tail vein of SD rats, the small vessels of the left optic nerve were photoactivated using a 514 nm argon green laser (RB-laser-induction). In the RB-laser-induction eyes, the capillaries within the optic disc were reduced markedly, the optic disc became swollen, and fluorescein angiography showed filling defect in the choroid and the optic disc at an early stage, followed by hyperfluorescence at a late stage. Electrophysiological evaluation revealed that visual evoked potential (VEP) amplitude was significantly decreased but an electroretinogram (ERG) did not show a significant difference either in the b wave or in the oscillatory potentials. The scotopic threshold response (STR) was significantly reduced 3 days after induction. These findings are similar to those of rNAION and indicate that we succeeded in reproducing the rNAION. Histopathologic examination in the acute phase of rNAION, showed acellular NFL swelling anterior to the optic disc. No accumulation of inflammatory cells was noted in several microscopic sections of the optic nerve. In addition, immunochemical staining was negative throughout the retina and optic nerve. These results suggested that the rNAION-induced NFL swelling was not a result of inflammation. In the chronic phase of rNAION, the morphologic retinal changes were apparent in only the retinal ganglion cell(RGC) layer, with a reduction in the number of cells in the RGC layer. Thus, we need to evaluate the degree of the NFL swelling in the acute phase and the following thinning of the NFL in the chronic phase for efficacy of the treatment of rNAION. Therefore, we used optical coherence tomography (OCT) for the objective and quantitative evaluation of the retinal nerve fiber layer (RNFL) thickness around the optic disc changes in rNAION. The second method was to use the STR for the evaluation of the RGC function. The third method was to count the number of surviving RGCs observed and photographed through the fluorescence microscope with the Fluorogold staining. A possible rationale for treatment of NAION is that dilation of the posterior ciliary artery (PCA) increases the blood flow to the optic nerve and could improve the optic nerve function. To clarify the vasodilatory effects of medications, we used in vitro isometric tension recording methods and examined the vasodilatory effects of bevacizumab as an anti-vascular endothelial growth factor (VEGF) antibody, methylprednisolone as a corticosteroid and sodium nitroprusside (SNP, a nitric oxide donor) as a vasodilator on high-K (potassium) solution-induced contraction in isolated rabbit PCA. Bevacizumab did not relax rabbit PCA. Methylprednisolone relaxed rabbit PCA nitric oxide (NO) independently. SNP relaxed rabbit PCA by exogenous NO. On the basis of these results, we selected the following candidates for rNAION treatment: methylprednisolone as the corticosteroid and L-arginine as the NO related agent. Intravenous infusion of methylprednisolone significantly decreased the degree of acute disc edema but did not reduce inner retinal thinning, decrease STR amplitude, or decrease RGC numbers in rNAION. Intravenous infusion of L-arginine after rNAION induction significantly decreased the disc edema at the acute stage and the thinning of the inner retina, reduced the decrease in STR amplitude, and reduced the decrease in RGC numbers during rNAION. These results indicated that L-arginine treatment is effective for reducing the anatomical changes and improving visual function in the acute stage of rNAION. To strengthen the neuroprotective effect for rNAION, we tried treatment using transcorneal electric stimulation (TES). We evaluated the effect using STR and survival RGCs. Decreased amplitude in the STR of the TES group was significantly better preserved than in the control group on the 28th day after treatment. RGC survival in the TES group was significantly larger than in the control group on the 14th and 28th days. The neuroprotective effect of TES was better than that of L-arginine. For preventive treatment of subsequent attack in the fellow eye, we investigated whether pretreatment with L-arginine might reduce the severity of the anatomical changes associated with NAION and preserve the visual function when NAION occurs in the other eye. In the L-arginine pretreated eyes, the disc edema at the acute stage and the thinning of inner retina were significantly decreased, and the decrease of STR amplitude and the decrease in RGC numbers during rNAION were reserved. These results indicate that pretreatment with L-arginine is effective for the reduction of the severity during recurrence in the other eye. We will perform clinical trials in a small series of cases, and if the treatment is effective, we will proceed to multicenter randomized treatment trials. In addition to that, more work needs to be done to discover better treatment options for NAION.

3D papillary image capturing by the stereo fundus camera system for clinical diagnosis on retina and optic nerve

NASA Astrophysics Data System (ADS)

Motta, Danilo A.; Serillo, André; de Matos, Luciana; Yasuoka, Fatima M. M.; Bagnato, Vanderlei S.; Carvalho, Luis A. V.

2014-03-01

Glaucoma is the second main cause of the blindness in the world and there is a tendency to increase this number due to the lifetime expectation raise of the population. Glaucoma is related to the eye conditions, which leads the damage to the optic nerve. This nerve carries visual information from eye to brain, then, if it has damage, it compromises the visual quality of the patient. In the majority cases the damage of the optic nerve is irreversible and it happens due to increase of intraocular pressure. One of main challenge for the diagnosis is to find out this disease, because any symptoms are not present in the initial stage. When is detected, it is already in the advanced stage. Currently the evaluation of the optic disc is made by sophisticated fundus camera, which is inaccessible for the majority of Brazilian population. The purpose of this project is to develop a specific fundus camera without fluorescein angiography and red-free system to accomplish 3D image of optic disc region. The innovation is the new simplified design of a stereo-optical system, in order to make capable the 3D image capture and in the same time quantitative measurements of excavation and topography of optic nerve; something the traditional fundus cameras do not do. The dedicated hardware and software is developed for this ophthalmic instrument, in order to permit quick capture and print of high resolution 3D image and videos of optic disc region (20° field-of-view) in the mydriatic and nonmydriatic mode.

Developmental Regulation of Nucleolus Size during Drosophila Eye Differentiation

PubMed Central

Baker, Nicholas E.

2013-01-01

When cell cycle withdrawal accompanies terminal differentiation, biosynthesis and cellular growth are likely to change also. In this study, nucleolus size was monitored during cell fate specification in the Drosophila eye imaginal disc using fibrillarin antibody labeling. Nucleolus size is an indicator of ribosome biogenesis and can correlate with cellular growth rate. Nucleolar size was reduced significantly during cell fate specification and differentiation, predominantly as eye disc cells entered a cell cycle arrest that preceded cell fate specification. This reduction in nucleolus size required Dpp and Hh signaling. A transient enlargement of the nucleolus accompanied cell division in the Second Mitotic Wave. Nucleoli continued to diminish in postmitotic cells following fate specification. These results suggest that cellular growth is regulated early in the transition from proliferating progenitor cells to terminal cell fate specification, contemporary with regulation of the cell cycle, and requiring the same extracellular signals. PMID:23472166

Developmental regulation of nucleolus size during Drosophila eye differentiation.

PubMed

Baker, Nicholas E

2013-01-01

When cell cycle withdrawal accompanies terminal differentiation, biosynthesis and cellular growth are likely to change also. In this study, nucleolus size was monitored during cell fate specification in the Drosophila eye imaginal disc using fibrillarin antibody labeling. Nucleolus size is an indicator of ribosome biogenesis and can correlate with cellular growth rate. Nucleolar size was reduced significantly during cell fate specification and differentiation, predominantly as eye disc cells entered a cell cycle arrest that preceded cell fate specification. This reduction in nucleolus size required Dpp and Hh signaling. A transient enlargement of the nucleolus accompanied cell division in the Second Mitotic Wave. Nucleoli continued to diminish in postmitotic cells following fate specification. These results suggest that cellular growth is regulated early in the transition from proliferating progenitor cells to terminal cell fate specification, contemporary with regulation of the cell cycle, and requiring the same extracellular signals.

A Sticky Situation.

PubMed

Weng, Christina Y; Khimani, Karima S; Foroozan, Rod; Gospe, Sidney M; Bhatti, M Tariq

2018-04-26

An 81-year-old man with bilateral progressively blurry vision and optic disc swelling was referred for evaluation. Examination and ancillary testing confirmed a diagnosis of bilateral vitreopapillary traction (VPT) accompanied by unilateral tractional retinoschisis in the right eye. Pars plana vitrectomy was performed to release the traction in both eyes. Visual acuity improved in the right eye and stabilized in the left eye. Retinoschisis in the right eye resolved. The visual field improved in both eyes, although the left eye demonstrated a persistent hemifield defect likely attributable to a prior optic neuropathy. Distinguishing VPT optic neuropathy (VPTON) from nonarteritic anterior ischemic optic neuropathy (NAION) is discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

Current concepts in the diagnosis, pathogenesis and management of nonarteritic anterior ischaemic optic neuropathy.

PubMed

Miller, N R; Arnold, A C

2015-01-01

Nonarteritic anterior ischaemic optic neuropathy (NAION) is the most common acute optic neuropathy in patients over the age of 50 and is the second most common cause of permanent optic nerve-related visual loss in adults after glaucoma. Patients typically present with acute, painless, unilateral loss of vision associated with a variable visual field defect, a relative afferent pupillary defect, a swollen, hyperaemic optic disc, and one or more flame-shaped peripapillary retinal haemorrhages. The pathogenesis of this condition is unknown, but it occurs primarily in patients with structurally small optic discs that have little or no cup and a variety of underlying vascular disorders that may or may not be known at the time of visual loss. There is no consistently beneficial medical or surgical treatment for the condition, but there are now animal models that allow testing of various potential therapies. About 40% of patients experience spontaneous improvement in visual acuity. Patients in whom NAION occurs in one eye have a 15-19% risk of developing a similar event in the opposite eye over the subsequent 5 years.

Current concepts in the diagnosis, pathogenesis and management of nonarteritic anterior ischaemic optic neuropathy

PubMed Central

Miller, N R; Arnold, A C

2015-01-01

Nonarteritic anterior ischaemic optic neuropathy (NAION) is the most common acute optic neuropathy in patients over the age of 50 and is the second most common cause of permanent optic nerve-related visual loss in adults after glaucoma. Patients typically present with acute, painless, unilateral loss of vision associated with a variable visual field defect, a relative afferent pupillary defect, a swollen, hyperaemic optic disc, and one or more flame-shaped peripapillary retinal haemorrhages. The pathogenesis of this condition is unknown, but it occurs primarily in patients with structurally small optic discs that have little or no cup and a variety of underlying vascular disorders that may or may not be known at the time of visual loss. There is no consistently beneficial medical or surgical treatment for the condition, but there are now animal models that allow testing of various potential therapies. About 40% of patients experience spontaneous improvement in visual acuity. Patients in whom NAION occurs in one eye have a 15–19% risk of developing a similar event in the opposite eye over the subsequent 5 years. PMID:24993324

A Diagnostic Calculator for Detecting Glaucoma on the Basis of Retinal Nerve Fiber Layer, Optic Disc, and Retinal Ganglion Cell Analysis by Optical Coherence Tomography.

PubMed

Larrosa, José Manuel; Moreno-Montañés, Javier; Martinez-de-la-Casa, José María; Polo, Vicente; Velázquez-Villoria, Álvaro; Berrozpe, Clara; García-Granero, Marta

2015-10-01

The purpose of this study was to develop and validate a multivariate predictive model to detect glaucoma by using a combination of retinal nerve fiber layer (RNFL), retinal ganglion cell-inner plexiform (GCIPL), and optic disc parameters measured using spectral-domain optical coherence tomography (OCT). Five hundred eyes from 500 participants and 187 eyes of another 187 participants were included in the study and validation groups, respectively. Patients with glaucoma were classified in five groups based on visual field damage. Sensitivity and specificity of all glaucoma OCT parameters were analyzed. Receiver operating characteristic curves (ROC) and areas under the ROC (AUC) were compared. Three predictive multivariate models (quantitative, qualitative, and combined) that used a combination of the best OCT parameters were constructed. A diagnostic calculator was created using the combined multivariate model. The best AUC parameters were: inferior RNFL, average RNFL, vertical cup/disc ratio, minimal GCIPL, and inferior-temporal GCIPL. Comparisons among the parameters did not show that the GCIPL parameters were better than those of the RNFL in early and advanced glaucoma. The highest AUC was in the combined predictive model (0.937; 95% confidence interval, 0.911-0.957) and was significantly (P = 0.0001) higher than the other isolated parameters considered in early and advanced glaucoma. The validation group displayed similar results to those of the study group. Best GCIPL, RNFL, and optic disc parameters showed a similar ability to detect glaucoma. The combined predictive formula improved the glaucoma detection compared to the best isolated parameters evaluated. The diagnostic calculator obtained good classification from participants in both the study and validation groups.

Measurement of Optic Disc Cup Surface Depth Using Cirrus HD-OCT.

PubMed

Kim, Young Kook; Ha, Ahnul; Lee, Won June; Jeoung, Jin Wook; Park, Ki Ho

2017-12-01

To introduce the measurement method of optic disc cup surface depth using spectral-domain optical coherence tomography (SD-OCT) and then evaluate the rates of cup surface depression at 3 different stages of glaucoma. We retrospectively identified 52 eyes with preperimetric glaucoma, 56 with mild-or-moderate glaucoma and 50 with severe glaucoma and followed them for at least 48 months. Eyes were imaged using SD-OCT (Cirrus HD-OCT) at 12-month intervals. The mean cup surface depth was calculated using the following formula: Cup volume/(disc area×average cup-to-disc ratio)-200 μm. The rates of mean cup surface depression (μm/y) were significantly greater in mild-or-moderate glaucoma (-7.96±1.03) than in preperimetric (-3.11±0.61) and severe glaucoma (-0.70±0.12; all P<0.001). The percentile rates of mean cup surface depression (%/y) were significantly greater than those of average of retinal nerve fiber layer (RNFL) thinning (%/y) in preperimetric glaucoma (-1.64±0.12 vs. -1.11±0.07; P<0.001) and mild-or-moderate glaucoma (-4.20±0.33 vs. -3.14±0.19; P<0.001); and conversely, in severe glaucoma, mean cup surface depth changed slower than did average RNFL thickness (-0.64±0.06 vs. -0.75±0.08%/y; P<0.001). In early-to-moderate glaucoma, the cup surface depth changed faster than did the RNFL thickness. These results signify the possibility that SD-OCT-based estimation of cup surface depth might be useful for monitoring of glaucoma development and progression.

Keratoconus and Normal-Tension Glaucoma: A Study of the Possible Association with Abnormal Biomechanical Properties as Measured by Corneal Hysteresis (An AOS Thesis)

PubMed Central

Cohen, Elisabeth J.

2009-01-01

Purpose: To test the hypothesis that keratoconus and pellucid patients who have glaucoma or are suspected of having glaucoma have lower corneal hysteresis (CH) and/or corneal resistance factor (CRF) measurements compared to controls. Methods: A prospective study at a tertiary eye center of keratoconus and pellucid patients with glaucoma or suspected of having glaucoma, and age-matched keratoconus and pellucid controls, was performed. After informed consent was obtained, corneal topography, ocular response analyzer measurements, pachymetry, intraocular pressure, A-scan measurements, Humphrey visual fields (VFs), and disc photos were done. Analyses compared cases to controls on primary (CH and CRF) and secondary variables. Disc photos and VFs were rated in a masked fashion. Results: The mean CH (8.2, SD=1.6, vs 8.3, SD=1.5) and CRF (7.3, SD=2.0, vs 6.9, SD=2.1) were low and did not differ significantly between 20 study patients (29 eyes) and 40 control patients (61 eyes), respectively. CH had a negative, significant correlation with maximum corneal curvature by topography (P < .002) and positive, significant correlation with central corneal thickness (P < .003). The mean cup-disc ratio was larger among cases than controls (0.54, SD=0.20, vs 0.38, SD=0.20; P = .003). VFs were suggestive of glaucoma more often among the study eyes than controls (11 of 29, 37.9%, vs 8 of 60, 13.3%; P =.019). Conclusions: CH was low in study and control patients and was correlated with severity of keratoconus/pellucid, but not with glaucoma/suspected glaucoma or control status. Evidence of glaucoma was more common in study eyes than controls, but was present in both. PMID:20126503

Effect of Recording Duration on the Diagnostic Performance of Multifocal Visual-evoked Potentials in High-risk Ocular Hypertension and Early Glaucoma

PubMed Central

Fortune, Brad; Zhang, Xian; Hood, Donald C.; Demirel, Shaban; Patterson, Emily; Jamil, Annisa; Mansberger, Steven L.; Cioffi, George A.; Johnson, Chris A.

2010-01-01

Purpose To evaluate the effect on diagnostic performance of reducing multifocal visual-evoked potential (mfVEP) recording duration from 16 to 8 minutes per eye. Methods Both eyes of 185 individuals with high-risk ocular hypertension or early glaucoma were studied. Two 8-minute mfVEP recordings were obtained for each eye in an ABBA order using VERIS. The first recording for each eye was compared against single run (1-Run) mfVEP normative data; the average of both recordings for each eye was compared against 2-Run normative data. Visual fields (VFs) were obtained by standard automated perimetry (SAP) within 22.3±27.0 days of the mfVEP. Stereo disc photographs and Heidelberg Retina Tomograph images were obtained together, within 24.8±50.4 days of the mfVEP and 33.1±62.9 days of SAP. Masked experts graded disc photographs as either glaucomatous optic neuropathy or normal. The overall Moorfields Regression Analysis result from the Heidelberg Retina Tomograph was used as a separate diagnostic classification. Thus, 4 diagnostic standards were applied in total, 2 based on optic disc structure alone and 2 others based on disc structure and SAP. Results Agreement between the 1-Run and 2-Run mfVEP was 90%. Diagnostic performance of the 1-Run mfVEP was similar to that of the 2-Run mfVEP for all 4 diagnostic standards. Sensitivity was slightly higher for the 2-Run mfVEP, whereas specificity was slightly higher for the 1-Run mfVEP. Conclusions If higher sensitivity is sought, the 2-Run mfVEP will provide better discrimination between groups of eyes with relatively high signal-to-noise ratio (eg, early glaucoma or high-risk suspects). But if higher specificity is a more important goal, the 1-Run mfVEP provides adequate sensitivity and requires only half the test time. Considered alongside prior studies, the present results suggest that the 1-Run mfVEP is an efficient way to confirm (or refute) the extent of VF loss in patients with moderate or advanced glaucoma, particularly in those with unreliable VFs, including malingering or other “functional” forms of VF loss. PMID:18414101

Comparison of the diagnostic ability of Moorfield’s regression analysis and glaucoma probability score using Heidelberg retinal tomograph III in eyes with primary open angle glaucoma

PubMed Central

Jindal, Shveta; Dada, Tanuj; Sreenivas, V; Gupta, Viney; Sihota, Ramanjit; Panda, Anita

2010-01-01

Purpose: To compare the diagnostic performance of the Heidelberg retinal tomograph (HRT) glaucoma probability score (GPS) with that of Moorfield’s regression analysis (MRA). Materials and Methods: The study included 50 eyes of normal subjects and 50 eyes of subjects with early-to-moderate primary open angle glaucoma. Images were obtained by using HRT version 3.0. Results: The agreement coefficient (weighted k) for the overall MRA and GPS classification was 0.216 (95% CI: 0.119 – 0.315). The sensitivity and specificity were evaluated using the most specific (borderline results included as test negatives) and least specific criteria (borderline results included as test positives). The MRA sensitivity and specificity were 30.61 and 98% (most specific) and 57.14 and 98% (least specific). The GPS sensitivity and specificity were 81.63 and 73.47% (most specific) and 95.92 and 34.69% (least specific). The MRA gave a higher positive likelihood ratio (28.57 vs. 3.08) and the GPS gave a higher negative likelihood ratio (0.25 vs. 0.44).The sensitivity increased with increasing disc size for both MRA and GPS. Conclusions: There was a poor agreement between the overall MRA and GPS classifications. GPS tended to have higher sensitivities, lower specificities, and lower likelihood ratios than the MRA. The disc size should be taken into consideration when interpreting the results of HRT, as both the GPS and MRA showed decreased sensitivity for smaller discs and the GPS showed decreased specificity for larger discs. PMID:20952832

Ganglion cell-inner plexiform layer and retinal nerve fiber layer thickness according to myopia and optic disc area: a quantitative and three-dimensional analysis.

PubMed

Seo, Sam; Lee, Chong Eun; Jeong, Jae Hoon; Park, Ki Ho; Kim, Dong Myung; Jeoung, Jin Wook

2017-03-11

To determine the influences of myopia and optic disc size on ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (RNFL) thickness profiles obtained by spectral domain optical coherence tomography (OCT). One hundred and sixty-eight eyes of 168 young myopic subjects were recruited and assigned to one of three groups according to their spherical equivalent (SE) values and optic disc area. All underwent Cirrus HD-OCT imaging. The influences of myopia and optic disc size on the GCIPL and RNFL thickness profiles were evaluated by multiple comparisons and linear regression analysis. Three-dimensional surface plots of GCIPL and RNFL thickness corresponding to different combinations of myopia and optic disc size were constructed. Each of the quadrant RNFL thicknesses and their overall average were significantly thinner in high myopia compared to low myopia, except for the temporal quadrant (all Ps ≤0.003). The average and all-sectors GCIPL were significantly thinner in high myopia than in moderate- and/or low-myopia (all Ps ≤0.002). The average OCT RNFL thickness was correlated significantly with SE (0.81 μm/diopter, P < 0.001), axial length (-1.44 μm/mm, P < 0.001), and optic disc area (5.35 μm/mm 2 , P < 0.001) by linear regression analysis. As for the OCT GCIPL parameters, average GCIPL thickness showed a significant correlation with SE (0.84 μm/diopter, P < 0.001) and axial length (-1.65 μm/mm, P < 0.001). There was no significant correlation of average GCIPL thickness with optic disc area. Three-dimensional curves showed that larger optic discs were associated with increased average RNFL thickness and that more-myopic eyes were associated with decreased average GCIPL and RNFL thickness. Myopia can significantly affect GCIPL and RNFL thickness profiles, and optic disc size has a significant influence on RNFL thickness. The current OCT maps employed in the evaluation of glaucoma should be analyzed in consideration of refractive status and optic disc size.

[Maculopathy in case of the pit of the disc].

PubMed

Kolár, P

2005-09-01

The pit of the disc is a congenital anomaly of the optic nerve disc. The prevalence is 1/11 000 patients. On the affected side, the optic disc is in 85% of cases larger than the disc of the other healthy eye. The pit of the disc is very often associated with the presence of the cilioretinal artery. Maculopathy in congenital pit of the optic nerve disc was described in the early 30's of the last century by Calhoun. The average age of the patients is roughly 30 years of age (20-40 years). The complementary examination method, which may help to clarify anatomical conditions of the macular region, is the optical coherence tomography. The defect of the optic disc of different depth caused by the pit and maculopathy caused by retinoschisis communicating with the temporal rim of the disc are found. This case report refers to a 29 years old man with disturbing relative central scotoma and decreased vision for one month in his right eye, who underwent classical three-ports pars plana vitrectomy with expansive gas tamponade. On the basis of differential diagnosis discretion, the temporally localized pit of the disc accompanied by maculopathy due to retonoschisis was detemined. The surgical treatment by means of three-ports pars plana vitrectomy and peeling of the inner limiting membrane with expansive gas tamponade restored in our patient the physiological macular structure followed by improvement of the best-corrected visual acuity. No complications were noticed during the surgery or after it as well. Among the differential diagnoses, it is necessary to eliminate other possible causes of maculopathy in young patients as well as other congenital anomalies of the optic disc, which may be related to the maculopathy. Maculopathy following the pit of the optic nerve disc represents relatively rare diagnostic entity. According to the literature, the natural course of this disease results in very low final best-corrected visual acuity, often worse than 5/50 (0,1 or 20/200). The therapeutic possibility for patients with this disease is operative approach by means of pars plana vitrectomy with peeling of the inner limiting membrane and accompanied by expansive gas tamponade as already mentioned in our case report.

Combined in-depth, 3D, en face imaging of the optic disc, optic disc pits and optic disc pit maculopathy using swept-source megahertz OCT at 1050 nm.

PubMed

Maertz, Josef; Kolb, Jan Philip; Klein, Thomas; Mohler, Kathrin J; Eibl, Matthias; Wieser, Wolfgang; Huber, Robert; Priglinger, Siegfried; Wolf, Armin

2018-02-01

To demonstrate papillary imaging of eyes with optic disc pits (ODP) or optic disc pit associated maculopathy (ODP-M) with ultrahigh-speed swept-source optical coherence tomography (SS-OCT) at 1.68 million A-scans/s. To generate 3D-renderings of the papillary area with 3D volume-reconstructions of the ODP and highly resolved en face images from a single densely-sampled megahertz-OCT (MHz-OCT) dataset for investigation of ODP-characteristics. A 1.68 MHz-prototype SS-MHz-OCT system at 1050 nm based on a Fourier-domain mode-locked laser was employed to acquire high-definition, 3D datasets with a dense sampling of 1600 × 1600 A-scans over a 45° field of view. Six eyes with ODPs, and two further eyes with glaucomatous alteration or without ocular pathology are presented. 3D-rendering of the deep papillary structures, virtual 3D-reconstructions of the ODPs and depth resolved isotropic en face images were generated using semiautomatic segmentation. 3D-rendering and en face imaging of the optic disc, ODPs and ODP associated pathologies showed a broad spectrum regarding ODP characteristics. Between individuals the shape of the ODP and the appending pathologies varied considerably. MHz-OCT en face imaging generates distinct top-view images of ODPs and ODP-M. MHz-OCT generates high resolution images of retinal pathologies associated with ODP-M and allows visualizing ODPs with depths of up to 2.7 mm. Different patterns of ODPs can be visualized in patients for the first time using 3D-reconstructions and co-registered high-definition en face images extracted from a single densely sampled 1050 nm megahertz-OCT (MHz-OCT) dataset. As the immediate vicinity to the SAS and the site of intrapapillary proliferation is located at the bottom of the ODP it is crucial to image the complete structure and the whole depth of ODPs. Especially in very deep pits, where non-swept-source OCT fails to reach the bottom, conventional swept-source devices and the MHz-OCT alike are feasible and beneficial methods to examine deep details of optic disc pathologies, while the MHz-OCT bears the advantage of an essentially swifter imaging process.

Diagnostic Accuracy of Optical Coherence Tomography and Scanning Laser Tomography for Identifying Glaucoma in Myopic Eyes.

PubMed

Malik, Rizwan; Belliveau, Anne C; Sharpe, Glen P; Shuba, Lesya M; Chauhan, Balwantray C; Nicolela, Marcelo T

2016-06-01

Ruling out glaucoma in myopic eyes often poses a diagnostic challenge because of atypical optic disc morphology and visual field defects that can mimic glaucoma. We determined whether neuroretinal rim assessment based on Bruch's membrane opening (BMO), rather than conventional optic disc margin (DM)-based assessment or retinal nerve fiber layer (RNFL) thickness, yielded higher diagnostic accuracy in myopic patients with glaucoma. Case-control, cross-sectional study. Myopic patients with glaucoma (n = 56) and myopic normal controls (n = 74). Myopic subjects with refraction error greater than -2 diopters (D) (spherical equivalent) and typical myopic optic disc morphology, with and without glaucoma, were recruited from a glaucoma clinic and a local optometry practice. The final classification of myopic glaucoma or myopic control was based on consensus assessment by 3 clinicians of visual fields and optic disc photographs. Participants underwent imaging with confocal scanning laser tomography for measurement of DM rim area (DM-RA) and with spectral domain optical coherence tomography (SD OCT) for quantification of a BMO-based neuroretinal rim parameter, minimum rim width (BMO-MRW), and RNFL thickness. Sensitivity of DM-RA, BMO-MRW, and RNFL thickness at a fixed specificity of 90% and partial area under the curves (pAUCs) for global and sectoral parameters for specificities ≥90%. Sensitivities at 90% specificity were 30% for DM-RA and 71% for both BMO-MRW and RNFL thickness. The pAUC was higher for the BMO-MRW compared with DM-RA (P < 0.001), but similar to RNFL thickness (P > 0.5). Sectoral values of BMO-MRW tended to have a higher, but nonsignificant, pAUC across all sectors compared with RNFL thickness. Bruch's membrane opening MRW is more sensitive than DM-RA and similar to RNFL thickness for the identification of glaucoma in myopic eyes and offers a valuable diagnostic tool for patients with glaucoma with myopic optic discs. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Anomalous coagulation factors in non-arteritic anterior ischemic optic neuropathy with central retinal vein occlusion: A case report.

PubMed

Kim, Ji Hong; Kang, Min Ho; Seong, Mincheol; Cho, Heeyoon; Shin, Yong Un

2018-04-01

Non-arteritic anterior ischemic optic neuropathy (NAION) is characterized by sudden, painless visual loss and optic disc edema. NAION occurs mainly in the presence of cardiovascular disease and hypercoagulability, mainly in patients over 50 years of age. We experienced a case of NAION associated with central retinal vein occlusion (CRVO) in a young man with no underlying disease. A 46-year-old man was referred to our clinic following a sudden loss of vision in his right eye. The patient exhibited no underlying disease and reported no ongoing medication. Significant visual loss and visual disturbance of the right eye were observed. The pupil of the right eye was enlarged and an afferent pupillary defect was observed. On fundus examination, retinal hemorrhage was observed in the peripheral retina; macular edema was observed in optical coherence tomography analysis. However, optic disc edema was not evident. No abnormal findings were found in routine blood tests for hypercoagulability. After 3 days of steroid intravenous injection, macular edema disappeared and visual acuity was improved, but optic disc edema began to appear. One week later, optic disc edema was evident and visual acuity was significantly reduced; thus, the patient was diagnosed with NAION. In fluorescein angiography, peripheral retinal ischemia was observed, suggesting that CRVO was complicated. Blood tests, including analysis of coagulation factors, were performed again, showing that coagulation factors IX and XI were increased. Anomalous coagulation factors in non-arteritic anterior ischemic optic neuropathy with central retinal vein occlusion. Systemic steroids were administered. One month later, optic disc edema and retinal hemorrhage gradually diminished and eventually disappeared; however, visual acuity did not recover. In young patients without underlying disease, cases of NAION require careful screening for coagulation disorders. Even if there is no abnormality in the test for routine coagulation status, it may be necessary to confirm a coagulation defect through an additional coagulation factor assay.

[Posterior vitrectomy with gas endotamponade and retinal laser therapy in treatment of patients with macular complications of the optic disc pit].

PubMed

Cywiński, Adam; Kałużny, Jakub; Ferda, Daniela; Piwońska-Lobermajer, Anna

2015-01-01

Retrospective evaluation of functional and anatomical treatment outcomes in patients with macular cornplications of optic disc pit. 9 patients (eyes) underwent central posterior vitrectomy in conjunction with posterior vitreous detachment, retinal laser therapy to the optic disc pit area and endotamponade with expansile gas. It was followed by the patient's forced positioning (recommended for a few days especially at night), which ended the treatment protocol. Improved anatomical relationships, accompanied by functional improvement were achieved in each reported case. The resolution of macular lesions was slow, lasting even for several months. Too long delay in performing the surgery (over 5 months since the onset of visual impairment) was associated with the development of retinal complications, mainly macular hole formation, most likely caused by the long-term ischemia. The central posterior vitrectomy combined with posterior vitreous detachment, laser therapy, andd expansile gas tamponade offers good outcomes in patients with retinal complications of optic disc pit. Surgery performed shortly after the onset of visual dysfunction gives the best functional outcomes. Restoration of normal anatomical relationships is a long-term process. In some cases, though, these abnormalities may not resolve completely.

Relationship between Secchi disc readings and light penetration in Lake Huron

USGS Publications Warehouse

Beeton, Alfred M.

1958-01-01

Fifty-seven paired photometer and Secchi disc measurements made at 18 stations in Saginaw Bay and Lake Huron support the view that a counter-clockwise current usually occurs in the Bay with more transparent Lake Huron water flowing in along the northwest shore and less transparent Bay water flowing out along the southeast shore. The average percentage transmission of surface light intensity, at the Secchi disc depth, was 14.7 percent. Discrepancies in the relationship of disc readings to percentage transmission of surface light are related to the condition of the sky and sea. It is suggested that these discrepancies can best be explained on the basis of the spectral sensitivity of the human eye and its response to surface glare.

Pathologic Myopia.

PubMed

Ohno-Matsui, Kyoko

Pathologic myopia (PM) is the only myopia that causes the loss of best-corrected visual acuity. The main reason for best-corrected visual acuity loss is complications specific to PM, such as myopic maculopathy, myopic traction maculopathy, and myopic optic neuropathy (or glaucoma). The meta-analyses of the PM study group (META-PM study) made a classification system for myopic maculopathy. On the basis of this study, PM has been defined as eyes having atrophic changes equal to or more severe than diffuse atrophy. Posterior staphyloma and eye deformity are important causes of developing vision-threatening complications. Posterior staphyloma is unique to PM, except for inferior staphyloma due to tilted disc syndrome. It is defined as an outpouching of the wall of the eye that has a radius of curvature that is less than the surrounding curvature of the wall of the eye. The mechanical load onto the important region for central vision (optic nerve and macula) is not comparable between eyes with and without posterior staphyloma. Three-dimensional magnetic resonance imaging is a powerful tool to analyze the entire shape of the eye. When ultra-widefield optical coherence tomography is available, it is expected to be a new tool that will surpass 3-dimensional magnetic resonance imaging. In the future, preventive therapies targeting staphyloma and eye deformity are expected before vision-threatening complications develop and it is too late for patients.

Initial Arcuate Defects within the Central 10 Degrees in Glaucoma

PubMed Central

Raza, Ali S.; de Moraes, Carlos Gustavo V.; Odel, Jeffrey G.; Greenstein, Vivienne C.; Liebmann, Jeffrey M.; Ritch, Robert

2011-01-01

Purpose. To better understand the relationship between the spatial patterns of functional (visual field [VF] loss) and structural (axon loss) abnormalities in patients with glaucomatous arcuate defects largely confined to the central 10° on achromatic perimetry. Methods. Eleven eyes (9 patients) with arcuate glaucomatous VF defects largely confined to the macula were selected from a larger group of patients with both 10-2 and 24-2 VF tests. Eyes were included if their 10-2 VF had an arcuate defect and if the 24-2 test was normal outside the central 10° (i.e., did not have a cluster of three contiguous points within a hemifield). For the structural analysis, plots of retinal nerve fiber layer (RNFL) thickness of the macula were obtained with frequency-domain optical coherence tomography (fdOCT). The optic disc locations of the RNFL defects were identified on peripapillary fdOCT scans. Results. The VF arcuate defects extended to within 1° of fixation on the 10-2 test and were present in the superior hemifield in 10 of the 11 eyes. The arcuate RNFL damage, seen in the macular fdOCT scans of all 11 eyes, involved the temporal and inferior temporal portions of the disc on the peripapillary scans. Conclusions. Glaucomatous arcuate defects of the macula's RNFL meet the disc temporal to the peak of the main arcuate bundles and produce a range of macular VF defects from clear arcuate scotomas to a papillofoveal horizontal step (“pistol barrel scotoma”). If RGC displacement is taken into consideration, the RNFL and VF defects can be compared directly. PMID:20881293

Characterization of big bang, a novel gene encoding for PDZ domain-containing proteins that are dynamically expressed throughout Drosophila development.

PubMed

Kim, Sabrina Y; Renihan, Maia K; Boulianne, Gabrielle L

2006-06-01

PDZ (PSD-95, Discs-large, ZO-1) domain proteins often function as scaffolding proteins and have been shown to play important roles in diverse cellular processes such as the establishment and maintenance of cell polarity, and signal transduction. Here, we report the identification and cloning of a novel Drosophila melanogaster gene that is predicted to produce several different PDZ domain-containing proteins through alternative promoter usage and alternative splicing. This gene, that we have named big bang (bbg), was first identified as C96-GAL4, a GAL4 enhancer trap line that was generated in our lab. To further characterize bbg, its expression pattern was examined in ovaries, embryos, and late third instar larvae using UAS reporter gene constructs, in situ hybridization, or immunocytochemistry. In addition, the expression of alternatively spliced transcripts was examined in more detail using in situ hybridization. We find that during embryogenesis bbg is predominantly expressed in the developing gut, but it is also expressed in external sensory organs found in the epidermis. In the late third instar larva, bbg is expressed along the presumptive wing margin in the wing disc, broadly in the eye disc, and in other imaginal discs as well as in the brain. The expression patterns observed are dynamic and specific during development, suggesting that like other genes that encode for several different PDZ domain protein isoforms, bbg likely plays important roles in multiple developmental processes.

Loss of the Drosophila cell polarity regulator Scribbled promotes epithelial tissue overgrowth and cooperation with oncogenic Ras-Raf through impaired Hippo pathway signaling

PubMed Central

2011-01-01

Background Epithelial neoplasias are associated with alterations in cell polarity and excessive cell proliferation, yet how these neoplastic properties are related to one another is still poorly understood. The study of Drosophila genes that function as neoplastic tumor suppressors by regulating both of these properties has significant potential to clarify this relationship. Results Here we show in Drosophila that loss of Scribbled (Scrib), a cell polarity regulator and neoplastic tumor suppressor, results in impaired Hippo pathway signaling in the epithelial tissues of both the eye and wing imaginal disc. scrib mutant tissue overgrowth, but not the loss of cell polarity, is dependent upon defective Hippo signaling and can be rescued by knockdown of either the TEAD/TEF family transcription factor Scalloped or the transcriptional coactivator Yorkie in the eye disc, or reducing levels of Yorkie in the wing disc. Furthermore, loss of Scrib sensitizes tissue to transformation by oncogenic Ras-Raf signaling, and Yorkie-Scalloped activity is required to promote this cooperative tumor overgrowth. The inhibition of Hippo signaling in scrib mutant eye disc clones is not dependent upon JNK activity, but can be significantly rescued by reducing aPKC kinase activity, and ectopic aPKC activity is sufficient to impair Hippo signaling in the eye disc, even when JNK signaling is blocked. In contrast, warts mutant overgrowth does not require aPKC activity. Moreover, reducing endogenous levels of aPKC or increasing Scrib or Lethal giant larvae levels does not promote increased Hippo signaling, suggesting that aPKC activity is not normally rate limiting for Hippo pathway activity. Epistasis experiments suggest that Hippo pathway inhibition in scrib mutants occurs, at least in part, downstream or in parallel to both the Expanded and Fat arms of Hippo pathway regulation. Conclusions Loss of Scrib promotes Yorkie/Scalloped-dependent epithelial tissue overgrowth, and this is also important for driving cooperative tumor overgrowth with oncogenic Ras-Raf signaling. Whether this is also the case in human cancers now warrants investigation since the cell polarity function of Scrib and its capacity to restrain oncogene-mediated transformation, as well as the tissue growth control function of the Hippo pathway, are conserved in mammals. PMID:21955824

The Spectrum of Optic Disc Ischemia in Patients Younger than 50 Years (An Amercian Ophthalmological Society Thesis)

PubMed Central

Arnold, Anthony C.; Costa, Roberta M. S.; Dumitrascu, Oana M.

2013-01-01

Purpose: To identify the spectrum of clinical and fluorescein angiographic features of optic disc ischemia in patients younger than 50 years. Methods: This retrospective comparative case series from a university consultative neuro-ophthalmology practice consisted of two phases. The first compared 108 cases of nonarteritic anterior ischemic optic neuropathy in patients younger than 50 years (NAIONy) to a cohort of 108 cases in patients 50 years or older (NAIONo). Predisposing risk factors, fluorescein angiographic features, and clinical course were compared. In the second phase, 12 cases of diabetic papillopathy under age 50 were assessed by fluorescein angiographic criteria for evidence of optic disc ischemia and compared to patients with NAIONy. Results: NAIONy comprised 108 (12.7%) of 848 NAION cases reviewed. Chronic renal failure with dialysis and migraine were more common in NAIONy. Fellow eye involvement rate was significantly higher for NAIONy patients (46/108, 42.6%) than for NAIONo patients (32/108, 29.6%). Fluorescein angiographic features of ischemia were documented in 44 (81.5%) of 54 eyes studied. In one case, these features were documented in pre-NAION edema. Diabetic papillopathy demonstrated delayed filling consistent with ischemia in 7 of 10 (70.0%), without significant visual field loss. Conclusions: Ischemic optic neuropathy in patients younger than 50 years is not rare. Fellow eye involvement is more frequent in younger patients. Fluorescein angiography confirmation of impaired perfusion in multiple syndromes of optic neuropathy corroborates a spectrum of optic disc ischemia ranging from perfusion delay without visual loss to severely impaired perfusion and visual loss and incorporates optic neuropathies previously considered nonischemic. PMID:24167327

The relationship between 3D morphology of optic disc and spatial patterns of visual field loss in glaucoma

NASA Astrophysics Data System (ADS)

Wang, Mengyu; Wang, Hui; Baniasadi, Neda; Elze, Tobias

2017-02-01

Purpose: Optic disc tilt defined over 3D optic disc morphology has been shown to be associated with the location of initial glaucomatous damages. In this work, we study the impact of optic cup depth (OCD) on spatial patterns of visual field loss in glaucoma. Methods: Pairs of reliable Cirrus OCT scans around optic disc and Humphrey visual fields of glaucoma patients without visually significant cataract and age-related macular degeneration were selected. The most recent visit of a randomly selected eye of each patient was chosen. The OCD was automatically calculated on the superior-inferior cross sectional image passing through the optic disc center. The correlations between the mean pattern deviation (PD) of each sector in glaucoma hemifield test (GHT) and Garway-Heath scheme and OCD were evaluated for all severities glaucoma and mild glaucoma (mean deviation >= -5 dB), respectively. Results: 424 eyes of 424 patients passed the data reliability criteria with 346 mild glaucoma patients. For all severities glaucoma, there was no significant correlation between the mean sector PD and OCD. For mild glaucoma, OCD was uniquely correlated to the mean PD of the inferior pericentral sector (r=-0.18, p=0.01) in GHT, which was independent of mean deviation and retinal nerve fiber layer thickness (p<0.001 for both). Conclusion: OCD was uniquely correlated to the vision loss of the inferior pericentral sector in GHT and Garway- Health scheme for mild glaucoma. Future advancement of OCT imaging techniques may provide better clinical diagnosis for early glaucoma by focusing on 3D morphological variation of the optic disc.

[Clinical evaluation of the effectiveness of cholinesterase inhibition with neuromidin in the treatment of primary glaucoma patients].

PubMed

Zakharova, I A; Avdeev, R V; Pristavka, V A; Surnin, S N; Makhmutov, V Yu; Savrasova, I I

to investigate neuromidin effectiveness in the treatment of patients with primary glaucoma and compensated intraocular pressure (IOP). A total of 40 patients (80 eyes) were examined. Of them, 10 eyes with early glaucoma, 36 eyes with moderate-stage glaucoma, 33 eyes with advanced glaucoma, and 1 eye with end-stage glaucoma. In 19 eyes, IOP was controlled through beta-blockers, in 11 eyes - through carbonic anhydrase inhibitors, in 10 eyes - through prostaglandin analogues, and in 39 eyes - through combination drugs. Twenty-six eyes had received glaucoma surgery some time earlier. Ipidacrine was prescribed in tablets at 20 mg 2 times daily for 25 days. Treatment effectiveness was judged by visual functions, hydrodynamics, and morphometric parameters of the optic disc. In moderate-stage eyes, visual acuity improved in 66.6% of cases and remained unchanged in 33.3%. In advanced-stage eyes, visual acuity improved in 51.5% of cases and remained unchanged in 48.5%. Visual field broadened in all cases. Moreover, under the neuromidin therapy, the number of scotomas in early-stage eyes decreased, while the number of areas with normal sensitivity of the retina increased by 14.9%. In advanced-stage glaucoma, the effect was less pronounced: the number of type 1 and type 2 scotomas decreased by 3.0±0.6% and 2.9±0.8%, respectively; the number of absolute scotomas did not change; the number of areas with normal sensitivity of the retina increased by 7.4±2.0%. Also, P0 was found to be reduced and intraocular fluid outflow - activated. In early and moderate glaucoma, there was a significant reduction in the cup area as well as an increase in the neuroretinal rim area and retinal nerve fiber layer thickness. In advanced-stage cases, it was only the retinal nerve fiber layer thickness that changed. Neuromidin has a positive impact on visual function, hydrodynamics, and morphometric parameters of the optic disc.

Diagnostic capability of Pulsar perimetry in pre-perimetric and early glaucoma.

PubMed

Hirasawa, Kazunori; Takahashi, Natsumi; Matsumura, Kazuhiro; Kasahara, Masayuki; Shoji, Nobuyuki

2017-06-12

This study aimed to compare the diagnostic capability of Pulsar perimetry (Pulsar) in pre-perimetric glaucoma (PPG) and early glaucoma (EG) with that of Flicker perimetry (Flicker) and spectral-domain optical conference tomography (SD-OCT). This prospective cross-sectional study included 25 eyes of 25 PPG patients, 35 eyes of 35 EG patients, and 42 eyes of 42 healthy participants. The diagnostic capability using the area under the curve (AUC) of the best parameter and agreement of detectability between structural and functional measurements were compared. For PPG patients, the AUC of Pulsar, Flicker, OCT-disc, and OCT-macular was 0.733, 0.663, 0.842, and 0.780, respectively. The AUC of Flicker was significantly lower than that of OCT-disc (p = 0.016). For EG patients, the AUC of Pulsar, Flicker, OCT-disc, and OCT-macular were 0.851, 0.869, 0.907, and 0.861, respectively. There was no significant difference in AUC among these methods. The agreement between structural and functional measurements expressed by kappa value ranged from -0.16 to 0.07 for PPG and from 0.01 to 0.25 for EG. Although the diagnostic capability of Pulsar in the PPG and EG groups was equal to that of Flicker and SD-OCT, the agreements between structural and functional measurements for both PPG and EG were poor.

Noonan's syndrome with keratoconus and optic disc coloboma.

PubMed

Ascaso, F J; Del Buey, M A; Huerva, V; Latre, B; Palomar, A

1993-01-01

We report the case of a 14-year-old girl with multiple findings characteristic of Noonan's syndrome, including short stature, mild mental retardation, facial, skeletal and renal abnormalities. In addition, ophthalmic examination revealed a keratoconus in the left eye and a right optic disc coloboma. To date, only two cases of Noonan's syndrome with keratoconus have been reported, and this is the second case of this syndrome with optic disc coloboma. To our knowledge, this is the first report of Noonan's syndrome associated with unilateral keratoconus and contralateral optic disc coloboma. In view of the large number of patients with Noonan's syndrome reported to date and the rarity of these ocular abnormalities, it is most likely that this association is fortuitous. Ocular findings reported in patients with Noonan's syndrome are reviewed.

Diagnostic classification of macular ganglion cell and retinal nerve fiber layer analysis: differentiation of false-positives from glaucoma.

PubMed

Kim, Ko Eun; Jeoung, Jin Wook; Park, Ki Ho; Kim, Dong Myung; Kim, Seok Hwan

2015-03-01

To investigate the rate and associated factors of false-positive diagnostic classification of ganglion cell analysis (GCA) and retinal nerve fiber layer (RNFL) maps, and characteristic false-positive patterns on optical coherence tomography (OCT) deviation maps. Prospective, cross-sectional study. A total of 104 healthy eyes of 104 normal participants. All participants underwent peripapillary and macular spectral-domain (Cirrus-HD, Carl Zeiss Meditec Inc, Dublin, CA) OCT scans. False-positive diagnostic classification was defined as yellow or red color-coded areas for GCA and RNFL maps. Univariate and multivariate logistic regression analyses were used to determine associated factors. Eyes with abnormal OCT deviation maps were categorized on the basis of the shape and location of abnormal color-coded area. Differences in clinical characteristics among the subgroups were compared. (1) The rate and associated factors of false-positive OCT maps; (2) patterns of false-positive, color-coded areas on the GCA deviation map and associated clinical characteristics. Of the 104 healthy eyes, 42 (40.4%) and 32 (30.8%) showed abnormal diagnostic classifications on any of the GCA and RNFL maps, respectively. Multivariate analysis revealed that false-positive GCA diagnostic classification was associated with longer axial length and larger fovea-disc angle, whereas longer axial length and smaller disc area were associated with abnormal RNFL maps. Eyes with abnormal GCA deviation map were categorized as group A (donut-shaped round area around the inner annulus), group B (island-like isolated area), and group C (diffuse, circular area with an irregular inner margin in either). The axial length showed a significant increasing trend from group A to C (P=0.001), and likewise, the refractive error was more myopic in group C than in groups A (P=0.015) and B (P=0.014). Group C had thinner average ganglion cell-inner plexiform layer thickness compared with other groups (group A=B>C, P=0.004). Abnormal OCT diagnostic classification should be interpreted with caution, especially in eyes with long axial lengths, large fovea-disc angles, and small optic discs. Our findings suggest that the characteristic patterns of OCT deviation map can provide useful clues to distinguish glaucomatous changes from false-positive findings. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Helicoid peripapillary chorioretinal degeneration complicated by choroidal neovascularization.

PubMed

Triantafylla, Magdalini; Panos, Georgios D; Dardabounis, Doukas; Nanos, Panagiotis; Konstantinidis, Aristeidis

2016-02-15

Helicoid peripapillary chorioretinal degeneration (HPCD) is a hereditary disease of the fundus that is characterized by atrophic chorioretinal areas that appear early in life and expand gradually from the optic disc towards the macula and the periphery. We describe the case of an elderly man with a known diagnosis of HPCD who developed choroidal neovascular membrane (CNV) in both eyes during the course of the disease. The patient was treated with intravitreal injection of ranibizumab, to which he had excellent response. The CNV subsided with 2 injections in the right eye and 1 in the left. Two years after the initial diagnosis of CNV in the right eye, visual acuity was 5/10 OD and 9/10 OS. Helicoid peripapillary chorioretinal degeneration is rarely complicated by CNV as the fundus lacks the trigger factors that would sustain this process. Although rare, HPCD complicated by CNV can be seen bilaterally, but responds well to few ranibizumab injections.

Anterior ischemic optic neuropathy in a patient with Churg-Strauss syndrome.

PubMed

Lee, Ji Eun; Lee, Seung Uk; Kim, Soo Young; Jang, Tae Won; Lee, Sang Joon

2012-12-01

We describe a patient with Churg-Strauss syndrome who developed unilateral anterior ischemic optic neuropathy. A 54-year-old man with a history of bronchial asthma, allergic rhinitis, and sinusitis presented with sudden decreased visual acuity in his right eye that had begun 2 weeks previously. The visual acuity of his right eye was 20 / 50. Ophthalmoscopic examination revealed a diffusely swollen right optic disc and splinter hemorrhages at its margin. Goldmann perimetry showed central scotomas in the right eye and fluorescein angiography showed remarkable hyperfluorescence of the right optic nerve head. Marked peripheral eosinphilia, extravascular eosinophils in a bronchial biopsy specimen, and an increased sedimentation rate supported the diagnosis of Churg-Strauss syndrome. Therapy with methylprednisolone corrected the laboratory abnormalities, improved clinical features, and preserved vision, except for the right central visual field defect. Early recognition of this systemic disease by ophthalmologists may help in preventing severe ocular complications.

Anterior Ischemic Optic Neuropathy in a Patient with Churg-Strauss Syndrome

PubMed Central

Lee, Ji Eun; Lee, Seung Uk; Kim, Soo Young; Jang, Tae Won

2012-01-01

We describe a patient with Churg-Strauss syndrome who developed unilateral anterior ischemic optic neuropathy. A 54-year-old man with a history of bronchial asthma, allergic rhinitis, and sinusitis presented with sudden decreased visual acuity in his right eye that had begun 2 weeks previously. The visual acuity of his right eye was 20 / 50. Ophthalmoscopic examination revealed a diffusely swollen right optic disc and splinter hemorrhages at its margin. Goldmann perimetry showed central scotomas in the right eye and fluorescein angiography showed remarkable hyperfluorescence of the right optic nerve head. Marked peripheral eosinphilia, extravascular eosinophils in a bronchial biopsy specimen, and an increased sedimentation rate supported the diagnosis of Churg-Strauss syndrome. Therapy with methylprednisolone corrected the laboratory abnormalities, improved clinical features, and preserved vision, except for the right central visual field defect. Early recognition of this systemic disease by ophthalmologists may help in preventing severe ocular complications. PMID:23204805

Developing new automated alternation flicker using optic disc photography for the detection of glaucoma progression

PubMed Central

Ahn, J; Yun, I S; Yoo, H G; Choi, J-J; Lee, M

2017-01-01

Purpose To evaluate a progression-detecting algorithm for a new automated matched alternation flicker (AMAF) in glaucoma patients. Methods Open-angle glaucoma patients with a baseline mean deviation of visual field (VF) test>−6 dB were included in this longitudinal and retrospective study. Functional progression was detected by two VF progression criteria and structural progression by both AMAF and conventional comparison methods using optic disc and retinal nerve fiber layer (RNFL) photography. Progression-detecting performances of AMAF and the conventional method were evaluated by an agreement between functional and structural progression criteria. RNFL thickness changes measured by optical coherence tomography (OCT) were compared between progressing and stable eyes determined by each method. Results Among 103 eyes, 47 (45.6%), 21 (20.4%), and 32 (31.1%) eyes were evaluated as glaucoma progression using AMAF, the conventional method, and guided progression analysis (GPA) of the VF test, respectively. The AMAF showed better agreement than the conventional method, using GPA of the VF test (κ=0.337; P<0.001 and κ=0.124; P=0.191, respectively). The rates of RNFL thickness decay using OCT were significantly different between the progressing and stable eyes when progression was determined by AMAF (−3.49±2.86 μm per year vs −1.83±3.22 μm per year; P=0.007) but not by the conventional method (−3.24±2.42 μm per year vs −2.42±3.33 μm per year; P=0.290). Conclusions The AMAF was better than the conventional comparison method in discriminating structural changes during glaucoma progression, and showed a moderate agreement with functional progression criteria. PMID:27662466

Comparison of Optic Disc Margin Identified by Color Disc Photography and High-Speed Ultrahigh-Resolution Optical Coherence Tomography

PubMed Central

Manassakorn, Anita; Ishikawa, Hiroshi; Kim, Jong S.; Wollstein, Gadi; Bilonick, Richard A.; Kagemann, Larry; Gabriele, Michelle L.; Sung, Kyung Rim; Mumcuoglu, Tarkan; Duker, Jay S.; Fujimoto, James G.; Schuman, Joel S.

2009-01-01

Objective To determine the correspondence between optic disc margins evaluated using disc photography (DP) and optical coherence tomography (OCT). Methods From May 1, 2005, through November 10, 2005, 17 healthy volunteers (17 eyes) had raster scans (180 frames, 501 samplings per frame) centered on the optic disc taken with stereo-optic DP and high-speed ultrahigh-resolution OCT (hsUHR-OCT). Two image outputs were derived from the hsUHR-OCT data set: an en face hsUHR-OCT fundus image and a set of 180 frames of cross-sectional images. Three ophthalmologists independently and in a masked, randomized fashion marked the disc margin on the DP, hsUHR-OCT fundus, and cross-sectional images using custom software. Disc size (area and horizontal and vertical diameters) and location of the geometric disc center were compared among the 3 types of images. Results The hsUHR-OCT fundus image definition showed a significantly smaller disc size than the DP definition (P<.001, mixed-effects analysis). The hsUHR-OCT cross-sectional image definition showed a significantly larger disc size than the DP definition (P<.001). The geometric disc center location was similar among the 3 types of images except for the y-coordinate, which was significantly smaller in the hsUHR-OCT fundus images than in the DP images. Conclusion The optic disc margin as defined by hsUHR-OCT was significantly different than the margin defined by DP. PMID:18195219

Novel Bruch's Membrane Opening Minimum Rim Area Equalizes Disc Size Dependency and Offers High Diagnostic Power for Glaucoma.

PubMed

Enders, Philip; Adler, Werner; Schaub, Friederike; Hermann, Manuel M; Dietlein, Thomas; Cursiefen, Claus; Heindl, Ludwig M

2016-12-01

The purpose of this study was to assess the diagnostic power of the novel two-dimensional parameter Bruch's membrane opening minimal rim area (BMO-MRA) in spectral-domain optical coherence tomography (SD-OCT) for detection of glaucoma compared to minimal rim width (BMO-MRW) and retinal nerve fiber layer (RNFL) thickness in large and small optic discs. In this case-control, cross-sectional study, 207 eyes of 207 participants, including 89 controls and 97 patients with glaucoma and 21 with ocular hypertension (OHT), with a disc size <1.63 mm2 or >2.43 mm2 underwent SD-OCT, confocal laser scanning tomography (CSLT), visual field testing, and clinical examination. Bruch's membrane opening-MRA BMO-MRW, RNFL thickness of SD-OCT and disc margin rim area (DM-RA) of CSLT were evaluated and analyzed for diagnostic power to detect glaucoma. In healthy eyes with macrodiscs, mean BMO-MRW of 243.14 ± 43.12 μm was significantly smaller than BMO-MRW in microdiscs (338.97 ± 69.39; P < 0.001). Bruch's membrane opening-MRA was comparable between disc size groups with 1.22 ± 0.25 mm2 for macrodiscs and 1.26 ± 0.27 mm2 for microdiscs (P = 0.51), as was RNFL thickness (82.69 ± 15.76 μm versus 78.53 ± 11.01 μm, respectively; P = 0.28). Perimetric mean deviation was -8.7 ± 6.3 dB in glaucoma and -0.6 ± 1.60 dB in OHT patients. Correlation of BMO-MRA and visual field function was rho (ρ) = 0.70 (P < 0.001). Diagnostic power to differentiate glaucoma patients was highest for BMO-MRA. Partial area under the curve (pAUC) for BMO-MRA was 0.14 for specificity between 0.8 and 1.0, exceeding pAUCs of BMO-MRW (P < 0.001), RNFL thickness (P = 0.03), and DM-RA (P = 0.01). Bruch's membrane opening-based minimum rim area measurements offer advantages compared to one-dimensional parameters assessing neuroretinal rim by SD-OCT. In nonglaucomatous eyes, BMO-MRA values seem comparable for the full range of disc sizes. Bruch's membrane opening-MRA surpasses other parameters in diagnostic power for glaucoma.

Glaucoma diagnostic accuracy of optical coherence tomography parameters in early glaucoma with different types of optic disc damage.

PubMed

Shin, Hye-Young; Park, Hae-Young Lopilly; Jung, Younhea; Choi, Jin-A; Park, Chan Kee

2014-10-01

To compare the initial visual field (VF) defect pattern and the spectral-domain optical coherence tomography (OCT) parameters and investigate the effects of distinct types of optic disc damage on the diagnostic performance of these OCT parameters in early glaucoma. Retrospective, observational study. A total of 138 control eyes and 160 eyes with early glaucoma were enrolled. The glaucomatous eyes were subdivided into 4 groups according to the type of optic disc damage: focal ischemic (FI) group, myopic (MY) group, senile sclerotic (SS) group, and generalized enlargement (GE) group. The values of total deviation (TD) maps were analyzed, and superior-inferior (S-I) differences of TD were calculated. The optic nerve head (ONH) parameters, peripapillary retinal nerve fiber layer (pRNFL), and ganglion cell-inner plexiform layer (GCIPL) thicknesses were measured. Comparison of diagnostic ability using area under the receiver operating characteristic curves (AUCs). The S-I and central S-I difference of the FI group were larger than those of the GE group. The rim area of the SS group was larger than those of the 3 other groups, and the vertical cup-to-disc ratio (CDR) of the GE group was larger than that of the MY group. In addition, the minimum and inferotemporal GCIPL thicknesses of the FI group were smaller than those of the GE group. The AUC of the rim area (0.89) was lower than that of the minimum GCIPL (0.99) in the SS group, and the AUC of the vertical CDR (0.90) was lower than that of the minimum GCIPL (0.99) in the MY group. Furthermore, the AUCs of the minimum GCIPL thicknesses of the FI and MY group were greater than those of the average pRNFL thickness for detecting glaucoma, as opposed to the SS and GE. The OCT parameters differed among the 4 groups on the basis of the distinct optic disc appearance and initial glaucomatous damage pattern. Clinicians should be aware that the diagnostic capability of OCT parameters could differ according to the type of optic disc damage in early glaucoma. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Application of reaction-diffusion models to cell patterning in Xenopus retina. Initiation of patterns and their biological stability.

PubMed

Shoaf, S A; Conway, K; Hunt, R K

1984-08-07

We have examined the behavior of two reaction-diffusion models, originally proposed by Gierer & Meinhardt (1972) and by Kauffman, Shymko & Trabert (1978), for biological pattern formation. Calculations are presented for pattern formation on a disc (approximating the geometry of a number of embryonic anlagen including the frog eye rudiment), emphasizing the sensitivity of patterns to changes in initial conditions and to perturbations in the geometry of the morphogen-producing space. Analysis of the linearized equations from the models enabled us to select appropriate parameters and disc size for pattern growth. A computer-implemented finite element method was used to solve the non-linear model equations reiteratively. For the Gierer-Meinhardt model, initial activation (varying in size over two orders of magnitude) of one point on the disc's edge was sufficient to generate the primary gradient. Various parts of the disc were removed (remaining only as diffusible space) from the morphogen-producing cycle to investigate the effects of cells dropping out of the cycle due to cell death or malfunction (single point removed) or differentiation (center removed), as occur in the Xenopus eye rudiment. The resulting patterns had the same general shape and amplitude as normal gradients. Nor did a two-fold increase in disc size affect the pattern-generating ability of the model. Disc fragments bearing their primary gradient patterns were fused (with gradients in opposite directions, but each parallel to the fusion line). The resulting patterns generated by the model showed many similarities to results of "compound eye" experiments in Xenopus. Similar patterns were obtained with the model of Kauffman's group (1978), but we found less stability of the pattern subject to simulations of central differentiation. However, removal of a single point from the morphogen cycle (cell death) did not result in any change. The sensitivity of the Kauffman et al. model to shape perturbations is not surprising since the model was originally designed to use shape and increasing size during growth to generate a sequence of transient patterns. However, the Gierer-Meinhardt model is remarkably stable even when subjected to a wide range of perturbations in the diffusible space, thus allowing it to cope with normal biological variability, and offering an exciting range of possibilities for reaction-diffusion models as mechanisms underlying the spatial patterns of tissue structures.

Quantitative comparison of disc rim color in optic nerve atrophy of compressive optic neuropathy and glaucomatous optic neuropathy.

PubMed

Nakano, Eri; Hata, Masayuki; Oishi, Akio; Miyamoto, Kazuaki; Uji, Akihito; Fujimoto, Masahiro; Miyata, Manabu; Yoshimura, Nagahisa

2016-08-01

The purpose was to investigate an objective and quantitative method to estimate the redness of the optic disc neuroretinal rim, and to determine the usefulness of this method to differentiate compressive optic neuropathy (CON) from glaucomatous optic neuropathy (GON). In our study there were 126 eyes: 40 with CON, 40 with normal tension glaucoma (NTG), and 46 normal eyes (NOR). Digital color fundus photographs were assessed for the redness of disc rim color using ImageJ software. We separately measured the intensity of red, green, and blue pixels from RGB images. Three disc color indices (DCIs), which indicate the redness intensity, were calculated through existing formulas. All three DCIs of CON were significantly smaller than those of NOR (P < 0.001). In addition, when compared with NTG, DCIs were also significantly smaller in CON (P < 0.05). A comparison of mild CON and mild NTG (mean deviation (MD) > -6 dB), in which the extent of retinal nerve fiber layer thinning is comparable, the DCIs of mild CON were significantly smaller than those of mild NTG (P < 0.05). In contrast, DCIs did not differ between moderate-to-severe stages of CON and NTG (MD ≤ -6 dB), though the retinal nerve fibers of CON were more severely damaged than those of NTG. To differentiate between mild CON and mild NTG, all AUROCs for the three DCIs were above 0.700. A quantitative and objective assessment of optic disc color was useful in differentiating early-stage CON from GON and NOR.

Influence of optic disc size on the diagnostic performance of macular ganglion cell complex and peripapillary retinal nerve fiber layer analyses in glaucoma.

PubMed

Cordeiro, Daniela Valença; Lima, Verônica Castro; Castro, Dinorah P; Castro, Leonardo C; Pacheco, Maria Angélica; Lee, Jae Min; Dimantas, Marcelo I; Prata, Tiago Santos

2011-01-01

To evaluate the influence of optic disc size on the diagnostic accuracy of macular ganglion cell complex (GCC) and conventional peripapillary retinal nerve fiber layer (pRNFL) analyses provided by spectral domain optical coherence tomography (SD-OCT) in glaucoma. Eighty-two glaucoma patients and 30 healthy subjects were included. All patients underwent GCC (7 × 7 mm macular grid, consisting of RNFL, ganglion cell and inner plexiform layers) and pRNFL thickness measurement (3.45 mm circular scan) by SD-OCT. One eye was randomly selected for analysis. Initially, receiver operating characteristic (ROC) curves were generated for different GCC and pRNFL parameters. The effect of disc area on the diagnostic accuracy of these parameters was evaluated using a logistic ROC regression model. Subsequently, 1.5, 2.0, and 2.5 mm(2) disc sizes were arbitrarily chosen (based on data distribution) and the predicted areas under the ROC curves (AUCs) and sensitivities were compared at fixed specificities for each. Average mean deviation index for glaucomatous eyes was -5.3 ± 5.2 dB. Similar AUCs were found for the best pRNFL (average thickness = 0.872) and GCC parameters (average thickness = 0.824; P = 0.19). The coefficient representing disc area in the ROC regression model was not statistically significant for average pRNFL thickness (-0.176) or average GCC thickness (0.088; P ≥ 0.56). AUCs for fixed disc areas (1.5, 2.0, and 2.5 mm(2)) were 0.904, 0.891, and 0.875 for average pRNFL thickness and 0.834, 0.842, and 0.851 for average GCC thickness, respectively. The highest sensitivities - at 80% specificity for average pRNFL (84.5%) and GCC thicknesses (74.5%) - were found with disc sizes fixed at 1.5 mm(2) and 2.5 mm(2). Diagnostic accuracy was similar between pRNFL and GCC thickness parameters. Although not statistically significant, there was a trend for a better diagnostic accuracy of pRNFL thickness measurement in cases of smaller discs. For GCC analysis, an inverse effect was observed.

SU-F-T-659: Nanoparticle-Aided Eye Plaque Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chin, J; Ngwa, W

Purpose: Eye plaque brachytherapy is one of the approaches for radiotherapy treatment for ocular cancers: retinoblastoma and choroidal melanoma. This study, investigates the potential benefits of using gold nanoparticles to enhance therapeutic efficacy during eye plaque brachytherapy. Methods: The EYE PHYSICS Inc. Plaque Simulator program distributed by IsoAid, LLC, Port Richey, Florida was used. It is based on the superposition of dose contributions from individual seeds following the TG–43 formalism. Dose enhancement factor (DEF) values for feasible nanoparticle concentrations from previous studies was used to investigate the benefit of using nanoparticles to enhance dose to tumour or reduce dose tomore » healthy tissue. The dose enhancement factor (DEF) represents the ratio of the dose deposited in tumour with nanoparticles divided by dose deposited in the tumour without nanoparticles. The investigation was done for I–125 and Pd–103 typical sources employed for eye plaque brachytherapy. The prescription dose used is 85 Gy. Results: Lower dose enhancement values were obtained for Pd–103. With DEF of 2 due to gold nanoparticles, critical structure doses reduce by a factor of 2. Optic disc dose is 6.69 Gy and 4.571 Gy, opposite retina dose is 4.064 and 2.484 Gy, lens dose is 12.66 Gy and 9.870 Gy, and fovea dose is 9.85 Gy and 7.275 Gy. With DEF of 3 due to gold nanoparticles, critical structure doses reduce by a factor of 3. Optic disc dose is 4.352 Gy and 2.975 Gy, opposite retina dose is 2.644 Gy and 1.618 Gy, lens dose is 8.322 Gy and 6.427 Gy, and fovea dose is 4.815 Gy and 4.737 Gy. Conclusion: The results of this research predict that using gold nanoparticles will lead to major sparing of dose to critical structures. The finding provides more impetus for the development of nanoparticle–aided brachytherapy.« less

ato-Gal4 fly lines for gene function analysis: Eya is required in late progenitors for eye morphogenesis

PubMed Central

Yu, Linlin; Zhou, Qingxiang; Pignoni, Francesca

2015-01-01

The Gal4/UAS system is one of the most powerful tools for the study of cellular and developmental processes in Drosophila. Gal4 drivers can be used to induce targeted expression of dominant-negative and dominant-active proteins, histological markers, activity sensors, gene-specific dsRNAs, modulators of cell survival or proliferation, and other reagents. We describe here novel atonal-Gal4 lines that contain regions of the regulatory DNA of atonal, the proneural gene for photoreceptors, stretch receptors, auditory organ and some olfactory sensilla. During neurogenesis, the atonal gene is expressed at a critical juncture, a time of transition from progenitor cell to developing neuron. Thus, these lines are particularly well suited for the study of the transcription factors and signaling molecules orchestrating this critical transition. To demonstrate their usefulness, we focus on two visual organs, the eye and the Bolwig. We demonstrate the induction of predicted eye phenotypes when expressing the dominant-negative EGF receptor, EGFRDN, or a dsRNA against Notch, NotchRNAi, in the developing eye disc. In another example, we show the deletion of the Bolwig’s organ using the proapoptotic factor Hid. Lastly, we investigate the function of the eye specification factor Eyes absent or Eya in late retinal progenitors, shortly before they begin morphogenesis. We show that Eya is still required in these late progenitors to promote eye formation, and show failure to induce the target gene atonal and consequent lack of neuron formation. PMID:25980363

ato-Gal4 fly lines for gene function analysis: Eya is required in late progenitors for eye morphogenesis.

PubMed

Yu, Linlin; Zhou, Qingxiang; Pignoni, Francesca

2015-06-01

The Gal4/UAS system is one of the most powerful tools for the study of cellular and developmental processes in Drosophila. Gal4 drivers can be used to induce targeted expression of dominant-negative and dominant-active proteins, histological markers, activity sensors, gene-specific dsRNAs, modulators of cell survival or proliferation, and other reagents. Here, we describe novel atonal-Gal4 lines that contain regions of the regulatory DNA of atonal, the proneural gene for photoreceptors, stretch receptors, auditory organ, and some olfactory sensilla. During neurogenesis, the atonal gene is expressed at a critical juncture, a time of transition from progenitor cell to developing neuron. Thus, these lines are particularly well suited for the study of the transcription factors and signaling molecules orchestrating this critical transition. To demonstrate their usefulness, we focus on two visual organs, the eye and the Bolwig. We demonstrate the induction of predicted eye phenotypes when expressing the dominant-negative EGF receptor or a dsRNA against Notch in the developing eye disc. In another example, we show the deletion of the Bolwig's organ using the proapoptotic factor Hid. Finally, we investigate the function of the eye specification factor Eyes absent or Eya in late retinal progenitors, shortly before they begin morphogenesis. We show that Eya is still required in these late progenitors to promote eye formation, and show failure to induce the target gene atonal and consequent lack of neuron formation. © 2015 Wiley Periodicals, Inc.

Optical-spectrum-synthesizer design within an all-optical semiconductor gate to reduce waveform distortion induced by carrier-cooling relaxation at sub-Teraherz frequencies

NASA Astrophysics Data System (ADS)

Ueno, Yoshiyasu; Nakamoto, Ryouichi; Sakaguchi, Jun; Suzuki, Rei

2006-12-01

In frequency ranges above 200-300 GHz, the second slowest relaxation in the optical response (such as carrier-cooling relaxation having a time constant of 1-2 ps) of a semiconductor optical amplifier inside the conventional delayed-interference signal-wavelength converter (DISC) scheme is thought to start the distortion of all-optically gated waveforms. In this work, we design a digital optical-spectrum-synthesizer block that is part of the expanded DISC scheme. Our numerically calculated spectra, waveforms, and eye diagrams with assumed pseudorandom digital data pulses indicate that this synthesizer significantly removes strong distortion from the gated waveforms. A signal-to-noise ratio of 20 dB was obtained from our random-data eye diagram, providing proof of effectiveness in principle.

Visual Impairment and Intracranial Hypertension: An Emerging Spaceflight Risk

NASA Technical Reports Server (NTRS)

Fogarty, Jennifer A.; Polk, J. D.; Tarver, W.; Gibson, C. R.; Sargsyan, A.; Taddeo, T.; Alexander, D.; Otto, C.

2010-01-01

What is the risk? Given that astronauts exposed to microgravity experience a cephalad fluid shift, and that both symptomatic and asymptomatic astronauts have exhibited optic nerve sheath edema on MRI, there is a high probability that all astronauts have some degree of increased intracranial pressure (ICP; intracranial hypertension), and that those susceptible (via eye architecture, anatomy, narrow optic disc) have a high likelihood of developing papilledema (optic disc edema, globe flattening), choroidal folds, and/or hyperopic shifts and that the degree of edema may determine long-term or permanent vision impairment or loss. Back to back panels on this topic have been developed to address this emerging risk. The first panel will focus on the 6 clinical cases with emphasis on ophthalmic findings and imaging techniques used pre-, in-, and post-flight. The second panel will discuss the operational mitigation and medical requirements, the potential role of CO2 on ISS, and the research approach being developed. In total these back to back panels will explore what is known about this risk, what has been done immediately to address it, and how an integrated research model is being developed.

Bilateral chorioretinal coloboma discovered with ultra-wide field retinal imaging

PubMed Central

Barnard, Simon; Shneor, Einat; Brauner, Joel; Millodot, Michel; Gordon-Shaag, Ariela

2012-01-01

Uveal coloboma results from incomplete closure of the optic cup fissure. While conducting an evaluation of a new ultra-wide field retinal imaging camera (Optomap), which provides a view of the fundus up to 200° at one time without mydriasis, we discovered a case of bilateral chorioretinal coloboma in a 21-year-old student. The lesion was located in the midperiphery of each eye less than 2 disc diameters (DD) below the optic disc in the inferonasal quadrants. The size of the coloboma in the right eye was 1.8 DD in height and 1.3 DD in width, while the left lesion was 2.4 DD in height and 2.6 DD in width. The subject was totally asymptomatic and without any complication such as retinal detachment or choroidal neovascularization, which often accompany this type of lesion. The visual field of each eye displayed an absolute scotoma corresponding to the size and location of the coloboma. No management was necessary but the subject was advised to report for visual examination at regular intervals because complications can occur at any age.

Biometry and spectral domain optical coherence tomography parameters in children with large cupping.

PubMed

Jung, Jong Jin; Baek, Seung-Hee; Kim, Ungsoo Samuel

2013-09-01

The purpose of this study is to investigate optic nerve head using spectral domain optical coherence tomography (SD-OCT) in children with large cupping. 111 eyes (4-10 years) were divided into three groups according to the cup to disc ratio: group 1, ≤0.3; group 2, 0.4-0.6; and group 3, ≥0.7. The rim area, disc area, average cup to disc ratio, vertical cup to disc ratio, and cup volume were investigated using SD-OCT (Cirrus HD-OCT, Carl Zeiss, Jena, Germany), and the axial length and anterior chamber depth (ACD) were measured by IOL master (IOL master 500, Carl Zeiss, Jena, Germany). Next, we compared ocular biometry and SD-OCT between the three groups. The mean age of group 1 was 6.48 ± 1.42 years, 7.00 ± 1.75 years in group 2, and 6.63 ± 1.82 years in group 3 (p = 0.370). A significant difference was seen in the spherical equivalent between the groups (p = 0.001). Group 2 had the most myopic refractive errors. As the cup to disc ratio increases, disc area, average cup to disc ratio, vertical cup to disc ratio, and cup volume increase significantly. When the results of ocular biometry and SD-OCT are adjusted for axial length, only disc area showed a significant correlation with cup to disc ratio (ACD: p = 0.473, rim area: p = 0.639, disc area: p = 0.005, and cup volume: p = 0.325). Axial length is the key factor determining disc size, which in turn is important for determining cup to disc ratio. Normal children with large cupping should be examined for axial length, myopic refractive errors, and disc size.

Comprehensive eye evaluation algorithm

NASA Astrophysics Data System (ADS)

Agurto, C.; Nemeth, S.; Zamora, G.; Vahtel, M.; Soliz, P.; Barriga, S.

2016-03-01

In recent years, several research groups have developed automatic algorithms to detect diabetic retinopathy (DR) in individuals with diabetes (DM), using digital retinal images. Studies have indicated that diabetics have 1.5 times the annual risk of developing primary open angle glaucoma (POAG) as do people without DM. Moreover, DM patients have 1.8 times the risk for age-related macular degeneration (AMD). Although numerous investigators are developing automatic DR detection algorithms, there have been few successful efforts to create an automatic algorithm that can detect other ocular diseases, such as POAG and AMD. Consequently, our aim in the current study was to develop a comprehensive eye evaluation algorithm that not only detects DR in retinal images, but also automatically identifies glaucoma suspects and AMD by integrating other personal medical information with the retinal features. The proposed system is fully automatic and provides the likelihood of each of the three eye disease. The system was evaluated in two datasets of 104 and 88 diabetic cases. For each eye, we used two non-mydriatic digital color fundus photographs (macula and optic disc centered) and, when available, information about age, duration of diabetes, cataracts, hypertension, gender, and laboratory data. Our results show that the combination of multimodal features can increase the AUC by up to 5%, 7%, and 8% in the detection of AMD, DR, and glaucoma respectively. Marked improvement was achieved when laboratory results were combined with retinal image features.

Bilateral nongranulomatous uveitis with infective endocarditis.

PubMed

Ha, Sang Won; Shin, Jae Pil; Kim, Si Yeol; Park, Dong Ho

2013-02-01

A 32-year-old male who had infective endocarditis complained of photophobia and blurred vision in both eyes. Biomicroscopic examination and fundus examination revealed anterior chamber reaction, vitritis, optic disc swelling, and Roth spots. He was diagnosed with bilateral nongranulomatous uveitis and treated with topical steroid eye drops and posterior sub-Tenon injection of triamcinolone. His visual symptoms were resolved within 1 week, and inflammation resolved within 4 weeks after treatment.

Bilateral Nongranulomatous Uveitis with Infective Endocarditis

PubMed Central

Ha, Sang Won; Shin, Jae Pil; Kim, Si Yeol

2013-01-01

A 32-year-old male who had infective endocarditis complained of photophobia and blurred vision in both eyes. Biomicroscopic examination and fundus examination revealed anterior chamber reaction, vitritis, optic disc swelling, and Roth spots. He was diagnosed with bilateral nongranulomatous uveitis and treated with topical steroid eye drops and posterior sub-Tenon injection of triamcinolone. His visual symptoms were resolved within 1 week, and inflammation resolved within 4 weeks after treatment. PMID:23372383

High-Frequency Oscillations Recorded on the Scalp of Patients With Epilepsy Using Tripolar Concentric Ring Electrodes.

PubMed

Besio, Walter G; Martínez-Juárez, Iris E; Makeyev, Oleksandr; Gaitanis, John N; Blum, Andrew S; Fisher, Robert S; Medvedev, Andrei V

2014-01-01

Epilepsy is the second most prevalent neurological disorder ([Formula: see text]% prevalence) affecting [Formula: see text] million people worldwide with up to 75% from developing countries. The conventional electroencephalogram is plagued with artifacts from movements, muscles, and other sources. Tripolar concentric ring electrodes automatically attenuate muscle artifacts and provide improved signal quality. We performed basic experiments in healthy humans to show that tripolar concentric ring electrodes can indeed record the physiological alpha waves while eyes are closed. We then conducted concurrent recordings with conventional disc electrodes and tripolar concentric ring electrodes from patients with epilepsy. We found that we could detect high frequency oscillations, a marker for early seizure development and epileptogenic zone, on the scalp surface that appeared to become more narrow-band just prior to seizures. High frequency oscillations preceding seizures were present in an average of 35.5% of tripolar concentric ring electrode data channels for all the patients with epilepsy whose seizures were recorded and absent in the corresponding conventional disc electrode data. An average of 78.2% of channels that contained high frequency oscillations were within the seizure onset or irritative zones determined independently by three epileptologists based on conventional disc electrode data and videos.

Nerve Fiber Layer Thickness and Characteristics Associated with Glaucoma in Community Living Older Adults: Prelude to a Screening Trial?

PubMed

Klein, Barbara E K; Johnson, Chris A; Meuer, Stacy M; Lee, Kyungmoo; Wahle, Andreas; Lee, Kristine E; Kulkarni, Amruta; Sonka, Milan; Abràmoff, Michael D; Klein, Ronald

2017-04-01

To examine the associations of nerve fiber layer (NFL) thickness with other ocular characteristics in older adults. Participants in the Beaver Dam Eye Study (2008-2010) underwent spectral domain optical coherence tomography (SD-OCT) scans of the optic nerve head, imaging of optic discs, frequency doubling technology (FDT) perimetry, measurement of intraocular pressure (IOP), and an interview concerning their history of glaucoma and use of drops to lower eye pressure. Self-reported histories of glaucoma and the use of drops to lower eye pressure were obtained at follow-up examinations (2014-2016). NFL thickness measured on OCTs varied by location around the optic nerve. Age was associated with mean NFL thickness. Mean NFL was thinnest in eyes with larger cup/disc (C/D) ratios. Horizontal hemifield defects or other optic nerve-field defects were associated with thinner NFL. NFL in persons who reported taking eye drops for high intraocular pressure was thinner compared to those not taking drops. After accounting for the presence of high intraocular pressure, large C/D ratios or hemifield defects, eyes with thinner NFL in the arcades were more likely (OR = 2.3 for 30 micron thinner NFL, p = 0.04) to have incident glaucoma at examination 5 years later. Retinal NFL thickness was associated with a new history of self-reported glaucoma 5 years later. A trial testing the usefulness of NFL as part of a screening battery for predicting glaucoma in those previously undiagnosed might lead to improved case finding and, ultimately, to diminishing the risk of visual field loss.

Optical coherence tomography detects characteristic retinal nerve fiber layer thickness corresponding to band atrophy of the optic discs.

PubMed

Kanamori, Akiyasu; Nakamura, Makoto; Matsui, Noriko; Nagai, Azusa; Nakanishi, Yoriko; Kusuhara, Sentaro; Yamada, Yuko; Negi, Akira

2004-12-01

To analyze retinal nerve fiber layer (RNFL) thickness in eyes with band atrophy by use of optical coherence tomography (OCT) and to evaluate the ability of OCT to detect this characteristic pattern of RNFL loss. Cross-sectional, retrospective study. Thirty-four eyes of 18 patients with bitemporal hemianopia caused by optic chiasm compression by chiasmal tumors were studied. All eyes were divided into 3 groups according to visual field loss grading after Goldmann perimetry. Retinal nerve fiber layer thickness measurements with OCT. Retinal nerve fiber layer thickness around the optic disc was measured by OCT (3.4-mm diameter circle). Calculation of the changes in OCT parameters, including the horizontal (nasal + temporal quadrant RNFL thickness) and vertical values (superior + inferior quadrant RNFL thickness) was based on data from 160 normal eyes. Comparison between the 3 visual field grading groups was done with the analysis of variance test. The receiver operating characteristic (ROC) curve for the horizontal and vertical value were calculated, and the areas under the curve (AUC) were compared. Retinal nerve fiber layer thickness in eyes with band atrophy decreased in all OCT parameters. The reduction rate in average and temporal RNFL thickness and horizontal value was correlated with visual field grading. The AUC of horizontal value was 0.970+/-0.011, which was significantly different from AUC of vertical value (0.903+/-0.022). The degree of RNFL thickness reduction correlated with that of visual field defects. Optical coherence tomography was able to identify the characteristic pattern of RNFL loss in these eyes.

Choroid vascular occlusion and ischemic optic neuropathy after facial calcium hydroxyapatite injection- a case report.

PubMed

Chou, Chien-Chih; Chen, Hsin-Han; Tsai, Yi-Yu; Li, You-Ling; Lin, Hui-Ju

2015-03-08

We reported a case of sudden monocular vision loss after calcium hydroxyapatite (CaHA) injection into the nasal tip and dorsum with detailed retina images. A healthy, 35-year-old woman received CaHA filler injection for nose augmentation. Ten minutes after the procedure, she developed nausea, vomiting, headache, ptosis, and left periorbital pain. After 30 minutes, she complained of progressively blurring vision in the left eye. The best-corrected visual acuity (BCVA) in her left eye was 30 cm ahead of hand motion. Left exotropia was noted in primary gaze. Limitations in adduction, supraduction, and infraduction of the left eye were also observed. Slit lamp examination of the left eye revealed a pink conjunctiva, a clear cornea, a mild anterior chamber reaction, a sluggish papillary light reflex, and a semi-dilated pupil. A positive relative afferent pupillary defect was observed in the left eye. Fundus examination revealed optic disc edema and some linear whitish opacity over the superior and temporal sites in the left eye, suggesting multiple CaHA emboli in the choroid vessels. Although the majority of adverse reactions are mild and transient, surgeons should be alert about extremely rare serious adverse events such as visual loss.

Combining measurements from three anatomical areas for glaucoma diagnosis using Fourier-domain optical coherence tomography.

PubMed

Loewen, Nils A; Zhang, Xinbo; Tan, Ou; Francis, Brian A; Greenfield, David S; Schuman, Joel S; Varma, Rohit; Huang, David

2015-09-01

To improve the diagnostic power for glaucoma by combining measurements of peripapillary nerve fibre layer (NFL), macular ganglion cell complex (GCC) and disc variables obtained with Fourier-domain optical coherence tomography (FD-OCT) into the glaucoma structural diagnostic index (GSDI). In this observational, cross-sectional study of subjects from the Advanced Imaging of Glaucoma Study, GCC and NFL of healthy and perimetrical glaucoma subjects from four major academic referral centres of the Advanced Imaging of Glaucoma Study were mapped with the RTVue FD-OCT. Global loss volume and focal loss volume parameters were defined using NFL and GCC normative reference maps. Optimal weights for NFL, GCC and disc variables were combined using multivariate logistic regression to build the GSDI. Glaucoma severity was classified using the Enhanced Glaucoma Staging System (GSS2). Diagnostic accuracy was assessed by sensitivity, specificity and the area under the receiver operator characteristic curve (AUC). We analysed 118 normal eyes of 60 subjects, 236 matched eyes of 166 subjects with perimetrical glaucoma, and 105 eyes from a healthy reference group of 61 subjects. The GSDI included composite overall thickness and focal loss volume with weighted NFL and GCC components, as well as the vertical cup-to-disc ratio. The AUC of 0.922 from leave-one-out cross validation was better than the best component variable alone (p=0.047). The partial AUC in the high specificity region was also better (p=0.01), with a sensitivity of 69% at 99% specificity, and a sensitivity of 80.3% at 95% specificity. For GSS2 stages 3-5 the sensitivity was 98% at 99% specificity, and 100% at 95% specificity. Combining structural measurements of GCC, NFL and disc variables from FD-OCT created a GSDI that improved the accuracy for glaucoma diagnosis. NCT01314326. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Micropulse laser for persistent optic disc pit maculopathy. A case report.

PubMed

Valdés-Lara, Carlos Andrés; Crim, Nicolás; García-Aguirre, Gerardo; Lule, Ismael Ávila; Morales-Cantón, Virgilio

2018-06-01

Optic disc pits (ODP) are rare and congenital anomalies of the optic disc, sometimes remaining asymptomatic. However, serous macular detachment or optic disc maculopathy is the most common complication, causing significant visual deterioration, without a current consensus about treatment. We describe a case of ODP maculopathy that was treated successfully with micropulse laser. A patient with ODP maculopathy remained with macular serous detachment after nine months of follow up after pars plana vitrectomy. Subthreshold micropulse laser was used to treat macular serous detachment, achieving a significant improvement in central macular thickness after one session. Subthreshold micropulse laser is designed to stimulate the retinal pigment epithelium without damage to the photoreceptors, resulting in absorption of subretinal and intraretinal fluid. Macular serous detachment in patients with ODP requires a prompt diagnosis and treatment to avoid damage to photoreceptors. Subthreshold micropulse laser is a potential treatment for eyes with ODP and macular serous detachment complication.

Relationship Between Anterior Lamina Cribrosa Surface Tilt and Glaucoma Development in Myopic Eyes.

PubMed

Lee, Eun Jung; Han, Jong Chul; Kee, Changwon

2017-05-01

To evaluate the anterior lamina cribrosa (LC) surface tilt angle in myopic eyes and associate it with glaucoma development. In this retrospective study, medical records of myopic patients referred for glaucoma examination from July 1, 2012 to March 30, 2016 were reviewed. Comprehensive ophthalmic examination including spectral-domain optical coherence tomography were performed. We measured the angle of anterior LC surface tilt against Bruch's membrane opening from optical coherence tomography images at the center of the clinical optic disc margin. In horizontal and vertical sections, the angles were defined as α and β, respectively. Patients were grouped according to the presence of glaucomatous damage and factors including optic nerve head morphologic parameters and LC tilt angles were compared between the 2 groups. Among 138 patients originally enrolled, 102 patients were finally analyzed. One eye from 1 patient was randomly chosen. Fifty-five eyes had glaucoma and 47 were normal. The degree of myopia and all optic nerve head morphologic parameters were not significantly different between the 2 groups. However, |α| and |β| were significantly larger in the glaucoma group (all P<0.001), and significances were maintained in multivariate analysis (P<0.001). Larger anterior LC surface tilt angles were related to the presence of glaucoma in normal-pressure myopic eyes. Angulation of the LC against Bruch's membrane opening plane might be associated with increased glaucoma susceptibility in myopic eyes. Further investigations are warranted before clinical utilization of LC tilt as glaucoma susceptibility biomarker.

Notch-dependent epithelial fold determines boundary formation between developmental fields in the Drosophila antenna.

PubMed

Ku, Hui-Yu; Sun, Y Henry

2017-07-01

Compartment boundary formation plays an important role in development by separating adjacent developmental fields. Drosophila imaginal discs have proven valuable for studying the mechanisms of boundary formation. We studied the boundary separating the proximal A1 segment and the distal segments, defined respectively by Lim1 and Dll expression in the eye-antenna disc. Sharp segregation of the Lim1 and Dll expression domains precedes activation of Notch at the Dll/Lim1 interface. By repressing bantam miRNA and elevating the actin regulator Enable, Notch signaling then induces actomyosin-dependent apical constriction and epithelial fold. Disruption of Notch signaling or the actomyosin network reduces apical constriction and epithelial fold, so that Dll and Lim1 cells become intermingled. Our results demonstrate a new mechanism of boundary formation by actomyosin-dependent tissue folding, which provides a physical barrier to prevent mixing of cells from adjacent developmental fields.

Notch-dependent epithelial fold determines boundary formation between developmental fields in the Drosophila antenna

PubMed Central

2017-01-01

Compartment boundary formation plays an important role in development by separating adjacent developmental fields. Drosophila imaginal discs have proven valuable for studying the mechanisms of boundary formation. We studied the boundary separating the proximal A1 segment and the distal segments, defined respectively by Lim1 and Dll expression in the eye-antenna disc. Sharp segregation of the Lim1 and Dll expression domains precedes activation of Notch at the Dll/Lim1 interface. By repressing bantam miRNA and elevating the actin regulator Enable, Notch signaling then induces actomyosin-dependent apical constriction and epithelial fold. Disruption of Notch signaling or the actomyosin network reduces apical constriction and epithelial fold, so that Dll and Lim1 cells become intermingled. Our results demonstrate a new mechanism of boundary formation by actomyosin-dependent tissue folding, which provides a physical barrier to prevent mixing of cells from adjacent developmental fields. PMID:28708823

Improved separability of dipole sources by tripolar versus conventional disk electrodes: a modeling study using independent component analysis.

PubMed

Cao, H; Besio, W; Jones, S; Medvedev, A

2009-01-01

Tripolar electrodes have been shown to have less mutual information and higher spatial resolution than disc electrodes. In this work, a four-layer anisotropic concentric spherical head computer model was programmed, then four configurations of time-varying dipole signals were used to generate the scalp surface signals that would be obtained with tripolar and disc electrodes, and four important EEG artifacts were tested: eye blinking, cheek movements, jaw movements, and talking. Finally, a fast fixed-point algorithm was used for signal independent component analysis (ICA). The results show that signals from tripolar electrodes generated better ICA separation results than from disc electrodes for EEG signals with these four types of artifacts.

Genetic Interaction of Centrosomin and Bazooka in Apical Domain Regulation in Drosophila Photoreceptor

PubMed Central

Chen, Geng; Rogers, Alicia K.; League, Garrett P.; Nam, Sang-Chul

2011-01-01

Background Cell polarity genes including Crumbs (Crb) and Par complexes are essential for controlling photoreceptor morphogenesis. Among the Crb and Par complexes, Bazooka (Baz, Par-3 homolog) acts as a nodal component for other cell polarity proteins. Therefore, finding other genes interacting with Baz will help us to understand the cell polarity genes' role in photoreceptor morphogenesis. Methodology/Principal Findings Here, we have found a genetic interaction between baz and centrosomin (cnn). Cnn is a core protein for centrosome which is a major microtubule-organizing center. We analyzed the effect of the cnn mutation on developing eyes to determine its role in photoreceptor morphogenesis. We found that Cnn is dispensable for retinal differentiation in eye imaginal discs during the larval stage. However, photoreceptors deficient in Cnn display dramatic morphogenesis defects including the mislocalization of Crumbs (Crb) and Bazooka (Baz) during mid-stage pupal eye development, suggesting that Cnn is specifically required for photoreceptor morphogenesis during pupal eye development. This role of Cnn in apical domain modulation was further supported by Cnn's gain-of-function phenotype. Cnn overexpression in photoreceptors caused the expansion of the apical Crb membrane domain, Baz and adherens junctions (AJs). Conclusions/Significance These results strongly suggest that the interaction of Baz and Cnn is essential for apical domain and AJ modulation during photoreceptor morphogenesis, but not for the initial photoreceptor differentiation in the Drosophila photoreceptor. PMID:21253601

Effect of two different doses of intravitreal bevacizumab with temporal retina-sparing laser photocoagulation for retinopathy of prematurity.

PubMed

Choi, A Young; Cho, Hochan; Kim, Yu Cheol

2018-01-01

This study aims to compare the efficacy and safety between two different doses of intravitreal bevacizumab (IVB) injection with temporal retina-sparing laser (TRSL) photocoagulation for retinopathy of prematurity (ROP). We retrospectively evaluated 22 eyes of ROP infants who underwent IVB combined with partial TRSL for stage 3+ zone I or posterior zone II ROP. Laser photocoagulation was applied on the avascular retina, sparing two-disc-diameter width temporal avascular area anterior to ridge. A half dose (0.625 mg) or minimal dose (0.25 mg) of IVB was conducted. Four eyes in minimal dose group were retreated with IVB and laser photocoagulation on the spared retina. Of those 4 retreated eyes, three developed preretinal hemorrhage around the ridge after the first treatment, resulting in fibrotic macular dragging. A half dose of IVB may be more effective than a minimal dose with partial TRSL for ROP. Preretinal hemorrhage may be a harbinger of poor prognosis.

Persistent Asymmetric Optic Disc Swelling After Long-Duration Space Flight: Implications for Pathogenesis.

PubMed

Mader, Thomas H; Gibson, C Robert; Otto, Christian A; Sargsyan, Ashot E; Miller, Neil R; Subramanian, Prem S; Hart, Stephen F; Lipsky, William; Patel, Nimesh B; Lee, Andrew G

2017-06-01

Several ophthalmic findings including optic disc swelling, globe flattening and choroidal folds have been observed in astronauts following long-duration space flight. The authors now report asymmetric choroidal expansion, disc swelling and optic disc morphologic changes in a 45-year-old astronaut which occurred during long-duration space flight and persisted following his space mission. Case study of ocular findings in an astronaut documented during and after a long-duration space flight of approximately 6 months. Before, during and after his spaceflight, he underwent complete eye examination, including fundus photography, ultrasound, and optical coherence tomography. We documented asymmetric choroidal expansion inflight that largely resolved by 30 days postflight, asymmetric disc swelling observed inflight that persisted for over 180 days postflight, asymmetric optic disc morphologic changes documented inflight by OCT that persisted for 630 days postflight and asymmetric globe flattening that began inflight and continued 660 days postflight. Lumbar puncture opening pressures obtained at 7 and 365 days post-mission were 22 and 16 cm H20 respectively. The persistent asymmetric findings noted above, coupled with the lumbar puncture opening pressures, suggest that prolonged microgravity exposure may have produced asymmetric pressure changes within the perioptic subarachnoid space.

Automatic Detection of Optic Disc in Retinal Image by Using Keypoint Detection, Texture Analysis, and Visual Dictionary Techniques

PubMed Central

Bayır, Şafak

2016-01-01

With the advances in the computer field, methods and techniques in automatic image processing and analysis provide the opportunity to detect automatically the change and degeneration in retinal images. Localization of the optic disc is extremely important for determining the hard exudate lesions or neovascularization, which is the later phase of diabetic retinopathy, in computer aided eye disease diagnosis systems. Whereas optic disc detection is fairly an easy process in normal retinal images, detecting this region in the retinal image which is diabetic retinopathy disease may be difficult. Sometimes information related to optic disc and hard exudate information may be the same in terms of machine learning. We presented a novel approach for efficient and accurate localization of optic disc in retinal images having noise and other lesions. This approach is comprised of five main steps which are image processing, keypoint extraction, texture analysis, visual dictionary, and classifier techniques. We tested our proposed technique on 3 public datasets and obtained quantitative results. Experimental results show that an average optic disc detection accuracy of 94.38%, 95.00%, and 90.00% is achieved, respectively, on the following public datasets: DIARETDB1, DRIVE, and ROC. PMID:27110272

Detection of Progressive Retinal Nerve Fiber Layer Loss in Glaucoma Using Scanning Laser Polarimetry with Variable Corneal Compensation

PubMed Central

Medeiros, Felipe A.; Alencar, Luciana M.; Zangwill, Linda M.; Bowd, Christopher; Vizzeri, Gianmarco; Sample, Pamela A.; Weinreb, Robert N.

2010-01-01

Purpose To evaluate the ability of scanning laser polarimetry with variable corneal compensation to detect progressive retinal nerve fiber layer (RNFL) loss in glaucoma patients and patients suspected of having the disease. Methods This was an observational cohort study that included 335 eyes of 195 patients. Images were obtained annually with the GDx VCC scanning laser polarimeter, along with optic disc stereophotographs and standard automated perimetry (SAP) visual fields. The median follow-up time was 3.94 years. Progression was determined using commercial software for SAP and by masked assessment of optic disc stereophotographs performed by expert graders. Random coefficient models were used to evaluate the relationship between RNFL thickness measurements over time and progression as determined by SAP and/or stereophotographs. Results From the 335 eyes, 34 (10%) showed progression over time by stereophotographs and/or SAP. Average GDx VCC measurements decreased significantly over time for both progressors as well as non-progressors. However, the rate of decline was significantly higher in the progressing group (−0.70 μm/year) compared to the non-progressing group (−0.14 μm/year; P = 0.001). Black race and male sex were significantly associated with higher rates of RNFL loss during follow-up. Conclusions The GDx VCC scanning laser polarimeter was able to identify longitudinal RNFL loss in eyes that showed progression in optic disc stereophotographs and/or visual fields. These findings suggest that this technology could be useful to detect and monitor progressive disease in patients with established diagnosis of glaucoma or suspected of having the disease. PMID:19029038

Macular slippage after macular hole surgery with internal limiting membrane peeling.

PubMed

Nakagomi, Tomomi; Goto, Teruhiko; Tateno, Yasushi; Oshiro, Tomohiro; Iijima, Hiroyuki

2013-12-01

To describe macular slippage toward the optic disc after macular hole surgery with internal limiting membrane (ILM) peeling. A total of 27 eyes of 27 patients with idiopathic macular hole were included in this retrospective study. The fovea-to-disc distance (FDD) was measured from digital color fundus images before and at least six months after surgery. The position of the fovea was determined as the center of the macular hole before surgery and the center of the macular pigment area after surgery. The thickness of the nasal and temporal macula was measured using spectral-domain optical coherence tomography. The difference in thickness between the nasal and temporal macula was determined as the degree of parafoveal asymmetry (PFA). The postoperative FDD was significantly shorter than the preoperative FDD: 4.00 ± 0.33 mm and 3.82 ± 0.34 mm, respectively (p < 0.0001). The mean decreased ratio of FDD was 4.68% (range, 0.38-9.24%). The appearance of the dissociated optic nerve fiber layer (DONFL) was finally found in 21 eyes (78%). The decreased FDD ratio was significantly larger in eyes with the DONFL appearance than in those without it: 5.61 ± 1.74% and 1.44 ± 1.12%, respectively (p < 0.0001). The decreased ratio of FDD was correlated with the postoperative PFA (r = 0.63, p = 0.0004). A macula in which the ILM has peeled off would slip toward the optic disc after macular hole surgery. Macular slippage can be a reasonable cause for the macular alterations such as an appearance of DONFL and changes in asymmetrical parafoveal thickness.

Proteasome, but not autophagy, disruption results in severe eye and wing dysmorphia: a subunit- and regulator-dependent process in Drosophila.

PubMed

Velentzas, Panagiotis D; Velentzas, Athanassios D; Pantazi, Asimina D; Mpakou, Vassiliki E; Zervas, Christos G; Papassideri, Issidora S; Stravopodis, Dimitrios J

2013-01-01

Proteasome-dependent and autophagy-mediated degradation of eukaryotic cellular proteins represent the two major proteostatic mechanisms that are critically implicated in a number of signaling pathways and cellular processes. Deregulation of functions engaged in protein elimination frequently leads to development of morbid states and diseases. In this context, and through the utilization of GAL4/UAS genetic tool, we herein examined the in vivo contribution of proteasome and autophagy systems in Drosophila eye and wing morphogenesis. By exploiting the ability of GAL4-ninaE. GMR and P{GawB}Bx(MS1096) genetic drivers to be strongly and preferentially expressed in the eye and wing discs, respectively, we proved that proteasomal integrity and ubiquitination proficiency essentially control fly's eye and wing development. Indeed, subunit- and regulator-specific patterns of severe organ dysmorphia were obtained after the RNAi-induced downregulation of critical proteasome components (Rpn1, Rpn2, α5, β5 and β6) or distinct protein-ubiquitin conjugators (UbcD6, but not UbcD1 and UbcD4). Proteasome deficient eyes presented with either rough phenotypes or strongly dysmorphic shapes, while transgenic mutant wings were severely folded and carried blistered structures together with loss of vein differentiation. Moreover, transgenic fly eyes overexpressing the UBP2-yeast deubiquitinase enzyme were characterized by an eyeless-like phenotype. Therefore, the proteasome/ubiquitin proteolytic activities are undoubtedly required for the normal course of eye and wing development. In contrast, the RNAi-mediated downregulation of critical Atg (1, 4, 7, 9 and 18) autophagic proteins revealed their non-essential, or redundant, functional roles in Drosophila eye and wing formation under physiological growth conditions, since their reduced expression levels could only marginally disturb wing's, but not eye's, morphogenetic organization and architecture. However, Atg9 proved indispensable for the maintenance of structural integrity of adult wings in aged flies. In toto, our findings clearly demonstrate the gene-specific fundamental contribution of proteasome, but not autophagy, in invertebrate eye and wing organ development.

HD 169142 in the eyes of ZIMPOL/SPHERE

NASA Astrophysics Data System (ADS)

Bertrang, G. H.-M.; Avenhaus, H.; Casassus, S.; Montesinos, M.; Kirchschlager, F.; Perez, S.; Cieza, L.; Wolf, S.

2018-03-01

We present new data of the protoplanetary disc surrounding the Herbig Ae/Be star HD 169142 obtained in the very broad-band (VBB) with the Zurich imaging polarimeter (ZIMPOL), a subsystem of the Spectro-Polarimetric High-contrast Exoplanet REsearch instrument (SPHERE) at the Very Large Telescope (VLT). Our Polarimetric Differential Imaging (PDI) observations probe the disc as close as 0.03 arcsec (3.5 au) to the star and are able to trace the disc out to ˜1.08 arcsec (˜126 au). We find an inner hole, a bright ring bearing substructures around 0.18 arcsec (21 au), and an elliptically shaped gap stretching from 0.25 to 0.47 arcsec (29-55 au). Outside of 0.47 arcsec, the surface brightness drops off, discontinued only by a narrow annular brightness minimum at ˜0.63 to 0.74 arcsec (74-87 au). These observations confirm features found in less-well-resolved data as well as reveal yet undetected indications for planet-disc interactions, such as small-scale structures, star-disc offsets, and potentially moving shadows.

Asymmetric severity of diabetic retinopathy in Waardenburg syndrome.

PubMed

Kashima, Tomoyuki; Akiyama, Hideo; Kishi, Shoji

2011-01-01

A 30-year-old female patient was referred to our institution due to vitreous hemorrhage. Best corrected visual acuity of her right and left eyes at her initial visit was 10/20 and 20/20, respectively. Although hypochromic iris was observed in the superior iris between the 10 and 2 o'clock positions in her right eye, her entire left eye exhibited hypochromic iris. Hypopigmentation of the fundus was seen in the superior part of her right eye. This eye also had a huge neovascularization on the optic disc that was 7 discs in diameter. Conversely, her left fundi showed hypopigmentation of the fundus in the entire region of the left eye, and dot hemorrhages were observed all over the left fundi, although no neovascularization could be seen microscopically. Fluorescein angiography showed a huge neovascularization in the right eye and a tiny neovascularization in the left eye. Gene analysis revealed the presence of the PAX3 gene homeobox domain mutation, which led to her being diagnosed as Waardenburg syndrome type 1. Magnetic resonance angiography showed there was no obstructive region at either of the internal carotid arteries and ophthalmic arteries. The severity of the diabetic retinopathy appeared to be correlated with the degree of hypopigmentation in the posterior fundus. We speculate that hypopigmentation of the fundus in Waardenburg syndrome may be responsible for the reduction in retinal metabolism, which led to a reduction in oxygen consumption and prevented further aggravation of the diabetic retinopathy. Only laser treatments using short wavelengths was effective in this case. While the extinction coefficient for hemoglobin when using green light is higher than when using yellow light, the differences between these wavelengths tend to disappear when oxygenated hemoglobin is present. To the best of the authors' knowledge, this is the first case report of a patient with Waardenburg syndrome and diabetic retinopathy.

Eye tracking reveals the cost of switching between self and other perspectives in a visual perspective-taking task.

PubMed

Ferguson, Heather J; Apperly, Ian; Cane, James E

2017-08-01

Previous studies have shown that while people can rapidly and accurately compute their own and other people's visual perspectives, they experience difficulty ignoring the irrelevant perspective when the two perspectives differ. We used the "avatar" perspective-taking task to examine the mechanisms that underlie these egocentric (i.e., interference from their own perspective) and altercentric (i.e., interference from the other person's perspective) tendencies. Participants were eye-tracked as they verified the number of discs in a visual scene according to either their own or an on-screen avatar's perspective. Crucially in some trials the two perspectives were inconsistent (i.e., each saw a different number of discs), while in others they were consistent. To examine the effect of perspective switching, performance was compared for trials that were preceded with the same versus a different perspective cue. We found that altercentric interference can be reduced or eliminated when participants stick with their own perspective across consecutive trials. Our eye-tracking analyses revealed distinct fixation patterns for self and other perspective taking, suggesting that consistency effects in this paradigm are driven by implicit mentalizing of what others can see, and not automatic directional cues from the avatar.

Multicenter study of pars plana vitrectomy for optic disc pit maculopathy: MACPIT study.

PubMed

Avci, R; Kapran, Z; Ozdek, Ş; Teke, M Y; Oz, O; Guven, D; Yilmaz, S; Kaderli, B; Durukan, A H; Sobaci, G; Unver, Y B; Akduman, L; Kaynak, S; Dogan, I; Inan, U U

2017-09-01

PurposeTo evaluate surgical intervention with pars plana vitrectomy (PPV) for correction of optic disc pit maculopathy (ODP-M).Patients and methodsRetrospective chart review from 13 centres of 51 eyes of 50 patients with ODP-M who underwent PPV between 2002-2014. Anatomic and final best-corrected visual acuity (BCVA) outcomes were evaluated for all cases with different adjuvant techniques.ResultsThere were 23 males and 27 females with median age 25.5 (6-68) years. Preoperative median foveal thickness was 694.5 (331-1384) μm and improved to 252.5 (153-1405) μm. Median BCVA improved from 20/200 (20/20000 to 20/40) to 20/40 (20/2000 to 20/20) with 20/40 or better in 31 eyes. Complete retinal reattachment was achieved in 44 eyes (86.3%) at 7.1 (5.9) months. The good surgical outcomes were achieved in different adjuvant groups. Median follow-up was 24 (6 to 120) months.ConclusionsThese results confirm the long-term effectiveness of PPV for ODP-M. Prospective studies are needed to determine the effectiveness of any adjuvant technique in improving the success of PPV for ODP-M.

Anterior ischemic optic neuropathy after conventional coronary artery bypass graft surgery.

PubMed

Dorecka, Mariola; Miniewicz-Kurkowska, Joanna; Romaniuk, Dorota; Gajdzik-Gajdecka, Urszula; Wójcik-Niklewska, Bogumiła

2011-06-01

Perioperative optic neuropathy is a disease which can lead to serious, irreversible damage of vision. This complication could be the result of non-ocular surgery, for example, cardiac or spinal procedures. We present a case of anterior ischemic neuropathy (AION) which occurred following a conventional coronary artery bypass graft procedure. A 57-year-old man, 4 days after Conventional Coronary Artery Bypass Graft surgery as result of multi-vessel stabile coronary artery disease and history of anterolateral wall myocardial infarction, was admitted to the Eye Clinic due to significant loss of vision in his right eye. The patient had hypertension and was a heavy smoker. On admission, the slit lamp examination revealed a relative afferent pupillary defect in the right eye. The fundus examination showed optic disc edema with the presence of flame hemorrhages. Best corrected visual acuity (BCVA) was 0.02. The results of eye examination and fluorescein angiography confirmed the diagnosis of AION. Anti-aggregation and antithrombotic treatment was continued with steroids and vasodilators. After 7 days of this treatment we noticed the improvement of BCVA to 0.2. At 6-month follow-up, the vision was stable, and fundus examination revealed optic disc atrophy. After cardiac surgical operations, such as coronary artery bypass graft procedures, anterior ischemic optic neuropathy may occur. In those cases, close cooperation between the various specialists is necessary.

Optical Coherence Tomography Angiography of Optic Disc Perfusion in Glaucoma

PubMed Central

Jia, Yali; Wei, Eric; Wang, Xiaogang; Zhang, Xinbo; Morrison, John C.; Parikh, Mansi; Lombardi, Lori H.; Gattey, Devin M.; Armour, Rebecca L.; Edmunds, Beth; Kraus, Martin F.; Fujimoto, James G.; Huang, David

2014-01-01

Purpose To compare optic disc perfusion between normal and glaucoma subjects using optical coherence tomography (OCT) angiography and detect optic disc perfusion changes in glaucoma. Design Observational, cross-sectional study. Participants Twenty-four normal subjects and 11 glaucoma patients were included. Methods One eye of each subject was scanned by a high-speed 1050 nm wavelength swept-source OCT instrument. The split-spectrum amplitude-decorrelation angiography algorithm (SSADA) was used to compute three-dimensional optic disc angiography. A disc flow index was computed from four registered scans. Confocal scanning laser ophthalmoscopy (cSLO) was used to measure disc rim area, and stereo photography was used to evaluate cup/disc ratios. Wide field OCT scans over the discs were used to measure retinal nerve fiber layer (NFL) thickness. Main Outcome Measurements Variability was assessed by coefficient of variation (CV). Diagnostic accuracy was assessed by sensitivity and specificity. Comparisons between glaucoma and normal groups were analyzed by Wilcoxon rank-sum test. Correlations between disc flow index, structural assessments, and visual field (VF) parameters were assessed by linear regression. Results In normal discs, a dense microvascular network was visible on OCT angiography. This network was visibly attenuated in glaucoma subjects. The intra-visit repeatability, inter-visit reproducibility, and normal population variability of the optic disc flow index were 1.2%, 4.2%, and 5.0% CV respectively. The disc flow index was reduced by 25% in the glaucoma group (p = 0.003). Sensitivity and specificity were both 100% using an optimized cutoff. The flow index was highly correlated with VF pattern standard deviation (R2 = 0.752, p = 0.001). These correlations were significant even after accounting for age, cup/disc area ratio, NFL, and rim area. Conclusions OCT angiography, generated by the new SSADA algorithm, repeatably measures optic disc perfusion. OCT angiography could be useful in the evaluation of glaucoma and glaucoma progression. PMID:24629312

Glaucoma in high myopia and parapapillary delta zone

PubMed Central

Weber, Pascal; Nagaoka, Natsuko; Ohno-Matsui, Kyoko

2017-01-01

Purpose To examine the prevalence of glaucomatous optic neuropathy (GON) in a medium myopic to highly myopic group of patients and its association with parapapillary gamma zone and parapapillary delta zone. Methods The retrospective observational hospital-based study included patients who had attended the Tokyo High Myopia Clinics within January 2012 and December 2012 and for whom fundus photographs were available. GON was defined based on the appearance of the optic nerve head on the fundus photographs. Results The study included 519 eyes (262 individuals) with a mean age of 62.0±14.3 years (range:13–89 years) and mean axial length of 29.5±2.2 mm (range:23.2–35.3mm). GON was present in 141 (27.2%; 95% confidence intervals (CI): 23.3, 31.0%) eyes. Prevalence of GON increased from 12.2% (1.7, 22.7) in eyes with an axial length of <26.5mm to 28.5% (24.4, 32.5) in eyes with an axial length of ≥26.5mm, to 32.6% (27.9, 37.2) in eyes with an axial length of ≥28mm, to 36.0% (30.5, 41.4) in eyes with an axial length of ≥29mm, and GON prevalence increased to 42.1% (35.5, 48.8) in eyes with an axial length of ≥30mm. In multivariate analysis, higher GON prevalence was associated (Nagelkerke r2: 0.28) with larger parapapillary delta zone diameter (P<0.001; odds ratio (OR):1.86;95%CI:1.33,2.61), longer axial length (P<0.001;OR:1.45;95%CI:1.26,1.67) and older age (P = 0.01;OR:1.03;95%CI:1.01,1.05). If parapapillary delta zone width was replaced by the vertical disc diameter, higher GON prevalence was associated (r2:0.24) with larger vertical optic disc diameter (P = 0.04;OR:1.70;95%CI:1.03,2.81), after adjusting for longer axial length (P<0.001;OR:1.44;95%CI:1.26,1.64) and older age (P<0.001;OR:1.04;95%CI:1.02,1.06). Conclusions Axial elongation associated increase in GON prevalence (mean: 28.1% in a medium to highly myopic study population) was associated with parapapillary delta zone as surrogate for an elongated peripapillary scleral flange and with larger optic disc size. PMID:28380081

Post-Cataract Surgery Optic Neuropathy: Prevalence, Incidence, Temporal Relationship, and Fellow Eye Involvement.

PubMed

Moradi, Ahmadreza; Kanagalingam, Sivashakthi; Diener-West, Marie; Miller, Neil R

2017-03-01

To reassess the prevalence and incidence of post-cataract surgery optic neuropathy (PCSON) in the modern era. Retrospective cohort study. Setting: Single-center tertiary care practice. All patients with a diagnosis of nonarteritic anterior ischemic optic neuropathy (NAION) seen in the Wilmer Eye Network system between January 1, 2010 and December 31, 2014 were included. Inclusion was based on the following: (1) a history of an acute unilateral decrease in vision, (2) a visual field defect consistent with NAION, (3) a relative afferent pupillary defect, (4) observed optic disc swelling, and (5) no other etiology being found. The prevalence and incidence of PCSON and the temporal association between surgery and onset of PCSON. The secondary outcome was the risk of PCSON in the fellow eye of patients with prior unilateral spontaneous NAION. One hundred eighty-eight patients had developed NAION during the study period. Of these, 18 (9.6%) had undergone cataract surgery (CS) during the year prior to developing NAION. There was no significant temporal pattern associated with the distribution of NAION cases (P = .28). The incidence of PCSON in patients who had noncomplex CS was 10.9 cases per 100 000 (95% CI, 1.3, 39.4). Our data indicate that both the prevalence and incidence of NAION after modern CS are comparable to those of the general population and that there is no significant temporal relationship between modern CS and the subsequent development of NAION in the operated eye. Thus, although this study has inherent biases owing to its retrospective nature, concern regarding an increased risk of PCSON in the fellow eye in patients who have experienced it or spontaneous NAION in 1 eye may be unwarranted. Copyright © 2016 Elsevier Inc. All rights reserved.

Analysis of Fundus Photography and Fluorescein Angiography in Nonarteritic Anterior Ischemic Optic Neuropathy and Optic Neuritis.

PubMed

Kim, Min Kyung; Kim, Ungsoo Samuel

2016-08-01

We evaluated fundus and fluorescein angiography (FAG) findings and characteristics that can help distinguish nonarteritic anterior ischemic optic neuropathy (NAION) from optic neuritis (ON). Twenty-three NAION patients and 17 ON with disc swelling patients were enrolled in this study. We performed fundus photography and FAG. The disc-swelling pattern, hyperemia grade, presence of splinter hemorrhages, cotton-wool spots, artery/vein ratio and degree of focal telangiectasia were investigated. The FAG findings for each patient were compared with respect to the following features: the pattern of disc leakage in the early phase, arteriovenous (artery/vein) transit time (second), and the presence and pattern of the filling delay. Cotton-wool spots, focal telangiectasia, and venous congestion were more common in the affected eyes of NAION patients. Upon FAG, 76.5% of the patients in the ON group exhibited normal choroidal circulation. However, 56.5% of patients in the NAION group demonstrated abnormal filling defects, such as peripapillary, generalized, or watershed zone filling delays. Fundus findings, including cotton-wool spots, focal telangiectasia, and venous congestion in the affected eye, may be clues that can be used to diagnose NAION. In addition, choroidal insufficiencies on FAG could be also helpful in differentiating NAION from ON.

Proteasome, but Not Autophagy, Disruption Results in Severe Eye and Wing Dysmorphia: A Subunit- and Regulator-Dependent Process in Drosophila

PubMed Central

Pantazi, Asimina D.; Mpakou, Vassiliki E.; Zervas, Christos G.; Papassideri, Issidora S.; Stravopodis, Dimitrios J.

2013-01-01

Proteasome-dependent and autophagy-mediated degradation of eukaryotic cellular proteins represent the two major proteostatic mechanisms that are critically implicated in a number of signaling pathways and cellular processes. Deregulation of functions engaged in protein elimination frequently leads to development of morbid states and diseases. In this context, and through the utilization of GAL4/UAS genetic tool, we herein examined the in vivo contribution of proteasome and autophagy systems in Drosophila eye and wing morphogenesis. By exploiting the ability of GAL4-ninaE. GMR and P{GawB}BxMS1096 genetic drivers to be strongly and preferentially expressed in the eye and wing discs, respectively, we proved that proteasomal integrity and ubiquitination proficiency essentially control fly’s eye and wing development. Indeed, subunit- and regulator-specific patterns of severe organ dysmorphia were obtained after the RNAi-induced downregulation of critical proteasome components (Rpn1, Rpn2, α5, β5 and β6) or distinct protein-ubiquitin conjugators (UbcD6, but not UbcD1 and UbcD4). Proteasome deficient eyes presented with either rough phenotypes or strongly dysmorphic shapes, while transgenic mutant wings were severely folded and carried blistered structures together with loss of vein differentiation. Moreover, transgenic fly eyes overexpressing the UBP2-yeast deubiquitinase enzyme were characterized by an eyeless-like phenotype. Therefore, the proteasome/ubiquitin proteolytic activities are undoubtedly required for the normal course of eye and wing development. In contrast, the RNAi-mediated downregulation of critical Atg (1, 4, 7, 9 and 18) autophagic proteins revealed their non-essential, or redundant, functional roles in Drosophila eye and wing formation under physiological growth conditions, since their reduced expression levels could only marginally disturb wing’s, but not eye’s, morphogenetic organization and architecture. However, Atg9 proved indispensable for the maintenance of structural integrity of adult wings in aged flies. In toto, our findings clearly demonstrate the gene-specific fundamental contribution of proteasome, but not autophagy, in invertebrate eye and wing organ development. PMID:24282550

Gene duplication, tissue-specific gene expression and sexual conflict in stalk-eyed flies (Diopsidae).

PubMed

Baker, Richard H; Narechania, Apurva; Johns, Philip M; Wilkinson, Gerald S

2012-08-19

Gene duplication provides an essential source of novel genetic material to facilitate rapid morphological evolution. Traits involved in reproduction and sexual dimorphism represent some of the fastest evolving traits in nature, and gene duplication is intricately involved in the origin and evolution of these traits. Here, we review genomic research on stalk-eyed flies (Diopsidae) that has been used to examine the extent of gene duplication and its role in the genetic architecture of sexual dimorphism. Stalk-eyed flies are remarkable because of the elongation of the head into long stalks, with the eyes and antenna laterally displaced at the ends of these stalks. Many species are strongly sexually dimorphic for eyespan, and these flies have become a model system for studying sexual selection. Using both expressed sequence tag and next-generation sequencing, we have established an extensive database of gene expression in the developing eye-antennal imaginal disc, the adult head and testes. Duplicated genes exhibit narrower expression patterns than non-duplicated genes, and the testes, in particular, provide an abundant source of gene duplication. Within somatic tissue, duplicated genes are more likely to be differentially expressed between the sexes, suggesting gene duplication may provide a mechanism for resolving sexual conflict.

Gene duplication, tissue-specific gene expression and sexual conflict in stalk-eyed flies (Diopsidae)

PubMed Central

Baker, Richard H.; Narechania, Apurva; Johns, Philip M.; Wilkinson, Gerald S.

2012-01-01

Gene duplication provides an essential source of novel genetic material to facilitate rapid morphological evolution. Traits involved in reproduction and sexual dimorphism represent some of the fastest evolving traits in nature, and gene duplication is intricately involved in the origin and evolution of these traits. Here, we review genomic research on stalk-eyed flies (Diopsidae) that has been used to examine the extent of gene duplication and its role in the genetic architecture of sexual dimorphism. Stalk-eyed flies are remarkable because of the elongation of the head into long stalks, with the eyes and antenna laterally displaced at the ends of these stalks. Many species are strongly sexually dimorphic for eyespan, and these flies have become a model system for studying sexual selection. Using both expressed sequence tag and next-generation sequencing, we have established an extensive database of gene expression in the developing eye-antennal imaginal disc, the adult head and testes. Duplicated genes exhibit narrower expression patterns than non-duplicated genes, and the testes, in particular, provide an abundant source of gene duplication. Within somatic tissue, duplicated genes are more likely to be differentially expressed between the sexes, suggesting gene duplication may provide a mechanism for resolving sexual conflict. PMID:22777023

Ras promotes cell survival by antagonizing both JNK and Hid signals in the Drosophila eye.

PubMed

Wu, Yue; Zhuang, Yuan; Han, Min; Xu, Tian; Deng, Kejing

2009-10-20

Programmed cell death, or apoptosis, is a fundamental physiological process during normal development or in pathological conditions. The activation of apoptosis can be elicited by numerous signalling pathways. Ras is known to mediate anti-apoptotic signals by inhibiting Hid activity in the Drosophila eye. Here we report the isolation of a new loss-of-function ras allele, rasKP, which causes excessive apoptosis in the Drosophila eye. This new function is likely to be mediated through the JNK pathway since the inhibition of JNK signalling can significantly suppress rasKP-induced apoptosis, whereas the removal of hid only weakly suppresses the phenotype. Furthermore, the reduction of JNK signalling together with the expression of the baculovirus caspase inhibitor p35, which blocks Hid activity, strongly suppresses the rasKP cell death. In addition, we find a strong correlation between rasKP-induced apoptosis in the eye disc and the activation of JNK signalling. In the Drosophila eye, Ras may protect cells from apoptosis by inhibiting both JNK and Hid activities. Surprisingly, reducing Ras activity in the wing, however, does not cause apoptosis but rather affects cell and organ size. Thus, in addition to its requirement for cell viability, Ras appears to mediate different biological roles depending on the developmental context and on the level of its expression.

Unilateral Macular Star in a Case of Hypertension and Retinitis Pigmentosa.

PubMed

Chawla, Rohan; Tripathy, Koushik; Chaudhary, Sunil; Phuljhele, Swati; Venkatesh, Pradeep

2017-01-01

To describe a case of hypertension and retinitis pigmentosa presenting with a unilateral macular star. Case report. A 17-year-old female with chronic kidney disease and hypertension presented with a mild blurring of vision in the left eye. There was a history of night blindness. Both eyes had optic disc pallor, arteriolar attenuation, and peripheral bony spicules suggestive of the triad of retinitis pigmentosa. Macular star was seen in the left eye alone. We ascribe the macular star to hypertension as the patient had only a mild decrease in vision, no relative afferent pupillary defect, and similar visual evoked response amplitude and latency in both eyes. Unilateral macular star may be seen in hypertension and may simulate neuroretinitis in the clinical setting.

Automatic classification of pathological myopia in retinal fundus images using PAMELA

NASA Astrophysics Data System (ADS)

Liu, Jiang; Wong, Damon W. K.; Tan, Ngan Meng; Zhang, Zhuo; Lu, Shijian; Lim, Joo Hwee; Li, Huiqi; Saw, Seang Mei; Tong, Louis; Wong, Tien Yin

2010-03-01

Pathological myopia is the seventh leading cause of blindness. We introduce a framework based on PAMELA (PAthological Myopia dEtection through peripapilLary Atrophy) for the detection of pathological myopia from fundus images. The framework consists of a pre-processing stage which extracts a region of interest centered on the optic disc. Subsequently, three analysis modules focus on detecting specific visual indicators. The optic disc tilt ratio module gives a measure of the axial elongation of the eye through inference from the deformation of the optic disc. In the texturebased ROI assessment module, contextual knowledge is used to demarcate the ROI into four distinct, clinically-relevant zones in which information from an entropy transform of the ROI is analyzed and metrics generated. In particular, the preferential appearance of peripapillary atrophy (PPA) in the temporal zone compared to the nasal zone is utilized by calculating ratios of the metrics. The PPA detection module obtains an outer boundary through a level-set method, and subtracts this region against the optic disc boundary. Temporal and nasal zones are obtained from the remnants to generate associated hue and color values. The outputs of the three modules are used as in a SVM model to determine the presence of pathological myopia in a retinal fundus image. Using images from the Singapore Eye Research Institute, the proposed framework reported an optimized accuracy of 90% and a sensitivity and specificity of 0.85 and 0.95 respectively, indicating promise for the use of the proposed system as a screening tool for pathological myopia.

Optical coherence tomography in papilledema and pseudopapilledema with and without optic nerve head drusen.

PubMed

Bassi, Shikha Talwar; Mohana, Kuppuswamy Parthasarthy

2014-12-01

To compare the spectral domain optical coherence tomography (SD-OCT) findings of the optic disc and the peripapillary retina of patients with a true papilledema and pseudopapilledema with and without optic nerve head drusen (ONHD). Retrospective Case Control Study. Peripapillary retinal nerve fiber layer (PPRNFL) thickness as depicted by SD-OCT of 94 eyes of 66 patients with papilledema (30 eyes), pseudopapiledema (31 eyes), and normal controls (33 eyes) was analyzed. The mean RNFL thickness, total retinal thickness (TRT) at a superior and inferior edge of the disc and the quadrant wise topography of increased RNFL were compared in all three groups. Sensitivity, specificity, and area under the receiver operating characteristic curve (AROC) were calculated for all the parameters. The median RNFL thickness was 185.4 (129.5-349.3 μm), 122.3 (109-156.3 μm) and 91.62 ± 7 μm in papilledema, pseudopapilledema, and controls, respectively. Papilledema group had thicker PPRNFL in all quadrants except temporal quadrant. TRT was thicker in papilledema and pseudopapilledema compared to controls. ONHD could be directly visualized as high reflective clumps in the sub-retinal space or the RNFL in 30 eyes. Increased RNFL thickness in all four quadrants was noted 43.3% in papilledema and 9.7% in pseudopapilledema. Normal RNFL thickness in all four quadrants was noted in 0% in papilledema and 32.3% in pseudopapilledema. Nasal RNFL had the highest AROC (0.792) indicating high diagnostic ability to differentiate papilledema from pseudopapilledema. SD-OCT can be used as a tool to differentiate between papilledema and pseudopapilledema.

Progression of Local Glaucomatous Damage Near Fixation as Seen with Adaptive Optics Imaging.

PubMed

Hood, Donald C; Lee, Dongwon; Jarukasetphon, Ravivarn; Nunez, Jason; Mavrommatis, Maria A; Rosen, Richard B; Ritch, Robert; Dubra, Alfredo; Chui, Toco Y P

2017-07-01

Deep glaucomatous defects near fixation were followed over time with an adaptive optics-scanning light ophthalmoscope (AO-SLO) to better understand the progression of these defects and to explore the use of AO-SLO in detecting them. Six eyes of 5 patients were imaged with an AO-SLO from 2 to 4 times for a range of 14.6 to 33.6 months. All eyes had open-angle glaucoma with deep defects in the superior visual field (VF) near fixation as defined by 10-2 VFs with 5 or more points less than -15 dB; two of the eyes had deep defects in the inferior VF as well. AO-SLO images were obtained around the temporal edge of the disc. In 4 of the 6 eyes, the edge of the inferior-temporal disc region of the retinal nerve fiber (RNF) defect seen on AO-SLO moved closer to fixation within 10.6 to 14.7 months. In 4 eyes, RNF bundles in the affected region appeared to lose contrast and/or disappear. Progressive changes in RNF bundles associated with deep defects on 10-2 VFs can be seen within about 1 year with AO-SLO imaging. These changes are well below the spatial resolution of the 10-2 VF. On the other hand, subtle thinning of regions with RNF bundles is not easy to see with current AO-SLO technology, and may be better followed with OCT. AO-SLO imaging may be useful in clinical trials designed to see very small changes in deep defects.

Population and High-Risk Group Screening for Glaucoma: The Los Angeles Latino Eye Study

PubMed Central

Francis, Brian A.; Vigen, Cheryl; Lai, Mei-Ying; Winarko, Jonathan; Nguyen, Betsy; Azen, Stanley

2011-01-01

Purpose. To evaluate the ability of various screening tests, both individually and in combination, to detect glaucoma in the general Latino population and high-risk subgroups. Methods. The Los Angeles Latino Eye Study is a population-based study of eye disease in Latinos 40 years of age and older. Participants (n = 6082) underwent Humphrey visual field testing (HVF), frequency doubling technology (FDT) perimetry, measurement of intraocular pressure (IOP) and central corneal thickness (CCT), and independent assessment of optic nerve vertical cup disc (C/D) ratio. Screening parameters were evaluated for three definitions of glaucoma based on optic disc, visual field, and a combination of both. Analyses were also conducted for high-risk subgroups (family history of glaucoma, diabetes mellitus, and age ≥65 years). Sensitivity, specificity, and receiver operating characteristic curves were calculated for those continuous parameters independently associated with glaucoma. Classification and regression tree (CART) analysis was used to develop a multivariate algorithm for glaucoma screening. Results. Preset cutoffs for screening parameters yielded a generally poor balance of sensitivity and specificity (sensitivity/specificity for IOP ≥21 mm Hg and C/D ≥0.8 was 0.24/0.97 and 0.60/0.98, respectively). Assessment of high-risk subgroups did not improve the sensitivity/specificity of individual screening parameters. A CART analysis using multiple screening parameters—C/D, HVF, and IOP—substantially improved the balance of sensitivity and specificity (sensitivity/specificity 0.92/0.92). Conclusions. No single screening parameter is useful for glaucoma screening. However, a combination of vertical C/D ratio, HVF, and IOP provides the best balance of sensitivity/specificity and is likely to provide the highest yield in glaucoma screening programs. PMID:21245400

Factors affecting the sensitivity and specificity of the Heidelberg Retina Tomograph parameters to glaucomatous progression in disc photographs.

PubMed

Saarela, Ville; Falck, Aura; Airaksinen, P Juhani; Tuulonen, Anja

2012-03-01

To evaluate the factors affecting the sensitivity and specificity of the stereometric optic nerve head (ONH) parameters of the Heidelberg Retina Tomograph (HRT) to glaucomatous progression in stereoscopic ONH photographs. The factors affecting the sensitivity and specificity of the vertical cup : disc ratio, the cup : disc area ratio, the cup volume, the rim area and a linear discriminant function to progression were analysed. These parameters were the best indicators of progression in a retrospective study of 476 eyes. The reference standard for progression was the masked evaluation of stereoscopic ONH photographs. The factors having the most significant effect on the sensitivity and specificity of the stereometric ONH parameters were the reference height difference and the mean topography standard deviation (TSD), indicating image quality. Also, the change in the TSD and age showed consistent, but variably significant, influence on all parameters tested. The sensitivity and specificity improved when there was little change in the reference height, the image quality was good and stable, and the patients were younger. The sensitivity and specificity of the vertical cup : disc ratio was improved by a large disc area and high baseline cup : disc area ratio. The rim area showed a better sensitivity and specificity for progression with a small disc area and low baseline cup : disc area ratio. The factors affecting the sensitivity and specificity of the stereometric ONH parameters to glaucomatous progression in disc photographs are essentially the same as those affecting the measurement variability of the HRT. © 2010 The Authors. Acta Ophthalmologica © 2010 Acta Ophthalmologica Scandinavica Foundation.

Calibration of strontium-90 eye applicator using a strontium external beam standard.

PubMed

Siddle, D; Langmack, K

1999-07-01

Four techniques for measuring the dose rate from Sr-90 concave eye plaques are presented. The techniques involve calibrating a concave eye plaque against a Sr-90 teletherapy unit using X-Omat film, radiochromic film, black LiF TLD discs and LiF chips. The mean dose rate predicted by these dosimeters is 7.5 cGy s(-1). The dose rate quoted by the manufacturer is 33% lower than this value, which is consistent with discrepancies reported by other authors. Calibration against a 6 MV linear accelerator was also carried out using each of the above dosimetric devices, and appropriate sensitivity correction factors have been presented.

Calibration of strontium-90 eye applicator using a strontium external beam standard

NASA Astrophysics Data System (ADS)

Siddle, D.; Langmack, K.

1999-07-01

Four techniques for measuring the dose rate from Sr-90 concave eye plaques are presented. The techniques involve calibrating a concave eye plaque against a Sr-90 teletherapy unit using X-Omat film, radiochromic film, black LiF TLD discs and LiF chips. The mean dose rate predicted by these dosimeters is 7.5 cGy s-1. The dose rate quoted by the manufacturer is 33% lower than this value, which is consistent with discrepancies reported by other authors. Calibration against a 6 MV linear accelerator was also carried out using each of the above dosimetric devices, and appropriate sensitivity correction factors have been presented.

Evaluation of Macular Ganglion Cell Complex and Peripapillary Retinal Nerve Fiber Layer in Primary Craniopharyngioma by Fourier-Domain Optical Coherence Tomography.

PubMed

Yang, Liu; Qu, Yuanzhen; Lu, Wen; Liu, Fengjun

2016-07-03

BACKGROUND The aim of this study was to compare the differences in macular ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (pRNFL) in child and adult patients with primary craniopharyngioma by Fourier-domain optical coherence tomography (FD-OCT) and to evaluate their significance in the diagnosis of primary craniopharyngioma. MATERIAL AND METHODS Ninety-six participants were divided into 3 groups: 32 in the child craniopharyngioma group (CCG) and 32 in the adult craniopharyngioma group (ACG) who were treated in Beijing Tiantan Hospital between November 2013 and October 2014, and 32 in the normal group (NG). All subjects were scanned by FD-OCT to map GCC and pRNFL thicknesses. Spearman correlation coefficient was used to assess the correlation between GCC and pRNFL thickness, and pRNFL thickness and optic nerve head (ONH) parameters, including horizontal cup-disc ratio (HCDR), vertical cup-disc ratio (VCDR), optic disc area (ODA), and cup area (CA), respectively. RESULTS The correlation between GCC and pRNFL thickness in the CCG was slightly stronger compared with the ACG. A significant difference in GCC thickness was observed among the CCG, ACG, and NG. Although the pRNFL thickness in both the CCG and ACG was significantly higher than that in NG, no significant difference in pRNFL thickness was detected between the 2 craniopharyngioma groups. The average, superior, and inferior pRNFL thicknesses were negatively correlated with VCDR in the CCG (in double eyes) and ACG (only in left eyes). CONCLUSIONS GCC was more sensitive than pRNFL in detecting optic nerve damage in the eyes of craniopharyngioma patients. A thinner pRNFL was especially correlated with VCDR in child craniopharyngioma patients.

Evaluation of Macular Ganglion Cell Complex and Peripapillary Retinal Nerve Fiber Layer in Primary Craniopharyngioma by Fourier-Domain Optical Coherence Tomography

PubMed Central

Yang, Liu; Qu, Yuanzhen; Lu, Wen; Liu, Fengjun

2016-01-01

Background The aim of this study was to compare the differences in macular ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (pRNFL) in child and adult patients with primary craniopharyngioma by Fourier-domain optical coherence tomography (FD-OCT) and to evaluate their significance in the diagnosis of primary craniopharyngioma. Material/Methods Ninety-six participants were divided into 3 groups: 32 in the child craniopharyngioma group (CCG) and 32 in the adult craniopharyngioma group (ACG) who were treated in Beijing Tiantan Hospital between November 2013 and October 2014, and 32 in the normal group (NG). All subjects were scanned by FD-OCT to map GCC and pRNFL thicknesses. Spearman correlation coefficient was used to assess the correlation between GCC and pRNFL thickness, and pRNFL thickness and optic nerve head (ONH) parameters, including horizontal cup-disc ratio (HCDR), vertical cup-disc ratio (VCDR), optic disc area (ODA), and cup area (CA), respectively. Results The correlation between GCC and pRNFL thickness in the CCG was slightly stronger compared with the ACG. A significant difference in GCC thickness was observed among the CCG, ACG, and NG. Although the pRNFL thickness in both the CCG and ACG was significantly higher than that in NG, no significant difference in pRNFL thickness was detected between the 2 craniopharyngioma groups. The average, superior, and inferior pRNFL thicknesses were negatively correlated with VCDR in the CCG (in double eyes) and ACG (only in left eyes). Conclusions GCC was more sensitive than pRNFL in detecting optic nerve damage in the eyes of craniopharyngioma patients. A thinner pRNFL was especially correlated with VCDR in child craniopharyngioma patients. PMID:27372909

Nemo regulates cell dynamics and represses the expression of miple, a midkine/pleiotrophin cytokine, during ommatidial rotation

PubMed Central

Muñoz-Soriano, Verónica; Ruiz, Carlos; Pérez-Alonso, Manuel; Mlodzik, Marek; Paricio, Nuria

2013-01-01

Ommatidial rotation is one of the most important events for correct patterning of the Drosophila eye. Although several signaling pathways are involved in this process, few genes have been shown to specifically affect it. One of them is nemo (nmo), which encodes a MAP-like protein kinase that regulates the rate of rotation throughout the entire process, and serves as a link between core planar cell polarity (PCP) factors and the E-cadherin–β-catenin complex. To determine more precisely the role of nmo in ommatidial rotation, live-imaging analyses in nmo mutant and wild-type early pupal eye discs were performed. We demonstrate that ommatidial rotation is not a continuous process, and that rotating and non-rotating interommatidial cells are very dynamic. Our in vivo analyses also show that nmo regulates the speed of rotation and is required in cone cells for correct ommatidial rotation, and that these cells as well as interommatidial cells are less dynamic in nmo mutants. Furthermore, microarray analyses of nmo and wild-type larval eye discs led us to identify new genes and signaling pathways related to nmo function during this process. One of them, miple, encodes the Drosophila ortholog of the midkine/pleiotrophin secreted cytokines that are involved in cell migration processes. miple is highly up-regulated in nmo mutant discs. Indeed, phenotypic analyses reveal that miple overexpression leads to ommatidial rotation defects. Genetic interaction assays suggest that miple is signaling through Ptp99A, the Drosophila ortholog of the vertebrate midkine/pleiotrophin PTPζ receptor. Accordingly, we propose that one of the roles of Nmo during ommatial rotation is to repress miple expression, which may in turn affect the dynamics in E-cadherin–β-catenin complexes. PMID:23428616

Optometry-based general population survey of pupil ruff atrophy and ocular hypertension.

PubMed

Ang, Ghee S; Stevenson, Peter J; Sargent, Geoff; Grimmer, Peter; Corbett, Patricia; Jourdain, Erin; Wells, Anthony P

2013-01-01

To evaluate and describe the pupil ruff changes and relationship to intraocular pressure, pseudoexfoliation syndrome and glaucoma status in an optometric population in New Zealand. Prospective cross-sectional survey of an optometric population. Six hundred and twenty subjects over 50 years old routinely attending the participating optometry practices. Exclusion criteria included previous intraocular surgery, ophthalmic laser, uveitis, angle closure and secondary glaucoma. Multicentre study involving 11 optometry practices in the Wellington region, New Zealand. The pupillary ruff and associated gonioscopy findings of study participants were graded based on the previously published Pupil Ruff Atrophy grading system. Parameters evaluated include pupillary ruff absence and abnormality, pseudoexfoliation material and trabecular meshwork pigmentation. Correlations between intereye Pupil Ruff Atrophy grading differences and inter-eye intraocular pressure and cup:disc ratio differences. Six hundred and twenty subjects were included, with a mean age of 62.2 ± 9.1 years and mean intraocular pressure of 14.8 ± 3.4 mmHg. Four hundred and fourteen (66.8%) had bilateral pupil ruff changes and 12 (1.5%) had pseudoexfoliation. Inter-eye intraocular pressure asymmetry was significantly correlated with amount of missing pupillary ruff (r = 0.111; P = 0.022) and trabecular meshwork pigmentation (r = 0.147; P = 0.002). Inter-eye cup:disc ratio asymmetry was not correlated with any of the Pupil Ruff Atrophy grading parameters. Asymmetry of pupillary ruff absence and trabecular meshwork pigmentation was correlated with intraocular pressure asymmetry (but not with cup:disc ratio asymmetry) in a general optometric population setting in New Zealand. © 2012 The Authors. Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.

The BTB-zinc Finger Transcription Factor Abrupt Acts as an Epithelial Oncogene in Drosophila melanogaster through Maintaining a Progenitor-like Cell State

PubMed Central

Turkel, Nezaket; Sahota, Virender K.; Bolden, Jessica E.; Goulding, Karen R.; Doggett, Karen; Willoughby, Lee F.; Blanco, Enrique; Martin-Blanco, Enrique; Corominas, Montserrat; Ellul, Jason; Aigaki, Toshiro; Richardson, Helena E.; Brumby, Anthony M.

2013-01-01

The capacity of tumour cells to maintain continual overgrowth potential has been linked to the commandeering of normal self-renewal pathways. Using an epithelial cancer model in Drosophila melanogaster, we carried out an overexpression screen for oncogenes capable of cooperating with the loss of the epithelial apico-basal cell polarity regulator, scribbled (scrib), and identified the cell fate regulator, Abrupt, a BTB-zinc finger protein. Abrupt overexpression alone is insufficient to transform cells, but in cooperation with scrib loss of function, Abrupt promotes the formation of massive tumours in the eye/antennal disc. The steroid hormone receptor coactivator, Taiman (a homologue of SRC3/AIB1), is known to associate with Abrupt, and Taiman overexpression also drives tumour formation in cooperation with the loss of Scrib. Expression arrays and ChIP-Seq indicates that Abrupt overexpression represses a large number of genes, including steroid hormone-response genes and multiple cell fate regulators, thereby maintaining cells within an epithelial progenitor-like state. The progenitor-like state is characterised by the failure to express the conserved Eyes absent/Dachshund regulatory complex in the eye disc, and in the antennal disc by the failure to express cell fate regulators that define the temporal elaboration of the appendage along the proximo-distal axis downstream of Distalless. Loss of scrib promotes cooperation with Abrupt through impaired Hippo signalling, which is required and sufficient for cooperative overgrowth with Abrupt, and JNK (Jun kinase) signalling, which is required for tumour cell migration/invasion but not overgrowth. These results thus identify a novel cooperating oncogene, identify mammalian family members of which are also known oncogenes, and demonstrate that epithelial tumours in Drosophila can be characterised by the maintenance of a progenitor-like state. PMID:23874226

A morphological study of amblyopic eyes in children failing to achieve normal visual acuity after electronically monitored long-term occlusion treatment.

PubMed

Kuhli-Hattenbach, Claudia; Koss, Michael Janusz; Kohnen, Thomas; Fronius, Maria

2015-11-01

To search for morphological abnormalities in compliant unilaterally amblyopic children with poor occlusion treatment outcomes, for the first time with electronically recorded patching dosage. We included school children with remaining interocular logMAR (logarithm of the minimum angle of resolution) difference ≥ 0.3 after patching time of more than 22 months and 1300 h total in a previous prospective study. Six patients with a mean age of 11.19 years were included. Four patients had anisometropic amblyopia and two patients had a mixed strabismic and anisometropic amblyopia. Best-corrected visual acuity, cycloplegic refraction, dilated fundus examination, optic disc morphology and macular thickness using optical coherence tomography (OCT), retinal visual acuity, color perception, and the presence of a relative afferent pupillary defect (RAPD) were assessed. Paired t tests were performed to compare optic disc values and macular thickness of the amblyopic eyes to those of the fellow eyes. Average (± SD) logMAR VA in the amblyopic eyes was 0.42 (±0.23) with a remaining average interocular difference (IOD) of 0.51 (± 0.23), despite electronically monitored occlusion treatment of more than 1300 h. All patients presented with hyperopia and a significantly different mean spherical equivalent of + 4.73 (± 2.73) D in the amblyopic eye compared with the fellow eye (p = 0.02). A statistically significant difference in macular thickness was found between amblyopic and fellow eyes, with amblyopic eyes having an increased average thickness (p = 0.0062) and total volume (p = 0.0091) of the macula. One patient had familial hereditary primary macrodisc in both eyes. Our results provide evidence that average macular thickness and total macular volume tended to be increased among these compliant amblyopic children with unsatisfactory occlusion treatment outcomes. Further studies are warranted to evaluate whether morphological changes may have an impact on the effectiveness of amblyopia treatment. Moreover, our findings suggest that greater magnitude of hyperopia and anisometropia as well as older age may be risk factors associated with a poor visual acuity outcome among compliant amblyopic children.

Open angle glaucoma in a case of Type IV Ehler Danlos syndrome: A rarely reported association

PubMed Central

Mitra, Arijit; Ramakrishnan, R.; Kader, Mohideen Abdul

2014-01-01

A 26-year-old male presented to us with defective vision in the left eye. He had best corrected visual acuity (BCVA) of hand movement (HM) in right eye and 6/9 in left eye. He had ptosis with ectropion in both eyes and relative afferent pupillary defect (RAPD) in right eye. Intraocular pressure (IOP) was 46 and 44 mmHg in right and left eye, respectively. Fundus showed glaucomatous optic atrophy (GOA) in right eye and cup disc ratio (CDR) of 0.75 with bipolar rim thinning in left eye. Systemic examination showed hyperextensible skin and joints, acrogeria, hypodontia, high arched palate, and varicose veins. He gave history of easy bruising and tendency to fall and history of intestinal rupture 5 years ago for which he had undergone surgery. He was diagnosed as a case of Type IV Ehler-Danlos syndrome (EDS) with open angle glaucoma. He underwent trabeculectomy in both eyes. This is a rare case that shows glaucoma in a patient of EDS Type IV. Very few such cases have been reported in literature. PMID:25230966

Open angle glaucoma in a case of Type IV Ehler Danlos syndrome: a rarely reported association.

PubMed

Mitra, Arijit; Ramakrishnan, R; Kader, Mohideen Abdul

2014-08-01

A 26-year-old male presented to us with defective vision in the left eye. He had best corrected visual acuity (BCVA) of hand movement (HM) in right eye and 6/9 in left eye. He had ptosis with ectropion in both eyes and relative afferent pupillary defect (RAPD) in right eye. Intraocular pressure (IOP) was 46 and 44 mmHg in right and left eye, respectively. Fundus showed glaucomatous optic atrophy (GOA) in right eye and cup disc ratio (CDR) of 0.75 with bipolar rim thinning in left eye. Systemic examination showed hyperextensible skin and joints, acrogeria, hypodontia, high arched palate, and varicose veins. He gave history of easy bruising and tendency to fall and history of intestinal rupture 5 years ago for which he had undergone surgery. He was diagnosed as a case of Type IV Ehler-Danlos syndrome (EDS) with open angle glaucoma. He underwent trabeculectomy in both eyes. This is a rare case that shows glaucoma in a patient of EDS Type IV. Very few such cases have been reported in literature.

Dual Role of Jun N-Terminal Kinase Activity in Bone Morphogenetic Protein-Mediated Drosophila Ventral Head Development.

PubMed

Park, Sung Yeon; Stultz, Brian G; Hursh, Deborah A

2015-12-01

The Drosophila bone morphogenetic protein encoded by decapentaplegic (dpp) controls ventral head morphogenesis by expression in the head primordia, eye-antennal imaginal discs. These are epithelial sacs made of two layers: columnar disc proper cells and squamous cells of the peripodial epithelium. dpp expression related to head formation occurs in the peripodial epithelium; cis-regulatory mutations disrupting this expression display defects in sensory vibrissae, rostral membrane, gena, and maxillary palps. Here we document that disruption of this dpp expression causes apoptosis in peripodial cells and underlying disc proper cells. We further show that peripodial Dpp acts directly on the disc proper, indicating that Dpp must cross the disc lumen to act. We demonstrate that palp defects are mechanistically separable from the other mutant phenotypes; both are affected by the c-Jun N-terminal kinase pathway but in opposite ways. Slight reduction of both Jun N-terminal kinase and Dpp activity in peripodial cells causes stronger vibrissae, rostral membrane, and gena defects than Dpp alone; additionally, strong reduction of Jun N-terminal kinase activity alone causes identical defects. A more severe reduction of dpp results in similar vibrissae, rostral membrane, and gena defects, but also causes mutant maxillary palps. This latter defect is correlated with increased peripodial Jun N-terminal kinase activity and can be caused solely by ectopic activation of Jun N-terminal kinase. We conclude that formation of sensory vibrissae, rostral membrane, and gena tissue in head morphogenesis requires the action of Jun N-terminal kinase in peripodial cells, while excessive Jun N-terminal kinase signaling in these same cells inhibits the formation of maxillary palps. Copyright © 2015 by the Genetics Society of America.

Fundal variations in the eyes of the osteoglossomorph fishes.

PubMed

Saidel, W M; Braford, M R

1985-01-01

The appearance of the fundus of the eye varies among the families of osteoglossomorph teleosts. In this study, four different fundal patterns were observed: (i) an anteroposterior (or horizontal) embryonic fissure with a septal falciform process (family Osteoglossidae); (ii) an embryonic fissure from the optic disc nasoventrally with a falciform process (family Arapaimidae); (iii) an embryonic fissure nasoventrally from the optic disc without a falciform process (family Hiodontidae); and (iv) neither an embryonic fissure nor a falciform process (families Notopteridae and Mormyridae). The distribution of these various forms among the osteoglossomorph fishes is consistent with the recent cladogram for the Osteoglossomorpha [Lauder and Liem, 1983] which was based on many characters. The embryonic fissure in adult Amia calva was also examined. Its existence in adult Amia, in most Osteoglossomorpha, and in many non-euteleostean bony fishes suggests that its persistence in the adult stage is a primitive trait of bony fishes, and its absence in the Notopteroidei (with the exception of Hiodon) is a derived condition.

Myopic keratomileusis by excimer laser on a lathe.

PubMed

Ganem, S; Aron-Rosa, D; Gross, M; Rosolen, S

1994-01-01

We designed an excimer laser keratomileusis delivery system to increase the regularity of the refractive cut surface and allow greater precision in the level and shape of the ablated zone. A parallel faced corneal disc was produced by microkeratectomy from six human eyes and surgical keratectomy in 12 beagle corneas. A 193-nanometer excimer laser that was used to project an oval beam onto the corneal disc was rotated on a flat surface to ensure overlapping of the ovally ablated areas between pulses. Electron microscopy of eye bank lenticules demonstrated a circular smooth regularly concave ablation zone. Histological examination of nine clear corneas confirmed thinning of the stroma without fibroblastic reaction and no epithelial hypertrophy. Mean preoperative corneal power of 43.15 +/- 2.18 decreased postoperatively to 33.61 +/- 2.34. The new technique of excimer laser keratomileusis has the advantage of a cut surface smoother and the clear zone is devoid of the stepwise concavity and irregularity seen in diaphragm based photoablation delivery systems.

Sensitivity and specificity of scanning laser polarimetry using the GDx.

PubMed

Munkwitz, S; Funk, J; Loeffler, K U; Harbarth, U; Kremmer, S

2004-09-01

To determine the sensitivity and the specificity of the GDx in the detection of (1) advanced glaucoma, (2) early glaucoma, and (3) nerve fibre bundle defects (NFBD). Group A comprised 20 eyes with reproducible glaucomatous visual field defects confirmed by octopus perimetry, group B consisted of 10 eyes with normal visual fields but either glaucomatous NFBD or deterioration of the disc over time clearly visible upon flicker comparison, and group C included 16 eyes with glaucomatous or non-glaucomatous NFBD clearly visible on red free photographs. Forty four eyes of 22 healthy volunteers served as controls. The GDx printouts of all subjects were evaluated by three independent observers in a masked fashion and without the clinical picture of the optic disc. Two of the three observers (SK, UH) were GDx experts, one (KUL) was an untrained GDx user. Among the GDx experts, sensitivity/specificity was 100%/100% (SK) and 90%/100% (UH) in detecting advanced glaucoma, and 100%/100% (SK) and 90%/100% (UH) in detecting early glaucoma. The sensitivity in detecting NFBD was only 37.5% (SK and UH). For the untrained GDx user the corresponding values were 50%/100% (group A), 20%/100% (group B), and 12.5%/91% (group C). Detection of (early) glaucoma damage by the GDx, evaluated by trained experts, can be extremely high. To optimise its benefit in clinical routine training in interpreting GDx printouts is highly recommended. Detection of localised NFBD is crucial, even for experts.

Influence of height, weight, and body mass index on optic disc parameters.

PubMed

Zheng, Yingfeng; Cheung, Carol Y L; Wong, Tien Y; Mitchell, Paul; Aung, Tin

2010-06-01

To examine the influence of body height, body weight, and body mass index (BMI) on optic disc parameters in a population-based study. The Singapore Malay Eye Study examined 3280 persons of Malay ethnicity, aged 40 to 80 years, of whom 2329 (71.0%) had reliable retinal scanning confocal laser tomography images for analyses. Intraocular pressure (IOP) was ascertained by Goldmann applanation tonometry. Body height and weight were measured with standardized protocols; BMI was calculated as weight (kilograms)/height squared (meters). Sociodemographic information was collected in an interviewer-administered questionnaire. In univariate analyses, body height, weight, and BMI were significantly associated with optic cup area, rim area, and cup-to-disc area ratio (all with P < 0.05) but none of the anthropometric parameters was significantly associated with optic disc area (all with P > 0.05). In multiple regression analyses after adjustment for age, sex, optic disc size, axial length, education, family income, and IOP, each SD increase in body height was associated with a 0.042-mm(2) decrease in optic rim area and a 0.020 increase in optic cup-to-disc area ratio; each SD decrease in body weight was associated with a 0.013-mm(2) decrease in optic rim area and a 0.010 increase in optic cup-to-disc ratio; and each SD decrease in BMI was associated with a 0.021-mm(2) decrease in optic rim area and a 0.010 increase in optic cup-to-disc ratio. Persons who are taller or have lower BMI have a smaller neuroretinal rim area and a larger optic cup-to-disc area ratio.

A Multi-Anatomical Retinal Structure Segmentation System for Automatic Eye Screening Using Morphological Adaptive Fuzzy Thresholding

PubMed Central

Elleithy, Khaled; Elleithy, Abdelrahman

2018-01-01

Eye exam can be as efficacious as physical one in determining health concerns. Retina screening can be the very first clue for detecting a variety of hidden health issues including pre-diabetes and diabetes. Through the process of clinical diagnosis and prognosis; ophthalmologists rely heavily on the binary segmented version of retina fundus image; where the accuracy of segmented vessels, optic disc, and abnormal lesions extremely affects the diagnosis accuracy which in turn affect the subsequent clinical treatment steps. This paper proposes an automated retinal fundus image segmentation system composed of three segmentation subsystems follow same core segmentation algorithm. Despite of broad difference in features and characteristics; retinal vessels, optic disc, and exudate lesions are extracted by each subsystem without the need for texture analysis or synthesis. For sake of compact diagnosis and complete clinical insight, our proposed system can detect these anatomical structures in one session with high accuracy even in pathological retina images. The proposed system uses a robust hybrid segmentation algorithm combines adaptive fuzzy thresholding and mathematical morphology. The proposed system is validated using four benchmark datasets: DRIVE and STARE (vessels), DRISHTI-GS (optic disc), and DIARETDB1 (exudates lesions). Competitive segmentation performance is achieved, outperforming a variety of up-to-date systems and demonstrating the capacity to deal with other heterogeneous anatomical structures. PMID:29888146

Fundus Photography as a Screening Method for Diabetic Retinopathy in Children With Type 1 Diabetes: Outcome of the Initial Photography.

PubMed

Gräsbeck, Thomas C; Gräsbeck, Sophia V; Miettinen, Päivi J; Summanen, Paula A

2016-09-01

To determine the success rate of the initial fundus photography session in producing gradable images for screening diabetic retinopathy in children <18 years of age with type 1 diabetes (T1D), and to analyze outcome-associated factors. Retrospective observational cohort study. Mydriatic red-free monochromatic 60-degree digital fundus images centered on the macula and optic disc of 213 patients were graded. Photography success was classified as "complete" if both images of both eyes were gradable, "partial" if both images of 1 eye were gradable, "macula-centered image(s) only" if only the macula-centered image of one or both eyes was gradable, and "unsuccessful" if neither macula-centered image was gradable. Complete success was reached in 97 (46%; 95% confidence interval [CI], 39-52) patients, at least partial success in 153 (72%; 95% CI, 65-78) patients, success of macula-centered image(s) only in 47 (22%; 95% CI, 17-28) patients, and in 13 (6%; 95%CI, 3-10) patients fundus photography was unsuccessful. Macula-centered images were more often gradable in both eyes than optic disc-centered images (P < .001). Success of photography did not differ between right and left eye. Sex, age at diagnosis of T1D, and the duration of diabetes, age, and glycemic control at the time of initial photography were unassociated with complete success. Partial success tended to decrease with increasing age category (P = .093), and the frequency of gradable macula-centered image(s) only increased with increasing age (P = .043). Less than half of the children achieved complete success, but in only 6% initial fundus photography was unsuccessful, indicating its value in assessing retinopathy in the pediatric setting. Copyright © 2016 Elsevier Inc. All rights reserved.

Optical coherence tomography in papilledema and pseudopapilledema with and without optic nerve head drusen

PubMed Central

Bassi, Shikha Talwar; Mohana, Kuppuswamy Parthasarthy

2014-01-01

Aim: To compare the spectral domain optical coherence tomography (SD-OCT) findings of the optic disc and the peripapillary retina of patients with a true papilledema and pseudopapilledema with and without optic nerve head drusen (ONHD). Study Design: Retrospective Case Control Study. Subjects and Methods: Peripapillary retinal nerve fiber layer (PPRNFL) thickness as depicted by SD-OCT of 94 eyes of 66 patients with papilledema (30 eyes), pseudopapiledema (31 eyes), and normal controls (33 eyes) was analyzed. The mean RNFL thickness, total retinal thickness (TRT) at a superior and inferior edge of the disc and the quadrant wise topography of increased RNFL were compared in all three groups. Sensitivity, specificity, and area under the receiver operating characteristic curve (AROC) were calculated for all the parameters. Results: The median RNFL thickness was 185.4 (129.5–349.3 μm), 122.3 (109–156.3 μm) and 91.62 ± 7 μm in papilledema, pseudopapilledema, and controls, respectively. Papilledema group had thicker PPRNFL in all quadrants except temporal quadrant. TRT was thicker in papilledema and pseudopapilledema compared to controls. ONHD could be directly visualized as high reflective clumps in the sub-retinal space or the RNFL in 30 eyes. Increased RNFL thickness in all four quadrants was noted 43.3% in papilledema and 9.7% in pseudopapilledema. Normal RNFL thickness in all four quadrants was noted in 0% in papilledema and 32.3% in pseudopapilledema. Nasal RNFL had the highest AROC (0.792) indicating high diagnostic ability to differentiate papilledema from pseudopapilledema. Conclusion: SD-OCT can be used as a tool to differentiate between papilledema and pseudopapilledema. PMID:25579359

Provider Agreement in the Assessment of Glaucoma Progression within a Team Model.

PubMed

Shah, Saumya; Choo, Clara; Odden, Jamie; Zhao, Bingying; Fang, Chengbo; Schornack, Muriel; Stalboerger, Gina; Bennett, Jeffrey R; Khanna, Cheryl L

2018-06-04

Glaucoma specialists and optometrists who work in a team model at a single institution utilize a common definition of glaucoma progression and treatment algorithm. The purpose of this study was to assess the consistency of agreement in identifying glaucoma progression among glaucoma specialists and optometrists of one team. 399 eyes of 200 patients age 18 or older with glaucoma were enrolled over two years. Clinical data, disc photographs, OCT, and visual fields were independently reviewed by two masked optometrists and two masked fellowship-trained glaucoma specialists. Each eye was judged as progression or no-progression of glaucomatous disease. The following were assessed: (1) agreement among optometrists; (2) agreement among glaucoma specialists; and (3) agreement among optometrists and glaucoma specialists. The frequency of use of testing modality to determine progression was also studied. Kappa statistics were used to evaluate agreements. Optometrists agreed with each other for 74.2% of the eyes assessed (κ=0.42), whereas glaucoma specialists agreed with each other for 78.7% of eyes (κ=0.39). All four providers agreed with each other for 54.4% of the eyes evaluated (κ=0.37). Providers had the highest agreement when the progression decision was based on disc hemorrhage (92%) and the lowest agreement when based on OCT progression analysis (36%). Compared to optometrists, glaucoma specialists used OCT (P= <0.01) more frequently to determine disease progression. Fair to moderate agreement levels were found among providers in their assessment of glaucoma progression, suggesting that a team approach to glaucoma management may be effective. Further work is needed to investigate ways to optimize consistency within the glaucoma team.

A Small Disc Area Is a Risk Factor for Visual Field Loss Progression in Primary Open-Angle Glaucoma: The Glaucoma Stereo Analysis Study.

PubMed

Kitaoka, Yasushi; Tanito, Masaki; Yokoyama, Yu; Nitta, Koji; Katai, Maki; Omodaka, Kazuko; Nakazawa, Toru

2018-01-01

The Glaucoma Stereo Analysis Study, a cross-sectional multicenter collaborative study, used a stereo fundus camera (nonmyd WX) to assess various morphological parameters of the optic nerve head (ONH) in glaucoma patients. We compared the associations of each parameter between the visual field loss progression group and no-progression group. The study included 187 eyes of 187 patients with primary open-angle glaucoma or normal-tension glaucoma. We divided the mean deviation (MD) slope values of all patients into the progression group (<-0.3 dB/year) and no-progression group (≧-0.3 dB/year). ONH morphological parameters were calculated with prototype analysis software. The correlations between glaucomatous visual field progression and patient characteristics or each ONH parameter were analyzed with Spearman's rank correlation coefficient. The MD slope averages in the progression group and no-progression group were -0.58 ± 0.28 dB/year and 0.05 ± 0.26 dB/year, respectively. Among disc parameters, vertical disc width (diameter), disc area, cup area, and cup volume in the progression group were significantly less than those in the no-progression group. Logistic regression analysis revealed a significant association between the visual field progression and disc area (odds ratio 0.49/mm 2 disc area). A smaller disc area may be associated with more rapid glaucomatous visual field progression.

Evaluation of a glaucoma patient

PubMed Central

Thomas, Ravi; Loibl, Klaus; Parikh, Rajul

2011-01-01

The diagnosis of glaucoma is usually made clinically and requires a comprehensive eye examination, including slit lamp, applanation tonometry, gonioscopy and dilated stereoscopic evaluation of the optic disc and retina. Automated perimetry is obtained if glaucoma is suspected. This establishes the presence of functional damage and provides a baseline for follow-up. Imaging techniques are not essential for the diagnosis but may have a role to play in the follow-up. We recommend a comprehensive eye examination for every clinic patient with the objective of detecting all potentially sight-threatening diseases, including glaucoma. PMID:21150033

Chronic optic disc swelling overlooked in a diabetic patient with a devastating outcome

PubMed Central

Braithwaite, Tasanee; Plant, Gordon T

2010-01-01

We present a case of asymmetrical but bilateral, progressive, painless visual deterioration over 5 years to no perception of light, in a 61-year-old male diabetic patient referred for a second opinion. The patient had a chronic history of bilateral diabetic maculopathy and unexplained swelling of the optic discs. He was diagnosed with optic atrophy secondary to pseudotumour cerebri (termed idiopathic intracranial hypertension when underlying causes have been excluded), which was associated with obstructive sleep apnoea. The case highlights the critical importance of identifying and investigating chronic papilloedema for reversible causes; the sometimes subtle presentation of pseudotumour cerebri; and the vital role of visual field testing and diagnostic lumbar puncture for timely diagnosis. It also reminds us that chronic bilateral optic disc swelling is not a normal feature of diabetic eye disease, and that alarm bells should sound if reduced visual acuity seems disproportionate to the degree of maculopathy. PMID:22442651

A case report of ophthalmic artery emboli secondary to Calcium Hydroxylapatite filler injection for nose augmentation- long-term outcome.

PubMed

Cohen, Eyal; Yatziv, Yossi; Leibovitch, Igal; Kesler, Anat; Cnaan, Ran Ben; Klein, Ainat; Goldenberg, Dafna; Habot-Wilner, Zohar

2016-07-08

Filler injection for face augmentation is a common cosmetic procedure in the last decades, in our case report we describe long-term outcomes of a devastating complication of ophthalmic artery emboli following Calcium Hydroxylapatite filler injection to the nose bridge. A healthy 24-year-old women received a Calcium Hydroxylapatite filler injection to her nose bridge for the correction of nose asymmetry 8 years post rhinoplasty. She developed sudden right eye ocular pain and visual disturbances. Visual acuity was 20/20 in both eyes and visual field in the right eye showed inferior arch with fixation sparing and supero-temporal central scotoma. Examination revealed marked periorbital edema and hematoma, ptosis, ocular movements limitation, an infero-temporal branch retinal artery occlusion and multiple choroidal emboli. Eighteen months post initial presentation ptosis and eye movements returned normal and choroidal emboli absorbed almost completely. However, visual acuity declined to 20/60, visual field showed severe progressive deterioration with a central and supero-nasal field remnant and the optic disc became pallor. Cosmetic injection of calcium hydroxylapatite to the nose bridge can result in arterial emboli to the ophthalmic system with optic nerve, retinal and choroidal involvement causing long term severe visual acuity and visual field impairment.

Glass promotes the differentiation of neuronal and non-neuronal cell types in the Drosophila eye

PubMed Central

Morrison, Carolyn A.; Chen, Hao; Cook, Tiffany; Brown, Stuart

2018-01-01

Transcriptional regulators can specify different cell types from a pool of equivalent progenitors by activating distinct developmental programs. The Glass transcription factor is expressed in all progenitors in the developing Drosophila eye, and is maintained in both neuronal and non-neuronal cell types. Glass is required for neuronal progenitors to differentiate as photoreceptors, but its role in non-neuronal cone and pigment cells is unknown. To determine whether Glass activity is limited to neuronal lineages, we compared the effects of misexpressing it in neuroblasts of the larval brain and in epithelial cells of the wing disc. Glass activated overlapping but distinct sets of genes in these neuronal and non-neuronal contexts, including markers of photoreceptors, cone cells and pigment cells. Coexpression of other transcription factors such as Pax2, Eyes absent, Lozenge and Escargot enabled Glass to induce additional genes characteristic of the non-neuronal cell types. Cell type-specific glass mutations generated in cone or pigment cells using somatic CRISPR revealed autonomous developmental defects, and expressing Glass specifically in these cells partially rescued glass mutant phenotypes. These results indicate that Glass is a determinant of organ identity that acts in both neuronal and non-neuronal cells to promote their differentiation into functional components of the eye. PMID:29324767

Binocular combination of luminance profiles

PubMed Central

Ding, Jian; Levi, Dennis M.

2017-01-01

We develop and test a new two-dimensional model for binocular combination of the two eyes' luminance profiles. For first-order stimuli, the model assumes that one eye's luminance profile first goes through a luminance compressor, receives gain-control and gain-enhancement from the other eye, and then linearly combines the other eye's output profile. For second-order stimuli, rectification is added in the signal path of the model before the binocular combination site. Both the total contrast and luminance energies, weighted sums over both the space and spatial-frequency domains, were used in the interocular gain-control, while only the total contrast energy was used in the interocular gain-enhancement. To challenge the model, we performed a binocular brightness matching experiment over a large range of background and target luminances. The target stimulus was a dichoptic disc with a sharp edge that has an increment or decrement luminance from its background. The disk's interocular luminance ratio varied from trial to trial. To refine the model we tested three luminance compressors, five nested binocular combination models (including the Ding–Sperling and the DSKL models), and examined the presence or absence of total luminance energy in the model. We found that (1) installing a luminance compressor, either a logarithmic luminance function or luminance gain-control, (2) including both contrast and luminance energies, and (3) adding interocular gain-enhancement (the DSKL model) to a combined model significantly improved its performance. The combined model provides a systematic account of binocular luminance summation over a large range of luminance input levels. It gives a unified explanation of Fechner's paradox observed on a dark background, and a winner-take-all phenomenon observed on a light background. To further test the model, we conducted two additional experiments: luminance summation of discs with asymmetric contour information (Experiment 2), similar to Levelt (1965) and binocular combination of second-order contrast-modulated gratings (Experiment 3). We used the model obtained in Experiment 1 to predict the results of Experiments 2 and 3 and the results of our previous studies. Model simulations further refined the contrast space weight and contrast sensitivity functions that are installed in the model, and provide a reasonable account for rebalancing of imbalanced binocular vision by reducing the mean luminance in the dominant eye. PMID:29098293

Peripapillary choroidal thickness in healthy controls and patients with focal, diffuse, and sclerotic glaucomatous optic disc damage.

PubMed

Roberts, Kenneth F; Artes, Paul H; O'Leary, Neil; Reis, Alexandre S C; Sharpe, Glen P; Hutchison, Donna M; Chauhan, Balwantray C; Nicolela, Marcelo T

2012-08-01

To examine peripapillary choroidal thickness in healthy controls and in patients with glaucoma who have focal, diffuse, and sclerotic optic disc damage. Healthy controls (n=92) and patients with glaucoma who have focal (n=34), diffuse (n=35), and sclerotic (n=34) optic disc damage were imaged with spectral-domain optical coherence tomography (12° circular scan protocol centered on optic nerve head). Peripapillary choroidal thickness was measured as the distance between the automatically segmented retinal pigment epithelium/Bruch's membrane and the manually outlined interface between the posterior choroid and the anterior border of the sclera in eyes in which the anterior scleral border was visible over more than 85% of the scan circumference. The anterior scleral border was visible in 76 controls (83%) and 89 patients (86%). Peripapillary choroidal thickness in healthy controls decreased linearly with age (-11 μm/decade; P.001; r2=0.16), with a predicted value of 137 μm at age 70 years (95% prediction interval, 62-212 μm). While this value was similar in patients with focal and diffuse optic disc damage (126 and 130 μm, respectively; P=.22 compared with controls), it was approximately 30% lower in patients with sclerotic optic disc damage (96 μm; P.001 compared with controls). The peripapillary choroid of patients with glaucoma who have sclerotic optic disc damage was approximately 25% to 30% thinner compared with that in patients with focal and diffuse optic disc damage and with that in healthy controls. The role of the choroid in the pathophysiology of sclerotic glaucomatous optic disc damage needs further investigation.

Comparison of Heidelberg Retina Tomograph-3 glaucoma probability score and Moorfields regression analysis of optic nerve head in glaucoma patients and healthy individuals.

PubMed

Caglar, Çagatay; Gul, Adem; Batur, Muhammed; Yasar, Tekin

2017-01-01

To compare the sensitivity and specificity of Moorfields regression analysis (MRA) and glaucoma probability score (GPS) between healthy and glaucomatous eyes with Heidelberg Retinal Tomograph 3 (HRT-3). The study included 120 eyes of 75 glaucoma patients and 138 eyes of 73 normal subjects, for a total of 258 eyes of 148 individuals. All measurements were performed with the HRT-3. Diagnostic test criteria (sensitivity, specificity, etc.) were used to evaluate how efficiently GPS and MRA algorithms in the HRT-3 discriminated between the glaucoma and control groups. The GPS showed 88 % sensitivity and 66 % specificity, whereas MRA had 71.5 % sensitivity and 82.5 % specificity. There was 71 % agreement between the final results of MRA and GPS in the glaucoma group. Excluding borderline patients from both analyses resulted in 91.6 % agreement. In the control group the level of agreement between MRA and GPS was 64 % including borderline patients and 84.1 % after excluding borderline patients. The accuracy rate is 92 % for MRA and 91 % for GPS in the glaucoma group excluding borderline patients. The difference was nor statistically different. In both cases, agreement was higher between MRA and GPS in the glaucoma group. We found that both sensitivity and specificity increased with disc size for MRA, while the sensitivity increased and specificity decreased with larger disc sizes for GPS. HRT is able to quantify and clearly reveal structural changes in the ONH and RNFL in glaucoma.

Lenticular astigmatism in tilted disc syndrome.

PubMed

Gündüz, Abuzer; Evereklioglu, Cem; Er, Hamdi; Hepşen, Ibrahim F

2002-10-01

To evaluate whether an abnormal optic disc shape in patients with tilted disc syndrome (TDS) is associated with an abnormal configuration of the crystalline lens measured as lenticular astigmatism. Department of Ophthalmology, Inönü University Medical Faculty, Turgut Ozal Medical Center, Malatya, Turkey. This cross-sectional masked case-control study comprised 32 eyes of 32 patients with established TDS (13 men, 19 women; mean age 21.31 years +/- 7.05 [SD]) and 20 age- and sex-matched healthy control subjects (8 men, 12 women; mean age 22.65 +/- 7.11 years) with a comparable amount of myopic astigmatism (spherical equivalent) without TDS. The optic disc was morphometrically analyzed by planimetric evaluation of optic disc photographs. The total refractive and keratometric corneal astigmatism was obtained, and lenticular astigmatism was calculated by vector analysis. The Mann-Whitney U test was used for statistical analysis; 1 eye of each patient was evaluated in both groups. A P value less than 0.05 was considered statistically significant. The mean spherical equivalent refraction was comparable in TDS patients (-4.73 +/- 1.12 diopters [D]) and controls (-4.28 +/- 1.29 D) (P =.210). The mean total astigmatism was higher in TDS patients (-2.96 +/- 1.04 D) than in the controls (-2.51 +/- 1.09 D), but the difference was not significant (P =.151). The mean corneal astigmatism was comparable in TDS patients (-2.07 +/- 0.83 D) and controls (-2.28 +/- 0.87 D) (P =.454), but the calculated mean lenticular astigmatism was significantly higher in TDS patients (-1.31 +/- 0.98 D and -0.20 +/- 0.35 D, respectively) (P <.001). Twenty-nine of 32 TDS patients (90.6%) had lenticular astigmatism; in 16 (50%), it was greater than -1.00 D. Lenticular astigmatism was present in 7 controls (35%); in 2 (10%), it was greater than -1.00 D. The mean keratometry was significantly higher in TDS patients (43.84 +/- 1.06 D) than in the controls (42.75 +/- 1.45 D) (P =.011). Clinically significant lenticular astigmatism was present in TDS patients. If an abnormal optic disc shape is found on ophthalmoscopy, lenticular astigmatism as well as corneal astigmatism should be carefully evaluated to prevent an unsatisfactory refractive outcome, especially in refractive surgery candidates.

Transplantation of cells from eye-like structures differentiated from embryonic stem cells in vitro and in vivo regeneration of retinal ganglion-like cells.

PubMed

Aoki, Hitomi; Hara, Akira; Niwa, Masayuki; Motohashi, Tsutomu; Suzuki, Takashi; Kunisada, Takahiro

2008-02-01

An embryonic stem (ES) cell-derived eye-like structure, made up of neural retinal lineage cells, retinal pigment epithelial (RPE) cells, and lens cells was constructed in our laboratory. We have shown that cells from these eye-like structures can be integrated into the developing optic vesicle of chicks. The purpose of this study was to determine whether the cells from these eye-like structures can differentiate into retinal ganglion cells (RGCs) when transplanted into the vitreous of an injured adult mouse retina. ES cells were induced to differentiate into eye-like structures in vitro for 6 or 11 days. Recipient mouse eyes were injected with NMDA to injure the RGCs prior to the transplantation. Sham-treated eyes received the same amount of carrier vehicle. Cells were extracted from the eye-like structures and transplanted into the vitreous of damaged and control eyes. The host eyes were analyzed both qualitatively and quantitatively by immunohistochemistry 10 days or 8 weeks after transplantation. Cells from the ES cell-derived eye-like structures were integrated into the RGC layer, and differentiated into neurons when transplanted into control (non-NMDA-treated) adult eyes. However, they rarely expressed RGC markers. When they were transplanted into NMDA-treated eyes, the cells spread on the surface of the retina and covered a relatively large area of the host RGC layer that had been injured by the NMDA. The cells from the ES cell-derived eye cells frequently differentiated into cells expressing RGC-specific markers, and formed a new RGC layer. In addition, a small number of these ES cell-derived cells were observed to extend axon-like processes toward the optic disc of the host. However, visually evoked responses could not be recorded from the visual cortex. These findings suggest that ES cell-derived eye-like structures contain cells that can differentiate into RG-like cells and regenerate a new RGC layer. These cells also appeared to be integrated into the retina and extend axon-like processes toward the optic nerve head.

Multiple evanescent white dot syndrome (MEWDS).

PubMed

Leys, A; Leys, M; Jonckheere, P; De Laey, J J

1990-01-01

We describe the course of MEWDS (multiple evanescent white dot syndrome) in 2 young females. The first patient presented with a very pronounced macular edema. The second patient had merely optic disc edema. Both had an enlargement of the blind spot, which normalized later. Only the granular aspect of the fovea persisted in the involved eye.

Preparation of adult Drosophila eyes for thin sectioning and microscopic analysis.

PubMed

Jenny, Andreas

2011-08-27

Drosophila has long been used as model system to study development, mainly due to the ease with which it is genetically tractable. Over the years, a plethora of mutant strains and technical tricks have been developed to allow sophisticated questions to be asked and answered in a reasonable amount of time. Fundamental insight into the interplay of components of all known major signaling pathways has been obtained in forward and reverse genetic Drosophila studies. The fly eye has proven to be exceptionally well suited for mutational analysis, since, under laboratory conditions, flies can survive without functional eyes. Furthermore, the surface of the insect eye is composed of some 800 individual unit eyes (facets or ommatidia) that form a regular, smooth surface when looked at under a dissecting microscope. Thus, it is easy to see whether a mutation might affect eye development or growth by externally looking for the loss of the smooth surface ('rough eye' phenotype; Fig. 1) or overall eye size, respectively (for examples of screens based on external eye morphology see e.g.). Subsequent detailed analyses of eye phenotypes require fixation, plastic embedding and thin-sectioning of adult eyes. The Drosophila eye develops from the so-called eye imaginal disc, a bag of epithelial cells that proliferate and differentiate during larval and pupal stages (for review see e.g.). Each ommatidium consists of 20 cells, including eight photoreceptors (PR or R-cells; Fig. 2), four lens-secreting cone cells, pigment cells ('hexagon' around R-cell cluster) and a bristle. The photoreceptors of each ommatidium, most easily identified by their light sensitive organelles, the rhabdomeres, are organized in a trapezoid made up of the six "outer" (R1-6) and two "inner" photoreceptors (R7/8; R8 [Fig. 2] is underneath R7 and thus only seen in sections from deeper areas of the eye). The trapezoid of each facet is precisely aligned with those of its neighbors and the overall anteroposterior and dorsoventral axes of the eye (Fig. 3A). In particular, the ommatidia of the dorsal and ventral (black and red arrows, respectively) halves of the eye are mirror images of each other and correspond to two chiral forms established during planar cell polarity signaling (for review see e.g.). The method to generate semi-thin eye sections (such as those presented in Fig. 3) described here is slightly modified from the one originally described by Tomlinson and Ready. It allows the morphological analysis of all cells except for the transparent cone cells. In addition, the pigment of R-cells (blue arrowheads in Fig. 2 and 3) can be used as a cell-autonomous marker for the genotype of a R-cell, thus genetic requirements of genes in a subset of R-cells can readily be determined.

Fundus fluorescence Angiography in diagnosing diabetic retinopathy.

PubMed

Wang, Shuhui; Zuo, Yuqin; Wang, Ning; Tong, Bin

2017-01-01

To investigate the manifestation characteristics of fundus fluorescence angiography (FFA) and its values in diagnosing diabetic retinopathy through comparing direct ophthalmoscopy. Two hundred fifty patients (500 eyes) who were suspected as diabetic retinopathy and admitted to the hospital between February 2015 and December 2016 were selected. They underwent direct ophthalmoscopy and FFA. The manifestation characteristics of FFA in the diagnosis of diabetic retinopathy were summarized. The two examination methods were compared. In the diagnosis with direct ophthalmoscopy, 375 eyes out of 500 eyes were diagnosed as diabetic retinopathy (75%); there were 74 eyes at stage I, 88 eyes at stage II, 92 eyes at stage III, 83 eyes of stage IV, 28 eyes of stage V and 10 eyes of stage VI. In the diagnosis with FFA, 465 eyes out of 500 eyes were diagnosed as diabetic retinopathy (93%); there were 94 eyes at stage I, 110 eyes at stage II, 112 at stage III, 92 eyes at stage IV, 41 eyes at stage V and 16 eyes at stage VI. The detection rate of diabetic retinopathy using FFA was significantly higher than that using direct ophthalmoscopy (P<0.05). FFA found that 316 eyes had non-proliferative retinopathy (67.96%), 75 eyes had pre-proliferative lesions (16.13%), 149 eyes had proliferative lesions (32.04%), 135 eyes had diabetic maculopathy (29.03%) and 31 eyes had diabetic optic disc lesions (6.67%). The detection rate of diabetic retinopathy using FFA is higher than that using direct ophthalmoscopy. FFA could accurately determine clinical stage. Therefore, it is an important approach in treatment efficacy evaluation and treatment guidance, suggesting a significant application value.

Profile and Determinants of Retinal Optical Intensity in Normal Eyes with Spectral Domain Optical Coherence Tomography.

PubMed

Chen, Binyao; Gao, Enting; Chen, Haoyu; Yang, Jianling; Shi, Fei; Zheng, Ce; Zhu, Weifang; Xiang, Dehui; Chen, Xinjian; Zhang, Mingzhi

2016-01-01

To investigate the profile and determinants of retinal optical intensity in normal subjects using 3D spectral domain optical coherence tomography (SD OCT). A total of 231 eyes from 231 healthy subjects ranging in age from 18 to 80 years were included and underwent a 3D OCT scan. Forty-four eyes were randomly chosen to be scanned by two operators for reproducibility analysis. Distribution of optical intensity of each layer and regions specified by the Early Treatment of Diabetic Retinopathy Study (ETDRS) were investigated by analyzing the OCT raw data with our automatic graph-based algorithm. Univariate and multivariate analyses were performed between retinal optical intensity and sex, age, height, weight, spherical equivalent (SE), axial length, image quality, disc area and rim/disc area ratio (R/D area ratio). For optical intensity measurements, the intraclass correlation coefficient of each layer ranged from 0.815 to 0.941, indicating good reproducibility. Optical intensity was lowest in the central area of retinal nerve fiber layer, ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer and photoreceptor layer, except for the retinal pigment epithelium (RPE). Optical intensity was positively correlated with image quality in all retinal layers (0.553<β<0.851, p<0.01), and negatively correlated with age in most retinal layers (-0.362<β<-0.179, p<0.01), except for the RPE (β = 0.456, p<0.01), outer nuclear layer and photoreceptor layer (p>0.05). There was no relationship between retinal optical intensity and sex, height, weight, SE, axial length, disc area and R/D area ratio. There was a specific pattern of distribution of retinal optical intensity in different regions. The optical intensity was affected by image quality and age. Image quality can be used as a reference for normalization. The effect of age needs to be taken into consideration when using OCT for diagnosis.

Clinical Validation of a Smartphone-Based Adapter for Optic Disc Imaging in Kenya.

PubMed

Bastawrous, Andrew; Giardini, Mario Ettore; Bolster, Nigel M; Peto, Tunde; Shah, Nisha; Livingstone, Iain A T; Weiss, Helen A; Hu, Sen; Rono, Hillary; Kuper, Hannah; Burton, Matthew

2016-02-01

Visualization and interpretation of the optic nerve and retina are essential parts of most physical examinations. To design and validate a smartphone-based retinal adapter enabling image capture and remote grading of the retina. This validation study compared the grading of optic nerves from smartphone images with those of a digital retinal camera. Both image sets were independently graded at Moorfields Eye Hospital Reading Centre. Nested within the 6-year follow-up (January 7, 2013, to March 12, 2014) of the Nakuru Eye Disease Cohort in Kenya, 1460 adults (2920 eyes) 55 years and older were recruited consecutively from the study. A subset of 100 optic disc images from both methods were further used to validate a grading app for the optic nerves. Data analysis was performed April 7 to April 12, 2015. Vertical cup-disc ratio for each test was compared in terms of agreement (Bland-Altman and weighted κ) and test-retest variability. A total of 2152 optic nerve images were available from both methods (also 371 from the reference camera but not the smartphone, 170 from the smartphone but not the reference camera, and 227 from neither the reference camera nor the smartphone). Bland-Altman analysis revealed a mean difference of 0.02 (95% CI, -0.21 to 0.17) and a weighted κ coefficient of 0.69 (excellent agreement). The grades of an experienced retinal photographer were compared with those of a lay photographer (no health care experience before the study), and no observable difference in image acquisition quality was found. Nonclinical photographers using the low-cost smartphone adapter were able to acquire optic nerve images at a standard that enabled independent remote grading of the images comparable to those acquired using a desktop retinal camera operated by an ophthalmic assistant. The potential for task shifting and the detection of avoidable causes of blindness in the most at-risk communities makes this an attractive public health intervention.

Three-dimensional vascular imaging of proliferative diabetic retinopathy by Doppler optical coherence tomography.

PubMed

Miura, Masahiro; Hong, Young-Joo; Yasuno, Yoshiaki; Muramatsu, Daisuke; Iwasaki, Takuya; Goto, Hiroshi

2015-03-01

To evaluate the 3-dimensional architecture of neovascularization in proliferative diabetic retinopathy using Doppler optical coherence tomography (OCT). Prospective, nonrandomized clinical trial. Seventeen eyes of 14 patients with proliferative diabetic retinopathy were prospectively studied. Prototype Doppler OCT was used to evaluate the 3-dimensional vascular architecture at vitreoretinal adhesions. Proliferative membranes were detected in all eyes with proliferative diabetic retinopathy by standard OCT images. Doppler OCT images detected blood flow by neovascularization of the disc in 12 eyes and neovascularization elsewhere in 11 eyes. Doppler OCT images showed the 3-dimensional extent of new vessels at various stages of neovascularization, and the extent of new vessels could be clearly confirmed at vitreoretinal adhesions. Doppler OCT is useful for the detection and evaluation of the 3-dimensional vascular structure of neovascularization, and can assist in the noninvasive assessment of proliferative diabetic retinopathy. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Safety of laser use under the dental microscope.

PubMed

Saegusa, Hidetoshi; Watanabe, Satoshi; Anjo, Tomoo; Ebihara, Arata; Suda, Hideaki

2010-04-01

The aim of this study was to investigate the safety of laser use under the dental microscope. Nd:YAG, Er:YAG and diode lasers were used. The end of the tips was positioned at a distance of 5 cm from the objective lens of a dental microscope. Each eye protector was made into a flat disc, which was fixed on the lens of the microscope. The filters were placed in front of the objective lens or behind the eye lens. Transmitted energy through the microscope with or without the filters was measured. No transmitted laser energy was detected when using matched eye protectors. Mismatched eye protectors were not effective for shutting out laser energy, especially for Nd:YAG and diode lasers. None or very little laser energy was detected through the microscope even without any laser filter. Matched filters shut out all laser energy irrespective of their positions.

Unilateral retinitis pigmentosa: 30 years follow-up

PubMed Central

Weller, Julia M; Michelson, Georg; Juenemann, Anselm G

2014-01-01

This case report depicts the clinical course of a female patient with unilateral retinitis pigmentosa (RP), who presented first in 1984 at the age of 43 years. At the beginning, there were cells in the vitreous leading to the diagnosis of uveitis with vasculitis. Within 30 years, the complete clinical manifestation of RP developed with bone spicule-shaped pigment deposits, pale optic disc, narrowed arterioles, cystoid macular oedema, posterior subcapsular cataract, concentric narrowing of the visual field and undetectable electroretinogram signal. At the age of 72 years, there are still no signs of retinal dystrophy in the other eye. PMID:24515232

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rueegsegger, Michael B.; Bach Cuadra, Meritxell; Pica, Alessia

Purpose: Ocular anatomy and radiation-associated toxicities provide unique challenges for external beam radiation therapy. For treatment planning, precise modeling of organs at risk and tumor volume are crucial. Development of a precise eye model and automatic adaptation of this model to patients' anatomy remain problematic because of organ shape variability. This work introduces the application of a 3-dimensional (3D) statistical shape model as a novel method for precise eye modeling for external beam radiation therapy of intraocular tumors. Methods and Materials: Manual and automatic segmentations were compared for 17 patients, based on head computed tomography (CT) volume scans. A 3Dmore » statistical shape model of the cornea, lens, and sclera as well as of the optic disc position was developed. Furthermore, an active shape model was built to enable automatic fitting of the eye model to CT slice stacks. Cross-validation was performed based on leave-one-out tests for all training shapes by measuring dice coefficients and mean segmentation errors between automatic segmentation and manual segmentation by an expert. Results: Cross-validation revealed a dice similarity of 95% {+-} 2% for the sclera and cornea and 91% {+-} 2% for the lens. Overall, mean segmentation error was found to be 0.3 {+-} 0.1 mm. Average segmentation time was 14 {+-} 2 s on a standard personal computer. Conclusions: Our results show that the solution presented outperforms state-of-the-art methods in terms of accuracy, reliability, and robustness. Moreover, the eye model shape as well as its variability is learned from a training set rather than by making shape assumptions (eg, as with the spherical or elliptical model). Therefore, the model appears to be capable of modeling nonspherically and nonelliptically shaped eyes.« less

Automated Detection of Optic Disc in Fundus Images

NASA Astrophysics Data System (ADS)

Burman, R.; Almazroa, A.; Raahemifar, K.; Lakshminarayanan, V.

Optic disc (OD) localization is an important preprocessing step in the automated image detection of fundus image infected with glaucoma. An Interval Type-II fuzzy entropy based thresholding scheme along with Differential Evolution (DE) is applied to determine the location of the OD in the right of left eye retinal fundus image. The algorithm, when applied to 460 fundus images from the MESSIDOR dataset, shows a success rate of 99.07 % for 217 normal images and 95.47 % for 243 pathological images. The mean computational time is 1.709 s for normal images and 1.753 s for pathological images. These results are important for automated detection of glaucoma and for telemedicine purposes.

Birth weight and optic nerve head parameters.

PubMed

Samarawickrama, Chameen; Huynh, Son C; Liew, Gerald; Burlutsky, George; Mitchell, Paul

2009-06-01

To assess the relationship of birth weight, birth length, and head circumference as proxy markers of intrauterine growth, cup/disc ratio, and other optic disc parameters measured using optical coherence tomography (OCT). Population-based cross sectional analysis. The Sydney Childhood Eye Study examined 2353 primarily 12-year-old children from 21 randomly selected secondary schools during 2003 to 2005. Of 2353 children examined, 2134 (90.7%) had OCT scans (Zeiss Stratus OCT, Carl Zeiss Meditec, Dublin, CA) and are included in this study. The "fast" optic disc scan protocol was used. Birth weight, birth length, and head circumference were ascertained from health records. Height and weight were measured using standardized protocols, body mass index (BMI) was defined as weight (kilograms)/ height squared (meters), and sociodemographic information was collected in a questionnaire completed by parents. Low birth weight was defined as birth weight

[Ocular manifestations in patients with systemic lupus erythematosus and antiphospholipid syndrome].

PubMed

Ostanek, Lidia; Modrzejewska, Monika; Bobrowska-Snarska, Danuta; Brzosko, Marek

2007-01-01

Systemic lupus erythematosus (SLE) is a systemic disease of connective tissue with broad band of symptoms. It could be the reason for many organs and tissues impairment. Changes in eyes that occurr in SLE are not frequent, but can lead to severe impairment of sight including blindness. The aim of the work was to asses the frequency of eye changes among patients with SLE and SLE with antiphospholipid syndrome (APS). Another aim was to asses the association between antiphospholipid antibodies and ocular lesions. There were 75 patients enrolled with SLE, 26 of them ha APS. All of patients had a comprehensive ophthalmological and physical examination. Moreover biochemica analysis including lipid profile and glucose metabolism and serological markers of APS and SLE were performe Thirty-six patients complained of ophthalmologic disturbances (48%), with "dry eyes" being the most common symptom (20 patients). The reduced visual acuity was detected in 17 patients (22.6%). Conjunctivitis was found in 8 patients (10.67%), corneal involvement in 31 (41.3%), and sclera changes in 40 patients (53.3%). Changes in retina were found in 15 (20%) of patients, the most frequent were sub-retinal edema in the region of yellow spot. Changes in yellow spot were found in 8 patients; in 2 of them it was associated with dry degenerative changes, in 6 patients exudates with or without hemorrhages were found. Vascular changes including their lumen diameter were found in 33 patients (44%). In 4 patients there were changes in optical nerve disc. Schirmer's test was pathological in 43 patients (57.3%), but in only 4 patients Sjögren's syndrome was diagnosed. In the group of SLE patients intraocular pressure was significantly higher. The presence of anticardiolipin antibodies IgG class (aCL IgG) was associated with reduced visual acuity. The presence of lupus anticoagulant and anti-beta2, glycoprotein-I antibodies (anti-beta2GPI) was associated with conjunctive involvement. The presence of aCL IgM and anti-beta2GPI was associated with less frequent symptoms of eye dryness. We found the following significant factors of the occurrence of eye involvement in our series of SLE patients: high activity of disease (conjuctiva, iris, uvea, retina, spot, vessels and optical nerve disc involvement), late diagnosis of SLE (retinopathy and conjuctive involvement), arterial hypertension (reduced visual acuity, cornea involvement, vessels involvement), age (reduced visual acuity, cornea involvement, retinopathy), glucose metabolism disorders (changes in optical nerve disc) and presence of anti-double stranded DNA antibodies (retinopathy).

Cross-regulatory protein-protein interactions between Hox and Pax transcription factors.

PubMed

Plaza, Serge; Prince, Frederic; Adachi, Yoshitsugu; Punzo, Claudio; Cribbs, David L; Gehring, Walter J

2008-09-09

Homeotic Hox selector genes encode highly conserved transcriptional regulators involved in the differentiation of multicellular organisms. Ectopic expression of the Antennapedia (ANTP) homeodomain protein in Drosophila imaginal discs induces distinct phenotypes, including an antenna-to-leg transformation and eye reduction. We have proposed that the eye loss phenotype is a consequence of a negative posttranslational control mechanism because of direct protein-protein interactions between ANTP and Eyeless (EY). In the present work, we analyzed the effect of various ANTP homeodomain mutations for their interaction with EY and for head development. Contrasting with the eye loss phenotype, we provide evidence that the antenna-to-leg transformation involves ANTP DNA-binding activity. In a complementary genetic screen performed in yeast, we isolated mutations located in the N terminus of the ANTP homeodomain that inhibit direct interactions with EY without abolishing DNA binding in vitro and in vivo. In a bimolecular fluorescence complementation assay, we detected the ANTP-EY interaction in vivo, these interactions occurring through the paired domain and/or the homeodomain of EY. These results demonstrate that the homeodomain supports multiple molecular regulatory functions in addition to protein-DNA and protein-RNA interactions; it is also involved in protein-protein interactions.

Cross-regulatory protein–protein interactions between Hox and Pax transcription factors

PubMed Central

Plaza, Serge; Prince, Frederic; Adachi, Yoshitsugu; Punzo, Claudio; Cribbs, David L.; Gehring, Walter J.

2008-01-01

Homeotic Hox selector genes encode highly conserved transcriptional regulators involved in the differentiation of multicellular organisms. Ectopic expression of the Antennapedia (ANTP) homeodomain protein in Drosophila imaginal discs induces distinct phenotypes, including an antenna-to-leg transformation and eye reduction. We have proposed that the eye loss phenotype is a consequence of a negative posttranslational control mechanism because of direct protein–protein interactions between ANTP and Eyeless (EY). In the present work, we analyzed the effect of various ANTP homeodomain mutations for their interaction with EY and for head development. Contrasting with the eye loss phenotype, we provide evidence that the antenna-to-leg transformation involves ANTP DNA-binding activity. In a complementary genetic screen performed in yeast, we isolated mutations located in the N terminus of the ANTP homeodomain that inhibit direct interactions with EY without abolishing DNA binding in vitro and in vivo. In a bimolecular fluorescence complementation assay, we detected the ANTP–EY interaction in vivo, these interactions occurring through the paired domain and/or the homeodomain of EY. These results demonstrate that the homeodomain supports multiple molecular regulatory functions in addition to protein–DNA and protein–RNA interactions; it is also involved in protein–protein interactions. PMID:18755899

Vitiligo iridis and glaucoma: a rare sequelae of small pox.

PubMed

Kavitha, S; Patel, S R; Mohini, P; Venkatesh, R; Sengupta, S

2015-10-01

Vitiligo iridis refers to focal areas of iris atrophy as sequelae of small pox infection. We report a series of patients with unilateral vitiligo iridis, some of whom presented with secondary open-angle glaucoma. Three patients with vitiligo iridis underwent a comprehensive ophthalmic examination including intraocular pressure (IOP) measurement, slit lamp biomicroscopy, gonioscopy, and fundus evaluation. Patients' facial features were also documented and photographed. All patients were in their sixth decade. Two out the three had elevated IOP (52 mm Hg and 36 mm Hg) in the same eye as vitiligo iridis, at initial presentation. Gonioscopy showed patchy iris hyperpigmentation and fundus evaluation showed glaucomatous optic disc changes in the involved eye. One patient responded favourably to topical antiglaucoma medications, whereas the other was taken up for combined phacoemulsification-trabeculectomy with good results. The third patient had normal IOP in the involved eye. All three patients gave a history of small pox in childhood and had pitted facial scars typical of previous small pox infection. Vitiligo iridis may be associated with the secondary glaucoma as a long-term sequelae of small pox. It may be prudent to periodically follow-up such patients for development of raised IOP in the future.

High-Frequency Oscillations Recorded on the Scalp of Patients With Epilepsy Using Tripolar Concentric Ring Electrodes

PubMed Central

Martínez-Juárez, Iris E.; Makeyev, Oleksandr; Gaitanis, John N.; Blum, Andrew S.; Fisher, Robert S.; Medvedev, Andrei V.

2014-01-01

Epilepsy is the second most prevalent neurological disorder (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}\\(\\sim 1\\) \\end{document}% prevalence) affecting \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}\\(\\sim 67\\) \\end{document} million people worldwide with up to 75% from developing countries. The conventional electroencephalogram is plagued with artifacts from movements, muscles, and other sources. Tripolar concentric ring electrodes automatically attenuate muscle artifacts and provide improved signal quality. We performed basic experiments in healthy humans to show that tripolar concentric ring electrodes can indeed record the physiological alpha waves while eyes are closed. We then conducted concurrent recordings with conventional disc electrodes and tripolar concentric ring electrodes from patients with epilepsy. We found that we could detect high frequency oscillations, a marker for early seizure development and epileptogenic zone, on the scalp surface that appeared to become more narrow-band just prior to seizures. High frequency oscillations preceding seizures were present in an average of 35.5% of tripolar concentric ring electrode data channels for all the patients with epilepsy whose seizures were recorded and absent in the corresponding conventional disc electrode data. An average of 78.2% of channels that contained high frequency oscillations were within the seizure onset or irritative zones determined independently by three epileptologists based on conventional disc electrode data and videos. PMID:27170874

Tracking dynamics of photoreceptor disc shedding with adaptive optics-optical coherence tomography

NASA Astrophysics Data System (ADS)

Zhang, Furu; Liu, Zhuolin; Kurokawa, Kazuhiro; Miller, Donald T.

2017-02-01

Absorption of light by photoreceptors initiates vision, but also leads to accumulation of toxic photo-oxidative compounds in the photoreceptor outer segment (OS). To prevent this buildup, small packets of OS discs are periodically pruned from the distal end of the OS, a process called disc shedding. Unfortunately dysfunction in any part of the shedding event can lead to photoreceptor and RPE dystrophy, and has been implicated in numerous retinal diseases, including age related macular degeneration and retinitis pigmentosa. While much is known about the complex molecular and signaling pathways that underpin shedding, all of these advancements have occurred in animal models using postmortem eyes. How these translate to the living retina and to humans remain major obstacles. To that end, we have recently discovered the optical signature of cone OS disc shedding in the living human retina, measured noninvasively using optical coherence tomography equipped with adaptive optics in conjunction with post processing methods to track and monitor individual cones in 4D. In this study, we improve on this method in several key areas: increasing image acquisition up to MHz A-scan rates, improving reliability to detect disc shedding events, establishing system precision, and developing cone tracking for use across the entire awake cycle. Thousands of cones were successfully imaged and tracked over the 17 hour period in two healthy subjects. Shedding events were detected in 79.5% and 77.4% of the tracked cones. Similar to previous animal studies, shedding prevalence exhibited a diurnal rhythm. But we were surprised to find that for these two subjects shedding occurred across the entire day with broad, elevated frequency in the morning and decreasing frequency as the day progressed. Consistent with this, traces of the average cone OS length revealed shedding dominated in the morning and afternoon and renewal in the evening.

Automated Quantification of Volumetric Optic Disc Swelling in Papilledema Using Spectral-Domain Optical Coherence Tomography

PubMed Central

Wang, Jui-Kai; Kardon, Randy H.; Kupersmith, Mark J.; Garvin, Mona K.

2012-01-01

Purpose. To develop an automated method for the quantification of volumetric optic disc swelling in papilledema subjects using spectral-domain optical coherence tomography (SD-OCT) and to determine the extent that such volumetric measurements correlate with Frisén scale grades (from fundus photographs) and two-dimensional (2-D) peripapillary retinal nerve fiber layer (RNFL) and total retinal (TR) thickness measurements from SD-OCT. Methods. A custom image-analysis algorithm was developed to obtain peripapillary circular RNFL thickness, TR thickness, and TR volume measurements from SD-OCT volumes of subjects with papilledema. In addition, peripapillary RNFL thickness measures from the commercially available Zeiss SD-OCT machine were obtained. Expert Frisén scale grades were independently obtained from corresponding fundus photographs. Results. In 71 SD-OCT scans, the mean (± standard deviation) resulting TR volumes for Frisén scale 0 to scale 4 were 11.36 ± 0.56, 12.53 ± 1.21, 14.42 ± 2.11, 17.48 ± 2.63, and 21.81 ± 3.16 mm3, respectively. The Spearman's rank correlation coefficient was 0.737. Using 55 eyes with valid Zeiss RNFL measurements, Pearson's correlation coefficient (r) between the TR volume and the custom algorithm's TR thickness, the custom algorithm's RNFL thickness, and Zeiss' RNFL thickness was 0.980, 0.929, and 0.946, respectively. Between Zeiss' RNFL and the custom algorithm's RNFL, and the study's TR thickness, r was 0.901 and 0.961, respectively. Conclusions. Volumetric measurements of the degree of disc swelling in subjects with papilledema can be obtained from SD-OCT volumes, with the mean volume appearing to be roughly linearly related to the Frisén scale grade. Using such an approach can provide a more continuous, objective, and robust means for assessing the degree of disc swelling compared with presently available approaches. PMID:22599584

The Practical Aspects of the Visual Act in Studying.

ERIC Educational Resources Information Center

Robinson, Bernard N.

This paper explores the role of vision in reading and studying. "How Vision Occurs" discusses the functions of rods, cones, the cerebral cortex, and the receptor senses. "The Optometrist and the Educator" views the role of the optometrist in relation to student learning. "Eye Anatomy Terms" defines the ciliary muscle, optic disc and nerve, macula…

Transition from film to digital fundus photography in the Longitudinal Studies of the Ocular Complications of AIDS (LSOCA)

PubMed Central

Gangaputra, Sapna; Pak, Jeong Won; Peng, Qian; Hubbard, Larry D.; Thayer, Dennis; Krason, Zbigniew; Joyce, Jeff; Danis, Ronald P.

2014-01-01

Purpose To describe the transition to digital imaging and assess any impact on ocular disease classification. Methods Film and digital images, acquired by certified photographers, were evaluated independently according to standard procedures for the following: image quality, presence of cytomegalovirus (CMV) retinitis lesions, their extent, and proximity from disc and macula. Inter-grader agreement within the digital medium was also assessed. Results Among the fifteen eyes with CMV retinitis, the mean difference between film and digital images for linear distance of lesion edge to disc was 0.02 disc diameters (DD), for distance to center of macula was −0.04 DD and area covered by CMV retinitis was 0.95 disc area (DA). There was no statistically significant difference in distance and area measurements between media. Inter grader agreement in measurements of digital images was excellent for distance and area estimated. Conclusion Our results suggest that digital grading of CMV retinitis in LSOCA is comparable to that from film with respect to disease classification, measurements, and reproducibility. These findings provide support for continuity of grading data, despite the necessary transition in imaging media. PMID:21857393

Characteristics and Ophthalmic Manifestations of the Classic Dengue Fever Epidemic in Singapore (2005-2006).

PubMed

Koh, Yan Tong; Sanjay, Srinivasan

2013-01-01

The aim of this study was to report the characteristics and ophthalmic manifestations associated with dengue fever (DF) in the 2005-2006 DF epidemic in Singapore. A retrospective case series. Eleven patients (7 males, 4 females) who were 14 to 40 years old (mean age, 27.3 years) with visual complaints occurring 1 to 2 weeks after the onset of DF underwent a complete ophthalmologic examination. The presenting visual acuity (VA) ranged from 6/6 to counting fingers. Five patients had bilateral eye involvement. Ophthalmic findings included retinal hemorrhages (15 eyes), cotton wool spots (15 eyes), retinal pigment epithelium alterations (5 eyes), optic disc swelling (3 eyes), foveolitis (3 eyes), and hyperemia (2 eyes). Impaired color vision was noted in 12 eyes. Visual field defects were noted in 13 eyes; 4 of these eyes were asymptomatic. Fundus fluorescein angiography was done in 9 patients; the findings include choroidal hyperfluorescence (9 eyes), blocked fluorescence (8 eyes), and capillary nonperfusion (1 eye). In 2 eyes, it was normal. Electrophysiology confirmed optic neuropathy in 3 eyes and maculopathy in 1 eye. The follow-up ranged from 12 days to 12 months. The VA at the last follow-up ranged from no light perception to 6/6. Visual field abnormalities were noted in 5 eyes despite a normal VA. Dengue fever is associated with a wide spectrum of ophthalmic manifestations. Rarely, ophthalmic complications in DF can result in permanent visual impairment. Further work can be done to elucidate the relationship between systemic and ocular manifestations of DF.

Registration of retinal sequences from new video-ophthalmoscopic camera.

PubMed

Kolar, Radim; Tornow, Ralf P; Odstrcilik, Jan; Liberdova, Ivana

2016-05-20

Analysis of fast temporal changes on retinas has become an important part of diagnostic video-ophthalmology. It enables investigation of the hemodynamic processes in retinal tissue, e.g. blood-vessel diameter changes as a result of blood-pressure variation, spontaneous venous pulsation influenced by intracranial-intraocular pressure difference, blood-volume changes as a result of changes in light reflection from retinal tissue, and blood flow using laser speckle contrast imaging. For such applications, image registration of the recorded sequence must be performed. Here we use a new non-mydriatic video-ophthalmoscope for simple and fast acquisition of low SNR retinal sequences. We introduce a novel, two-step approach for fast image registration. The phase correlation in the first stage removes large eye movements. Lucas-Kanade tracking in the second stage removes small eye movements. We propose robust adaptive selection of the tracking points, which is the most important part of tracking-based approaches. We also describe a method for quantitative evaluation of the registration results, based on vascular tree intensity profiles. The achieved registration error evaluated on 23 sequences (5840 frames) is 0.78 ± 0.67 pixels inside the optic disc and 1.39 ± 0.63 pixels outside the optic disc. We compared the results with the commonly used approaches based on Lucas-Kanade tracking and scale-invariant feature transform, which achieved worse results. The proposed method can efficiently correct particular frames of retinal sequences for shift and rotation. The registration results for each frame (shift in X and Y direction and eye rotation) can also be used for eye-movement evaluation during single-spot fixation tasks.

Diverse Clinical Signs of Ocular Involvement in Cat Scratch Disease.

PubMed

Oray, Merih; Önal, Sumru; Koç Akbay, Aylin; Tuğal Tutkun, İlknur

2017-01-01

To describe ocular manifestations, diagnosis, and treatment of cat scratch disease. Clinical records of patients with ocular cat scratch disease were reviewed. Thirteen eyes of 10 patients (7 female, 3 male) with a mean age of 26.9±18.5 years were included. Nine patients had a history of cat contact and had systemic symptoms associated with cat scratch disease 2-90 days prior to the ocular symptoms. Ocular signs were: neuroretinitis in 4 eyes (associated with serous retinal detachment in the inferior quadrant in 1 eye), optic neuropathy in 2 eyes (1 papillitis and optic disc infiltration, 1 optic neuritis), retinal infiltrates in 6 eyes, retinochoroiditis in 1 eye, branch retinal arteriolar occlusion in 3 eyes, and endophthalmitis in 1 eye. Visual acuities at presentation were 1.0 in 7 eyes, 0.3 in 1 eye, ≤0.1 in 4 eyes, and light perception in 1 eye. Bartonella henselae immunoglobulin (Ig) M and/or IgG were positive in all patients. Systemic antibiotic therapy was administered in all patients. Systemic corticosteroid treatment (15-40 mg/day) was added to the therapy in 4 patients, following 5 days of intravenous pulse methylprednisolone in 2 patients. Treatment was ongoing for 1 patient and the mean treatment duration of the other 9 patients was 47±14.5 days. Visual acuities at final visit were 1.0 in 9 eyes, 0.8 in 1 eye, 0.4 in 1 eye, and no light perception in 1 eye. Cat scratch disease may present with different ocular signs and should be considered in the differential diagnosis in patients with such presentations.

Specific Location of Disc Hemorrhage is Linked to Nerve Fiber Layer Defects.

PubMed

Yoo, Young Cheol; Kim, Joon Mo; Park, Han Seok; Yoo, Chungkwon; Shim, Seong Hee; Won, Yu Sam; Park, Ki Ho; Chang, Robert T

2017-06-01

To investigate the relationship between retinal nerve fiber layer (RNFL) defects and the quadrant and proximal location of disc hemorrhages (DHs) in a large population examined for health screening. A total of 168,044 subjects older than 20 years underwent a single screening ophthalmic examination with color fundus photography as part of a comprehensive health screening program. The presence and location of DHs and RNFL defects were assessed. The DH locations were defined according to the quadrant location (inferotemporal, superotemporal, inferonasal, or superonasal) and the most proximal end of DHs relative to the disc center (cup base, cup margin, disc rim, or extrapapillary region). Using these two location descriptors as independent variables, a logistic regression analysis was conducted to explore the effects of DH location on RNFL defects. Two hundred twenty-six eyes had DH and 120 (53.1%) of them had RNFL defects. After adjusting for proximal location, DHs located in the inferotemporal quadrant accompanied RFNL defects 12 times more frequently than those in the superonasal quadrant (odds ratio [OR], 11.81; P = .004). Conversely, after adjusting for quadrant location, the ORs for an associated RNFL defect were 3.73 (P < .001), 16.54 (P < .001), and 8.91 (P = .002) for DHs with the proximal end at the disc rim, cup margin, and cup base, respectively. Among the four quadrants and four proximal locations, DHs were identified most frequently in the inferotemporal quadrant and outside the disc, respectively. Some DH locations, such as the inferotemporal quadrant and the cup margin, were associated with RNFL defects, whereas others were not.

Diagnostic Accuracy of Nonmydriatic Fundus Photography for the Detection of Glaucoma in Diabetic Patients.

PubMed

Muñoz-Negrete, Francisco J; Contreras, Inés; Oblanca, Noelia; Pinazo-Durán, M Dolores; Rebolleda, Gema

2015-01-01

To determine the diagnostic accuracy for glaucoma of a set of criteria with nonmydriatic monoscopic fundus photography (NMFP) in diabetics. Diabetics recruited from a screening program for diabetic retinopathy and diabetic glaucoma patients recruited from our glaucoma unit were included. Any patient with evidence of diabetic retinopathy was excluded. Diabetic patients had to have no visual field defects to be included as controls. Glaucoma patients had to have a glaucomatous field defect in at least one eye to be included. One NMFP was taken per eye for all subjects. These photographs were evaluated by two masked glaucoma specialists for the presence of the following: bilateral cup to disc (C/D) ratio ≥ 0.6, notching or thinning of the neuroretinal rim, disc hemorrhages, and asymmetry in the C/D ratio between both eyes ≥ 0.2. This evaluation led to a dichotomous classification: if any of the above criteria was present, the patient was classified as glaucoma. If none were present, the patient was classified as normal. 72 control subjects and 72 glaucoma patients were included. Evaluation of NMFP had a sensitivity of 79.17% and a specificity of 80.56% for specialist 1 and a sensitivity of 72.22% and a specificity of 88.88% for specialist 2 for the detection of glaucoma. The overall accuracy was 79.83% and 80.55%, respectively. NMFP evaluation by a glaucoma specialist may be useful for the detection of glaucoma in diabetics.

Space Flight-Induced Intracranial Hypertension: An Ophthalmic Review

NASA Technical Reports Server (NTRS)

Gibson, Charles Robert; Mader, Thomas H.

2010-01-01

Background: Although physiologic and pathologic changes associated with microgravity exposure have been studied extensively, the effect of this environment on the eye is largely unknown. Over the last several years, NASA s Space Medicine Division has documented astronauts presenting with varying degrees of disc edema, globe flattening, choroidal folds, cotton wool spots, and hyperopic shifts after long-duration space flight. Methods: Before and after long-duration space flight, six astronauts underwent complete eye examinations to include cycloplegic and/or manifest refraction and fundus photography. Five of these astronauts had Optical Coherence Tomography (OCT) and Magnetic Resonance Imaging (MRI) performed following their missions. Results: Following exposure to space flight of approximately 6-months duration, six astronauts had neuro-ophthalmic findings. These consisted of disc edema in four astronauts, globe flattening in four astronauts, choroidal folds in four astronauts, cotton wool spots in three astronauts, nerve fiber layer thickening by OCT in five astronauts, and decreased near vision in five astronauts. Four of the astronauts with near vision complaints had a hyperopic shift equal to or greater than + 0.50D between pre- and post-mission spherical equivalent refraction in one or both eyes (range +0.50D to +1.50D). These same four had globe flattening by MRI. Conclusions: The findings we describe may have resulted from a rise in intracranial pressure caused by microgravity fluid shifts, and could represent parts of a spectrum of ocular and cerebral responses to extended microgravity.

[Diagnostic capability of PULSAR, FDT y HRT-II in glaucoma suspects].

PubMed

González-de-la-Rosa, M; González-Hernández, M; Aguilar-Estévez, J; Díaz-Alemán, T; Armas-Plasencia, R

2007-07-01

To determine the diagnostic capability of PULSAR-T30W, FDT-Threshold-N30 and HRT-II in glaucoma suspects. Forty-seven eyes from 47 referred glaucoma suspects (GS) were examined twice with each technique. Cases with TOP-WW-MD>6dB were excluded. Results were compared with those of 70 eyes from 70 normal controls (C). Mean MD value using TOP-WW in the GS group (0.96dB. sd=1.7) was not significantly different from C (0.8dB. sd=1.77) (p>0.05). Disc area in GS group (2.12 mm(2). sd=0.34) was significantly greater than in C (1.97 mm2. sd=0.45) (p<0.01). For 95.7% specificity, PULSAR-sLV showed the highest sensitivity of 30.9% in individual examinations. The highest reproducible sensitivity in the two examinations was obtained using HRT-II maximum contour elevation (23.4%) and reference height (23.4%), and was 14.9% for various indices after correcting for the influence of disc area (cup area, cup/disc area ratio, maximum contour depression and mean RNFL thickness). Reproducible sensitivity of the perimetric indices was: PULSAR-MD=8.5%, PULSAR-sLV=17%, FDT-MD=6.4%, FDT-PSD=4.3%. The association of perimetric and HRT-II indices achieved high sensitivity but low diagnostic reproducibility. The most effective indices were maximum contour elevation, reference height and PULSAR-sLV, although the inclusion of the optic nerve head assessment in the selection of the GS sample may have favored the HRT-II results.

Alterations in retinal nerve fiber layer thickness in early stages of diabetic retinopathy and potential risk factors.

PubMed

Shi, Rui; Guo, Zhonglan; Wang, Feng; Li, Rong; Zhao, Lei; Lin, Rong

2018-02-01

To investigate the loss of retinal nerve fiber layer (RNFL) in type-2 diabetic patients with early-stage diabetic retinopathy (DR) and to identify potential risk factors accounting for these alterations. In this cross-sectional study, 158 type-2 diabetic patients were divided into three groups based on their DR status. RNFL thickness and other optic disc parameters were obtained by optical coherence tomography (OCT) and then compared among different groups. We investigated the potential association between RNFL loss and systemic risk factors for DR, including diabetes duration, body mass index (BMI), serum lipids, hemoglobin A1c (HbA1c) and albumin-creatinine ratio (ACR). One-way ANOVA was carried out to compare RNFL thickness among different groups, Pearson correlation and multivariate linear regression analysis were performed to determine potential risk factors related to RNFL thickness in these patients. There were significant differences in the average (F = 8.872, P = 0.003), superior (F = 8.769, P = 0.004), and inferior (F = 8.857, P = 0.003) RNFL thickness of both eyes among the groups, but no obvious difference in optic disc parameters was found. Diabetic duration, BMI, TG, High density lipoprotein cholesterol (HDL), HbA1c, and ACR were found negatively related to the RNFL thickness in both or single eye according to Pearson correlation analysis. After controlling for age, gender, and axis length (AL) in multivariate linear regression analysis, the diabetic duration was associated significantly with RNFL thickness of superior in both eye (right eye: p = 0.016, left eye: p = 0.024), BMI was related to the nasal quadrant of the right eye (p = 0.034), and TG was related to the inferior of the right eye (p = 0.037), HbA1c (p = 0.026) was associated significantly with the average RNFL thickness of the right eye. In addition, ACR was found negatively related to average (p = 0.042) and inferior quadrant (p = 0.014) of the left eye, respectively. RNFL loss might be the earliest structural change of retina in diabetic patients, and associated with diabetic duration, BMI, TG, HbA1c, and ACR. The conclusions of this study need to be proved by other well-matched and large-scale prospective clinical trials in the future, because the correlations discovered in our study were weak.

Comparative study of optic disc measurement by Copernicus optical coherence tomography and Heidelberg retinal tomography.

PubMed

Yang, Qing-Song; Yu, Ya-Jie; Li, Shu-Ning; Liu, Juan; Hao, Ying-Juan

2012-08-01

Copernicus optical coherence tomography (SOCT) is a new, ultra high-speed and high-resolution instrument available for clinical evaluation of optic nerve. The purpose of the study was to compare the agreements between SOCT and Heidelberg retinal tomography (HRT). A total of 44 healthy normal volunteers were recruited in this study. One eye in each subject was selected randomly. Agreement between SOCT and HRT-3 in measuring optic disc area was assessed using Bland-Altman plots. Relationships between measurements of optic nerve head parameter obtained by SOCT and HRT-3 were assessed by Pearson correlation. There was no significant difference in the average cup area (0.306 vs. 0.355 mm, P = 0.766), cup volume (0.158 vs. 0.130 mm, P = 0.106) and cup/disc ration (0.394 vs. 0.349 mm, P = 0.576) measured by the two instruments. However, other optic disc parameters from SOCT were significantly lower compared with HRT-3. The Bland-Altman plot revealed good agreement of cup area and cup volume measured by SOCT and HRT-3. Bad agreement of disc area, rim area, rim volume and cup/disc ratio were found between SOCT and HRT-3. The highest correlations between the two instruments were observed for cup area (r(2) = 0.783, P = 0.000) and cup/disc ratio (r(2) = 0.669, P = 0.000), whereas the lowest correlation was observed for disc area (r(2) = 0.100, P = 0.037), rim area (r(2) = 0.275, P = 0.000), cup volume (r(2) = 0.005, P = 0.391) and rim volume (r(2) = 0.021, P = 0.346). There were poor agreements between SOCT and HRT-3 for measurement of optic nerve parameters except cup area and cup volume. Measurement results of the two instruments are not interchangeable.

Stopping time: Henry Fox Talbot and the origins of freeze-frame photography.

PubMed

Ramalingam, Chitra

2008-09-01

As an image-making tool for scientists studying the transient, instantaneous photography has long been seen as opening up a visual realm previously inaccessible to the inferior testimony of the human eye. But when photographic pioneer Henry Fox Talbot took the first photograph of a moving object by the light of an electric spark in 1851, he was guided by existing visual practices designed to create instantaneous vision in the eye itself. Exploring the background behind the peculiar subject of his experiment - a mechanically spinning disc - reveals a hidden prehistory of spark-illuminated photography: physicists' pre-photographic techniques for stopping time.

Bilateral Non-arteritic Anterior Ischaemic Optic Neuropathy as the Presentation of Systemic Amyloidosis.

PubMed

Kanaan, M Z; Lorenzi, A R; Thampy, N; Pandit, R; Dayan, Margaret

2017-12-01

A 75-year-old hypertensive female with stable idiopathic intermediate uveitis presented with bilateral sequential optic neuropathy with optic disc swelling. The optic neuropathy in the first affected eye (right) was thought to be due to non-arteritic anterior ischaemic optic neuropathy (NAION). Asymptomatic left optic disc swelling was found at routine review 2 months later, and a diagnosis of giant cell arteritis (GCA) was sought. Temporal artery duplex ultrasound showed the "halo sign," but a subsequent temporal artery biopsy showed light-chain (AL) amyloidosis with no signs of giant cell arteritis. In this case, bilateral sequential ischaemic optic neuropathy mimicking non-arteritic anterior ischaemic optic neuropathy was the presenting sign of systemic amyloidosis involving the temporal arteries.

Quantitative evaluation of reduction of plaque-like hard exudates in diabetic macular edema after intravitreal triamcinolone injection.

PubMed

Cekiç, Osman; Bardak, Yavuz; Tiğ, U Sahin; Yildizoğlu, Uzeyir; Bardak, Handan

2008-04-01

To describe a new method of quantifying the amount of plaque-like hard exudates after intravitreal triamcinolone acetonide injection in diabetic macular edema. This study included 22 eyes of 14 patients (mean age, 63 years) with chronic diabetic macular edema and plaque-like hard exudates. The patients were injected with a single dose of 4 mg intravitreal triamcinolone acetonide. The optic disc size as relative size unit was taken to quantify the hard exudates: Total areas of exudates and the optic nerve head were computed from fundus pictures with a digital analysis program on magnified images. The former was divided by the latter, and the results were expressed as a percentage value. The ratio was used to track improvements in a given eye over 6 months. Average ratio of hard exudates to optic nerve head area reduced to 81% of its initial value at 1 month (P=0.007), to 54% at 3 months (P<0.001) and to 41% at 6 months (P<0.001). The new method allowed detection of a significant reduction of ratio of hard exudates to optic disc area of diabetic plaque-like hard exudates following 4 mg intravitreal triamcinolone.

Into the Chrysalis

NASA Astrophysics Data System (ADS)

2007-09-01

A team of European astronomers has used ESO's Very Large Telescope Interferometer and its razor-sharp eyes to discover a reservoir of dust trapped in a disc that surrounds an elderly star. The discovery provides additional clues about the shaping of planetary nebulae. ESO PR Photo 43/07 ESO PR Photo 43/07 A Disc Around an Aged Star In the last phases of their life, stars such as our Sun evolve from a red giant which would engulf the orbit of Mars to a white dwarf, an object that is barely larger than the Earth. The transition is accomplished by the shedding of a huge envelope of gas and dust that sparkles in many colours, producing a most spectacular object: a planetary nebula. The celestial chrysalis becomes a cosmic butterfly. This metamorphosis, rapid in terms of the star's lifetime, is rather complex and poorly understood. In particular, astronomers want to understand how a spherical star can produce a great variety of planetary nebulae, some with very asymmetrical shapes. A team of scientists therefore embarked upon the study of a star which is presently on its way to becoming a cosmic butterfly. The star, V390 Velorum, is 5000 times as bright as our Sun and is located 2,600 light-years away. It is also known to have a companion that accomplishes its ballet in 500 days. Astronomers postulate that elderly stars with companions possess a reservoir of dust that is thought to play a lead role in the final chapters of their lives. The shape and structure of these reservoirs remain, however, largely unknown. To scrutinise the object with great precision, the astronomers linked observations taken with ESO's powerful interferometric instruments, AMBER and MIDI, at the Very Large Telescope Interferometer. In particular, they combined, using AMBER, the near-infrared light of three of VLT's 8.2-m Unit Telescopes. "Only this triple combination of powerful telescopes allows us to pinpoint the position and the shape of the dusty reservoir on a milli-arcsecond scale," explains Pieter Deroo, lead-author of the paper that presents these results in the research journal Astronomy and Astrophysics. These observations clearly demonstrate that the dust present around the star cannot be distributed in a spherical shell. "This shows that whatever mechanism is shaping asymmetric planetary nebulae is already present prior to the metamorphosis taking place," says Hans Van Winckel, member of the team. The astronomers found indeed evidence for a disc extending from 9 Astronomical Units to several hundreds of AU. "This disc is found around a star that is in a very brief phase of its life - just a blink of an eye over the star's lifespan of billions of years - but this phase is very important," says Deroo. "It is in this period that a huge morphological change occurs, leading to the creation of a planetary nebula," he adds. The very high spatial resolution measurements allowed the astronomers to decouple the unresolved contribution of the central star from the resolved disc emission. Even the very inner structure of the disc as well as its orientation and inclination could be determined. The observations probe the physical nature of the disc and reveal that the dust in the inner rim is extremely hot and puffed up. The disc is circumbinary as it surrounds both stars. Dust processing (coagulation, crystallisation) is found to be very efficient in this circumbinary disc, despite the rather short evolutionary timescales involved. The disc around this evolved object is very similar to those around young stellar objects, in which planets are formed. "The combination of MIDI and AMBER on ESO's VLTI is an extremely powerful and perhaps unique tool to study the geometry of the material around stars," concludes Van Winckel. It looks like it is the season for disc 'hunting': the detection of a dusty disc in the notable Ant Nebula was also just announced (see ESO 42/07).

Statin use and the incidence of advanced age-related macular degeneration in the Complications of Age-related Macular Degeneration Prevention Trial.

PubMed

Maguire, Maureen G; Ying, Gui-shuang; McCannel, Colin A; Liu, Chengcheng; Dai, Yang

2009-12-01

To evaluate the impact of statin use on the incidence of advanced age-related macular degeneration (AMD) and its components, choroidal neovascularization (CNV) and geographic atrophy (GA), among patients with bilateral large drusen. Cohort study within a multicenter, randomized, clinical trial. Patients enrolled in the Complications of Age-related Macular Degeneration Prevention Trial (CAPT). Eligibility criteria for the clinical trial required that participants have >or=10 large (>125 microm) drusen and visual acuity >or=20/40 in each eye. Patients scheduled for their final CAPT visit after May 2005 were interviewed on their history of use of cholesterol-lowering medications, including statins. Trained readers identified CNV and end point GA (>1 Macular Photocoagulation Study disc area of GA) based on review of fluorescein angiograms and fundus photographs taken at annual follow-up visits and when patients reported symptoms. The risk ratio for participants developing CNV or developing GA associated with statin use was estimated with time-dependent Cox proportional hazards models. Development of advanced AMD, CNV, and end point GA. Among 764 patients eligible for the interview, 744 (97.4%) patients completed the interview on medication use. Statin use was reported by 296 (39.8%) of those interviewed, with the majority, 187 (63.2%) of the 296, beginning use after enrollment in CAPT. Among 744 patients, advanced AMD developed in 332 (22.5%) eyes of 242 (32.5%) patients, CNV in 222 (15%) eyes of 176 (23.7%) patients, and GA in 114 (7.7%) eyes of 80 (10.8%) patients. With adjustment for other risk factors, the estimated risk ratio for eyes (95% confidence interval) associated with statin use was 1.15 (0.87-1.52) for advanced AMD, 1.35 (0.99-1.83) for CNV, and 0.80 (0.46-1.39) for GA. The CAPT data are not consistent with a strong protective effect (risk ratio,

[Evaluation of the arterial blood flow parameters in the eye of myopic patients].

PubMed

Mrugacz, Małgorzata; Bryl, Anna

2013-04-01

Myopia is a common refractive defect. Has a good vision from near and deterioration of vision with increasing distance. The main reason for its occurrence is too long axis of the eyeball. The consequence of elongation of the eyeball is the development of degenerative changes in the retina. Despite much research has failed to clearly identify the causes of degenerative changes in those short-sighted. The aim of the study was to evaluate the maximum and minimum speed in arterial blood vessels of the eye in people with myopia. The study included 70 patients (138 eyes), 53 women and 17 men, aged from 18 to 79 years, with myopia of -0.25 to -18.0 Dsph and length of the eyeball from 22.61 to 33.36 mm. Depending on the kind and the degree of the progress of degenerative changes, patients were divided in 4 groups: I - without degenerative changes on the fundus (n=32; K-23, M-9); II- with the short-sighted sickle (n=20; K-14, M-6); Ill - with the structure thinned down of the retina, accompanying the short-sighted sickle (n = 8; K-6, M-2); IV - with extensive choroidal-retina disappearances in the fundus (n = 10; K-7, M-3). In all individuals enrolled underwent Color Doppler ultrasound with apparatus SSA 770A Toshiba Aplio with linear probe frequency 12 MHz, judging maximum (Vmax) and minimum (Vmin) speed in the arteries of the eye: ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (SPCA) located on the nasal and temporal side of the optic disc. The results were statistically analyzed. No statistically significant relationship between the nature of degenerative changes of the eye, and blood velocity in the OA. There was a increase in Vmax and Vmin blood in OA in Group IV, but these changes were not statistically significant. Statistically significant correlation was observed while in the CRA. With a decrease in Vmax and Vmin of blood flowing through a vessel exacerbation of retinal degeneration. Vmax and Vmin changes in the blood did not correlate significantly SPCA with retinal degeneration, although the results were much worse in the temporal vessels. With the deterioration of blood flow parameters of the central retinal artery and short posterior ciliary arteries comes to the severity of the retinal degeneration in myopic patients. More severe impairment of blood circulation in the temporal ciliary explain higher incidence of degenerative changes in the temporal side of the optic disc.

Longitudinal Andhra Pradesh Eye Disease Study: rationale, study design and research methodology.

PubMed

Khanna, Rohit C; Murthy, Gudlavalleti Vs; Marmamula, Srinivas; Mettla, Asha Latha; Giridhar, Pyda; Banerjee, Seema; Shekhar, Konegari; Chakrabarti, Subhabrata; Gilbert, Clare; Rao, Gullapalli N

2016-03-01

The rationale, objectives, study design and procedures for the longitudinal Andhra Pradesh Eye Disease Study are described. A longitudinal cohort study was carried out. Participants include surviving cohort from the rural component of Andhra Pradesh Eye Disease Study. During 1996-2000, Andhra Pradesh Eye Disease Survey was conducted in three rural (n = 7771) and one urban (n = 2522) areas (now called Andhra Pradesh Eye Disease Study 1). In 2009-2010, a feasibility exercise (Andhra Pradesh Eye Disease Study 2) for a longitudinal study (Andhra Pradesh Eye Disease Study 3) was undertaken in the rural clusters only, as urban clusters no longer existed. In Andhra Pradesh Eye Disease Study 3, a detailed interview will be carried out to collect data on sociodemographic factors, ocular and systemic history, risk factors, visual function, knowledge of eye diseases and barriers to accessing services. All participants will also undergo a comprehensive eye examination including photography of lens, optic disc and retina, Optic Coherence Tomography of the posterior segment, anthropometry, blood pressure and frailty measures. Measures include estimates of the incidence of visual impairment and age-related eye disease (lens opacities, glaucoma and age-related macular degeneration) and the progression of eye disease (lens opacities and myopia) and associated risk factors. Of the 7771 respondents examined in rural areas in Andhra Pradesh Eye Disease Study 1, 5447 (70.1%) participants were traced in Andhra Pradesh Eye Disease Study 2. These participants will be re-examined. Andhra Pradesh Eye Disease Study 3 will provide data on the incidence and progression of visual impairment and major eye diseases and their associated risk factors in India. The study will provide further evidence to aid planning eye care services. © 2015 Royal Australian and New Zealand College of Ophthalmologists.

Intravitreal clindamycin and dexamethasone for toxoplasmic retinochoroiditis.

PubMed

Kishore, K; Conway, M D; Peyman, G A

2001-01-01

To present a new method for the management of toxoplasmic retinochoroiditis (TRC). The patients were females ranging in age from 10 to 61 years (average 26.5). Four eyes of 4 patients were treated with intravitreal injections of 1.0 mg clindamycin in 0.1 mL and 1.0 mg of dexamethasone in 0.1 mL. The injections were given under general or peribulbar anesthesia. Three patients continued one systemic drug. Follow-up ranged from 11 to 26 months (mean 17.5). A favorable response was noted in each eye within two weeks after the intravitreal injections. All patients required 2 to 4 intravitreal injections in the affected eye for the control of TRC. Visual acuity improved in each eye. The disc and macula were preserved in all eyes. Recurrence was noted in one case, which responded to a repeated intravitreal injection of clindamycin and dexamethasone. Intravitreal injections of clindamycin and dexamethasone are well tolerated and may offer an additional strategy to treat TRC in patients who are unable to afford or tolerate systemic therapy, or whose disease progresses despite systemic therapy.

Improvement of horizontal macular contraction after surgical removal of epiretinal membranes.

PubMed

Yang, H K; Kim, S J; Jung, Y S; Kim, K G; Kim, J H; Yu, H G

2011-06-01

To determine whether horizontal macular contraction caused by epiretinal membranes (ERMs) improves after surgical removal. In this prospective, single-center, observational study, 63 consecutive patients with unilateral idiopathic ERM in one eye and no retinal disease in the fellow eye underwent pars plana vitrectomy. Fundus photography and optical coherence tomography (OCT) were performed preoperatively and at 3 months postoperatively. The area enclosed by superior and inferior major vessels from the optic disc to the fovea (area under major vessel (AUV)) and the macroscopic diverging angle (MDA) between superior and inferior major vessels were calculated using digital image analysis of fundus photographs and compared pre- and postoperatively. AUV was significantly smaller in the eyes with ERM compared with the normal fellow eyes (P<0.001). Significant postoperative change in AUV and MDA was demonstrated after ERM removal (P<0.001). However, postoperative AUV of grade 2 and 3 ERM eyes was still significantly smaller than that of normal fellow eyes. Macular thickness differences measured with stratus OCT were positively correlated with AUV differences. Retinal topographic changes caused by ERM improved in part after ERM removal. The improvement of topographic changes were correlated with tomographic changes detected with OCT.

Imaginal Disc Abnormalities in Lethal Mutants of Drosophila

PubMed Central

Shearn, Allen; Rice, Thomas; Garen, Alan; Gehring, Walter

1971-01-01

Late lethal mutants of Drosophila melanogaster, dying after the larval stage of development, were isolated. The homozygous mutant larvae were examined for abnormal imaginal disc morphology, and the discs were injected into normal larval hosts to test their capacities to differentiate into adult structures. In about half of the mutants analyzed, disc abnormalities were found. Included among the abnormalities were missing discs, small discs incapable of differentiating, morphologically normal discs with limited capacities for differentiation, and discs with homeotic transformations. In some mutants all discs were affected, and in others only certain discs. The most extreme abnormal phenotype is a class of “discless” mutants. The viability of these mutant larvae indicates that the discs are essential only for the development of an adult and not of a larva. The late lethals are therefore a major source of mutants for studying the genetic control of disc formation. Images PMID:5002822

Notochord Cells in Intervertebral Disc Development and Degeneration

PubMed Central

McCann, Matthew R.; Séguin, Cheryle A.

2016-01-01

The intervertebral disc is a complex structure responsible for flexibility, multi-axial motion, and load transmission throughout the spine. Importantly, degeneration of the intervertebral disc is thought to be an initiating factor for back pain. Due to a lack of understanding of the pathways that govern disc degeneration, there are currently no disease-modifying treatments to delay or prevent degenerative disc disease. This review presents an overview of our current understanding of the developmental processes that regulate intervertebral disc formation, with particular emphasis on the role of the notochord and notochord-derived cells in disc homeostasis and how their loss can result in degeneration. We then describe the role of small animal models in understanding the development of the disc and their use to interrogate disc degeneration and associated pathologies. Finally, we highlight essential development pathways that are associated with disc degeneration and/or implicated in the reparative response of the tissue that might serve as targets for future therapeutic approaches. PMID:27252900

Optic Disc Melanocytoma Report of 5 Patients From Singapore With a Review of the Literature.

PubMed

Lee, Elin; Sanjay, Srinivasan

2015-01-01

The aim of this study was to report the clinical features of optic disc melanocytoma (ODMC). This study was a retrospective case series. Five patients (6 eyes) with ODMC followed up over a mean duration of 3 years (range, 4-61 months) were included in this series. The mean age of diagnosis was 55.2 years with Chinese female predominance. Four of 6 ODMCs were unilateral with predominance to the left side. Four patients had visual acuity of 6/9 or better at presentation, and all ODMCs were discovered incidentally. All ODMCs were black, with an average size of 0.8 disc diameter and partially covering the optic disc. Five of 6 ODMCs were inferiorly located and involved adjacent choroid and retina. Three of 6 ODMCs had ill-defined borders. Fundus fluorescein angiogram findings in 1 patient showed blocked fluorescence due to pigments. No loss of visual acuity of 2 or more Snellen lines, ODMC enlargement, or malignant transformation were noted in any patients during follow-up. There were no local complications. Ocular and systemic associations were not seen. Our case series did not show any features of progression during our follow-up. Annual fundoscopic examinations are still important to detect enlargement and malignant transformation.

En face Doppler total retinal blood flow measurement with 70 kHz spectral optical coherence tomography

NASA Astrophysics Data System (ADS)

Tan, Ou; Liu, Gangjun; Liang, Liu; Gao, Simon S.; Pechauer, Alex D.; Jia, Yali; Huang, David

2015-06-01

An automated algorithm was developed for total retinal blood flow (TRBF) using 70-kHz spectral optical coherence tomography (OCT). The OCT was calibrated for the transformation from Doppler shift to speed based on a flow phantom. The TRBF scan pattern contained five repeated volume scans (2×2 mm) obtained in 3 s and centered on central retinal vessels in the optic disc. The TRBF was calculated using an en face Doppler technique. For each retinal vein, blood flow was measured at an optimal plane where the calculated flow was maximized. The TRBF was calculated by summing flow in all veins. The algorithm tracked vascular branching so that either root or branch veins are summed, but never both. The TRBF in five repeated volumes were averaged to reduce variation due to cardiac cycle pulsation. Finally, the TRBF was corrected for eye length variation. Twelve healthy eyes and 12 glaucomatous eyes were enrolled to test the algorithm. The TRBF was 45.4±6.7 μl/min for healthy control and 34.7±7.6 μl/min for glaucomatous participants (p-value=0.01). The intravisit repeatability was 8.6% for healthy controls and 8.4% for glaucoma participants. The proposed automated method provided repeatable TRBF measurement.

Development of a risk score for geographic atrophy in complications of the age-related macular degeneration prevention trial.

PubMed

Ying, Gui-Shuang; Maguire, Maureen G

2011-02-01

To develop a risk score for developing geographic atrophy (GA) involving easily obtainable information among patients with bilateral large drusen. Cohort study within a multicenter randomized clinical trial. We included 1052 participants with ≥ 10 large (>125 μm) drusen and visual acuity ≥ 20/40 in each eye. In the Complications of Age-related Macular Degeneration (AMD) Prevention Trial (CAPT), 1 eye of each participant was randomly assigned to laser treatment and the contralateral eye was assigned to observation to evaluate whether laser treatment of drusen could prevent vision loss. Gradings by a reading center were used to identify: CAPT end point GA (total area of GA [>250 μm] > 1 disc area), GA (>175 μm) involving the foveal center (CGA), and GA of any size and location (any GA). Established risk factors (age, smoking status, hypertension, Age-related Eye Disease Study simple severity scale score), both with and without a novel risk factor (night vision score), were used in assigning risk points. The risk scores were evaluated for the ability to discriminate and calibrate GA risk. Development of end point GA, CGA, and any GA. Among 942 CAPT participants who completed 5 years of follow-up and did not have any GA at baseline, 6.8% participants developed CAPT end point GA, 9.6% developed CGA, and 34.4% developed any GA. The 5-year incidence of end point GA in 1 or both eyes of a participant increased with the 15-point GA risk score, from 0.6% for <7 points to 15% for ≥ 12 points. The 5-factor risk score predicted development of GA moderately well with the area under the receiver operating characteristic curve (AUC) 0.76 (95% confidence interval [CI], 0.71-0.81) for end point GA; 0.76 (95% CI, 0.71-0.80) for CGA, and 0.68 (95% CI, 0.65-0.72) for any GA. Prediction from the risk score without the night vision score had lower AUCs (range, 0.67-0.72). If validated in other patients, the GA risk score will be useful for identifying high-risk patients for clinical trials of prevention of GA and for clinical assessment of GA risk in early AMD patients. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Long-term Results of the UCSF-LBNL Randomized Trial: Charged Particle With Helium Ion Versus Iodine-125 Plaque Therapy for Choroidal and Ciliary Body Melanoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishra, Kavita K., E-mail: Kavita.mishra@ucsf.edu; Quivey, Jeanne M.; Daftari, Inder K.

Purpose: Relevant clinical data are needed given the increasing national interest in charged particle radiation therapy (CPT) programs. Here we report long-term outcomes from the only randomized, stratified trial comparing CPT with iodine-125 plaque therapy for choroidal and ciliary body melanoma. Methods and Materials: From 1985 to 1991, 184 patients met eligibility criteria and were randomized to receive particle (86 patients) or plaque therapy (98 patients). Patients were stratified by tumor diameter, thickness, distance to disc/fovea, anterior extension, and visual acuity. Tumors close to the optic disc were included. Local tumor control, as well as eye preservation, metastases due tomore » melanoma, and survival were evaluated. Results: Median follow-up times for particle and plaque arm patients were 14.6 years and 12.3 years, respectively (P=.22), and for those alive at last follow-up, 18.5 and 16.5 years, respectively (P=.81). Local control (LC) for particle versus plaque treatment was 100% versus 84% at 5 years, and 98% versus 79% at 12 years, respectively (log rank: P=.0006). If patients with tumors close to the disc (<2 mm) were excluded, CPT still resulted in significantly improved LC: 100% versus 90% at 5 years and 98% versus 86% at 12 years, respectively (log rank: P=.048). Enucleation rate was lower after CPT: 11% versus 22% at 5 years and 17% versus 37% at 12 years, respectively (log rank: P=.01). Using Cox regression model, likelihood ratio test, treatment was the most important predictor of LC (P=.0002) and eye preservation (P=.01). CPT was a significant predictor of prolonged disease-free survival (log rank: P=.001). Conclusions: Particle therapy resulted in significantly improved local control, eye preservation, and disease-free survival as confirmed by long-term outcomes from the only randomized study available to date comparing radiation modalities in choroidal and ciliary body melanoma.« less

Validation of the UNC OCT Index for the Diagnosis of Early Glaucoma

PubMed Central

Lee, Gary; Budenz, Donald L.; Warren, Joshua L.; Wall, Michael; Artes, Paul H.; Callan, Thomas M.; Flanagan, John G.

2018-01-01

Purpose To independently validate the performance of the University of North Carolina Optical Coherence Tomography (UNC OCT) Index in diagnosing and predicting early glaucoma. Methods Data of 118 normal subjects (118 eyes) and 96 subjects (96 eyes) with early glaucoma defined as visual field mean deviation (MD) greater than −4 decibels (dB), aged 40 to 80 years, and who were enrolled in the Full-Threshold Testing Size III, V, VI comparison study were used in this study. CIRRUS OCT average and quadrants' retinal nerve fiber layer (RNFL); optic disc vertical cup-to-disc ratio (VCDR), cup-to-disc area ratio, and rim area; and average, minimum, and six sectoral ganglion cell-inner plexiform layer (GCIPL) measurements were run through the UNC OCT Index algorithm. Area under the receiver operating characteristic curve (AUC) and sensitivities at 95% and 99% specificity were calculated and compared between single parameters and the UNC OCT Index. Results Mean age was 60.1 ± 11.0 years for normal subjects and 66.5 ± 8.1 years for glaucoma patients (P < 0.001). MD was 0.29 ± 1.04 dB and −1.30 ± 1.35 dB in normal and glaucomatous eyes (P < 0.001), respectively. The AUC of the UNC OCT Index was 0.96. The best single metrics when compared to the UNC OCT Index were VCDR (0.93, P = 0.054), average RNFL (0.92, P = 0.014), and minimum GCIPL (0.91, P = 0.009). The sensitivities at 95% and 99% specificity were 85.4% and 76.0% (UNC OCT Index), 71.9% and 62.5% (VCDR, all P < 0.001), 64.6% and 53.1% (average RNFL, all P < 0.001), and 66.7% and 58.3% (minimum GCIPL, all P < 0.001), respectively. Conclusions The findings confirm that the UNC OCT Index may provide improved diagnostic perforce over that of single OCT parameters and may be a good tool for detection of early glaucoma. Translational Relevance The UNC OCT Index algorithm may be incorporated easily into routine clinical practice and be useful for detecting early glaucoma. PMID:29629238

Validation of the UNC OCT Index for the Diagnosis of Early Glaucoma.

PubMed

Mwanza, Jean-Claude; Lee, Gary; Budenz, Donald L; Warren, Joshua L; Wall, Michael; Artes, Paul H; Callan, Thomas M; Flanagan, John G

2018-04-01

To independently validate the performance of the University of North Carolina Optical Coherence Tomography (UNC OCT) Index in diagnosing and predicting early glaucoma. Data of 118 normal subjects (118 eyes) and 96 subjects (96 eyes) with early glaucoma defined as visual field mean deviation (MD) greater than -4 decibels (dB), aged 40 to 80 years, and who were enrolled in the Full-Threshold Testing Size III, V, VI comparison study were used in this study. CIRRUS OCT average and quadrants' retinal nerve fiber layer (RNFL); optic disc vertical cup-to-disc ratio (VCDR), cup-to-disc area ratio, and rim area; and average, minimum, and six sectoral ganglion cell-inner plexiform layer (GCIPL) measurements were run through the UNC OCT Index algorithm. Area under the receiver operating characteristic curve (AUC) and sensitivities at 95% and 99% specificity were calculated and compared between single parameters and the UNC OCT Index. Mean age was 60.1 ± 11.0 years for normal subjects and 66.5 ± 8.1 years for glaucoma patients ( P < 0.001). MD was 0.29 ± 1.04 dB and -1.30 ± 1.35 dB in normal and glaucomatous eyes ( P < 0.001), respectively. The AUC of the UNC OCT Index was 0.96. The best single metrics when compared to the UNC OCT Index were VCDR (0.93, P = 0.054), average RNFL (0.92, P = 0.014), and minimum GCIPL (0.91, P = 0.009). The sensitivities at 95% and 99% specificity were 85.4% and 76.0% (UNC OCT Index), 71.9% and 62.5% (VCDR, all P < 0.001), 64.6% and 53.1% (average RNFL, all P < 0.001), and 66.7% and 58.3% (minimum GCIPL, all P < 0.001), respectively. The findings confirm that the UNC OCT Index may provide improved diagnostic perforce over that of single OCT parameters and may be a good tool for detection of early glaucoma. The UNC OCT Index algorithm may be incorporated easily into routine clinical practice and be useful for detecting early glaucoma.

Risk factors for open-angle glaucoma in Nigeria: results from the Nigeria National Blindness and Visual Impairment Survey.

PubMed

Kyari, Fatima; Abdull, Mohammed M; Wormald, Richard; Evans, Jennifer R; Nolan, Winifred; Murthy, Gudlavelleti V S; Gilbert, Clare E

2016-06-07

The glaucoma-specific blindness prevalence in Nigeria (0.7 %, 95 % CI 0.6-0.9 %) among those aged ≥40 years is one of the highest ever reported. This study determined the risk factors for open-angle glaucoma (OAG) in adults examined in the Nigeria National Blindness and Visual Impairment Survey. A nationally representative sample of 13,591 people aged ≥40 years in 305 clusters in Nigeria were examined (response rate 90.4 %) between January 2005 to June 2007. Everyone had logMAR visual acuity measurement, Frequency Doubling Technology (FDT) visual field testing, autorefraction, A-scan biometry and optic disc assessment. Full ocular examination (n = 6397), included Goldmann applanation tonometry. Values for defining glaucoma using International Society of Geographical and Epidemiological Ophthalmology criteria were derived from the study population. Disc images were graded by Moorfields Eye Hospital Reading Centre. Socio-demographic factors (age, gender, ethnicity, literacy and place of residence), ocular parameters (intraocular pressure [IOP], axial length and mean ocular perfusion pressure [MOPP]) and systemic parameters (blood pressure, blood glucose and body mass index [BMI]) were assessed for association with OAG. Thirteen thousand eighty-one (96 %) of 13,591 participants had vertical cup:disc ratio measured in at least one eye. 682 eyes of 462 participants were classified as OAG, with 12,738 controls. In univariate analyses the following were associated with OAG: increasing age, male gender, Igbo and Yoruba ethnic groups, illiteracy, longer axial length, higher IOP, lower MOPP, greater severity of hypertension and low BMI (underweight). In multivariate analysis, increasing age (odds ratio [OR] 1.04, 95 % CI 1.03-1.05), higher IOP (OR 1.22, 95 % CI 1.18-1.25) and Igbo ethnicity (OR 1.73, 95 % CI 1.18-2.56) were independent risk factors for OAG. Case detection strategies for OAG should be improved for those aged ≥40 years and for ethnic groups most at risk as a public health intervention.

Angle-closure glaucoma in an urban population in southern India. The Andhra Pradesh eye disease study.

PubMed

Dandona, L; Dandona, R; Mandal, P; Srinivas, M; John, R K; McCarty, C A; Rao, G N

2000-09-01

To assess the prevalence and features of angle-closure glaucoma (ACG) in an urban population in southern India. A population-based, cross-sectional study. A total of 2522 (85.4% of those eligible) persons of all ages, including 1399 persons 30 years of age or older, from 24 clusters representative of the population of Hyderabad city. The participants underwent an interview and detailed eye examination that included logarithm of minimum angle of resolution visual acuity, refraction, slit-lamp biomicroscopy, applanation tonometry, and gonioscopy; pupil dilatation and stereoscopic fundus evaluation was performed if the risk of angle-closure as a result of dilatation was not believed to be imminent. Humphrey threshold 24-2 visual fields (Humphrey Instruments Inc., San Leandro, CA) were performed when indicated by standardized criteria for disc damage or if intraocular pressure (IOP) was 22 mmHg or more. An occludable angle was defined as pigmented posterior trabecular meshwork not visible by gonioscopy in three quarters or more of the angle circumference. Manifest primary angle-closure glaucoma (PACG) was defined as IOP of 22 mmHg or more or glaucomatous optic disc damage with visual field loss in the presence of an occludable angle. An IOP of 22 mmHg or more or glaucomatous optic disc damage in the presence of an occludable angle secondary to an obvious cause was defined as secondary ACG. Manifest PACG and occludable angles without ACG were present in 12 and 24 participants, respectively, with age- and gender-adjusted prevalence (95% confidence interval [CI]) of 0.71% (0.34%-1.31%) and 1.41% (0.73%-2.09%) in participants 30 years of age or older, and 1.08% (0.36%-1.80%) and 2.21% (1.15%-3.27%) in participants 40 years of age or older, respectively. With multivariate analysis, the prevalence of these two conditions considered together increased significantly with age (P < 0.001); although not statistically significant, these were more common in females (odds ratio 1.70; 95% CI, 0.82-3.54) and in those belonging to lower socioeconomic strata as compared with middle and upper strata (odds ratio, 1.82; 95% CI, 0.88-3.74). The odds of manifest PACG were higher in the presence of hyperopia of more than 2 diopters ([D]; odds ratio, 3.69; 95% CI, 0.89-15.2). Only four of 12 participants (33.3%) with manifest PACG had been previously diagnosed, and one of 12 (8.3%) had peripheral iridotomy performed previously. Manifest PACG had caused blindness in one or both eyes in five of these 12 participants (41.7%); best-corrected distance visual acuity less than 20/400 in one or both eyes in four patients, and acuity less than 20/200 in one eye in another patient. Most (83.3%) of those with manifest PACG could be classified as having chronic form of the disease. We may have underestimated manifest PACG because visual fields were per- formed only on those with clinical suspicion of optic disc damage. Secondary ACG was present in two participants. The prevalence of PACG in this urban population in southern India is close to that reported recently in a Mongolian population. A large proportion of the PACG in this population was undiagnosed and untreated. Because visual loss resulting from PACG is potentially preventable if peripheral iridotomy or iridectomy is performed in the early stage, strategies for early detection of PACG could reduce the high risk of blindness resulting from PACG seen in this urban population in India.

Diagnostic power of optic disc morphology, peripapillary retinal nerve fiber layer thickness, and macular inner retinal layer thickness in glaucoma diagnosis with fourier-domain optical coherence tomography.

PubMed

Huang, Jehn-Yu; Pekmezci, Melike; Mesiwala, Nisreen; Kao, Andrew; Lin, Shan

2011-02-01

To evaluate the capability of the optic disc, peripapillary retinal nerve fiber layer (P-RNFL), macular inner retinal layer (M-IRL) parameters, and their combination obtained by Fourier-domain optical coherent tomography (OCT) in differentiating a glaucoma suspect from perimetric glaucoma. Two hundred and twenty eyes from 220 patients were enrolled in this study. The optic disc morphology, P-RNFL, and M-IRL were assessed by the Fourier-domain OCT (RTVue OCT, Model RT100, Optovue, Fremont, CA). A linear discriminant function was generated by stepwise linear discriminant analysis on the basis of OCT parameters and demographic factors. The diagnostic power of these parameters was evaluated with receiver operating characteristic (ROC) curve analysis. The diagnostic power in the clinically relevant range (specificity ≥ 80%) was presented as the partial area under the ROC curve (partial AROC). The individual OCT parameter with the largest AROC and partial AROC in the high specificity (≥ 80%) range were cup/disc vertical ratio (AROC = 0.854 and partial AROC = 0.142) for the optic disc parameters, average thickness (AROC = 0.919 and partial AROC = 0.147) for P-RNFL parameters, inferior hemisphere thickness (AROC = 0.871 and partial AROC = 0.138) for M-IRL parameters, respectively. The linear discriminant function further enhanced the ability in detecting perimetric glaucoma (AROC = 0.970 and partial AROC = 0.172). Average P-RNFL thickness is the optimal individual OCT parameter to detect perimetric glaucoma. Simultaneous evaluation on disc morphology, P-RNFL, and M-IRL thickness can improve the diagnostic accuracy in diagnosing glaucoma.

Joint optic disc and cup boundary extraction from monocular fundus images.

PubMed

Chakravarty, Arunava; Sivaswamy, Jayanthi

2017-08-01

Accurate segmentation of optic disc and cup from monocular color fundus images plays a significant role in the screening and diagnosis of glaucoma. Though optic cup is characterized by the drop in depth from the disc boundary, most existing methods segment the two structures separately and rely only on color and vessel kink based cues due to the lack of explicit depth information in color fundus images. We propose a novel boundary-based Conditional Random Field formulation that extracts both the optic disc and cup boundaries in a single optimization step. In addition to the color gradients, the proposed method explicitly models the depth which is estimated from the fundus image itself using a coupled, sparse dictionary trained on a set of image-depth map (derived from Optical Coherence Tomography) pairs. The estimated depth achieved a correlation coefficient of 0.80 with respect to the ground truth. The proposed segmentation method outperformed several state-of-the-art methods on five public datasets. The average dice coefficient was in the range of 0.87-0.97 for disc segmentation across three datasets and 0.83 for cup segmentation on the DRISHTI-GS1 test set. The method achieved a good glaucoma classification performance with an average AUC of 0.85 for five fold cross-validation on RIM-ONE v2. We propose a method to jointly segment the optic disc and cup boundaries by modeling the drop in depth between the two structures. Since our method requires a single fundus image per eye during testing it can be employed in the large-scale screening of glaucoma where expensive 3D imaging is unavailable. Copyright © 2017 Elsevier B.V. All rights reserved.

Insights into autofluorescence patterns in Stargardt macular dystrophy using ultra-wide-field imaging.

PubMed

Kumar, Vinod

2017-10-01

To characterize autofluorescence (AF) patterns occurring in Stargardt macular dystrophy (STGD1) using ultra-wide-field (UWF) imaging. This paper is a cross-sectional observational study of 22 eyes of 11 patients (mean age 23.44 years) with Stargardt disease-fundus flavimaculatus who presented with decrease of vision at a tertiary eye care center. UWF short-wave AF images were obtained from all the patients using an Optos TX200 instrument. The main outcome measures were to assess patterns of AF changes seen on UWF AF imaging. All eyes showed a central area of hypoautofluorescence at the macula along with retinal flecks extending centrifugally as well as to the nasal side of the optic disc. Peripapillary sparing was seen in 100% of the eyes. Flecks were seen to be hypoautofluorescent in the center and hyperautofluorescent in the periphery in 77.8% eyes and were only hyperfluorescent in 27.2%. A background-increased fluorescence was visible in 100% of eyes, the outer boundary of which was marked by distribution of flecks in 81.9% eyes. A characteristic inferonasal vertical line was seen separating the nasal hypoautofluorescent area from the temporal hyperautofluorescent area in all the eyes. UWF AF changes in STGD1 are not limited to the posterior pole and may extend more peripherally. UWF imaging is a useful tool for the assessment of patients with Stargardt macular dystrophy.

Correlation between glycemic control and peripapillary retinal nerve fiber layer thickness in Saudi type II diabetics

PubMed Central

Fahmy, Rania M; Bhat, Ramesa S; Al-Mutairi, Manar; Aljaser, Feda S; El-Ansary, Afaf

2018-01-01

Objective To evaluate the effect of diabetes mellitus (DM), diabetic retinopathy, and degree of glycemic control (glycosylated hemoglobin [HbA1c]) on peripapillary retinal nerve fiber layer thickness (RNFLT) using optical coherence tomography. Methods The study included 126 eyes of healthy controls (n=32) and diabetics patients (n=31), whose ages ranged from 40 to 70 years. The diabetic group was divided into: Subgroup 1: with HbA1c <7% and Subgroup 2: with HbA1c ≥7%. All patients underwent full ophthalmic examination. HbA1c level was obtained with the A1cNow+ system and the peripapillary RNFLT was measured using 3D-OCT 2000 Topcon (360-degree circular scan with 3.4 mm diameter centered on optic disc). Results The obtained data demonstrates significant decrease in peripapillary RNFLT in superior and inferior quadrants of the right eye (p=0.000 and p=0.039, respectively), and in superior quadrant of the left eye (p=0.002) with impairment of glycemic control. Pearson’s correlation test showed significant negative correlation of RNFLT with HbA1c in the superior quadrant in both eyes. Conclusion Impairment of glycemic control affects the peripapillary RNFLT mainly in the superior quadrant. This thickness also tends to decrease with long-standing DM, use of DM medications, and development of diabetic retinopathy. The measurement of peripapillary RNFLT may become a useful method to monitor early retinal changes in diabetic patients. PMID:29535499

Diagnostic ability of macular ganglion cell-inner plexiform layer thickness in glaucoma suspects.

PubMed

Xu, Xiaoyu; Xiao, Hui; Guo, Xinxing; Chen, Xiangxi; Hao, Linlin; Luo, Jingyi; Liu, Xing

2017-12-01

The purpose is to assess the diagnostic ability for early glaucoma of macular ganglion cell-inner plexiform layer (GCIPL) thickness in a Chinese population including glaucoma suspects.A total of 367 eyes with primary open-angle glaucoma (168 early glaucoma, 78 moderate glaucoma, and 121 advanced glaucoma), 52 eyes with ocular hypertension (OHT), 59 eyes with enlarged cup-to-disc ratio (C/D), and 225 normal eyes were included. GCIPL thickness (average, minimum, superotemporal, superior, superonasal, inferonasal, inferior, and inferotemporal), retinal nerve fiber layer (RNFL) thickness, and optic nerve head (ONH) parameters were measured using Cirrus high-definition optical coherence tomography (OCT) and compared. The diagnostic ability of OCT parameters was assessed by area under receiver operating characteristic curve (AUROC) in 3 distinguishing groups: normal eyes and eyes with early glaucoma, normal eyes and eyes with glaucoma regardless of disease stage, and nonglaucomatous eyes (normal eyes, eyes with OHT, and enlarged C/D) and early glaucomatous eyes.Glaucomatous eyes showed a significant reduction in GCIPL thickness compared with nonglaucomatous eyes. In all 3 distinguishing groups, best-performing parameters of GCIPL thickness, RNFL thickness, and ONH parameters were minimum GCIPL thickness (expressed in AUROC, 0.899, 0.952, and 0.900, respectively), average RNFL thickness (0.904, 0.953, and 0.892, respectively), and rim area (0.861, 0.925, and 0.824, respectively). There was no statistical significance of AUROC between minimum GCIPL thickness and average RNFL thickness (all P > .05).GCIPL thickness could discriminate early glaucoma from normal and glaucoma suspects with good sensitivity and specificity. The glaucoma diagnostic ability of GCIPL thickness was comparable to that of RNFL thickness. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Multifocal Choroiditis with Retinal Vasculitis, Optic Neuropathy, and Keratoconus in a Young Saudi Male.

PubMed

Dhafiri, Yousef; Al Rubaie, Khalid; Kirat, Omar; May, William N; Nguyen, Quan D; Kozak, Igor

2017-01-01

The purpose of this study is to describe an association of unilateral multifocal choroiditis (MFC), retinal vasculitis, optic neuropathy, and bilateral keratoconus in a young Saudi male. A 27-year-old male patient with stable bilateral keratoconus presented with a painless vision loss in his left eye. Ophthalmic examinations revealed multiple foci of idiopathic chorioretinitis, retinal vasculitis, and mild optic disc leakage on fluorescein angiography, all of which resolved on systemic therapy with mycophenolate mofetil and prednisone after 3 months. Systemic medication was stopped after 8 months. One year after presentation, patient's visual acuity has improved and remained stable. Systemic immunomodulatory therapy can be effective in managing and leading to resolution of MFC, retinal vasculitis, and optic disc leak in young patients.

Comparative study of the innervation of the facila disc of selected mammals.

PubMed

Montagna, W; Roman, N A; Macpherson, E

1975-11-01

The greatest concentration of sensory nerves in the muzzle and facial disc of mammals is in the nose. In most nocturnal mammals, these nerves penetrate the epidermis of the naked nose either or in bundles which resemble the corpuscles of Eimer. The hair follicles around the nose, lips, and eyes, as well as the heaviply innervated vibrissae follicles found in all hairy mammals except man, are well innervated; those elsewhaere are not. Everywhere on the human body both large and small follicles abound in sensory nerves. These morphologic observations suggest that in most mammals the most sensitivie areas of the skin are at the anterior and posterior ends (not reported here), and that human skin is better equipped for cutaneous sensibility than that of any other mammal.

[Vitrectomy and gas-fluid exchange for the treatment of serous macular detachment due to optic disc pit: long-term evaluation].

PubMed

Moreira Neto, Carlos Augusto; Moreira Junior, Carlos Augusto

2013-01-01

To evaluate 5 patients with serous macular detachment due to optic disc pit that were submitted to pars plana vitrectomy and were followed for at least 7 years. Patients were submitted to pars plana vitrectomy, posterior hyaloid removal, autologous serum injection and gas-fluid exchange, without laser photocoagulation, and were evaluated pre and post-operatively with visual acuity and Amsler grid testing, retinography, and recently, with autofluorescence imaging and high resolution OCT. All 5 eyes improved visual acuity significantly following the surgical procedure maintaining good vision throughout the follow-up period. Mean pre-operative visual acuity was 20/400 and final visual acuity was 20/27 with a mean follow-up time of 13.6 years. No recurrences of serous detachments were observed. OCT examinations demonstrated an attached retina up to the margin of the pit. Serous macular detachments due to optic disc pits were adequately treated with pars plana vitrectomy and gas fluid exchange, without the need for laser photocoagulation, maintaining excellent visual results for a long period of time.

Evolution of reticular pseudodrusen.

PubMed

Sarks, John; Arnold, Jennifer; Ho, I-Van; Sarks, Shirley; Killingsworth, Murray

2011-07-01

To report observations relating to the clinical recognition and possible basis of reticular pseudodrusen (RPD). This retrospective study reports the evolution of RPD in 166 patients who had follow-up of over 1 year using multiple imaging techniques. Mean age when first seen was 73.3 years and the mean period of observation was 4.9 years (range 1-18 years). Associated macular changes were recorded. RPD were first identified in the upper fundus as a reticular network, which then became less obvious, developing a diffuse yellowish appearance. RPD also faded around choroidal neovascularisation (CNV). RPD therefore could be transient but the pattern often remained visible outside the macula or nasal to the discs. Manifestations of age-related macular degeneration (AMD) were present in nearly all eyes and there was a particularly high association with CNV (52.1%). In one clinicopathological case abnormal material was found in the subretinal space. The prevalence of RPD may be underestimated because their recognition depends upon the imaging method used, the area of fundus examined and the confusion with typical drusen. The pathology of one eye suggests that RPD may correspond to material in the subretinal space.

The operation was a success, but the patient cannot see.

PubMed

Semmer, Anne E; Lee, Michael S; Taban, Mehran; Smith, Scott; Kosmorsky, Gregory

2009-01-01

A 71-year-old African American woman presented with severe vision loss in her left eye one day following trabeculectomy with mitomycin C and retrobulbar anesthesia. She had a new left relative afferent pupillary defect and macular whitening. The optic disc appeared normal. Intraocular pressure and fluorescein angiography were normal. Westergren erythrocyte sedimentation rate and C-reactive protein were elevated. Temporal artery biopsy was positive for giant cell arteritis.

Ocular refractive and biometric characteristics in patients with tilted disc syndrome.

PubMed

Dehghani, Cirous; Nowroozzadeh, Mohammad Hosein; Shankar, Sunita; Razeghinejad, Mohammad Reza

2010-12-01

Tilted disc syndrome (TDS) is associated with characteristic ocular findings. The purpose of this study was to evaluate the ocular, refractive, and biometric characteristics in patients with TDS. This case-control study included 41 eyes of 25 patients who had established TDS and 40 eyes of 20 healthy control subjects. All participants underwent a complete ocular examination, including refraction and analysis using Fourier transformation, slit lamp biomicroscopy, pachymetry, keratometry, and ocular biometry. Corneal topography examinations were performed in the syndrome group only. There were no significant differences in spherical equivalent (P = 0.13) and total astigmatism (P = 0.37) between groups. However, mean best spectacle-corrected visual acuity (Log Mar) was significantly worse in TDS patients (P = 0.003). The lenticular astigmatism was greater in the syndrome group, whereas the corneal component was greater in controls (P = 0.059 and P = 0.028, respectively). The measured biometric features were the same in both groups, except for the lens thickness and lens-axial length factor, which were greater in the TDS group (P = 0.007 and P = 0.055, respectively). Clinically significant lenticular astigmatism, more oblique corneal astigmatism, and thicker lenses were characteristic findings in patients with TDS. Copyright © 2010 American Optometric Association. Published by Elsevier Inc. All rights reserved.

Macular detachment associated with an optic pit: optical coherence tomography patterns and surgical outcomes.

PubMed

Skaat, Alon; Moroz, Iris; Moisseiev, Joseph

2013-01-01

To describe the different optical coherence tomography (OCT) patterns in macular detachment associated with an optic disc pit and their long-term evolution following vitrectomy.
 The data of 5 patients (9-43 years of age) with unilateral macular detachment associated with an optic disc pit, who had at least 1 year of follow-up, were compiled. Pars plana vitrectomy combined with gas tamponade was performed as the primary procedure in all patients. The OCT scans, best-corrected visual acuity (BCVA), and anatomic outcomes were documented.
 Two main OCT patterns were identified: a multilayer schisis pattern and a serous detachment pattern. Patients with multilayer schisis pattern were older and demonstrated worse mean preoperative (20/160) and postoperative (20/50) BCVA compared to serous detachment pattern patients (20/30 and 20/20, respectively). An average of 2.3 procedures per patient was needed in the multilayer schisis pattern compared to just one procedure in the serous detachment pattern. In 3 patients, additional pneumatic retinopexy was performed with full resolution of the subretinal fluid achieved.
 Two distinct OCT patterns were observed in eyes with macular detachments with an optic pit, with different clinical features and prognoses. Excellent final visual acuity was obtained in all eyes, including those that required several surgical procedures.

Vitreous cinematography in the study of vitreoretinal diseases.

PubMed

Trempe, C L; Takahashi, M; Freeman, H M

1981-07-01

A new technique of vitreous cinematography involves scanning of the vitreous cavity using optical sections to provide objective, reproducible information on the dynamics of the posterior vitreous and vitreoretinal relationships. Using a newly developed preset lens (El Bayadi-Kajiura lens), this technique makes it possible to document an entire optical section of the posterior vitreous. This is done by mechanically displacing the vitreous so that maximum reflectivity can be obtained from the vitreous gel. This article describes the technique and presents clinical examples documenting complete and incomplete vitreous detachment in normal eyes, Cloquet's canal associated with an optic disc pit, vitreous traction associated with a lamellar hole in an area of preretinal macular fibrosis, and vitreous traction at the anterior flap of a retinal break.

Comparison of optic area measurement using fundus photography and optical coherence tomography between optic nerve head drusen and control subjects.

PubMed

Flores-Rodríguez, Patricia; Gili, Pablo; Martín-Ríos, María Dolores; Grifol-Clar, Eulalia

2013-03-01

To compare optic disc area measurement between optic nerve head drusen (ONHD) and control subjects using fundus photography, time-domain optical coherence tomography (TD-OCT) and spectral-domain optical coherence tomography (SD-OCT). We also made a comparison between each of the three techniques. We performed our study on 66 eyes (66 patients) with ONHD and 70 healthy control subjects (70 controls) with colour ocular fundus photography at 20º (Zeiss FF 450 IR plus), TD-OCT (Stratus OCT) with the Fast Optic Disc protocol and SD-OCT (Cirrus OCT) with the Optic Disc Cube 200 × 200 protocol for measurement of the optic disc area. The measurements were made by two observers and in each measurement a correction of the image magnification factor was performed. Measurement comparison using the Student's t-test/Mann-Whitney U test, the intraclass correlation coefficient, Pearson/Spearman rank correlation coefficient and the Bland-Altman plot was performed in the statistical analysis. Mean and standard deviation (SD) of the optic disc area in ONHD and in controls was 2.38 (0.54) mm(2) and 2.54 (0.42) mm(2), respectively with fundus photography; 2.01 (0.56) mm(2) and 1.66 (0.37) mm(2), respectively with TD-OCT, and 2.03 (0.49) mm(2) and 1.75 (0.38) mm(2), respectively with SD-OCT. In ONHD and controls, repeatability of optic disc area measurement was excellent with fundus photography and optical coherence tomography (TD-OCT and SD-OCT), but with a low degree of agreement between both techniques. Optic disc area measurement is smaller in ONHD compared to healthy subjects with fundus photography, unlike time-domain and spectral-domain optical coherence tomography in which the reverse is true. Both techniques offer good repeatability, but a low degree of correlation and agreement, which means that optic disc area measurement is not interchangeable or comparable between techniques. Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

Morphological and functional differences between normal-tension and high-tension glaucoma.

PubMed

Häntzschel, Janek; Terai, Naim; Sorgenfrei, Friederike; Haustein, Michael; Pillunat, Karin; Pillunat, Lutz E

2013-08-01

To compare visual field (VF) and nerve fibre loss in patients with normal-tension (NTG) and high-tension glaucoma (HTG) at an equal level of glaucomatous structural damage of the optic nerve head (ONH). In a retrospective, pair-matched, comparative study, 126 eyes with NTG and 126 eyes with HTG were matched according to the same glaucomatous ONH damage based on rim volume, rim area and disc size measured by the Heidelberg Retina Tomograph (HRT III). Visual field by Humphrey perimetry and nerve fibre layer thickness measured by scanning laser polarimetry (GdxVCC) were compared between both groups. Based on the HRT, NTG and HTG displayed comparable structural damage of the ONH without a statistically significant difference between both groups (mean, NTG/HTG: disc area 2.32/2.32 mm², p =0.342; rim area 1.03/1.00 mm², p = 0.279; rim volume 0.2/0.19 mm³; p = 0.274). Eyes with NTG had significantly less VF damage than eyes with HTG (mean, NTG/HTG: mean deviation (MD) -3.69/-9.77 dB, p = 0.0001; pattern standard deviation (PSD) 4.80/7.17 dB, p = 0.0001). The nerve fibre layer of NTG patients was thicker than that of HTG patients (mean, NTG/HTG: GDx total: 46.9/44.0 μm, p = 0.073; GDx superior: 57.2/49.9 μm, p = 0.0001; GDx inferior: 54.9/49.7 μm, p = 0.001). At an equal level of glaucomatous structural damage of the ONH indicated by cupping, rim area and rim volume, NTG patients seem to have a less affected visual field and a better preserved nerve fibre layer than HTG patients. © 2013 The Authors. Acta Ophthalmologica © 2013 Acta Ophthalmologica Scandinavica Foundation. Published by Blackwell Publishing Ltd.

Automated Registration of Multimodal Optic Disc Images: Clinical Assessment of Alignment Accuracy.

PubMed

Ng, Wai Siene; Legg, Phil; Avadhanam, Venkat; Aye, Kyaw; Evans, Steffan H P; North, Rachel V; Marshall, Andrew D; Rosin, Paul; Morgan, James E

2016-04-01

To determine the accuracy of automated alignment algorithms for the registration of optic disc images obtained by 2 different modalities: fundus photography and scanning laser tomography. Images obtained with the Heidelberg Retina Tomograph II and paired photographic optic disc images of 135 eyes were analyzed. Three state-of-the-art automated registration techniques Regional Mutual Information, rigid Feature Neighbourhood Mutual Information (FNMI), and nonrigid FNMI (NRFNMI) were used to align these image pairs. Alignment of each composite picture was assessed on a 5-point grading scale: "Fail" (no alignment of vessels with no vessel contact), "Weak" (vessels have slight contact), "Good" (vessels with <50% contact), "Very Good" (vessels with >50% contact), and "Excellent" (complete alignment). Custom software generated an image mosaic in which the modalities were interleaved as a series of alternate 5×5-pixel blocks. These were graded independently by 3 clinically experienced observers. A total of 810 image pairs were assessed. All 3 registration techniques achieved a score of "Good" or better in >95% of the image sets. NRFNMI had the highest percentage of "Excellent" (mean: 99.6%; range, 95.2% to 99.6%), followed by Regional Mutual Information (mean: 81.6%; range, 86.3% to 78.5%) and FNMI (mean: 73.1%; range, 85.2% to 54.4%). Automated registration of optic disc images by different modalities is a feasible option for clinical application. All 3 methods provided useful levels of alignment, but the NRFNMI technique consistently outperformed the others and is recommended as a practical approach to the automated registration of multimodal disc images.

Central corneal thickness and progression of the visual field and optic disc in glaucoma

PubMed Central

Chauhan, B C; Hutchison, D M; LeBlanc, R P; Artes, P H; Nicolela, M T

2005-01-01

Aims: To determine whether central corneal thickness (CCT) is a significant predictor of visual field and optic disc progression in open angle glaucoma. Methods: Data were obtained from a prospective study of glaucoma patients tested with static automated perimetry and confocal scanning laser tomography every 6 months. Progression was determined using a trend based approach called evidence of change (EOC) analysis in which sectoral ordinal scores based on the significance of regression coefficients of visual field pattern deviation and neuroretinal rim area over time are summed. Visual field progression was also determined using the event based glaucoma change probability (GCP) analysis using both total and pattern deviation. Results: The sample contained 101 eyes of 54 patients (mean (SD) age 56.5 (9.8) years) with a mean follow up of 9.2 (0.7) years and 20.7 (2.3) sets of examinations every 6 months. Lower CCT was associated with worse baseline visual fields and lower mean IOP in the follow up. In the longitudinal analysis CCT was not correlated with the EOC scores for visual field or optic disc change. In the GCP analyses, there was a tendency for groups classified as progressing to have lower CCT compared to non-progressing groups. In a multivariate analyses accounting for IOP, the opposite was found, whereby higher CCT was associated with visual field progression. None of the independent factors were predictive of optic disc progression. Conclusions: In this cohort of patients with established glaucoma, CCT was not a useful index in the risk assessment of visual field and optic disc progression. PMID:16024855

Detecting early functional damage in glaucoma suspect and ocular hypertensive patients with the multifocal VEP technique.

PubMed

Thienprasiddhi, Phamornsak; Greenstein, Vivienne C; Chu, David H; Xu, Li; Liebmann, Jeffrey M; Ritch, Robert; Hood, Donald C

2006-08-01

To determine whether the multifocal visual evoked potential (mfVEP) technique can detect early functional damage in ocular hypertensive (OHT) and glaucoma suspect (GS) patients with normal standard achromatic automated perimetry (SAP) results. Twenty-five GS patients (25 eyes), 25 patients with OHT (25 eyes), and 50 normal controls (50 eyes) were enrolled in this study. All GS, OHT and normal control eyes had normal SAP as defined by a pattern standard deviation and mean deviation within the 95% confidence interval and a glaucoma hemifield test within normal limits on the Humphrey visual field 24-2 program. Eyes with GS had optic disc changes consistent with glaucoma with or without raised intraocular pressure (IOP), and eyes with OHT showed no evidence of glaucomatous optic neuropathy and IOPs >or=22 mm Hg. Monocular mfVEPs were obtained from both eyes of each subject using a pattern-reversal dartboard array with 60 sectors. The entire display had a radius of 22.3 degrees. The mfVEPs, for each eye, were defined as abnormal when either the monocular or interocular probability plot had a cluster of 3 or more contiguous points with P<0.05 and at least 2 of these points with P<0.01. The mfVEP results were abnormal in 4% of the eyes from normal subjects. Abnormal mfVEPs were detected in 20% of the eyes of GS patients and 16% of the eyes of OHT patients. Significantly more mfVEP abnormalities were detected in GS patients than in normal controls. However, there was no significant difference in mfVEP results between OHT patients and normal controls. The mfVEP technique can detect visual field deficits in a minority of eyes with glaucomatous optic disks and normal SAP results.

Investigation of Product Performance of Al-Metal Matrix Composites Brake Disc using Finite Element Analysis

NASA Astrophysics Data System (ADS)

Fatchurrohman, N.; Marini, C. D.; Suraya, S.; Iqbal, AKM Asif

2016-02-01

The increasing demand of fuel efficiency and light weight components in automobile sectors have led to the development of advanced material parts with improved performance. A specific class of MMCs which has gained a lot of attention due to its potential is aluminium metal matrix composites (Al-MMCs). Product performance investigation of Al- MMCs is presented in this article, where an Al-MMCs brake disc is analyzed using finite element analysis. The objective is to identify the potentiality of replacing the conventional iron brake disc with Al-MMCs brake disc. The simulation results suggested that the MMCs brake disc provided better thermal and mechanical performance as compared to the conventional cast iron brake disc. Although, the Al-MMCs brake disc dissipated higher maximum temperature compared to cast iron brake disc's maximum temperature. The Al-MMCs brake disc showed a well distributed temperature than the cast iron brake disc. The high temperature developed at the ring of the disc and heat was dissipated in circumferential direction. Moreover, better thermal dissipation and conduction at brake disc rotor surface played a major influence on the stress. As a comparison, the maximum stress and strain of Al-MMCs brake disc was lower than that induced on the cast iron brake disc.

Structure-Function Correlation Using Confocal Laser Ophthalmoscope in Primary Open-Angle Glaucoma and Pseudoexfoliative Glaucoma.

PubMed

Pappas, Theofanis; Founti, Panayiota; Yin, Xiang Jun; Koskosas, Archimidis; Anastasopoulos, Eleftherios; Salonikiou, Angeliki; Kilintzis, Vasilios; Antoniadis, Antonios; Ziakas, Nikolaos; Topouzis, Fotis

2016-04-01

To compare Heidelberg Retina Tomograph (HRT) optic disc parameters and structure-function correlation between primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEXG). Prospective, observation case series. A total of 54 POAG and 33 PEXG cases, consecutively recruited from a University Glaucoma Service, underwent a comprehensive ophthalmic examination, including HRT optic disc imaging. Glaucoma definition required the presence of both structural and functional damage. One eye per subject was included in the analysis. T test, Mann-Whitney U test, and analysis of covariance were used to compare HRT parameters between POAG and PEXG, adjusting for age, mean deviation (MD) in the visual field, intraocular pressure, and disc area. The correlation between HRT and MD was assessed in each group. Cup area (P=0.048), height variation contour (P=0.016), and cup/disc area ratio (P=0.023) were higher in POAG, whereas the mean retinal nerve fiber layer thickness (P=0.048), retinal nerve fiber layer cross-section area (P=0.044), and rim area (P=0.048) were lower in POAG, compared with PEXG. The correlation of HRT parameters with MD was significant only in the POAG group. At a similar level of functional damage, POAG subjects presented with more pronounced structural damage than PEXG subjects. The correlation between HRT and visual field parameters was more evident in POAG, compared with PEXG.

Chromosome 6p25 deletion syndrome: report of a case with optic disc coloboma and review of published ophthalmic findings.

PubMed

Beby, Francis; Des Portes, Vincent; Till, Marianne; Mottolese, Carmine; Denis, Philippe

2012-12-01

The 6p25 deletion syndrome is a rare disorder characterized by Dandy-Walker malformation, congenital heart defects, developmental delay, dysmorphic facial features, and malformations of the anterior segment of the eye with a risk for glaucoma. Here we report a child harboring a cryptic de novo 6p25 deletion, bilateral optic disc coloboma and characteristic anterior segment anomalies. We review reported ophthalmic findings in patients with this syndrome. Retrospective case review of a 4-day-old male with Dandy-Walker malformation and cardiac defects who was referred with a suspected diagnosis of iris coloboma. The ophthalmic examination showed bilateral corectopia associated with posterior embryotoxon. Fundus examination revealed bilateral optic disc excavation, which was diagnosed as colobomatous because of its configuration and stability over time. Because of the association of posterior embryotoxon with Dandy-Walker malformation, a terminal 6p deletion syndrome was clinically suspected. Array comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH) studies revealed a 3.2 Mb deletion at 6p25.2p25.3 including the FOXC1 gene. Neither unaffected parent carried this deletion. Optic disc colobomas may be found in patients carrying a 6p25 deletion. This has the potential to confound assessment of affected children for glaucoma and intracranial hypertension.

Vascular endothelial growth factor Trap-Eye for macular edema secondary to central retinal vein occlusion: six-month results of the phase 3 COPERNICUS study.

PubMed

Boyer, David; Heier, Jeffrey; Brown, David M; Clark, W Lloyd; Vitti, Robert; Berliner, Alyson J; Groetzbach, Georg; Zeitz, Oliver; Sandbrink, Rupert; Zhu, Xiaoping; Beckmann, Karola; Haller, Julia A

2012-05-01

To assess the efficacy and safety of intravitreal vascular endothelial growth factor (VEGF) Trap-Eye in eyes with macular edema secondary to central retinal vein occlusion (CRVO). Multicenter, randomized, prospective, controlled trial. One hundred eighty-nine eyes with macular edema secondary to CRVO. Eyes were randomized 3:2 to receive VEGF Trap-Eye 2 mg or sham injection monthly for 6 months. The proportion of eyes with a ≥15-letter gain or more in best-corrected visual acuity (BCVA) at week 24 (primary efficacy end point), mean changes in BCVA and central retinal thickness (CRT), and proportion of eyes progressing to neovascularization of the anterior segment, optic disc, or elsewhere in the retina. At week 24, 56.1% of VEGF Trap-Eye treated eyes gained 15 letters or more from baseline versus 12.3% of sham-treated eyes (P<0.001). The VEGF Trap-Eye treated eyes gained a mean of 17.3 letters versus sham-treated eyes, which lost 4.0 letters (P<0.001). Central retinal thickness decreased by 457.2 μm in eyes treated with VEGF Trap-Eye versus 144.8 μm in sham-treated eyes (P<0.001), and progression to any neovascularization occurred in 0 and 5 (6.8%) of eyes treated with VEGF Trap-Eye and sham-treated eyes, respectively (P = 0.006). Conjunctival hemorrhage, reduced visual acuity, and eye pain were the most common adverse events (AEs). Serious ocular AEs were reported by 3.5% of VEGF Trap-Eye patients and 13.5% of sham patients. Incidences of nonocular serious AEs generally were well balanced between both groups. At 24 weeks, monthly intravitreal injection of VEGF Trap-Eye 2 mg in eyes with macular edema resulting from CRVO improved visual acuity and CRT, eliminated progression resulting from neovascularization, and was associated with a low rate of ocular AEs related to treatment. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Optical Coherence Tomography Angiography of Retinal Cavernous Hemangioma.

PubMed

Pierro, Luisa; Marchese, Alessandro; Gagliardi, Marco; Bandello, Francesco

2017-08-01

Retinal cavernous hemangioma is a rare, benign, retinal tumor characterized by angiomatous proliferation of vessels within the inner retina or the optic disc.1 Here we report a case of retinal cavernous hemangioma on the margin of the optic disc in the right eye of a 61-year-old asymptomatic female. The lesion was studied with multimodal imaging which included structural optical coherence tomography, fluorescein angiography, blue fundus auto-fluorescence, optical coherence tomography angiography (OCTA) (DRI OCT Triton; Topcon, Tokyo, Japan) and visual field examination. Blood circulation inside retinal cavernous hemangioma lesion is typically low-stagnant.2 However, OCTA demonstrated blood flow inside the lesion, illustrating its vascular circulation.3 Visual field was within the normal limits, except from a slight enlargement of the blind spot. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:684-685.]. Copyright 2017, SLACK Incorporated.

Optic disc detection using ant colony optimization

NASA Astrophysics Data System (ADS)

Dias, Marcy A.; Monteiro, Fernando C.

2012-09-01

The retinal fundus images are used in the treatment and diagnosis of several eye diseases, such as diabetic retinopathy and glaucoma. This paper proposes a new method to detect the optic disc (OD) automatically, due to the fact that the knowledge of the OD location is essential to the automatic analysis of retinal images. Ant Colony Optimization (ACO) is an optimization algorithm inspired by the foraging behaviour of some ant species that has been applied in image processing for edge detection. Recently, the ACO was used in fundus images to detect edges, and therefore, to segment the OD and other anatomical retinal structures. We present an algorithm for the detection of OD in the retina which takes advantage of the Gabor wavelet transform, entropy and ACO algorithm. Forty images of the retina from DRIVE database were used to evaluate the performance of our method.

Unilateral Vision Loss after a Dental Visit

PubMed Central

Khattab, Mohammed H.; Wiegand, Annette; Storch, Marcus; Hoerauf, Hans; Feltgen, Nicolas

2018-01-01

Intraoral local anesthetics are widely used for performing painless dental treatments; however, in some cases, they may cause ocular complications such as meiosis, diplopia, nystagmus, ophthalmoplegia, ptosis, and amaurosis. Mostly, the symptoms disappear after several hours; rarely, they have a prolonged character. We describe the case of a 38-year-old young man who had reduced vision in the left eye 5 days after having received intraoral local anesthesia. A diagnosis of cilioretinal artery occlusion with optic disc swelling was made. Ten weeks later, the patient's visual acuity had increased to 20/20, and the swelling of the optic disc had subsided. Although various possible mechanisms for ocular complications after intraoral local anesthetic administration were suggested in the literature, the exact etiology remains unclear. In this case, inadvertent intravascular injection is believed to be the cause. PMID:29681838

The structure of the external rectus eye muscles of the carpet shark Cephaloscyllium isabella.

PubMed Central

Housley, G D; Montgomery, J C

1984-01-01

The external rectus muscles of the carpet shark Cephaloscyllium isabella contain two types of muscle fibre. A core of large white fibres which have regular myofibrils with extensive sarcoplasmic reticulum, triads located at the Z disc and a pronounced H band and M line. Mitochondria are frequent but tend to be smaller and less abundant than mitochondria of the smaller red fibre type. The red fibres which surround the central region are rich in mitochondria, have little sarcoplasmic reticulum and triads which are infrequent and dispersed. Sarcomere banding of red fibres is characterised by a faint H band and M line while the Z disc is thick in comparison with that found on the white muscle fibre sarcomere. Images Fig. 1 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:6746403

Engineered disc-like angle-ply structures for intervertebral disc replacement.

PubMed

Nerurkar, Nandan L; Sen, Sounok; Huang, Alice H; Elliott, Dawn M; Mauck, Robert L

2010-04-15

To develop a construction algorithm in which electrospun nanofibrous scaffolds are coupled with a biocompatible hydrogel to engineer a mesenchymal stem cell (MSC)-based disc replacement. To engineer a disc-like angle-ply structure (DAPS) that replicates the multiscale architecture of the intervertebral disc. Successful engineering of a replacement for the intervertebral disc requires replication of its mechanical function and anatomic form. Despite many attempts to engineer a replacement for ailing and degenerated discs, no prior study has replicated the multiscale hierarchical architecture of the native disc, and very few have assessed the mechanical function of formed neo-tissues. A new algorithm for the construction of a disc analogue was developed, using agarose to form a central nucleus pulposus (NP) and oriented electrospun nanofibrous scaffolds to form the anulus fibrosus region (AF). Bovine MSCs were seeded into both regions and biochemical, histologic, and mechanical maturation were evaluated with in vitro culture. We show that mechanical testing in compression and torsion, loading methods commonly used to assess disc mechanics, reveal equilibrium and time-dependent behaviors that are qualitatively similar to native tissue, although lesser in magnitude. Further, we demonstrate that cells seeded into both AF and NP regions adopt distinct morphologies that mirror those seen in native tissue, and that, in the AF region, this ordered community of cells deposit matrix that is organized in an angle-ply configuration. Finally, constructs demonstrate functional development with long-term in vitro culture. These findings provide a new approach for disc tissue engineering that replicates multi-scale form and function of the intervertebral disc, providing a foundation from which to build a multi-scale, biologic, anatomically and hierarchically relevant composite disc analogue for eventual disc replacement.

Developments in intervertebral disc disease research: pathophysiology, mechanobiology, and therapeutics.

PubMed

Weber, Kathryn T; Jacobsen, Timothy D; Maidhof, Robert; Virojanapa, Justin; Overby, Chris; Bloom, Ona; Quraishi, Shaheda; Levine, Mitchell; Chahine, Nadeen O

2015-03-01

Low back pain is a leading cause of disability worldwide and the second most common cause of physician visits. There are many causes of back pain, and among them, disc herniation and intervertebral disc degeneration are the most common diagnoses and targets for intervention. Currently, clinical treatment outcomes are not strongly correlated with diagnoses, emphasizing the importance for characterizing more completely the mechanisms of degeneration and their relationships with symptoms. This review covers recent studies elucidating cellular and molecular changes associated with disc mechanobiology, as it relates to degeneration and regeneration. Specifically, we review findings on the biochemical changes in disc diseases, including cytokines, chemokines, and proteases; advancements in disc disease diagnostics using imaging modalities; updates on studies examining the response of the intervertebral disc to injury; and recent developments in repair strategies, including cell-based repair, biomaterials, and tissue engineering. Findings on the effects of the omega-6 fatty acid, linoleic acid, on nucleus pulposus tissue engineering are presented. Studies described in this review provide greater insights into the pathogenesis of disc degeneration and may define new paradigms for early or differential diagnostics of degeneration using new techniques such as systemic biomarkers. In addition, research on the mechanobiology of disease enriches the development of therapeutics for disc repair, with potential to diminish pain and disability associated with disc degeneration.

En face Doppler total retinal blood flow measurement with 70 kHz spectral optical coherence tomography

PubMed Central

Tan, Ou; Liu, Gangjun; Liang, Liu; Gao, Simon S.; Pechauer, Alex D.; Jia, Yali; Huang, David

2015-01-01

Abstract. An automated algorithm was developed for total retinal blood flow (TRBF) using 70-kHz spectral optical coherence tomography (OCT). The OCT was calibrated for the transformation from Doppler shift to speed based on a flow phantom. The TRBF scan pattern contained five repeated volume scans (2×2  mm) obtained in 3 s and centered on central retinal vessels in the optic disc. The TRBF was calculated using an en face Doppler technique. For each retinal vein, blood flow was measured at an optimal plane where the calculated flow was maximized. The TRBF was calculated by summing flow in all veins. The algorithm tracked vascular branching so that either root or branch veins are summed, but never both. The TRBF in five repeated volumes were averaged to reduce variation due to cardiac cycle pulsation. Finally, the TRBF was corrected for eye length variation. Twelve healthy eyes and 12 glaucomatous eyes were enrolled to test the algorithm. The TRBF was 45.4±6.7  μl/min for healthy control and 34.7±7.6  μl/min for glaucomatous participants (p-value=0.01). The intravisit repeatability was 8.6% for healthy controls and 8.4% for glaucoma participants. The proposed automated method provided repeatable TRBF measurement. PMID:26062663

Effect of spectrum bias on the diagnostic accuracy of spectral-domain optical coherence tomography in glaucoma.

PubMed

Rao, Harsha L; Kumbar, Tukaram; Addepalli, Uday K; Bharti, Neha; Senthil, Sirisha; Choudhari, Nikhil S; Garudadri, Chandra S

2012-02-29

To evaluate the influence of a control group on the diagnostic accuracy of spectral-domain optical coherence tomography (SD-OCT) in early glaucoma. In a diagnostic, case-control study, 119 eyes of 60 normal subjects with no findings suspicious for glaucoma (control cohort 1); 76 eyes of 41 subjects referred by general ophthalmologists as glaucoma suspects based on optic disc morphology, but found by glaucoma experts to be normal but with physiological variations in their optic nerves (control cohort 2); and 65 eyes of 46 early-glaucoma patients (cases) underwent imaging of the optic nerve head (ONH), retinal nerve fiber layer (RNFL), and ganglion cell complex (GCC) by SD-OCT. Areas under the receiver operating characteristic curves (AUC) of ONH parameters discriminating glaucomatous eyes from normal eyes of control cohort 2 were significantly lesser (P < 0.001) than those discriminating glaucomatous eyes from normal eyes of control cohort 1. AUCs of RNFL parameters discriminating glaucomatous eyes from normal eyes of control cohorts 2 and 1 were comparable. Although the AUCs of GCC thickness parameters were comparable, AUCs of GCC focal and global loss volume in control cohort 2 (0.684 and 0.671. respectively) were significantly less (P < 0.05) than in control cohort 1 (0.881 and 0.841, respectively). The effectiveness of most SD-OCT parameters in detecting glaucoma significantly decreased when evaluated against a clinically relevant control group with suspicious-looking optic nerves compared with that against a control group consisting of normal subjects with no findings suspicious for glaucoma.

Clinical manifestations of optic pit maculopathy as demonstrated by spectral domain optical coherence tomography.

PubMed

Tzu, Jonathan H; Flynn, Harry W; Berrocal, Audina M; Smiddy, William E; Murray, Timothy G; Fisher, Yale L

2013-01-01

The purpose of this retrospective study was to evaluate the characteristic features, including spectral-domain optical coherence tomography (SD-OCT), clinical course, and outcome of treatment if given for patients with optic disc pit maculopathy. We investigated a consecutive series of patients with a diagnosis of optic pit maculopathy treated between 2001 and 2012 at the Bascom Palmer Eye Institute. Patients were divided into two main groups, ie, patients who were observed without surgery and patients who received surgical intervention. The main outcome measures were presenting and final visual acuity, and changes in SD-OCT imaging were recorded. Other data including age, gender, eye, age of onset, length of follow-up, location of optic pit, and location of fluid by OCT were also recorded. On OCT, 67% (12/18) of the eyes showed schisis-like cavities, 22% (4/18) had only subretinal fluid, and 17% (3/18) had only a schisis-like cavity without subretinal fluid. In the patients managed by observation, visual acuity was ≥20/200 in 6/8 eyes initially and 6/8 eyes at last follow-up. Ten of 18 patients received either focal laser, surgery or both. Six of 10 eyes undergoing surgery had initial visual acuity ≥ 20/200, and 8 of 10 eyes undergoing surgery had a visual acuity of ≥20/200 at last follow-up. In this study, many eyes were observed and remained stable during follow-up. In eyes with reduced vision, surgical intervention produced variable outcomes, and persistent intraretinal/subretinal fluid was a common occurrence.

Optic nerve head parameters of high-definition optical coherence tomography and Heidelberg retina tomogram in perimetric and preperimetric glaucoma.

PubMed

Begum, Viquar Unnisa; Addepalli, Uday Kumar; Senthil, Sirisha; Garudadri, Chandra Sekhar; Rao, Harsha Laxmana

2016-04-01

Heidelberg retina tomogram (HRT) and optical coherence tomography (OCT) are two widely used imaging modalities to evaluate the optic nerve head (ONH) in glaucoma. To compare the ONH parameters of HRT3 and high-definition OCT (HD-OCT) and evaluate their diagnostic abilities in perimetric and preperimetric glaucoma. Cross-sectional analysis. 35 control eyes (24 subjects), 21 preperimetric glaucoma eyes (15 patients), and 64 perimetric glaucoma eyes (44 patients) from the Longitudinal Glaucoma Evaluation Study underwent HRT3 and HD-OCT examinations. Agreement between the ONH parameters of HRT and HD-OCT were assessed using Bland-Altman plots. Diagnostic abilities of ONH parameters were evaluated using area under the receiver operating characteristic curves (AUCs), sensitivity at fixed specificity, and likelihood ratios (LR). Optic disc area, vertical cup to disc ratio, and cup volume with HD-OCT were larger than with HRT, while the rim area was smaller with HD-OCT (P < 0.001 for all comparisons). AUCs of all HD-OCT ONH parameters (0.90-0.97 in perimetric and 0.62-0.71 in preperimetric glaucoma) were comparable (P > 0.10) to the corresponding HRT ONH parameters (0.81-0.95 in perimetric and 0.55-0.72 in preperimetric glaucoma). LRs associated with diagnostic categorization of ONH parameters of both HD-OCT and HRT were associated with larger effects on posttest probability of perimetric compared to preperimetric glaucoma. ONH measurements of HD-OCT and HRT3 cannot be used interchangeably. Though the diagnostic abilities of ONH parameters of HD-OCT and HRT in glaucoma were comparable, the same were significantly lower in preperimetric compared to perimetric glaucoma.

Diagnostic Consistency and Relation Between Optical Coherence Tomography and Standard Automated Perimetry in Primary Open-Angle Glaucoma.

PubMed

Toprak, Ibrahim; Yaylalı, Volkan; Yildirim, Cem

2017-01-01

To assess diagnostic consistency and relation between spectral-domain optical coherence tomography (SD-OCT) and standard automated perimetry (SAP) in patients with primary open-angle glaucoma (POAG). This retrospective study comprised 51 eyes of 51 patients with a confirmed diagnosis of POAG. The qualitative and quantitative SD-OCT parameters (retinal nerve fiber layer thicknesses [RNFL; average, superior, inferior, nasal and temporal], RNFL symmetry, rim area, disc area, average and vertical cup/disc [C/D] ratio and cup volume) were compared with parameters of SAP (mean deviation, pattern standard deviation, visual field index, and glaucoma hemifield test reports). Fifty-one eyes of 51 patients with POAG were recruited. Twenty-nine eyes (56.9%) had consistent RNFL and visual field (VF) damage. However, nine patients (17.6%) showed isolated RNFL damage on SD-OCT and 13 patients (25.5%) had abnormal VF test with normal RNFL. In patients with VF defect, age, average C/D ratio, vertical C/D ratio, and cup volume were significantly higher and rim area was lower when compared to those of the patients with normal VF. In addition to these parameters, worsening in average, superior, inferior, and temporal RNFL thicknesses and RNFL symmetry was significantly associated with consistent SD-OCT and SAP outcomes. In routine practice, patients with POAG can be manifested with inconsistent reports between SD-OCT and SAP. An older age, higher C/D ratio, larger cup volume, and lower rim area on SD-OCT appears to be associated with detectable VF damage. Moreover, additional worsening in RNFL parameters might reinforce diagnostic consistency between SD-OCT and SAP.

Optic nerve head parameters of high-definition optical coherence tomography and Heidelberg retina tomogram in perimetric and preperimetric glaucoma

PubMed Central

Begum, Viquar Unnisa; Addepalli, Uday Kumar; Senthil, Sirisha; Garudadri, Chandra Sekhar; Rao, Harsha Laxmana

2016-01-01

Background: Heidelberg retina tomogram (HRT) and optical coherence tomography (OCT) are two widely used imaging modalities to evaluate the optic nerve head (ONH) in glaucoma. Purpose: To compare the ONH parameters of HRT3 and high-definition OCT (HD-OCT) and evaluate their diagnostic abilities in perimetric and preperimetric glaucoma. Design: Cross-sectional analysis. Methods: 35 control eyes (24 subjects), 21 preperimetric glaucoma eyes (15 patients), and 64 perimetric glaucoma eyes (44 patients) from the Longitudinal Glaucoma Evaluation Study underwent HRT3 and HD-OCT examinations. Statistical Analysis: Agreement between the ONH parameters of HRT and HD-OCT were assessed using Bland-Altman plots. Diagnostic abilities of ONH parameters were evaluated using area under the receiver operating characteristic curves (AUCs), sensitivity at fixed specificity, and likelihood ratios (LR). Results: Optic disc area, vertical cup to disc ratio, and cup volume with HD-OCT were larger than with HRT, while the rim area was smaller with HD-OCT (P < 0.001 for all comparisons). AUCs of all HD-OCT ONH parameters (0.90-0.97 in perimetric and 0.62-0.71 in preperimetric glaucoma) were comparable (P > 0.10) to the corresponding HRT ONH parameters (0.81-0.95 in perimetric and 0.55-0.72 in preperimetric glaucoma). LRs associated with diagnostic categorization of ONH parameters of both HD-OCT and HRT were associated with larger effects on posttest probability of perimetric compared to preperimetric glaucoma. Conclusions: ONH measurements of HD-OCT and HRT3 cannot be used interchangeably. Though the diagnostic abilities of ONH parameters of HD-OCT and HRT in glaucoma were comparable, the same were significantly lower in preperimetric compared to perimetric glaucoma. PMID:27221679

HEMI-TEMPORAL INTERNAL LIMITING MEMBRANE PEELING IS AS EFFECTIVE AND SAFE AS CONVENTIONAL FULL PEELING FOR MACULAR HOLE SURGERY.

PubMed

Shiono, Akira; Kogo, Jiro; Sasaki, Hiroki; Yomoda, Ryo; Jujo, Tatsuya; Tokuda, Naoto; Kitaoka, Yasushi; Takagi, Hitoshi

2018-05-09

To investigate the efficacy of hemi-temporal internal limiting membrane (ILM) peeling for idiopathic macular hole. The medical records of patients with macular holes who had undergone vitrectomy with ILM peeling were studied. Forty-two eyes with macular hole were divided into 2 groups based on surgical procedure (hemi-temporal ILM peeling [hemi group]: 15 eyes; 360° ILM peeling [360° group]: 27 eyes). The closure rates and distances between the optic disc and the intersection of two retinal vessels most closely located nasally or temporally to the macular hole were compared. The primary closure rates were not significantly different between the two groups (hemi group: 93.3%; 360° group: 92.5%, P = 0.92). The temporal retinal vessels in the hemi group were displaced 120.5 ± 102.0 µm toward the optic disc at 1 week postoperatively, which did not differ significantly from the 360° group (136.1 ± 106.1 µm) (P = 0.107). However, the nasal retinal vessels in the hemi group were displaced by 42.4 ± 42.9 µm at 1 week postoperatively, which was significantly less than the 90.1 ± 77.3 µm displacement seen in the 360° group (P = 0.040). Hemi-temporal ILM peeling may be preferable to 360° ILM peeling because of less displacement of the retina and greater safety.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

Diagnostic capability of scanning laser polarimetry with variable cornea compensator in Indian patients with early primary open-angle glaucoma.

PubMed

Parikh, Rajul S; Parikh, Shefali R; Kumar, Rajesh S; Prabakaran, S; Babu, J Gansesh; Thomas, Ravi

2008-07-01

To evaluate the diagnostic ability of scanning laser polarimetry (GDx variable corneal compensator [VCC]) for early glaucoma in Asian Indian eyes. Cross-sectional observational study. Two groups of patients (early glaucoma and normal) who satisfied the inclusion and exclusion criteria were included. Early glaucoma was diagnosed in presence of open angles, characteristic glaucomatous optic disc changes correlating with the visual field (VF) on automated perimetry (VF defect fulfilling at least 2 of 3 Anderson and Patella's criteria with mean deviation >or= -6 decibels). Normal subjects had visual acuity >or= 20/30 and intraocular pressure < 22 mmHg, with a normal optic disc and fields and no ocular abnormality. All patients underwent complete ophthalmic evaluation, including VF examination (24-2/30-2 Swedish interactive threshold algorithm standard program) and imaging with GDx VCC. Sensitivity, specificity, positive predictive value and negative predictive value, area under the receiving operating characteristic curve, and likelihood ratios (LRs) were calculated for various GDx VCC parameters. Seventy-four eyes (74 patients) with early glaucoma and 104 eyes (104 normal subjects) were enrolled. TSNIT Std Dev (temporal-superior-nasal-inferior-temporal standard deviation) had the best combination of sensitivity and specificity-61.3 and 95.2, respectively-followed by nerve fiber index score > 50 (sensitivity, 52.7%; specificity, 99%). Nerve fiber index score > 50 had positive and negative predictive values of 74.3% and 97.6%, respectively, for an assumed glaucoma prevalence of 5%. Nerve fiber index score > 50 had a positive LR (+LR) of 54.8 for early glaucoma. GDx VCC has moderate sensitivity, with high specificity, in the diagnosis of early glaucoma. The high +LR for the nerve fiber index score can provide valuable diagnostic information for individual patients.

Visuo-proprioceptive interactions in degenerative cervical spine diseases requiring surgery.

PubMed

Freppel, S; Bisdorff, A; Colnat-Coulbois, S; Ceyte, H; Cian, C; Gauchard, G; Auque, J; Perrin, P

2013-01-01

Cervical proprioception plays a key role in postural control, but its specific contribution is controversial. Postural impairment was shown in whiplash injuries without demonstrating the sole involvement of the cervical spine. The consequences of degenerative cervical spine diseases are underreported in posture-related scientific literature in spite of their high prevalence. No report has focused on the two different mechanisms underlying cervicobrachial pain: herniated discs and spondylosis. This study aimed to evaluate postural control of two groups of patients with degenerative cervical spine diseases with or without optokinetic stimulation before and after surgical treatment. Seventeen patients with radiculopathy were recruited and divided into two groups according to the spondylotic or discal origin of the nerve compression. All patients and a control population of 31 healthy individuals underwent a static posturographic test with 12 recordings; the first four recordings with the head in 0° position: eyes closed, eyes open without optokinetic stimulation, with clockwise and counter clockwise optokinetic stimulations. These four sensorial situations were repeated with the head rotated 30° to the left and to the right. Patients repeated these 12 recordings 6weeks postoperatively. None of the patients reported vertigo or balance disorders before or after surgery. Prior to surgery, in the eyes closed condition, the herniated disc group was more stable than the spondylosis group. After surgery, the contribution of visual input to postural control in a dynamic visual environment was reduced in both cervical spine diseases whereas in a stable visual environment visual contribution was reduced only in the spondylosis group. The relative importance of visual and proprioceptive inputs to postural control varies according to the type of pathology and surgery tends to reduce visual contribution mostly in the spondylosis group. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Cornea and anterior eye assessment with placido-disc keratoscopy, slit scanning evaluation topography and scheimpflug imaging tomography

PubMed Central

Martin, Raul

2018-01-01

Current corneal assessment technologies make the process of corneal evaluation extremely fast and simple and several devices and technologies allow to explore and to manage patients. The purpose of this special issue is to present and also to update in the evaluation of cornea and ocular surface and this second part, reviews a description of the corneal topography and tomography techniques, providing updated information of the clinical recommendations of these techniques in eye care practice. Placido-based topographers started an exciting anterior corneal surface analysis that allows the development of current corneal tomographers that provide a full three-dimensional reconstruction of the cornea including elevation, curvature, and pachymetry data of anterior and posterior corneal surfaces. Although, there is not an accepted reference standard technology for corneal topography description and it is not possible to determine which device produces the most accurate topographic measurements, placido-based topographers are a valuable technology to be used in primary eye care and corneal tomograhers expanding the possibilities to explore cornea and anterior eye facilitating diagnosis and follow-up in several situations, raising patient follow-up, and improving the knowledge regarding to the corneal anatomy. Main disadvantages of placido-based topographers include the absence of information about the posterior corneal surface and limited corneal surface coverage without data from the para-central and/or peripheral corneal surface. However, corneal tomographers show repeatable anterior and posterior corneal surfaces measurements, providing full corneal thickness data improving cornea, and anterior surface assessment. However, differences between devices suggest that they are not interchangeable in clinical practice. PMID:29480244

Cornea and anterior eye assessment with placido-disc keratoscopy, slit scanning evaluation topography and scheimpflug imaging tomography.

PubMed

Martin, Raul

2018-03-01

Current corneal assessment technologies make the process of corneal evaluation extremely fast and simple and several devices and technologies allow to explore and to manage patients. The purpose of this special issue is to present and also to update in the evaluation of cornea and ocular surface and this second part, reviews a description of the corneal topography and tomography techniques, providing updated information of the clinical recommendations of these techniques in eye care practice. Placido-based topographers started an exciting anterior corneal surface analysis that allows the development of current corneal tomographers that provide a full three-dimensional reconstruction of the cornea including elevation, curvature, and pachymetry data of anterior and posterior corneal surfaces. Although, there is not an accepted reference standard technology for corneal topography description and it is not possible to determine which device produces the most accurate topographic measurements, placido-based topographers are a valuable technology to be used in primary eye care and corneal tomograhers expanding the possibilities to explore cornea and anterior eye facilitating diagnosis and follow-up in several situations, raising patient follow-up, and improving the knowledge regarding to the corneal anatomy. Main disadvantages of placido-based topographers include the absence of information about the posterior corneal surface and limited corneal surface coverage without data from the para-central and/or peripheral corneal surface. However, corneal tomographers show repeatable anterior and posterior corneal surfaces measurements, providing full corneal thickness data improving cornea, and anterior surface assessment. However, differences between devices suggest that they are not interchangeable in clinical practice.

MRI evaluation of spontaneous intervertebral disc degeneration in the alpaca cervical spine.

PubMed

Stolworthy, Dean K; Bowden, Anton E; Roeder, Beverly L; Robinson, Todd F; Holland, Jacob G; Christensen, S Loyd; Beatty, Amanda M; Bridgewater, Laura C; Eggett, Dennis L; Wendel, John D; Stieger-Vanegas, Susanne M; Taylor, Meredith D

2015-12-01

Animal models have historically provided an appropriate benchmark for understanding human pathology, treatment, and healing, but few animals are known to naturally develop intervertebral disc degeneration. The study of degenerative disc disease and its treatment would greatly benefit from a more comprehensive, and comparable animal model. Alpacas have recently been presented as a potential large animal model of intervertebral disc degeneration due to similarities in spinal posture, disc size, biomechanical flexibility, and natural disc pathology. This research further investigated alpacas by determining the prevalence of intervertebral disc degeneration among an aging alpaca population. Twenty healthy female alpacas comprised two age subgroups (5 young: 2-6 years; and 15 older: 10+ years) and were rated according to the Pfirrmann-grade for degeneration of the cervical intervertebral discs. Incidence rates of degeneration showed strong correlations with age and spinal level: younger alpacas were nearly immune to developing disc degeneration, and in older animals, disc degeneration had an increased incidence rate and severity at lower cervical levels. Advanced disc degeneration was present in at least one of the cervical intervertebral discs of 47% of the older alpacas, and it was most common at the two lowest cervical intervertebral discs. The prevalence of intervertebral disc degeneration encourages further investigation and application of the lower cervical spine of alpacas and similar camelids as a large animal model of intervertebral disc degeneration. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

DISC1 regulates new neuron development in the adult brain via modulation of AKT-mTOR signaling through KIAA1212.

PubMed

Kim, Ju Young; Duan, Xin; Liu, Cindy Y; Jang, Mi-Hyeon; Guo, Junjie U; Pow-anpongkul, Nattapol; Kang, Eunchai; Song, Hongjun; Ming, Guo-li

2009-09-24

Disrupted-in-schizophrenia 1 (DISC1), a susceptibility gene for major mental illnesses, regulates multiple aspects of embryonic and adult neurogenesis. Here, we show that DISC1 suppression in newborn neurons of the adult hippocampus leads to overactivated signaling of AKT, another schizophrenia susceptibility gene. Mechanistically, DISC1 directly interacts with KIAA1212, an AKT binding partner that enhances AKT signaling in the absence of DISC1, and DISC1 binding to KIAA1212 prevents AKT activation in vitro. Functionally, multiple genetic manipulations to enhance AKT signaling in adult-born neurons in vivo exhibit similar defects as DISC1 suppression in neuronal development that can be rescued by pharmacological inhibition of mammalian target of rapamycin (mTOR), an AKT downstream effector. Our study identifies the AKT-mTOR signaling pathway as a critical DISC1 target in regulating neuronal development and provides a framework for understanding how multiple susceptibility genes may functionally converge onto a common pathway in contributing to the etiology of certain psychiatric disorders.

Review of past, present, and future of recording technology

NASA Astrophysics Data System (ADS)

Al-Jibouri, Abdul-Rahman

2003-03-01

The revolution of information storage and recording has been advanced significantly over the past two decades. Since the development of computers in early 1950s by IBM, the data (information) was stored on magnetic disc by inducing magnetic flux to define the pit direction. The first disc was developed by IBM with diameter of 25inch to store around 10 kByte. After four decades, the disc drive has become more advanced by reducing the drive size, increasing ariel density and cost reduction. The introduction of new computer operating systems and the Internet resulted in the need to develop high ariel density in the 1990s. Therefore, the disc drive manufacturers were pushed harder to develop new technologies at low cost to survive the competitive market. The disc drives, which are based on media (where the data/information is stored) and the head (which will write and read data/information). The head and disc are separated and with the current technology the spacing between the disc and head is about 40nm. A new technology based on magnetic recording was developed to serve the audio market. This technology is called magnetic type, it is similar to the disc drive, but the media is based on tape rather than rigid disc. Another difference being the head and media are in direct contact. Magnetic tape was developed for audio application and a few years later this technology was extended to allow and accept another technology, called video. This allows consumers to record and view movies in their home. The magnetic tape also used the computer industries for back up data. Magnetic tape is still used in computers and has advanced further over the past decade, companies like Quantum Corp has developed digital linear tape.

Conditional knockout of retinal determination genes in differentiating cells in Drosophila.

PubMed

Jin, Meng; Eblimit, Aiden; Pulikkathara, Merlyn; Corr, Stuart; Chen, Rui; Mardon, Graeme

2016-08-01

Conditional gene knockout in postmitotic cells is a valuable technique which allows the study of gene function with spatiotemporal control. Surprisingly, in contrast to its long-term and extensive use in mouse studies, this technology is lacking in Drosophila. Here, we use a novel method for generating complete loss of eyes absent (eya) or sine oculis (so) function in postmitotic cells posterior to the morphogenetic furrow (MF). Specifically, genomic rescue constructs with flippase recognition target (FRT) sequences flanking essential exons are used to generate conditional null alleles. By removing gene function in differentiating cells, we show that eya and so are dispensable for larval photoreceptor differentiation, but are required for differentiation during pupal development. Both eya and so are necessary for photoreceptor survival and the apoptosis caused by loss of eya or so function is likely a secondary consequence of inappropriate differentiation. We also confirm their requirement for cone cell development and reveal a novel role in interommatidial bristle (IOB) formation. In addition, so is required for normal eye disc morphology. This is the first report of a knockout method to study eya and so function in postmitotic cells. This technology will open the door to a large array of new functional studies in virtually any tissue and at any stage of development or in adults. © 2016 Federation of European Biochemical Societies.

Developing NanoFoil-Heated Thin-Film Thermal Battery

DTIC Science & Technology

2013-09-01

buffer discs (in gray) sandwiching the NanoFoil disc (in yellow). Two Microtherm discs (in dark gray) bracketed the sandwich to prevent excessive heat...of the fuse strip with a Microtherm disc. Cathode Electrolyte Anode Microtherm Heat paper NanoFoil Buffer Agilent 34970A 606.5 Nichrome wire Maccor...gray) sandwiching the NanoFoil disc (in yellow). Two Microtherm discs (in dark gray) bracketed the sandwich to prevent excessive heat loss

Comparison of Predictable Smooth Ocular and Combined Eye-Head Tracking Behaviour in Patients with Lesions Affecting the Brainstem and Cerebellum

NASA Technical Reports Server (NTRS)

Grant, Michael P.; Leigh, R. John; Seidman, Scott H.; Riley, David E.; Hanna, Joseph P.

1992-01-01

We compared the ability of eight normal subjects and 15 patients with brainstem or cerebellar disease to follow a moving visual stimulus smoothly with either the eyes alone or with combined eye-head tracking. The visual stimulus was either a laser spot (horizontal and vertical planes) or a large rotating disc (torsional plane), which moved at one sinusoidal frequency for each subject. The visually enhanced Vestibulo-Ocular Reflex (VOR) was also measured in each plane. In the horizontal and vertical planes, we found that if tracking gain (gaze velocity/target velocity) for smooth pursuit was close to 1, the gain of combined eye-hand tracking was similar. If the tracking gain during smooth pursuit was less than about 0.7, combined eye-head tracking was usually superior. Most patients, irrespective of diagnosis, showed combined eye-head tracking that was superior to smooth pursuit; only two patients showed the converse. In the torsional plane, in which optokinetic responses were weak, combined eye-head tracking was much superior, and this was the case in both subjects and patients. We found that a linear model, in which an internal ocular tracking signal cancelled the VOR, could account for our findings in most normal subjects in the horizontal and vertical planes, but not in the torsional plane. The model failed to account for tracking behaviour in most patients in any plane, and suggested that the brain may use additional mechanisms to reduce the internal gain of the VOR during combined eye-head tracking. Our results confirm that certain patients who show impairment of smooth-pursuit eye movements preserve their ability to smoothly track a moving target with combined eye-head tracking.

High-resolution imaging of retinal nerve fiber bundles in glaucoma using adaptive optics scanning laser ophthalmoscopy.

PubMed

Takayama, Kohei; Ooto, Sotaro; Hangai, Masanori; Ueda-Arakawa, Naoko; Yoshida, Sachiko; Akagi, Tadamichi; Ikeda, Hanako Ohashi; Nonaka, Atsushi; Hanebuchi, Masaaki; Inoue, Takashi; Yoshimura, Nagahisa

2013-05-01

To detect pathologic changes in retinal nerve fiber bundles in glaucomatous eyes seen on images obtained by adaptive optics (AO) scanning laser ophthalmoscopy (AO SLO). Prospective cross-sectional study. Twenty-eight eyes of 28 patients with open-angle glaucoma and 21 normal eyes of 21 volunteer subjects underwent a full ophthalmologic examination, visual field testing using a Humphrey Field Analyzer, fundus photography, red-free SLO imaging, spectral-domain optical coherence tomography, and imaging with an original prototype AO SLO system. The AO SLO images showed many hyperreflective bundles suggesting nerve fiber bundles. In glaucomatous eyes, the nerve fiber bundles were narrower than in normal eyes, and the nerve fiber layer thickness was correlated with the nerve fiber bundle widths on AO SLO (P < .001). In the nerve fiber layer defect area on fundus photography, the nerve fiber bundles on AO SLO were narrower compared with those in normal eyes (P < .001). At 60 degrees on the inferior temporal side of the optic disc, the nerve fiber bundle width was significantly lower, even in areas without nerve fiber layer defect, in eyes with glaucomatous eyes compared with normal eyes (P = .026). The mean deviations of each cluster in visual field testing were correlated with the corresponding nerve fiber bundle widths (P = .017). AO SLO images showed reduced nerve fiber bundle widths both in clinically normal and abnormal areas of glaucomatous eyes, and these abnormalities were associated with visual field defects, suggesting that AO SLO may be useful for detecting early nerve fiber bundle abnormalities associated with loss of visual function. Copyright © 2013 Elsevier Inc. All rights reserved.

Archival-grade optical disc design and international standards

NASA Astrophysics Data System (ADS)

Fujii, Toru; Kojyo, Shinichi; Endo, Akihisa; Kodaira, Takuo; Mori, Fumi; Shimizu, Atsuo

2015-09-01

Optical discs currently on the market exhibit large variations in life span among discs, making them unsuitable for certain business applications. To assess and potentially mitigate this problem, we performed accelerated degradation testing under standard ISO conditions, determined the probable disc failure mechanisms, and identified the essential criteria necessary for a stable disc composition. With these criteria as necessary conditions, we analyzed the physical and chemical changes that occur in the disc components, on the basis of which we determined technological measures to reduce these degradation processes. By applying these measures to disc fabrication, we were able to develop highly stable optical discs.

Displacement of foveal area toward optic disc after macular hole surgery with internal limiting membrane peeling.

PubMed

Kawano, K; Ito, Y; Kondo, M; Ishikawa, K; Kachi, S; Ueno, S; Iguchi, Y; Terasaki, H

2013-07-01

To determine whether there is a displacement of the fovea toward the optic disc after successful macular hole (MH) surgery with internal limiting membrane (ILM) peeling. The medical records of 54 eyes of 53 patients that had undergone pars plana vitrectomy with ILM peeling and gas or air tamponade for an idiopathic MH were evaluated. Spectral-domain optical coherence tomography (OCT) had been performed before and >6 months after the surgery. The preoperative distances between the center of the MH and the optic disc (MH-OD), center of the MH and the bifurcation or crossing of retinal vessels (MH-RV) were measured in the OCT images. In addition, the postoperative distance between the center of the fovea and optic disc (F-OD) and the center of the fovea and the same bifurcation or crossing of retinal vessels (F-RV) were measured in the OCT images. The F-OD was 2.67±0.33 disc diameters (DD), which was significantly shorter than that of the MH-OD of 2.77±0.33 DD (P<0.001). The F-RV was also significantly shorter than the MH-RV on the inner nasal area (from 0.85±0.16DD to 0.79±0.15DD; P<0.001), the inner temporal area (from 0.82±0.15DD to 0.77±0.14DD; P<0.001), and outer nasal area (from 1.70±0.31DD to 1.65±0.32DD; P<0.001), but it was significantly longer than the MH-RV in the outer temporal area (from 1.65±0.29DD to 1.68±0.29DD; P<0.001). Our results showed that successful closure of a MH by vitrectomy with ILM peeling and gas tamponade leads to a displacement of the center of the macula toward the optic disc.

Preliminary results of a computerized Placido disk surgical corneal topographer

NASA Astrophysics Data System (ADS)

Carvalho, Luis A.; Tonissi, S. A.; Castro, Jarbas C.

1999-06-01

We have developed a novel instrument for computerized corneal topography during surgery. The instrument measures a region of approximately 7 mm in diameter, providing the surgeon with precise values of power and astigmatism. The system is based on a Placido Disc projecting system, which is attached to the objective lens of the surgical microscope. The Placido Disc pattern is reflected by a 50% beam splitter attached to the body of the microscope. At the beam splitter we installed our home-made adaptor and a CCD monochromatic high resolution camera. A high quality frame grabber is installed on a PC and images are digitized at a 480x640 resolution. Algorithms based on image processing techniques were implemented for edge detection of pattern. Calibrating curves based on 4 spherical surfaces were generated and approximately 3600 points were calculated for each exam. Preliminary measurements on 10 healthy corneas were compared with the measurements made on an EyeSys Corneal Topographer. Mean deviation was 0.05 for radius of curvature, 0.24 D for power and 5 degrees for cylinder. This system, with some improvements, may be successfully used to diminish high post surgical astigmatisms in surgeries such as cataract and corneal transplant. This system could also be used to gather preoperative data in corneal topography assisted LASIK.

The 14th Hoyt Lecture: Ischemic Optic Neuropathy: The Evolving Profile, 1966-2015.

PubMed

Arnold, Anthony C

2016-06-01

Since the first English language description by Miller and Smith in 1966 of ischemic optic neuropathy as a distinct ophthalmic syndrome, a long series of studies has refined the clinical profile to what we consider to be accurate today. From the specifics of pathogenesis to the clinical appearance to the effect of therapy, the basic tenets of diagnosis and management have evolved over 5 decades. What we thought we knew about the following topics has changed: location of vasculopathy; incidence; age at onset; optic disc appearance; risk factors for development; natural history; rate of fellow eye involvement; ischemia as an all-or-none phenomenon; and treatment. A look back at these discoveries shows both how far we have come and how far we have to go in managing this disorder.

Interaction between DISC1 and CHL1 in regulation of neurite outgrowth.

PubMed

Ren, Jun; Zhao, Tian; Xu, Yiliang; Ye, Haihong

2016-10-01

Disrupted-in-schizophrenia 1 (DISC1), a gene susceptible for major mental illnesses, including schizophrenia, plays multiple roles in neural development, including neuronal proliferation, maturation, migration and neurite outgrowth. DISC1 regulates neurite length via interaction with several intracellular proteins, such as NDEL1, FEZ1 and dysbindin. However, the signal transduction mechanism upstream of DISC1 in regulating neurite outgrowth remains to be elucidated. Here we show that DISC1 interacts with the intracellular domain of close homolog of L1 (CHL1), a member of the L1 family of neural cell adhesion molecules. DISC1 and CHL1 proteins co-localize in growth cones of cortical neurons. Moreover, in neurite outgrowth assay, CHL1 rescues the inhibitory effect of DISC1 on the initial phase of neurite outgrowth. Considering the fact that CHL1 also plays crucial roles in neural development, and its coding gene is associated with schizophrenia, our findings indicate that DISC1 and CHL1 may engage in physical and functional interaction in neural development, supporting the notion that DISC1 regulates neurite outgrowth with a receptor belonging to the neural cell adhesion molecules, and disruption of such interaction may contribute to increased risk for schizophrenia. Copyright © 2016. Published by Elsevier B.V.

A new in vivo animal model to create intervertebral disc degeneration characterized by MRI, radiography, CT/discogram, biochemistry, and histology.

PubMed

Zhou, HaoWei; Hou, ShuXun; Shang, WeiLin; Wu, WenWen; Cheng, Yao; Mei, Fang; Peng, BaoGan

2007-04-15

A new in vivo sheep model was developed that produced disc degeneration through the injection of 5-bromodeoxyuridine (BrdU) into the intervertebral disc. This process was studied using magnetic resonance imaging (MRI), radiography, CT/discogram, histology, and biochemistry. To develop a sheep model of intervertebral disc degeneration that more faithfully mimics the pathologic hallmarks of human intervertebral disc degeneration. Recent studies have shown age-related alterations in proteoglycan structure and organization in human intervertebral discs. An animal model that involves the use of age-related changes in disc cells can be beneficial over other more invasive degenerative models that involves directly damaging the matrix of disc tissue. Twelve sheep were injected with BrdU or vehicle (phosphate-buffered saline) into the central region of separate lumbar discs. Intact discs were used as controls. At the 2-, 6-, 10-, and 14-week time points, discs underwent MRI, radiography, histology, and biochemical analyses. A CT/discogram study was performed at the 14-week time point. MRI demonstrated a progressive loss of T2-weighted signal intensity at BrdU-injected discs over the 14-week study period. Radiograph findings included osteophyte and disc space narrowing formed by 10 weeks post-BrdU treatment. CT discography demonstrated internal disc disruption in several BrdU-treated discs at the 14-week time point. Histology showed a progressive loss of the normal architecture and cell density of discs from the 2-week time point to the 14-week time point. A progressive loss of cell proliferation capacity, water content, and proteoglycans was also documented. BrdU injection into the central region of sheep discs resulted in degeneration of intervertebral discs. This progressive, degenerative process was confirmed using MRI, histology, and by observing changes in biochemistry. Degeneration occurred in a manner that was similar to that observed in human disc degeneration.

Ethambutol/Linezolid Toxic Optic Neuropathy.

PubMed

Libershteyn, Yevgeniya

2016-02-01

To report a rare toxic optic neuropathy after long-term use of two medications: ethambutol and linezolid. A 65-year-old man presented to the Miami Veterans Affairs Medical Center in December 2014 for evaluation of progressive vision decrease in both eyes. The patient presented with best-corrected visual acuities of 20/400 in the right eye and counting fingers at 5 feet in the left eye. Color vision was significantly reduced in both eyes. Visual fields revealed a cecocentral defect in both eyes. His fundus and optic nerve examination was unremarkable. Because vision continued to decline after discontinuation of ethambutol, linezolid was also discontinued, after which vision, color vision, and visual fields improved. Because of these findings, the final diagnosis was toxic optic neuropathy. Final visual outcome was 20/30 in the right eye and 20/40 in the left eye. Drug-associated toxic optic neuropathy is a rare but vision-threatening condition. Diagnosis is made based on an extensive case history and careful clinical examination. The examination findings include varying decrease in vision, normal pupils and extraocular muscles, and unremarkable fundoscopy, with the possibility of swollen optic discs in the acute stage of the optic neuropathy. Other important findings descriptive of toxic optic neuropathy include decreased color vision and cecocentral visual field defects. This case illustrates the importance of knowledge of all medications and/or substances a patient consumes that may cause a toxic reaction and discontinuing them immediately if the visual functions are worsening or not improving.

Lenticular changes in congenital iridolenticular choroidal coloboma.

PubMed

Mohamed, Ashik; Chaurasia, Sunita; Ramappa, Muralidhar; Sangwan, Virender S; Jalali, Subhadra

2014-10-01

To evaluate the lenticular changes associated with congenital iridolenticular choroidal coloboma. Retrospective, observational case series. setting: Tertiary eye care center in south India. study population: Total of 145 eyes of 98 patients. observation procedure: Medical records of all patients with the diagnosis of congenital iridolenticular choroidal coloboma between January 2011 and December 2012 were reviewed retrospectively for demographic profile, extent of coloboma, and associated lenticular changes. Median age of patients at the time of initial visit was 23 years (interquartile range, 13-38 years). The male-to-female ratio was ∼ 1:1. Forty-eight percent had bilateral involvement. Lens showed cataract changes in 68 eyes (48.9%). The most common type of cataract was nuclear sclerosis, which was noted in 51% of cases. A distinct type of cataract, called "coloboma cataract" (characterized by linear opacity in the region of the coloboma), was observed in 29% of cases. Other associated findings were phacodonesis in 3 eyes, dislocation in 3 eyes, and subluxation in 5 eyes. Disc and/or macular involvement in 57 eyes (39.3%) did not influence the type or density of cataract (P > .05). Congenital iridolenticular choroidal coloboma is associated with early cataractous changes. The most common type of cataract is nuclear sclerosis. The type and density of cataract do not seem to be related to the extent of the choroidal coloboma. We suggest a distinct description with the nomenclature "coloboma cataract" to be considered in the clinical grading of cataracts in patients with this condition. Copyright © 2014 Elsevier Inc. All rights reserved.

Childhood bilateral limbal stem cell deficiency: long-term management and outcome

PubMed Central

Jain, Rajat; Sangwan, Virender S

2013-01-01

A 6-year-old boy presented in 1998 with a 1 month history of lime injury in both eyes. Grade 4 chemical injury (Roper-Hall classification) progressed to total limbal stem cell deficiency in both eyes. Between July 2000 and July 2009, he cumulatively underwent 11 limbal stem cell transplantation surgeries, either direct or cultivated from either his father or mother, and 3 corneal transplants in both eyes. Each of the procedures led to a transient clearing of his visual axis to give vision in the range of 20/60 to 20/100 for a period of 1–3 months after which it failed. He finally underwent Boston keratoprosthesis implantation and now enjoys 20/20 vision with stable optic disc and visual field at a follow-up of 41 months. Timely intervention in childhood helped in prevention of amblyopia in this patient. Perseverance by the patient, his relatives and treating ophthalmologist is very important. PMID:23723104

Corneal Protection for Burn Patients

DTIC Science & Technology

2013-10-01

inflammation. BODY This Grant Agreement was for a joint project with Col Anthony J. Johnson, MD, PI on Grant Agreement W81XWH-09-2-0069. The ...project could be placed on the inflamed eye in a Prokera®–like device or be sutured to the cornea as is done in AM transplantation. However we have...in place and prevent bacterial infection under the contact lens. A hydrophilic hydrogel contact lens was sealed between two discs of AM. One of

The Chinese American Eye Study: Design and Methods

PubMed Central

Varma, Rohit; Hsu, Chunyi; Wang, Dandan; Torres, Mina; Azen, Stanley P.

2016-01-01

Purpose To summarize the study design, operational strategies and procedures of the Chinese American Eye Study (CHES), a population-based assessment of the prevalence of visual impairment, ocular disease, and visual functioning in Chinese Americans. Methods This population-based, cross-sectional study, included 4,570 Chinese, 50 years and older, residing in the city of Monterey Park, California. Each eligible participant completed a detailed interview and eye examination. The interview included an assessment of demographic, behavioral, and ocular risk factors and health-related and vision-related quality of life. The eye examination included measurements of visual acuity, intraocular pressure, visual fields, fundus and optic disc photography, a detailed anterior and posterior segment examination, and measurements of blood pressure, glycosylated hemoglobin levels, and blood glucose levels. Results The objectives of the CHES are to obtain prevalence estimates of visual impairment, refractive error, diabetic retinopathy, open-angle and angle-closure glaucoma, lens opacities, and age-related macular degeneration in Chinese-Americans. In addition, outcomes include effect estimates for risk factors associated with eye diseases. Lastly, CHES will investigate the genetic determinates of myopia and glaucoma. Conclusion The CHES will provide information about the prevalence and risk factors of ocular diseases in one of the fastest growing minority groups in the United States. PMID:24044409

Terson syndrome and leukemia: a case report

PubMed Central

Lorenzi, Umberto; Buschini, Elisa; Fea, Antonio; Machetta, Federica; Grignolo, Federico Maria

2014-01-01

Background Terson syndrome is defined as intraocular hemorrhage associated with intracranial bleeding. This syndrome can occur in the event of intracranial hemorrhage or elevated intracranial pressure. To our knowledge, it has never been associated with chronic myeloid leukemia. A 45-year-old woman suffering from chronic myeloid leukemia was referred to our clinic with Terson syndrome after intracranial bleeding. We followed this patient for a year, performing visual acuity assessment, fundus examination, color retinography, and A-scan and B-scan ultrasonography. At presentation, her best-corrected visual acuity on the right was 20/63 and on the left was 20/320. In the right eye, retinoscopy showed blurring of the optic margins surrounded by retinal and preretinal hemorrhages, preretinal fibrosis of the optic disc along the vascular arcades, and perivascular retinal infiltrates. In the left eye, the optic disc was surrounded by retinal and preretinal hemorrhages, and massive fibrosis with hard exudates and severe preretinal hemorrhage were observed at the posterior pole. Roth spots and many circular hemorrhages were noted at the periphery of the retina. A-scan and B-scan ultrasonography did not show intraocular leukemic infiltration. The clinical picture remained stable over the following 12 months. In this patient, we observed the ophthalmoscopic features of chronic myeloid leukemia, but also coexistence of features typical of Terson syndrome. To our knowledge, no similar cases have been reported previously. PMID:24729684

Drosophila MOF regulates DIAP1 and induces apoptosis in a JNK dependent pathway.

PubMed

Pushpavalli, Sreerangam N C V L; Sarkar, Arpita; Ramaiah, M Janaki; Koteswara Rao, G; Bag, Indira; Bhadra, Utpal; Pal-Bhadra, Manika

2016-03-01

Histone modulations have been implicated in various cellular and developmental processes where in Drosophila Mof is involved in acetylation of H4K16. Reduction in the size of larval imaginal discs is observed in the null mutants of mof with increased apoptosis. Deficiency involving Hid, Reaper and Grim [H99] alleviated mof (RNAi) induced apoptosis in the eye discs. mof (RNAi) induced apoptosis leads to activation of caspases which is suppressed by over expression of caspase inhibitors like P35 and Diap1 clearly depicting the role of caspases in programmed cell death. Also apoptosis induced by knockdown of mof is rescued by JNK mutants of bsk and tak1 indicating the role of JNK in mof (RNAi) induced apoptosis. The adult eye ablation phenotype produced by ectopic expression of Hid, Rpr and Grim, was restored by over expression of Mof. Accumulation of Mof at the Diap1 promoter 800 bp upstream of the transcription start site in wild type larvae is significantly higher (up to twofolds) compared to mof (1) mutants. This enrichment coincides with modification of histone H4K16Ac indicating an induction of direct transcriptional up regulation of Diap1 by Mof. Based on these results we propose that apoptosis triggered by mof (RNAi) proceeds through a caspase-dependent and JNK mediated pathway.

Construction Strategy and Progress of Whole Intervertebral Disc Tissue Engineering.

PubMed

Yang, Qiang; Xu, Hai-wei; Hurday, Sookesh; Xu, Bao-shan

2016-02-01

Degenerative disc disease (DDD) is the major cause of low back pain, which usually leads to work absenteeism, medical visits and hospitalization. Because the current conservative procedures and surgical approaches to treatment of DDD only aim to relieve the symptoms of disease but not to regenerate the diseased disc, their long-term efficiency is limited. With the rapid developments in medical science, tissue engineering techniques have progressed markedly in recent years, providing a novel regenerative strategy for managing intervertebral disc disease. However, there are as yet no ideal methods for constructing tissue-engineered intervertebral discs. This paper reviews published reports pertaining to intervertebral disc tissue engineering and summarizes data concerning the seed cells and scaffold materials for tissue-engineered intervertebral discs, construction of tissue-engineered whole intervertebral discs, relevant animal experiments and effects of mechanics on the construction of tissue-engineered intervertebral disc and outlines the existing problems and future directions. Although the perfect regenerative strategy for treating DDD has not yet been developed, great progress has been achieved in the construction of tissue-engineered intervertebral discs. It is believed that ongoing research on intervertebral disc tissue engineering will result in revolutionary progress in the treatment of DDD. © 2016 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

Automated detection of kinks from blood vessels for optic cup segmentation in retinal images

NASA Astrophysics Data System (ADS)

Wong, D. W. K.; Liu, J.; Lim, J. H.; Li, H.; Wong, T. Y.

2009-02-01

The accurate localization of the optic cup in retinal images is important to assess the cup to disc ratio (CDR) for glaucoma screening and management. Glaucoma is physiologically assessed by the increased excavation of the optic cup within the optic nerve head, also known as the optic disc. The CDR is thus an important indicator of risk and severity of glaucoma. In this paper, we propose a method of determining the cup boundary using non-stereographic retinal images by the automatic detection of a morphological feature within the optic disc known as kinks. Kinks are defined as the bendings of small vessels as they traverse from the disc to the cup, providing physiological validation for the cup boundary. To detect kinks, localized patches are first generated from a preliminary cup boundary obtained via level set. Features obtained using edge detection and wavelet transform are combined using a statistical approach rule to identify likely vessel edges. The kinks are then obtained automatically by analyzing the detected vessel edges for angular changes, and these kinks are subsequently used to obtain the cup boundary. A set of retinal images from the Singapore Eye Research Institute was obtained to assess the performance of the method, with each image being clinically graded for the CDR. From experiments, when kinks were used, the error on the CDR was reduced to less than 0.1 CDR units relative to the clinical CDR, which is within the intra-observer variability of 0.2 CDR units.

Evaluation of actual vs expected photodynamic therapy spot size.

PubMed

Ranchod, Tushar M; Brucker, Alexander J; Liu, Chengcheng; Cukras, Catherine A; Hopkins, Tim B; Ying, Gui-Shuang

2009-05-01

To determine the accuracy of the photodynamic therapy (PDT) laser spot size on the retina as generated by 2 Food and Drug Administration (FDA)-approved lasers. Prospective observational case series. Fundus photographs were taken of 1 eye of each of 10 subjects with the WinStation 4000 fundus photography system (OIS; Ophthalmic Imaging Systems, Sacramento, California, USA); disc size was calculated using OIS software. Slit-lamp photographs were taken of the PDT laser spot focused on the retina adjacent to the optic disc, using various spot sizes in combination with 3 different contact lenses and 2 different lasers. Spot size at the retina was determined by measuring the ratio of disc diameter to spot diameter in Adobe Photoshop (San Jose, California, USA) and applying this ratio to the OIS disc measurements. Spot size at the retina averaged 87% of expected spot size for the Coherent Opal laser (Coherent Inc, Santa Clara, California, USA) and 104% of expected spot size for the Zeiss Visulas laser (Carl Zeiss Meditec Inc, Dublin, California, USA)(P = .002). Multivariate analysis demonstrated that percentage of expected spot size decreased with larger spot diameter (P = .01 for Coherent laser; P = .02 for Zeiss laser). PDT spot size at the retina appears to be consistently smaller than expected for the Coherent laser while the spot size was consistently within 10% of expected size for the Zeiss laser. The deviation from expected size increased with larger spot size using the Coherent laser.

In vivo biofunctional evaluation of hydrogels for disc regeneration.

PubMed

Reitmaier, Sandra; Kreja, Ludwika; Gruchenberg, Katharina; Kanter, Britta; Silva-Correia, Joana; Oliveira, Joaquim Miguel; Reis, Rui Luís; Perugini, Valeria; Santin, Matteo; Ignatius, Anita; Wilke, Hans-Joachim

2014-01-01

Regenerative strategies aim to restore the original biofunctionality of the intervertebral disc. Different biomaterials are available, which might support disc regeneration. In the present study, the prospects of success of two hydrogels functionalized with anti-angiogenic peptides and seeded with bone marrow derived mononuclear cells (BMC), respectively, were investigated in an ovine nucleotomy model. In a one-step procedure iliac crest aspirates were harvested and, subsequently, separated BMC were seeded on hydrogels and implanted into the ovine disc. For the cell-seeded approach a hyaluronic acid-based hydrogel was used. The anti-angiogenic potential of newly developed VEGF-blockers was investigated on ionically crosslinked metacrylated gellan gum hydrogels. Untreated discs served as nucleotomy controls. 24 adult merino sheep were used. After 6 weeks histological, after 12 weeks histological and biomechanical analyses were conducted. Biomechanical tests revealed no differences between any of the implanted and nucleotomized discs. All implanted discs significantly degenerated compared to intact discs. In contrast, there was no marked difference between implanted and nucleotomized discs. In tendency, albeit not significant, degeneration score and disc height index deteriorated for all but not for the cell-seeded hydrogels from 6 to 12 weeks. Cell-seeded hydrogels slightly decelerated degeneration. None of the hydrogel configurations was able to regenerate biofunctionality of the intervertebral disc. This might presumably be caused by hydrogel extrusion. Great importance should be given to the development of annulus sealants, which effectively exploit the potential of (cell-seeded) hydrogels for biological disc regeneration and restoration of intervertebral disc functioning.

Characteristics of Incident Geographic Atrophy in the Complications of Age-related Macular Degeneration Prevention Trial

PubMed Central

Brader, Hilary Smolen; Ying, Gui-shuang; Martin, E. Revell; Maguire, Maureen G.

2013-01-01

Objective To characterize the size, location, conformation, and features of incident geographic atrophy (GA) as detected by annual stereoscopic color photographs and fluorescein angiograms (FAs). Design Retrospective cohort study within a larger clinical trial Participants Patients with bilateral large drusen who developed GA during the course of the Complications of Age-related Macular Degeneration Prevention Trial (CAPT). Methods Annual stereoscopic color photographs and FAs were reviewed from 114 CAPT patients who developed GA in the untreated eye during 5-6 years of follow-up. Geographic atrophy was defined according to the Revised GA Criteria for identifying early GA23. Color-optimized fundus photographs were viewed concurrently with the FAs during grading. Main Outcome Measures Size and distance from the fovea of individual GA lesions, number of areas of atrophy, and change in visual acuity (VA) when GA first developed in an eye. Results At presentation, the median total GA area was 0.26mm2 (0.1 Disc area). GA presented as a single lesion in 89 (78%) of eyes. The median distance from the fovea was 395μm. Twenty percent of incident GA lesions were subfoveal and an additional 18% were within 250μm of the foveal center. Development of GA was associated with a mean decrease of 7 letters from the baseline visual acuity level compared to 1 letter among matched early age-related macular degeneration (AMD) eyes without GA. GA that formed in areas previously occupied by drusenoid pigment epithelial detachments (DPED) were on average larger (0.53 vs. 0.20 mm2; p=0.0001), more central (50 vs. 500 microns from the center of the fovea; p<0.0001), and associated with significantly worse visual outcome (20/50 vs. 20/25; p=0.0003) than GA with other drusen types as precursors. Conclusions Incident geographic atrophy most often appears on color fundus photographs and fluorescein angiograms as a small, singular, parafoveal lesion, though a large minority of lesions are subfoveal or multifocal at initial detection. The characteristics of incident geographic atrophy vary with precursor drusen types. These data can facilitate design of future clinical trials of therapies for GA. PMID:23622873

Il fenomeno della "goccia nera" e l'astigmatismo

NASA Astrophysics Data System (ADS)

Horn D'Arturo, Guido

2004-03-01

The Venus transit on the Solar disc was for the first time observed in 1639, using "modern" instruments, by Gassendi. Yet since the following transit, an effect was perceived which modified Venus and Sun profiles at the moments of the first and second visual contact between the two celestial bodies. This effect was called "gutta nigra", i.e. black drop. Horn d'Arturo was widely interested in studies on the vision and on its effects on astronomical observations. In the following paper, he suggested what probably was the first correct explanation of the black drop effect. As stated on the Dictionary of Scientific Biography (ad vocem), Horn "clarified the effect on vision, especially in the astigmatic eye, of the suture of the eye lens and the formation of the so-called black drop".

Patterns of Progressive Ganglion Cell-Inner Plexiform Layer Thinning in Glaucoma Detected by OCT.

PubMed

Shin, Joong Won; Sung, Kyung Rim; Park, Sun-Won

2018-04-25

To investigate the spatial characteristics and patterns of progressive macular ganglion cell-inner plexiform layer (GCIPL) thinning in glaucomatous eyes assessed by OCT Guided Progression Analysis (GPA). Longitudinal, retrospective, observational study. Two hundred ninety-two eyes of 192 patients with primary open-angle glaucoma with a mean follow-up of 6.0 years (range, 3.2-8.1 years) were included. Macular GCIPL imaging and visual field (VF) examination were performed at 6-month intervals for 3 years or more. Progressive GCIPL thinning was evaluated by a Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA) GPA device. Spatial characteristics of progressive GCIPL thinning were assessed by the GCIPL thickness change map. The pattern of progressive GCIPL thinning was evaluated by comparing the baseline GCIPL thickness deviation map and the final GCIPL thickness change map. Visual field progression was determined by Early Manifest Glaucoma Trial criteria and linear regression of the VF index. Spatial characteristics and patterns of progressive GCIPL thinning. Seventy-two eyes of 62 participants (24.7% [72/292]) showed progressive GCIPL thinning in the GCIPL thickness change map. Progressive GCIPL thinning was detected most frequently (25.0%) at 2.08 mm from the fovea, and it extended in an arcuate shape in the inferotemporal region (250°-339°). Compared with the baseline GCIPL defects, the progressive GCIPL thinning extended toward the fovea and optic disc. The most common pattern of progressive GCIPL thinning was widening of GCIPL defects (42 eyes [58.3%]), followed by deepening of GCIPL defects (19 eyes [26.4%]) and newly developed GCIPL defects (15 eyes [20.8%]). Visual field progression was accompanied by progressive GCIPL thinning in 41 of 72 eyes (56.9%). Progressive GCIPL thinning preceded (61.0% [25/41]) or occurred concomitantly with (21.9% [9/41]) VF progression. The use of OCT GPA maps offers an effective approach to evaluate the topographic patterns of progressive GCIPL thinning in glaucomatous eyes. Progression of GCIPL thinning occurred before apparent progression on standard automated perimetry in most glaucomatous eyes. Understanding specific patterns and sequences of macular damage may provide important insights in the monitoring of glaucomatous progression. Copyright © 2018 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Protocol-driven adjustment of ocular hypotensive medication in patients at low risk of conversion to glaucoma.

PubMed

Chan, Poemen P M; Leung, Christopher K S; Chiu, Vivian; Gangwani, Rita; Sharma, Abhishek; So, Sophie; Congdon, Nathan

2015-09-01

To investigate the safety and potential savings of decreasing medication use in low-risk patients with ocular hypertension (OH). Patients with OH receiving pressure-lowering medication identified by medical record review at a university hospital underwent examination by a glaucoma specialist with assessment of visual field (VF), vertical cup-to-disc ratio (vCDR), central corneal thickness and intraocular pressure (IOP). Subjects with estimated 5-year risk of glaucoma conversion <15% were asked to discontinue ≥1 medication, IOP was remeasured 1 month later and risk was re-evaluated at 1 year. Among 212 eyes of 126 patients, 44 (20.8%) had 5-year risk >15% and 14 (6.6%) had unreliable baseline VF. At 1 month, 15 patients (29 eyes, 13.7%) defaulted follow-up or refused to discontinue medication and 11 eyes (5.2%) had risk >15%. The remaining 69 patients (107 eyes, 50.7%) successfully discontinued 141 medications and completed 1-year follow-up. Mean IOP (20.5±2.65 mm Hg vs 20.3±3.40, p=0.397) did not change, though mean VF pattern SD (1.58±0.41 dB vs 1.75±0.56 dB, p=0.001) and glaucoma conversion risk (7.31±3.74% vs 8.76±6.28%, p=0.001) increased at 1 year. Mean defect decreased (-1.42±1.60 vs -1.07±1.52, p=0.022). One eye (0.47%) developed a repeatable VF defect and 13 eyes (6.1%) had 5-year risk >15% at 1 year. The total 1-year cost of medications saved was US$4596. Nearly half (43.9%) of low-risk OH eyes in this setting could safely reduce medications over 1 year, realising substantial savings. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Tracing notochord-derived cells using a Noto-cre mouse: implications for intervertebral disc development.

PubMed

McCann, Matthew R; Tamplin, Owen J; Rossant, Janet; Séguin, Cheryle A

2012-01-01

Back pain related to intervertebral disc degeneration is the most common musculoskeletal problem, with a lifetime prevalence of 82%. The lack of effective treatment for this widespread problem is directly related to our limited understanding of disc development, maintenance and degeneration. The aim of this study was to determine the developmental origins of nucleus pulposus cells within the intervertebral disc using a novel notochord-specific Cre mouse. To trace the fate of notochordal cells within the intervertebral disc, we derived a notochord-specific Cre mouse line by targeting the homeobox gene Noto. Expression of this gene is restricted to the node and the posterior notochord during gastrulation [embryonic day 7.5 (E7.5)-E12.5]. The Noto-cre mice were crossed with a conditional lacZ reporter for visualization of notochord fate in whole-mount embryos. We performed lineage-tracing experiments to examine the contribution of the notochord to spinal development from E12.5 through to skeletally mature mice (9 months). Fate mapping studies demonstrated that, following elongation and formation of the primitive axial skeleton, the notochord gives rise to the nucleus pulposus in fully formed intervertebral discs. Cellular localization of β-galactosidase (encoded by lacZ) and cytokeratin-8 demonstrated that both notochordal cells and chondrocyte-like nucleus pulposus cells are derived from the embryonic notochord. These studies establish conclusively that notochordal cells act as embryonic precursors to all cells found within the nucleus pulposus of the mature intervertebral disc. This suggests that notochordal cells might serve as tissue-specific progenitor cells within the disc and establishes the Noto-cre mouse as a unique tool to interrogate the contribution of notochordal cells to both intervertebral disc development and disc degeneration.

Tracing notochord-derived cells using a Noto-cre mouse: implications for intervertebral disc development

PubMed Central

McCann, Matthew R.; Tamplin, Owen J.; Rossant, Janet; Séguin, Cheryle A.

2012-01-01

SUMMARY Back pain related to intervertebral disc degeneration is the most common musculoskeletal problem, with a lifetime prevalence of 82%. The lack of effective treatment for this widespread problem is directly related to our limited understanding of disc development, maintenance and degeneration. The aim of this study was to determine the developmental origins of nucleus pulposus cells within the intervertebral disc using a novel notochord-specific Cre mouse. To trace the fate of notochordal cells within the intervertebral disc, we derived a notochord-specific Cre mouse line by targeting the homeobox gene Noto. Expression of this gene is restricted to the node and the posterior notochord during gastrulation [embryonic day 7.5 (E7.5)-E12.5]. The Noto-cre mice were crossed with a conditional lacZ reporter for visualization of notochord fate in whole-mount embryos. We performed lineage-tracing experiments to examine the contribution of the notochord to spinal development from E12.5 through to skeletally mature mice (9 months). Fate mapping studies demonstrated that, following elongation and formation of the primitive axial skeleton, the notochord gives rise to the nucleus pulposus in fully formed intervertebral discs. Cellular localization of β-galactosidase (encoded by lacZ) and cytokeratin-8 demonstrated that both notochordal cells and chondrocyte-like nucleus pulposus cells are derived from the embryonic notochord. These studies establish conclusively that notochordal cells act as embryonic precursors to all cells found within the nucleus pulposus of the mature intervertebral disc. This suggests that notochordal cells might serve as tissue-specific progenitor cells within the disc and establishes the Noto-cre mouse as a unique tool to interrogate the contribution of notochordal cells to both intervertebral disc development and disc degeneration. PMID:22028328

Radial optic neurotomy for ischaemic central vein occlusion

PubMed Central

Martínez-Jardón, C S; Meza-de Regil, A; Dalma-Weiszhausz, J; Leizaola-Fernández, C; Morales-Cantón, V; Guerrero-Naranjo, J L; Quiroz-Mercado, H

2005-01-01

Background/aims: Ischaemic central retinal vein occlusion (CRVO) accounts for 20–50% of all CRVO. No treatment has been proved to be effective. The efficacy of radial optic neurotomy (RON) was evaluated in eyes with ischaemic CRVO. Methods: 10 patients with ischaemic CRVO underwent RON. After pars plana vitrectomy, a microvitreoretinal blade was used to incise the scleral ring, cribriform plate, and adjacent sclera at the nasal edge of the optic disc. Best corrected visual acuity (BCVA), intraocular pressure (IOP), fluorescein angiography (FA), multifocal electroretinography (mfERG), and optical coherence tomography (OCT) were measured preoperatively and at 1, 3, and 6 months postoperatively. Results: No visual improvement was noted in the eyes that underwent RON. FA and mfERG showed no increase in retinal perfusion or retinal function postoperatively. Mean macular central thickness changed from 841 (SD 170) μm preoperatively to 162 (SD 34) μm at the sixth postoperative month. One patient had retinal central artery perforation intraoperatively. One patient developed neovascular glaucoma. Conclusion: RON in ischaemic CRVO did not improve visual function (by mfERG) or visual acuity although macular thickness did improve. This technique may be associated with potential risks. Randomised studies are needed to corroborate these results. PMID:15834084

Bartonella and intraocular inflammation: a series of cases and review of literature

PubMed Central

Kalogeropoulos, Chris; Koumpoulis, Ioannis; Mentis, Andreas; Pappa, Chrisavgi; Zafeiropoulos, Paraskevas; Aspiotis, Miltiadis

2011-01-01

Purpose: To present various forms of uveitis and/or retinal vasculitis attributed to Bartonella infection and review the impact of this microorganism in patients with uveitis. Methods: Retrospective case series study. Review of clinical records of patients diagnosed with Bartonella henselae and Bartonella quintana intraocular inflammation from 2001 to 2010 in the Ocular Inflammation Department of the University Eye Clinic, Ioannina, Greece. Presentation of epidemiological and clinical data concerning Bartonella infection was provided by the international literature. Results: Eight patients with the diagnosis of Bartonella henselae and two patients with B. quintana intraocular inflammation were identified. Since four patients experienced bilateral involvement, the affected eyes totaled 14. The mean age was 36.6 years (range 12–62). Uveitic clinical entities that we found included intermediate uveitis in seven eyes (50%), vitritis in two eyes (14.2%), neuroretinitis in one eye (7.1%), focal retinochoroiditis in one eye (7.1%), branch retinal vein occlusion (BRVO) due to vasculitis in one eye (7.1%), disc edema with peripapillary serous retinal detachment in one eye (7.1%), and iridocyclitis in one eye (7.1%). Most of the patients (70%) did not experience systemic symptoms preceding the intraocular inflammation. Antimicrobial treatment was efficient in all cases with the exception of the case with neuroretinitis complicated by anterior ischemic optic neuropathy and tubulointerstitial nephritis. Conclusion: Intraocular involvement caused not only by B. henselae but also by B. quintana is being diagnosed with increasing frequency. A high index of suspicion is needed because the spectrum of Bartonella intraocular inflammation is very large. In our study the most common clinical entity was intermediate uveitis. PMID:21750616

Evaluation of retinal nerve fiber layer thickness and choroidal thickness in pseudoexfoliative glaucoma and pseudoexfoliative syndrome.

PubMed

Ozge, Gokhan; Koylu, Mehmet Talay; Mumcuoglu, Tarkan; Gundogan, Fatih Cakir; Ozgonul, Cem; Ayyildiz, Onder; Kucukevcilioglu, Murat

2016-05-01

To compare retinal nerve fiber layer thickness (RNFLT) and choroidal thickness (ChT) measurements in eyes with pseudoexfoliative (PEX) glaucoma, PEX syndrome and healthy control eyes. Eighteen patients with PEX glaucoma in one eye and PEX syndrome in the fellow eye were included. The right eyes of thirty-nine age- and sex-matched healthy subjects were included as control group. All participants underwent a detailed biomicroscopic and funduscopic examination. RNFLT and ChT measurements were performed with a commercially available spectral-domain optical coherence tomography (SD-OCT). ChT measurements were performed by using enhanced depth imaging (EDI) mode. Patients with PEX underwent diurnal IOP measurements with 4-hour intervals before inclusion in the study. RNFLT results included the average measurement and 6 quadrants (temporal, inferotemporal, inferonasal, nasal, superonasal and supero-temporal). ChT measurements were performed in the subfoveal region and around the fovea (500µm and 1500 µm nasal and temporal to the fovea), as well as around the optic disc (average peripapillary and eight quadrants in the peripapillary region (temporal, inferotemporal, inferior, inferonasal, nasal, superonasal, superior, supero-temporal)). RNFLT in all quadrants and average thickness were significantly lower in PEX glaucoma eyes compared to PEX syndrome eyes and healthy control eyes (p<0.001 for both). RNFLT comparisons between PEX syndrome and healthy control eyes did not show a significant difference (p>0.05) except the inferotemporal quadrant. ChT measurements were similar between groups (p>0.05). Thinning of the RNFL in association with unchanged ChT may mean that the presence of PEX material is a much more significant risk factor than choroidal changes in the progression of PEX syndrome to PEX glaucoma.

Translation of an Engineered Nanofibrous Disc-like Angle Ply Structure for Intervertebral Disc Replacement in a Small Animal Model

PubMed Central

Martin, John T.; Milby, Andrew H.; Chiaro, Joseph A.; Kim, Dong Hwa; Hebela, Nader M.; Smith, Lachlan J.; Elliott, Dawn M.; Mauck, Robert L.

2015-01-01

Intervertebral disc degeneration has been implicated in the etiology of low back pain; however the current surgical strategies for treating symptomatic disc disease are limited. A variety of materials have been developed to replace disc components, including the nucleus pulposus (NP), the annulus fibrosus (AF), and their combination into disc-like engineered constructs. We have previously shown that layers of electrospun poly(ε-caprolactone) scaffold, mimicking the hierarchical organization of the native AF, have functional parity with native tissue. Likewise, we have combined these structures with cell-seeded hydrogels (as an NP replacement) to form disc-like angle ply structures (DAPS). The objective of this study was to develop a model for the evaluation of DAPS in vivo. Through a series of studies, we developed a surgical approach to replace the rat caudal disc with an acellular DAPS and then stabilize the motion segment by external fixation. We then optimized cell infiltration into DAPS by including sacrificial poly(ethylene oxide) layers interspersed throughout the angle-ply structure. Our findings illustrate that DAPS are stable in the caudal spine, are infiltrated by cells from the peri-implant space, and that infiltration is expedited by providing additional routes for cell migration. These findings establish a new in vivo platform in which to evaluate and optimize the design of functional disc replacements. PMID:24560621

High-Resolution Imaging of the Optic Nerve and Retina in Optic Nerve Hypoplasia

PubMed Central

Pilat, Anastasia; Sibley, Daniel; McLean, Rebecca J.; Proudlock, Frank A.; Gottlob, Irene

2015-01-01

Purpose To investigate the optic nerve and macular morphology in patients with optic nerve hypoplasia (ONH) using spectral-domain optical coherence tomography (SD OCT). Design Prospective, cross-sectional, observational study. Subjects A total of 16 participants with ONH (10 female and 6 male; mean age, 17.2 years; 6 bilateral involvement) and 32 gender-, age-, ethnicity-, and refraction-matched healthy controls. Methods High-resolution SD OCT (Copernicus [Optopol Technology S.A., Zawiercie, Poland], 3 μm resolution) and handheld SD OCT (Bioptigen Inc [Research Triangle Park, NC], 2.6 μm resolution) devices were used to acquire horizontal scans through the center of the optic disc and macula. Main Outcome Measures Horizontal optic disc/cup and rim diameters, cup depth, peripapillary retinal nerve fiber layer (RNFL), and thickness of individual retinal layers in participants with ONH and in controls. Results Patients with ONH had significantly smaller discs (P < 0.03 and P < 0.001 compared with unaffected eye and healthy controls, respectively), horizontal cup diameter (P < 0.02 for both), and cup depth (P < 0.02 and P < 0.01, respectively). In the macula, significantly thinner RNFL (nasally), ganglion cell layer (GCL) (nasally and temporally), inner plexiform layer (IPL) (nasally), outer nuclear layer (ONL) (nasally), and inner segment (centrally and temporally) were found in patients with ONH compared with the control group (P < 0.05 for all comparisons). Continuation of significantly thicker GCL, IPL, and outer plexiform layer in the central retinal area (i.e., foveal hypoplasia) was found in more than 80% of patients with ONH. Clinically unaffected fellow eyes of patients with ONH showed mild features of underdevelopment. Visual acuity and presence of septo-optic dysplasia were associated with changes in GCL and IPL. Sensitivity and specificity for the detection of ONH based on disc and retinal optical coherence tomography (OCT) parameters were >80%. Conclusions Our study provides evidence of retinal changes in ONH. In addition to thinning of retina layers mainly involving the RNFL and GCL, signs reminiscent of foveal hypoplasia were observed in patients with ONH. Optic nerve and foveal parameters measured using OCT showed high sensitivity and specificity for detecting ONH, demonstrating their useful for clinical diagnosis. PMID:25939636

Design of optical system for binocular fundus camera.

PubMed

Wu, Jun; Lou, Shiliang; Xiao, Zhitao; Geng, Lei; Zhang, Fang; Wang, Wen; Liu, Mengjia

2017-12-01

A non-mydriasis optical system for binocular fundus camera has been designed in this paper. It can capture two images of the same fundus retinal region from different angles at the same time, and can be used to achieve three-dimensional reconstruction of fundus. It is composed of imaging system and illumination system. In imaging system, Gullstrand Le Grand eye model is used to simulate normal human eye, and Schematic eye model is used to test the influence of ametropia in human eye on imaging quality. Annular aperture and black dot board are added into illumination system, so that the illumination system can eliminate stray light produced by corneal-reflected light and omentoscopic lens. Simulation results show that MTF of each visual field at the cut-off frequency of 90lp/mm is greater than 0.2, system distortion value is -2.7%, field curvature is less than 0.1 mm, radius of Airy disc is 3.25um. This system has a strong ability of chromatic aberration correction and focusing, and can image clearly for human fundus in which the range of diopters is from -10 D to +6 D(1 D = 1 m -1 ).

Accuracy of Diagnostic Imaging Modalities for Classifying Pediatric Eyes as Papilledema Versus Pseudopapilledema.

PubMed

Chang, Melinda Y; Velez, Federico G; Demer, Joseph L; Bonelli, Laura; Quiros, Peter A; Arnold, Anthony C; Sadun, Alfredo A; Pineles, Stacy L

2017-12-01

To identify the most accurate diagnostic imaging modality for classifying pediatric eyes as papilledema (PE) or pseudopapilledema (PPE). Prospective observational study. Nineteen children between the ages of 5 and 18 years were recruited. Five children (10 eyes) with PE, 11 children (19 eyes) with PPE owing to suspected buried optic disc drusen (ODD), and 3 children (6 eyes) with PPE owing to superficial ODD were included. All subjects underwent imaging with B-scan ultrasonography, fundus photography, autofluorescence, fluorescein angiography (FA), optical coherence tomography (OCT) of the retinal nerve fiber layer (RNFL), and volumetric OCT scans through the optic nerve head with standard spectral-domain (SD OCT) and enhanced depth imaging (EDI OCT) settings. Images were read by 3 masked neuro-ophthalmologists, and the final image interpretation was based on 2 of 3 reads. Image interpretations were compared with clinical diagnosis to calculate accuracy and misinterpretation rates of each imaging modality. Accuracy of each imaging technique for classifying eyes as PE or PPE, and misinterpretation rates of each imaging modality for PE and PPE. Fluorescein angiography had the highest accuracy (97%, 34 of 35 eyes, 95% confidence interval 92%-100%) for classifying an eye as PE or PPE. FA of eyes with PE showed leakage of the optic nerve, whereas eyes with suspected buried ODD demonstrated no hyperfluorescence, and eyes with superficial ODD showed nodular staining. Other modalities had substantial likelihood (30%-70%) of misinterpretation of PE as PPE. The best imaging technique for correctly classifying pediatric eyes as PPE or PE is FA. Other imaging modalities, if used in isolation, are more likely to lead to misinterpretation of PE as PPE, which could potentially result in failure to identify a life-threatening disorder causing elevated intracranial pressure and papilledema. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Vitreous hemorrhage and Rhegmatogenous retinal detachment that developed after botulinum toxin injection to the extraocular muscle: case report.

PubMed

Lee, Dong Hyun; Han, Jinu; Han, Sueng-Han; Lee, Sung Chul; Kim, Min

2017-12-13

The authors report a case of a rare complication that occurred after botulinum toxin injection to the extraocular muscle, which was easily overlooked and successfully corrected by surgery. A 34-year-old female patient visited our clinic for diplopia and ocular motility disorder after removal of an epidermoid tumor of the brain. At her initial visit, her best-corrected visual acuity (BCVA) was 20/20 for both eyes. An alternate cover test showed 45 prism-diopter esotropia and 3 prism-diopter hypertropia in the right eye. Following 6 months of observation, the deviation of the strabismus did not improve, and botulinum toxin was injected into the right medial rectus (RMR). After 6 days, she visited our clinic with decreased visual acuity of her right eye. The BCVA was found to be 20/50 for her right eye. Funduscopic examination presented a retinal tear inferonasal to the optic disc with preretinal hemorrhage. Subretinal fluid nasal to the fovea was seen on optical coherence tomography (OCT). Barrier laser photocoagulation was done around the retinal tear; however, her visual acuity continued to decrease, and vitreous hemorrhage and subretinal fluid at the lesion did not improve. In addition, a newly developed epiretinal membrane was seen on OCT. An alternate cover test presented 30 prism-diopter right esotropia. 19 weeks after RMR botulinum toxin injection, she received pars plana vitrectomy, membranectomy, endolaser barrier photocoagulation, and intravitreal bevacizumab (Avastin®) injection. After 4 months, her visual acuity improved to 20/20, and only 4 prism-diopter of right hypertropia and 3 prism-diopter of exotropia were noted. Vitreous opacity and the epiretinal membrane were completely removed, as confirmed by funduscopic and examination. Sudden loss of vision after injection of botulinum toxin into the extraocular muscle may suggest a serious complication, and a prompt, thorough ophthalmic examination should be performed. If improvements are not observed, rapid surgical intervention is recommended to prevent additional complications.

Vortex stretching in self-gravitating protoplanetary discs

NASA Astrophysics Data System (ADS)

Regály, Zs.; Vorobyov, E.

2017-10-01

Horseshoe-shaped brightness asymmetries of several transitional discs are thought to be caused by large-scale vortices. Anticyclonic vortices efficiently collect dust particles, therefore they can play a major role in planet formation. Former studies suggest that the disc self-gravity weakens vortices formed at the edge of the gap opened by a massive planet in discs whose masses are in the range of 0.01 ≤ Mdisc/M* ≤ 0.1. Here, we present an investigation on the long-term evolution of the large-scale vortices formed at the viscosity transition of the discs' dead zone outer edge by means of two-dimensional hydrodynamic simulations taking disc self-gravity into account. We perform a numerical study of low-mass, 0.001 ≤ Mdisc/M* ≤ 0.01, discs, for which cases disc self-gravity was previously neglected. The large-scale vortices are found to be stretched due to disc self-gravity even for low-mass discs with Mdisc/M* ≳ 0.005, where initially the Toomre Q-parameter was ≲ 50 at the vortex distance. As a result of stretching, the vortex aspect ratio increases and a weaker azimuthal density contrast develops. The strength of the vortex stretching is proportional to the disc mass. The vortex stretching can be explained by a combined action of a non-vanishing gravitational torque caused by the vortex and the Keplerian shear of the disc. Self-gravitating vortices are subject to significantly faster decay than non-self-gravitating ones. We found that vortices developed at sharp viscosity transitions of self-gravitating discs can be described by a Goodman - Narayan - Goldreich (GNG) model as long as the disc viscosity is low, I.e. αdz ≤ 10-5.

[Application of spectral optical coherent tomography (SOCT) in ophthalmology].

PubMed

Bieganowski, Lech; Wojtkowski, Maciej; Kowalczyk, Andrzej; Kałuzny, Jakub J

2004-01-01

The article describes spectral optical coherent tomography (SOCT) constructed by Medical Physics Group, Faculty of Physics, Astronomy and Informatics at Nicholas Copernicus University in Toruń (Poland). It presents the physical bases for the functioning of the constructed device and includes pictures of optical sections of various elements of the eyeball: an optic disc and the region of central fovea, a cornea and angle structures (trabecular meshwork). The article also discusses potential application of SOCT in ophthalmic diagnosis of anterior and posterior segments of the eye.

Multiple ocular colobomas in the snow leopard (Uncia uncia).

PubMed

Barnett, K C; Lewis, J C M

2002-09-01

Two singleton female snow leopard cubs are reported with bilateral central upper lid colobomas. In addition, one cub had a coloboma of the fundus in one eye extending from the lower optic disc region. Surgical treatment by wedge resection was successful in both cases. Details of ocular colobomas in other snow leopards reported in the literature are described and it is suggested that the exact etiology of the condition in this species may be discovered by further study of similar colobomas in the domestic cat.

Assessment of targeting accuracy of a low-energy stereotactic radiosurgery treatment for age-related macular degeneration

NASA Astrophysics Data System (ADS)

Taddei, Phillip J.; Chell, Erik; Hansen, Steven; Gertner, Michael; Newhauser, Wayne D.

2010-12-01

Age-related macular degeneration (AMD), a leading cause of blindness in the United States, is a neovascular disease that may be controlled with radiation therapy. Early patient outcomes of external beam radiotherapy, however, have been mixed. Recently, a novel multimodality treatment was developed, comprising external beam radiotherapy and concomitant treatment with a vascular endothelial growth factor inhibitor. The radiotherapy arm is performed by stereotactic radiosurgery, delivering a 16 Gy dose in the macula (clinical target volume, CTV) using three external low-energy x-ray fields while adequately sparing normal tissues. The purpose of our study was to test the sensitivity of the delivery of the prescribed dose in the CTV using this technique and of the adequate sparing of normal tissues to all plausible variations in the position and gaze angle of the eye. Using Monte Carlo simulations of a 16 Gy treatment, we varied the gaze angle by ±5° in the polar and azimuthal directions, the linear displacement of the eye ±1 mm in all orthogonal directions, and observed the union of the three fields on the posterior wall of spheres concentric with the eye that had diameters between 20 and 28 mm. In all cases, the dose in the CTV fluctuated <6%, the maximum dose in the sclera was <20 Gy, the dose in the optic disc, optic nerve, lens and cornea were <0.7 Gy and the three-field junction was adequately preserved. The results of this study provide strong evidence that for plausible variations in the position of the eye during treatment, either by the setup error or intrafraction motion, the prescribed dose will be delivered to the CTV and the dose in structures at risk will be kept far below tolerance doses.

Using and Developing with CD-Interactive: Frequently Asked Questions Are Answered.

ERIC Educational Resources Information Center

Lediaev, Lucy; van Sonderen, Lex

1994-01-01

Discusses Compact Disc-Interactive (CD-I) using a question-and-answer format. Highlights include development of the CD-I technology; where to purchase discs and players; compatibility with other CD-ROM drives; how to make discs; authoring systems versus custom programs; entertainment and educational applications; licensing issues; specifications;…

Scanning laser ophthalmoscope fundus cyclometry in near-natural viewing conditions.

PubMed

Ehrt, O; Boergen, K P

2001-09-01

For a better understanding of motor and sensory adaptations in cyclodeviations, subjective and objective ocular torsion have to be measured under the same conditions. The search coil technique and videooculography allow natural viewing but only assess relative cycloduction, the dynamics of torsion over a short period of time. Cycloposition, on the other hand, can be measured by analysing the position of the foveola relative to the optic disc with fundus photographs but only in nonphysiological viewing. The aim of the study was to develop a technique that allows natural viewing conditions during fundus cyclometry. The scanning laser beam of the SLO was deflected by 90 degrees with a semitransparent mirror in front of the patient's eyes. The patient was able to look through the semitransparent mirror with both eyes into the room, e.g. at Harms' tangent screen. The infrared SLO images the central retina via the mirror through the undilated pupil. Digital image analysis quantifies the cycloposition of the eye. Controlled head movements while fixating the centre of Harms' tangent screen allow measurements in reproducible gaze positions. The semitransparent mirror reduces SLO image brightness, but image quality is sufficient for cyclometry after contrast enhancement. The laser light can be vaguely perceived by the patient but does not interfere with natural viewing. Reproducibility of the measurement is within +/- 1 degree SD. Our modification of SLO fundus cyclometry allows direct measurements of cycloposition in natural viewing conditions. This opens a new field for investigations of cyclodeviations and their sensory and motor adaptations.

Anticipatory Smooth Eye Movements in Autism Spectrum Disorder

PubMed Central

Aitkin, Cordelia D.; Santos, Elio M.; Kowler, Eileen

2013-01-01

Smooth pursuit eye movements are important for vision because they maintain the line of sight on targets that move smoothly within the visual field. Smooth pursuit is driven by neural representations of motion, including a surprisingly strong influence of high-level signals representing expected motion. We studied anticipatory smooth eye movements (defined as smooth eye movements in the direction of expected future motion) produced by salient visual cues in a group of high-functioning observers with Autism Spectrum Disorder (ASD), a condition that has been associated with difficulties in either generating predictions, or translating predictions into effective motor commands. Eye movements were recorded while participants pursued the motion of a disc that moved within an outline drawing of an inverted Y-shaped tube. The cue to the motion path was a visual barrier that blocked the untraveled branch (right or left) of the tube. ASD participants showed strong anticipatory smooth eye movements whose velocity was the same as that of a group of neurotypical participants. Anticipatory smooth eye movements appeared on the very first cued trial, indicating that trial-by-trial learning was not responsible for the responses. These results are significant because they show that anticipatory capacities are intact in high-functioning ASD in cases where the cue to the motion path is highly salient and unambiguous. Once the ability to generate anticipatory pursuit is demonstrated, the study of the anticipatory responses with a variety of types of cues provides a window into the perceptual or cognitive processes that underlie the interpretation of events in natural environments or social situations. PMID:24376667

Anticipatory smooth eye movements in autism spectrum disorder.

PubMed

Aitkin, Cordelia D; Santos, Elio M; Kowler, Eileen

2013-01-01

Smooth pursuit eye movements are important for vision because they maintain the line of sight on targets that move smoothly within the visual field. Smooth pursuit is driven by neural representations of motion, including a surprisingly strong influence of high-level signals representing expected motion. We studied anticipatory smooth eye movements (defined as smooth eye movements in the direction of expected future motion) produced by salient visual cues in a group of high-functioning observers with Autism Spectrum Disorder (ASD), a condition that has been associated with difficulties in either generating predictions, or translating predictions into effective motor commands. Eye movements were recorded while participants pursued the motion of a disc that moved within an outline drawing of an inverted Y-shaped tube. The cue to the motion path was a visual barrier that blocked the untraveled branch (right or left) of the tube. ASD participants showed strong anticipatory smooth eye movements whose velocity was the same as that of a group of neurotypical participants. Anticipatory smooth eye movements appeared on the very first cued trial, indicating that trial-by-trial learning was not responsible for the responses. These results are significant because they show that anticipatory capacities are intact in high-functioning ASD in cases where the cue to the motion path is highly salient and unambiguous. Once the ability to generate anticipatory pursuit is demonstrated, the study of the anticipatory responses with a variety of types of cues provides a window into the perceptual or cognitive processes that underlie the interpretation of events in natural environments or social situations.

Translation of an engineered nanofibrous disc-like angle-ply structure for intervertebral disc replacement in a small animal model.

PubMed

Martin, John T; Milby, Andrew H; Chiaro, Joseph A; Kim, Dong Hwa; Hebela, Nader M; Smith, Lachlan J; Elliott, Dawn M; Mauck, Robert L

2014-06-01

Intervertebral disc degeneration has been implicated in the etiology of low back pain; however, the current surgical strategies for treating symptomatic disc disease are limited. A variety of materials have been developed to replace disc components, including the nucleus pulposus (NP), the annulus fibrosus (AF) and their combination into disc-like engineered constructs. We have previously shown that layers of electrospun poly(ε-caprolactone) scaffold, mimicking the hierarchical organization of the native AF, can achieve functional parity with native tissue. Likewise, we have combined these structures with cell-seeded hydrogels (as an NP replacement) to form disc-like angle-ply structures (DAPS). The objective of this study was to develop a model for the evaluation of DAPS in vivo. Through a series of studies, we developed a surgical approach to replace the rat caudal disc with an acellular DAPS and then stabilized the motion segment via external fixation. We then optimized cell infiltration into DAPS by including sacrificial poly(ethylene oxide) layers interspersed throughout the angle-ply structure. Our findings illustrate that DAPS are stable in the caudal spine, are infiltrated by cells from the peri-implant space and that infiltration is expedited by providing additional routes for cell migration. These findings establish a new in vivo platform in which to evaluate and optimize the design of functional disc replacements. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Prevalence of myelinated retinal nerve fibres in adult Indians: the Central India Eye and Medical Study.

PubMed

Nangia, Vinay; Jonas, Jost B; Khare, Anshu; Bhate, Karishma; Agarwal, Shubhra; Panda-Jonas, Songhomitra

2014-05-01

To determine the prevalence of myelinated retinal nerve fibers in the adult Indian population. The Central India Eye and Medical Study performed in rural Central India included 4711 participants aged 30+ years. The participants underwent a detailed ophthalmic and medical examination. Readable fundus photographs were available for 8645 eyes of 4485 (95.2%) subjects. Myelinated retinal nerve fibers were detected in 52 eyes (46 subjects) with a prevalence rate of 0.58±0.08 per 100 eyes [95% confidence interval (CI): 0.42, 0.74] and 1.03±0.15 per 100 subjects (95%CI: 0.73, 1.32). Prevalence of myelinated retinal nerve fibers was significantly associated hyperopic refractive error (p=0.008; OR: 1.31; 95%CI: 1.07, 1.59). It was not significantly associated with age (p=0.11), best corrected visual acuity (logMAR; p=0.33), intraocular pressure (p=0.09), amount of nuclear cataract (p=0.93), optic disc area (p=0.60), presence of glaucomatous optic nerve atrophy (p=0.62), and early age-related macular degeneration (p=0.53). Myelinated retinal nerve fibers are present in about 10 out of 1000 adult Indians in rural Central India, with a higher prevalence in hyperopic eyes. Prevalence of myelinated retinal nerve fibers was not associated with age, visual acuity, glaucoma and macular degeneration. © 2013 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Lack of Radiation Maculopathy After Palladium-103 Plaque Radiotherapy for Iris Melanoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yousef, Yacoub A.; Finger, Paul T., E-mail: pfinger@eyecancer.com

2012-07-15

Purpose: To report on the risk of radiation maculopathy for iris and iridociliary melanomas treated by {sup 103}Pd plaque radiotherapy. Methods and Materials: This is a retrospective clinical case series of 30 eyes in 30 patients with melanomas limited to the iris or invading the ciliary body. The main outcome measures included demographic information, laterality, tumor size, location, visual acuity, radiation dose, local control, retinal evaluation, and duration of follow-up. Results: Thirty patients were followed for a median 36 months (range, 12-90 months). Sixteen of 30 tumors (53%) were pure iris melanomas, and 14 (47%) were primary iris melanomas extendingmore » into the ciliary body. Radiation dosimetry showed that the median tumor apex dose was 85 Gy (range, 75-100 Gy), lens dose 43.5 Gy (range, 17.8-60 Gy), fovea dose 1.8 Gy (range, 1.3-5 Gy), and central optic disc dose 1.7 Gy (range, 1.3-4.7 Gy). Cataracts developed in 20 of the 28 phakic eyes (71.4%). No patient in this series developed radiation maculopathy or radiation optic neuropathy. Last best-corrected visual acuity was {>=}20/25 in 28 patients (93%) at a median 36 months' follow-up. Conclusion: Though visual acuities were transiently affected by radiation cataract, no radiation maculopathy or optic neuropathy has been noted after {sup 103}Pd treatment of iris and iridociliary melanomas.« less

Light and portable novel device for diabetic retinopathy screening.

PubMed

Ting, Daniel S W; Tay-Kearney, Mei Ling; Kanagasingam, Yogesan

2012-01-01

To validate the use of an economical portable multipurpose ophthalmic imaging device, EyeScan (Ophthalmic Imaging System, Sacramento, CA, USA), for diabetic retinopathy screening. Evaluation of a diagnostic device. One hundred thirty-six (272 eyes) were recruited from diabetic retinopathy screening clinic of Royal Perth Hospital, Western Australia, Australia. All patients underwent three-field (optic disc, macular and temporal view) mydriatic retinal digital still photography captured by EyeScan and FF450 plus (Carl Zeiss Meditec, North America) and were subsequently examined by a senior consultant ophthalmologist using the slit-lamp biomicroscopy (reference standard). All retinal images were interpreted by a consultant ophthalmologist and a medical officer. The sensitivity, specificity and kappa statistics of EyeScan and FF450 plus with reference to the slit-lamp examination findings by a senior consultant ophthalmologist. For detection of any grade of diabetic retinopathy, EyeScan had a sensitivity and specificity of 93 and 98%, respectively (ophthalmologist), and 92 and 95%, respectively (medical officer). In contrast, FF450 plus images had a sensitivity and specificity of 95 and 99%, respectively (ophthalmologist), and 92 and 96%, respectively (medical officer). The overall kappa statistics for diabetic retinopathy grading for EyeScan and FF450 plus were 0.93 and 0.95 for ophthalmologist and 0.88 and 0.90 for medical officer, respectively. Given that the EyeScan requires minimal training to use and has excellent diagnostic accuracy in screening for diabetic retinopathy, it could be potentially utilized by the primary eye care providers to widely screen for diabetic retinopathy in the community. © 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists.

The comparative analysis of rocks' resistance to forward-slanting disc cutters and traditionally installed disc cutters

NASA Astrophysics Data System (ADS)

Zhang, Zhao-Huang; Fei, Sun; Liang, Meng

2016-08-01

At present, disc cutters of a full face rock tunnel boring machine are mostly mounted in the traditional way. Practical use in engineering projects reveals that this installation method not only heavily affects the operation life of disc cutters, but also increases the energy consumption of a full face rock tunnel boring machine. To straighten out this issue, therefore, a rock-breaking model is developed for disc cutters' movement after the research on the rock breaking of forward-slanting disc cutters. Equations of its displacement are established based on the analysis of velocity vector of a disc cutter's rock-breaking point. The functional relations then are brought forward between the displacement parameters of a rock-breaking point and its coordinate through the analysis of micro displacement of a rock-breaking point. Thus, the geometric equations of rock deformation are derived for the forward-slanting installation of disc cutters. With a linear relationship remaining between the acting force and its deformation either before or after the leap breaking, the constitutive relation of rock deformation can be expressed in the form of generalized Hooke law, hence the comparative analysis of the variation in the resistance of rock to the disc cutters mounted in the forward-slanting way with that in the traditional way. It is discovered that with the same penetration, strain of the rock in contact with forward-slanting disc cutters is apparently on the decline, in other words, the resistance of rock to disc cutters is reduced. Thus wear of disc cutters resulted from friction is lowered and energy consumption is correspondingly decreased. It will be useful for the development of installation and design theory of disc cutters, and significant for the breakthrough in the design of full face rock tunnel boring machine.

Automatic non-proliferative diabetic retinopathy screening system based on color fundus image.

PubMed

Xiao, Zhitao; Zhang, Xinpeng; Geng, Lei; Zhang, Fang; Wu, Jun; Tong, Jun; Ogunbona, Philip O; Shan, Chunyan

2017-10-26

Non-proliferative diabetic retinopathy is the early stage of diabetic retinopathy. Automatic detection of non-proliferative diabetic retinopathy is significant for clinical diagnosis, early screening and course progression of patients. This paper introduces the design and implementation of an automatic system for screening non-proliferative diabetic retinopathy based on color fundus images. Firstly, the fundus structures, including blood vessels, optic disc and macula, are extracted and located, respectively. In particular, a new optic disc localization method using parabolic fitting is proposed based on the physiological structure characteristics of optic disc and blood vessels. Then, early lesions, such as microaneurysms, hemorrhages and hard exudates, are detected based on their respective characteristics. An equivalent optical model simulating human eyes is designed based on the anatomical structure of retina. Main structures and early lesions are reconstructed in the 3D space for better visualization. Finally, the severity of each image is evaluated based on the international criteria of diabetic retinopathy. The system has been tested on public databases and images from hospitals. Experimental results demonstrate that the proposed system achieves high accuracy for main structures and early lesions detection. The results of severity classification for non-proliferative diabetic retinopathy are also accurate and suitable. Our system can assist ophthalmologists for clinical diagnosis, automatic screening and course progression of patients.

Ocular ultrasonography focused on the posterior eye segment: what radiologists should know.

PubMed

De La Hoz Polo, Marcela; Torramilans Lluís, Anna; Pozuelo Segura, Oscar; Anguera Bosque, Albert; Esmerado Appiani, Catalina; Caminal Mitjana, Josep Maria

2016-06-01

Ocular B-mode ultrasonography (US) is an important adjuvant for the clinical assessment of a variety of ocular diseases. When ophthalmoscopy is not possible, mainly due to opacification of the transparent media (e.g., mature cataract or vitreous haemorrhage), US can guide the ophthalmologist in diagnosing disease and choosing treatment. The superficial location and cystic structure of the eye make US ideal for imaging of the eye. Moreover, dynamic study helps distinguish between various conditions that would otherwise be difficult to differentiate in some clinical setting, such as vitreous, retinal, and choroidal detachment. US is also good technique for detecting other pathologic conditions such as lens dislocation, vitreous haemorrhage, asteroid hyalosis, optic disc drusen, and tumors (e.g., choroidal melanoma, metastases, hemangioma). An understanding of the basic anatomy of the eye, the US technique, and common entities that affect the ocular globe will allow radiologists to offer this valuable imaging modality to patients and referring clinicians. This article focuses on the US anatomy and pathologic conditions that affect the posterior ocular segment. • US is specially indicated when ocular fundus cannot be assessed on ophthalmoscopy. • Multipurpose equipment with high-frequency transducers is optimal for imaging the eye. • Ultrasound can reliably depict ocular anatomy and pathology as detachments and tumours. • Dynamic examination is vital for distinguishing certain pathologic conditions as detachments.

Efficient radiative transfer techniques in hydrodynamic simulations

NASA Astrophysics Data System (ADS)

Mercer, A.; Stamatellos, D.; Dunhill, A.

2018-05-01

Radiative transfer is an important component of hydrodynamic simulations as it determines the thermal properties of a physical system. It is especially important in cases where heating and cooling regulate significant processes, such as in the collapse of molecular clouds, the development of gravitational instabilities in protostellar discs, disc-planet interactions, and planet migration. We compare two approximate radiative transfer methods which indirectly estimate optical depths within hydrodynamic simulations using two different metrics: (i) the gravitational potential and density of the gas (Stamatellos et al.), and (ii) the pressure scale-height (Lombardi et al.). We find that both methods are accurate for spherical configurations e.g. in collapsing molecular clouds and within clumps that form in protostellar discs. However, the pressure scale-height approach is more accurate in protostellar discs (low and high-mass discs, discs with spiral features, discs with embedded planets). We also investigate the β-cooling approximation which is commonly used when simulating protostellar discs, and in which the cooling time is proportional to the orbital period of the gas. We demonstrate that the use of a constant β cannot capture the wide range of spatial and temporal variations of cooling in protostellar discs, which may affect the development of gravitational instabilities, planet migration, planet mass growth, and the orbital properties of planets.

Dusty disc-planet interaction with dust-free simulations

NASA Astrophysics Data System (ADS)

Chen, Jhih-Wei; Lin, Min-Kai

2018-05-01

Protoplanets may be born into dust-rich environments if planetesimals formed through streaming or gravitational instabilities, or if the protoplanetary disc is undergoing mass loss due to disc winds or photoevaporation. Motivated by this possibility, we explore the interaction between low mass planets and dusty protoplanetary discs with focus on disc-planet torques. We implement Lin & Youdin's newly developed, purely hydrodynamic model of dusty gas into the PLUTO code to simulate dusty protoplanetary discs with an embedded planet. We find that for imperfectly coupled dust and high metallicity, e.g. Stokes number 10-3 and dust-to-gas ratio Σd/Σg = 0.5, a `bubble' develops inside the planet's co-orbital region, which introduces unsteadiness in the flow. The resulting disc-planet torques sustain large amplitude oscillations that persists well beyond that in simulations with perfectly coupled dust or low dust-loading, where co-rotation torques are always damped. We show that the desaturation of the co-rotation torques by finite-sized particles is related to potential vorticity generation from the misalignment of dust and gas densities. We briefly discuss possible implications for the orbital evolution of protoplanets in dust-rich discs. We also demonstrate Lin & Youdin's dust-free framework reproduces previous results pertaining to dusty protoplanetary discs, including dust-trapping by pressure bumps, dust settling, and the streaming instability.

Myoblast cytonemes mediate Wg signaling from the wing imaginal disc and Delta-Notch signaling to the air sac primordium.

PubMed

Huang, Hai; Kornberg, Thomas B

2015-05-07

The flight muscles, dorsal air sacs, wing blades, and thoracic cuticle of the Drosophila adult function in concert, and their progenitor cells develop together in the wing imaginal disc. The wing disc orchestrates dorsal air sac development by producing decapentaplegic and fibroblast growth factor that travel via specific cytonemes in order to signal to the air sac primordium (ASP). Here, we report that cytonemes also link flight muscle progenitors (myoblasts) to disc cells and to the ASP, enabling myoblasts to relay signaling between the disc and the ASP. Frizzled (Fz)-containing myoblast cytonemes take up Wingless (Wg) from the disc, and Delta (Dl)-containing myoblast cytonemes contribute to Notch activation in the ASP. Wg signaling negatively regulates Dl expression in the myoblasts. These results reveal an essential role for cytonemes in Wg and Notch signaling and for a signal relay system in the myoblasts.

Automated volumetric evaluation of stereoscopic disc photography

PubMed Central

Xu, Juan; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A; Kagemann, Larry; Craig, Jamie E; Mackey, David A; Hewitt, Alex W; Schuman, Joel S

2010-01-01

PURPOSE: To develop a fully automated algorithm (AP) to perform a volumetric measure of the optic disc using conventional stereoscopic optic nerve head (ONH) photographs, and to compare algorithm-produced parameters with manual photogrammetry (MP), scanning laser ophthalmoscope (SLO) and optical coherence tomography (OCT) measurements. METHODS: One hundred twenty-two stereoscopic optic disc photographs (61 subjects) were analyzed. Disc area, rim area, cup area, cup/disc area ratio, vertical cup/disc ratio, rim volume and cup volume were automatically computed by the algorithm. Latent variable measurement error models were used to assess measurement reproducibility for the four techniques. RESULTS: AP had better reproducibility for disc area and cup volume and worse reproducibility for cup/disc area ratio and vertical cup/disc ratio, when the measurements were compared to the MP, SLO and OCT methods. CONCLUSION: AP provides a useful technique for an objective quantitative assessment of 3D ONH structures. PMID:20588996

Design and Development of Micro-Power Generating Device for Biomedical Applications of Lab-on-a-Disc.

PubMed

Joseph, Karunan; Ibrahim, Fatimah; Cho, Jongman; Thio, Tzer Hwai Gilbert; Al-Faqheri, Wisam; Madou, Marc

2015-01-01

The development of micro-power generators for centrifugal microfluidic discs enhances the platform as a green point-of-care diagnostic system and eliminates the need for attaching external peripherals to the disc. In this work, we present micro-power generators that harvest energy from the disc's rotational movement to power biomedical applications on the disc. To implement these ideas, we developed two types of micro-power generators using piezoelectric films and an electromagnetic induction system. The piezoelectric-based generator takes advantage of the film's vibration during the disc's rotational motion, whereas the electromagnetic induction-based generator operates on the principle of current generation in stacks of coil exposed to varying magnetic flux. We have successfully demonstrated that at the spinning speed of 800 revolutions per minute (RPM) the piezoelectric film-based generator is able to produce up to 24 microwatts using 6 sets of films and the magnetic induction-based generator is capable of producing up to 125 milliwatts using 6 stacks of coil. As a proof of concept, a custom made localized heating system was constructed to test the capability of the magnetic induction-based generator. The heating system was able to achieve a temperature of 58.62 °C at 2200 RPM. This development of lab-on-a-disc micro power generators preserves the portability standards and enhances the future biomedical applications of centrifugal microfluidic platforms.

Changes in ocular flora in eyes exposed to ophthalmic antibiotics.

PubMed

Dave, Sarita B; Toma, Hassanain S; Kim, Stephen J

2013-05-01

To determine changes in ocular flora in individuals repeatedly exposed to topical macrolide or fluoroquinolone antibiotics. Prospective, controlled, longitudinal study with 1-year follow-up. Forty-eight eyes of 24 patients undergoing serial unilateral intravitreal injection for choroidal neovascularization. Patients received 4 consecutive monthly unilateral intravitreal injections and were then treated as needed. Each patient was randomized to 1 of 4 antibiotics (azithromycin 1%, gatifloxacin 0.3%, moxifloxacin 0.5%, ofloxacin 0.3%) and used only their assigned antibiotic for 4 days after each injection. Conjunctival cultures of the treated eye and untreated fellow eye (control) were taken at baseline and before each injection. All bacterial isolates were tested for antibiotic susceptibility to 16 different antibiotics using the Kirby-Bauer disc diffusion technique. Changes in bacteria composition of the conjunctiva over time. In azithromycin-treated eyes, Staphylococcus epidermidis and Staphylococcus aureus accounted for 54.5% and 18.2% of cultured isolates, respectively, at baseline and 90.9% (P<0.01) and 4.5% (P<0.01), respectively, after azithromycin exposure. In fluoroquinolone-treated eyes, 45.7% and 6.5% of cultured isolates at baseline were S epidermidis and S aureus, respectively, but these percentages increased to 63.4% (P<0.03) and 13% (P = 0.24), respectively, after fluoroquinolone exposure. In contrast, the percentage of gram-negative species decreased from 8.7% at baseline to 1.6% (P<0.05) in fluoroquinolone-treated eyes. The percentage of S epidermidis isolated from azithromycin-treated eyes was significantly greater when compared with fellow control eyes (P<0.01) or fluoroquinolone-treated eyes (P<0.01). The percentage of S epidermidis isolated from the conjunctival surface significantly increases after repeated exposure to azithromycin and to a lesser degree fluoroquinolone antibiotics at the expense of other commensal flora. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Expression of Mutant Human DISC1 in Mice Supports Abnormalities in Differentiation of Oligodendrocytes

PubMed Central

Katsel, Pavel; Tan, Weilun; Abazyan, Bagrat; Davis, Kenneth L; Ross, Christopher; Pletnikov, Mikhail V; Haroutunian, Vahram

2011-01-01

Abnormalities in oligodendrocyte (OLG) differentiation and OLG gene expression deficit have been described in schizophrenia (SZ). Recent studies revealed a critical requirement for Disrupted-in-Schizophrenia 1 (DISC1) in neural development. Transgenic mice with forebrain restricted expression of mutant human DISC1 (ΔhDISC1) are characterized by neuroanatomical and behavioral abnormalities reminiscent of some features of SZ. We sought to determine whether the expression of ΔhDISC1 may influence the development of OLGs in this mouse model. OLG- and cell cycle-associated gene and protein expression were characterized in the forebrain of ΔhDISC1 mice during different stages of neurodevelopment (E15 and P1 days) and in adulthood. The results suggest that the expression of ΔhDISC1 exerts a significant influence on oligodendrocyte differentiation and function, evidenced by premature OLG differentiation and increased proliferation of their progenitors. Additional findings showed that neuregulin 1 and its receptors may be contributing factors to the observed upregulation of OLG genes. Thus, OLG function may be perturbed by mutant hDISC1 in a model system that provides new avenues for studying aspects of the pathogenesis of SZ. PMID:21605958

Early detection of glaucoma by means of a novel 3D computer‐automated visual field test

PubMed Central

Nazemi, Paul P; Fink, Wolfgang; Sadun, Alfredo A; Francis, Brian; Minckler, Donald

2007-01-01

Purpose A recently devised 3D computer‐automated threshold Amsler grid test was used to identify early and distinctive defects in people with suspected glaucoma. Further, the location, shape and depth of these field defects were characterised. Finally, the visual fields were compared with those obtained by standard automated perimetry. Patients and methods Glaucoma suspects were defined as those having elevated intraocular pressure (>21 mm Hg) or cup‐to‐disc ratio of >0.5. 33 patients and 66 eyes with risk factors for glaucoma were examined. 15 patients and 23 eyes with no risk factors were tested as controls. The recently developed 3D computer‐automated threshold Amsler grid test was used. The test exhibits a grid on a computer screen at a preselected greyscale and angular resolution, and allows patients to trace those areas on the grid that are missing in their visual field using a touch screen. The 5‐minute test required that the patients repeatedly outline scotomas on a touch screen with varied displays of contrast while maintaining their gaze on a central fixation marker. A 3D depiction of the visual field defects was then obtained that was further characterised by the location, shape and depth of the scotomas. The exam was repeated three times per eye. The results were compared to Humphrey visual field tests (ie, achromatic standard or SITA standard 30‐2 or 24‐2). Results In this pilot study 79% of the eyes tested in the glaucoma‐suspect group repeatedly demonstrated visual field loss with the 3D perimetry. The 3D depictions of visual field loss associated with these risk factors were all characteristic of or compatible with glaucoma. 71% of the eyes demonstrated arcuate defects or a nasal step. Constricted visual fields were shown in 29% of the eyes. No visual field changes were detected in the control group. Conclusions The 3D computer‐automated threshold Amsler grid test may demonstrate visual field abnormalities characteristic of glaucoma in glaucoma suspects with normal achromatic Humphrey visual field testing. This test may be used as a screening tool for the early detection of glaucoma. PMID:17504855

Geometrical aspects of patient-specific modelling of the intervertebral disc: collagen fibre orientation and residual stress distribution.

PubMed

Marini, Giacomo; Studer, Harald; Huber, Gerd; Püschel, Klaus; Ferguson, Stephen J

2016-06-01

Patient-specific modelling of the spine is a powerful tool to explore the prevention and the treatment of injuries and pathologies. Albeit several methods have been proposed for the discretization of the bony structures, the efficient representation of the intervertebral disc anisotropy remains a challenge, especially with complex geometries. Furthermore, the swelling of the disc's nucleus pulposus is normally added to the model after geometry definition, at the cost of changes of the material properties and an unrealistic description of the prestressed state. The aim of this study was to develop techniques, which preserve the patient-specific geometry of the disc and allow the representation of the system anisotropy and residual stresses, independent of the system discretization. Depending on the modelling features, the developed approaches resulted in a response of patient-specific models that was in good agreement with the physiological response observed in corresponding experiments. The proposed methods represent a first step towards the development of patient-specific models of the disc which respect both the geometry and the mechanical properties of the specific disc.

A 1q42 Deletion Involving DISC1, DISC2, and TSNAX in an Autism Spectrum Disorder

PubMed Central

Williams, Jaime M.; Beck, Tyler F.; Pearson, David M.; Proud, Monica B.; Cheung, Sau Wai; Scott, Daryl A.

2010-01-01

Individuals with autism spectrum disorders have impairments in social, communicative, and behavior development that are often accompanied by abnormalities in cognitive functioning, learning, attention, and sensory processing. In this report, we describe a 3-year-old male child with an autism spectrum disorder who carries a 2Mb deletion of chromosome 1q42. Array comparative genome hybridization revealed that this deletion involves at least three genes—DISC1, DISC2, and TSNAX—which have been found to be associated with neuropsychiatric disorders and are likely to play key roles in normal CNS development. Further studies revealed that the deletion was inherited from his unaffected mother. This suggests that other genetic and/or environmental factors, some of which may be sex specific, may modify the phenotypic effects of this deletion. While this case provides evidence for the potential role of DISC1, DISC2, and TSNAX in the development of autism spectrum disorders, it is equally clear that caution must be taken when providing families with prognostic information and genetic counseling regarding such deletions. PMID:19606485

In Vitro Maturation and In Vivo Integration and Function of an Engineered Cell-Seeded Disc-like Angle Ply Structure (DAPS) for Total Disc Arthroplasty.

PubMed

Martin, J T; Gullbrand, S E; Kim, D H; Ikuta, K; Pfeifer, C G; Ashinsky, B G; Smith, L J; Elliott, D M; Smith, H E; Mauck, R L

2017-11-17

Total disc replacement with an engineered substitute is a promising avenue for treating advanced intervertebral disc disease. Toward this goal, we developed cell-seeded disc-like angle ply structures (DAPS) and showed through in vitro studies that these constructs mature to match native disc composition, structure, and function with long-term culture. We then evaluated DAPS performance in an in vivo rat model of total disc replacement; over 5 weeks in vivo, DAPS maintained their structure, prevented intervertebral bony fusion, and matched native disc mechanical function at physiologic loads in situ. However, DAPS rapidly lost proteoglycan post-implantation and did not integrate into adjacent vertebrae. To address this, we modified the design to include polymer endplates to interface the DAPS with adjacent vertebrae, and showed that this modification mitigated in vivo proteoglycan loss while maintaining mechanical function and promoting integration. Together, these data demonstrate that cell-seeded engineered discs can replicate many characteristics of the native disc and are a viable option for total disc arthroplasty.

The formation of rings and gaps in magnetically coupled disc-wind systems: ambipolar diffusion and reconnection

NASA Astrophysics Data System (ADS)

Suriano, Scott S.; Li, Zhi-Yun; Krasnopolsky, Ruben; Shang, Hsien

2018-06-01

Radial substructures in circumstellar discs are now routinely observed by Atacama Large Millimeter/submillimeter Array. There is also growing evidence that disc winds drive accretion in such discs. We show through 2D (axisymmetric) simulations that rings and gaps develop naturally in magnetically coupled disc-wind systems on the scale of tens of au, where ambipolar diffusion (AD) is the dominant non-ideal magnetohydrodynamic effect. In simulations where the magnetic field and matter are moderately coupled, the disc remains relatively laminar with the radial electric current steepened by AD into a thin layer near the mid-plane. The toroidal magnetic field sharply reverses polarity in this layer, generating a large magnetic torque that drives fast accretion, which drags the poloidal field into a highly pinched radial configuration. The reconnection of this pinched field creates magnetic loops where the net poloidal magnetic flux (and thus the accretion rate) is reduced, yielding dense rings. Neighbouring regions with stronger poloidal magnetic fields accrete faster, forming gaps. In better magnetically coupled simulations, the so-called avalanche accretion streams develop continuously near the disc surface, rendering the disc-wind system more chaotic. Nevertheless, prominent rings and gaps are still produced, at least in part, by reconnection, which again enables the segregation of the poloidal field and the disc material similar to the more diffusive discs. However, the reconnection is now driven by the non-linear growth of magnetorotational instability channel flows. The formation of rings and gaps in rapidly accreting yet laminar discs has interesting implications for dust settling and trapping, grain growth, and planet formation.

Development of Ultrasound to Measure In-Vivo Dynamic Cervical Spine Intervertebral Disc Mechanics

DTIC Science & Technology

2016-01-01

Award Number: W81XWH-13-1-0050 TITLE: Development of Ultrasound to Measure In-vivo Dynamic Cervical Spine Intervertebral Disc Mechanics PRINCIPAL...CONTRACT NUMBER W81XWH-13-1-0050 Development of Ultrasound to Measure In-vivo Dynamic Cervical Spine Intervertebral Disc Mechanics 5b. GRANT NUMBER 5c...elasticity during compression or tension. As a portable, low cost imaging modality, the dual ultrasound system quantified cervical spine IVD displacement and

Chlorotic feeding injury by the black pecan aphid (hemiptera: aphididae) to pecan foliage promotes aphid settling and nymphal development.

PubMed

Cottrell, Ted E; Wood, Bruce W; Ni, Xinzhi

2009-04-01

The nature of the interaction between the black pecan aphid, Melanocallis caryaefoliae (Davis) (Hemiptera: Aphididae), and the chlorosis it causes to foliage of its pecan [Carya illinoinensis (Wangenh.) K. Koch)] host is poorly understood. Laboratory experiments were conducted on the settling behavior of the black pecan aphid, when provided chlorotic pecan leaf discs resulting from previous black pecan aphid feeding and nonchlorotic leaf discs, under a normal photoperiod and constant dark. Additionally, aphid development from the first instar to the adult stage was examined when nymphs were either allowed to feed on the same leaf disc or moved daily to a new, nondamaged, same age leaf disc. After 24 h, a significantly higher percentage of black pecan aphids settled on chlorotic than on nonchlorotic leaf discs, regardless of photoperiod. When starting from the first instar, nymphs that were prevented from inducing leaf chlorosis by moving daily to new, same-age leaf discs took approximately 5 d longer to complete development, had a shorter body length, and had higher mortality than when aphids remained on the same leaf disc. These results show that black pecan aphid-induced leaf chlorosis plays an important role in the interaction of the black pecan aphid with its pecan host.

Fungal corneal ulcer and bacterial orbital cellulitis occur as complications of bacterial endophthalmitis after cataract surgery in an immunocompetent patient.

PubMed

Kim, Eun Chul; Kim, Man Soo; Kang, Nam Yeo

2013-03-01

To report a case of fungal corneal ulcer and bacterial orbital cellulitis as complications of bacterial endophthalmitis following cataract surgery. A 51-year-old man underwent anterior chamber irrigation and aspiration in the left eye one day after cataract surgery because of bacterial endophthalmitis. Marked lid swelling with purulent discharge was developed after 5 days. Slit lamp examination showed generalized corneal ulcer and pus in the total anterior chamber. A computerized tomography scan showed left retrobulbar fat stranding with thickened optic disc. Streptococcus pneumonia was cultured from corneal scraping, vireous, and subconjunctival pus. The patient improved gradually with antibiotics treatments, but the corneal ulcer did not fully recover 2 months after cataract surgery. Candida albicans was detected in repetitive corneal culture. After antifungal and antibacterial therapy, the corneal epithelium had healed, but phthisis bulbi had developed. Fungal corneal ulcer and bacterial orbital cellulitis can occur as complications of endophthalmitis in an immunocompetent patient.

Morning glory syndrome associated with primary open angle glaucoma--case report.

PubMed

Bozić, Marija; Hentova-Senćanić, Paraskeva; Marković, Vujica; Marjanović, Ivan

2014-01-01

Morning glory syndrome (MGS) is a rare congenital optic disc anomaly, first reported in 1970. MGS is a nonprogressive and untreatable condition, which usually occurs as an isolated ocular anomaly, and can be associated with the increased incidence of nonrhegmatogenous retinal detachment, and also with strabismus, afferent pupillary defect, visual field defects, presence of hyaloids artery remnants, ciliary body cyst, congenital cataract, lid hemangioma and preretinal gliosis. We report a clinical case of MGS associated with primary open angle glaucoma. The use of sophisticated diagnostic tools, such as retinal tomography and visual field testing is limited if multiple eye conditions are present, since optic disc does not have "usual" appearance that can be analyzed according to standard statistical databases. In treating and follow up of glaucoma cases associated with other diseases and conditions that affect the appearance and function of the optic nerve head, sometimes the use of modern technological methods is limited due to difficult interpretation of the obtained results.

Pars plana vitrectomy with juxtapapillary laser photocoagulation versus vitrectomy without juxtapapillary laser photocoagulation for the treatment of optic disc pit maculopathy: the results of the KKESH International Collaborative Retina Study Group.

PubMed

Abouammoh, Marwan A; Alsulaiman, Sulaiman M; Gupta, Vishali S; Mousa, Ahmed; Hirakata, Akito; Berrocal, Maria H; Chenworth, Megan; Chhablani, Jay; Oshima, Yusuke; AlZamil, Waseem M; Casella, Antonio Marcelo; Papa-Oliva, Gabriela; Banker, Alay S; Arevalo, J Fernando

2016-04-01

To compare the functional and anatomic outcomes of pars plana vitrectomy (PPV) with juxtapapillary laser photocoagulation (JLP) versus vitrectomy without JLP in optic disc pit maculopathy. This was a multicentre, retrospective study of 46 consecutive patients with optic disc pit maculopathy presenting at tertiary eye centres between 1992 and 2012. Indications for surgery included distorted or decreased vision. Surgical intervention included PPV, posterior vitreous detachment, with or without gas tamponade. Twenty-four patients received laser photocoagulation at the temporal edge of the optic disc pit (group A) and 22 patients had no laser (group B). Postoperative best-corrected visual acuity (BCVA) and optical coherence tomography findings were the main outcome measures. Mean follow-up was 44 months (range 12-98 months). BCVA in group A improved significantly from 0.7 logMAR (20/100) preoperatively to 0.5 logMAR (20/60) postoperatively (p=0.017). In group B, BCVA improved from 0.7 logMAR (20/100) preoperatively to 0.4 logMAR (20/40) postoperatively (p=0.014). The difference in final BCVA between groups was not statistically significant (p=0.693). The mean central macular thickness (CMT) in group A improved significantly from 750 μm preoperatively to 309 μm at last follow-up (p<0.0001). The mean CMT in group B improved from 616 μm preoperatively to 291 μm at last follow-up (p=0.028). The difference in final CMT between groups was not statistically significant (p=0.747). PPV with JLP for optic disc pit maculopathy had similar functional and anatomic outcomes compared with vitrectomy without JLP. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

DEEP, SHALLOW AND EYE LENS DOSES FROM 106Ru/106Rh-A COMPARSION.

PubMed

Kumar, Munish; Bakshi, A K; Rakesh, R B; Ratna, P; Kulkarni, M S; Datta, D

2017-11-01

106Ru/106Rh is unique amongst other commonly used beta sources such as 147Pm, 85Kr, 204Tl, 32P, natU and 90Sr/90Y in the sense that it is capable of simultaneously delivering shallow/skin, eye lens and deep/whole body doses (WBDs) and they differ from each other substantially. In view of this, the investigation of various quantities defined for individual monitoring is possible and this makes 106Ru/106Rh beta source, a classical example in radiation protection and dosimetry. This led us to estimate skin, eye lens and WBDs for 106Ru/106Rh beta source. Optically stimulated luminescence based ultra-thin α-Al2O3:C disc dosimeters were used in the present study. Typical values (relative) of the eye lens and whole body/deep doses with respective to the skin dose (100%) were experimentally measured as ~66 ± 4.6% and 17 ± 3.9%, respectively. The study shows that 106Ru/106Rh beta source is capable of delivering even WBD which is not the case with other beta sources. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Survey of ocular injury by solar eclipse 2009].

PubMed

Obana, Akira; Takahashi, Jun; Ohnishi, Kouji; Shinohara, Hideo; Matsuo, Atsushi; Saito, Izumi; Ohkawa, Takuya; Ono, Tomoko

2011-07-01

Incidence of ocular injury caused by the solar eclipse of 2009 has been investigated using the questionnaire of the Japan Committee of the International Year of Astronomy 2009. The questionnaire was available to the public on the website. Answers were obtained from 14 people (12 men, 2 women), aged from sixteen to fifty-four. All had looked at the sun either with the naked eye or through some shading device (plastic sheet, plastic bag, compact disc, etc.) the safty of which is unknown. Reported symptoms included a sense of incongruity, heat, pain, central scotoma or visual disturbance, classified into four periods of duration. Three people with transient symptoms watched the eclipse with the naked eye for one minute in cloudy weather. Three people with symptoms lasting for one day and three people with symptoms lasting for one week had watched it with the naked eye and some shading device for 10 minutes in cloudy weather. Five people with symptoms lasting for more than one week watched the eclipse with the naked eye and through some sort of device in fine or slightly cloudy weather. Three people consulted their ophthalmologist. Those who reported adverse symptoms did not comply with the instructions for safe watching of the eclipse and the duration of the symptoms depended on the weather and the type of device used.

Corneal status in primary angle-closure glaucoma with a history of acute attack.

PubMed

Chen, Mei-Ju; Liu, Catherine Jui-Ling; Cheng, Ching-Yu; Lee, Shui-Mei

2012-01-01

The corneal status of patients with primary angle-closure glaucoma (PACG) with a history of acute attack was investigated. This cross-sectional study included 40 eyes of PACG patients with an earlier documented symptomatic acute angle-closure attack (aPACG), 40 uninvolved fellow eyes of aPACG patients (fPACG), 44 eyes of chronic PACG patients without such a history (cPACG), and 50 eyes of age-matched normal participants. All glaucoma patients had patent peripheral iridotomies with adequate intraocular pressure control. The examinations and recorded parameters included visual acuity, intraocular pressure, gonioscopy, vertical cup-to-disc ratio, specular microscopy, central corneal pachymetry, refraction, corneal curvature radius, anterior chamber depth, axial length, and lens thickness measurements, and the presenting intraocular pressure and the duration of acute angle-closure attack for aPACG eyes. The mean endothelial cell density was 2271±80 cells/mm(2) in aPACG, 2458±79 cells/mm(2) in fPACG, 2379±50 cells/mm(2) in cPACG, and 2559±45 cells/mm(2) in controls. The aPACG eyes had significantly lower endothelial cell density compared with normal eyes (P=0.002). There was no significant difference in endothelial cell density of aPACG eyes compared with fPACG or cPACG eyes. Multivariate analysis showed the duration of the acute attack was the only factor independently associated with corneal endothelial density of aPACG eyes. The mean central corneal thickness of aPACG (549±32 μm) did not differ significantly from control eyes (552±27 μm), cPACG (557±32 μm), and fPACG (553±31 μm) (P=0.911, 0.274, and 0.725, respectively). Corneal curvature radius of aPACG eyes was not significantly different from that of the comparison groups (all P>0.05). Corneal endothelial cell density was significantly reduced in aPACG eyes compared with normal eyes. No significant difference in endothelial cell density of aPACG eyes was noted when compared with fPACG or cPACG eyes. Corneal endothelial cell density was negatively associated with the duration of the acute attack, but was not associated with demographic and biometric characteristics. Central corneal thickness and corneal curvature radius were not associated with an earlier acute angle-closure attack.

Thoracolumbar Intervertebral Disc Area Morphometry in Elderly Chinese Men and Women: Radiographic Quantifications at Baseline and Changes at Year-4 Follow-up.

PubMed

Wáng, Jùn-Qīng; Káplár, Zoltán; Deng, Min; Griffith, James F; Leung, Jason C S; Kwok, Anthony W L; Kwok, Timothy; Leung, Ping Chung; Wáng, Yì Xiáng J

2018-05-15

A population-based radiographic study with longitudinal follow-up. To develop a quantitative index for lumbar disc space narrowing (DSN) evaluation in elderly subjects; to determine how DSN in the elderly is influenced by osteoporosis and sex. There is paucity of research on quantitative classification of lumbar DSN based on disc areal morphometry. With the database of Osteoporotic Fractures in Men (Hong Kong) and Osteoporotic Fractures in Women (Hong Kong) Studies and those who attended the year-4 follow-up (n = 1519 for men and n = 1546 for women), data of 491 women and 592 men were randomly selected. The anterior, middle, and posterior heights; anteroposterior diameter; and area of intervertebral discs (T4T5 to L4L5) were measured on lateral radiographs. Disc area index for lumbar spine (DAIL, disc area divided by the mean of the sum of square of the adjacent upper and lower vertebrae mid-height anterior-posterior diameter) was developed and compared with semiquantitative DSN expert grading. DAIL correlated with semiquantitative grading, with sensitivity and specificity varying from 87.3% to 96.8% for grade 1 DSN (<30% reduction in disc height), and 92.9% to 100% for grade 3 DSN (>60% reduction in disc height). The thoracolumbar disc area loss among men and women during 4-years' follow-up period varied between 1.32% and 3.56%, and it was greater for women (mean: 2.44%) than for men (mean: 1.90%, P = 0.044). Majority of lumbar DSN progressions during 72 to 76 years old were progression from normal disc space to grade 1 DSN. Osteoporosis was associated with greater disc area decrease, both for thoracic and lumbar discs. Lumbar DSN can be quantified using DAIL. In elderly Chinese, intervertebral disc narrowing over a 4-year period was greater in women than men, and associated with the presence of osteoporosis. 3.

Relationships Between Measures of the Ability to Perform Vision-Related Activities, Vision-Related Quality of Life, and Clinical Findings in Patients With Glaucoma.

PubMed

Ekici, Feyzahan; Loh, Rebecca; Waisbourd, Michael; Sun, Yi; Martinez, Patricia; Nayak, Natasha; Wizov, Sheryl S; Hegarty, Sarah; Hark, Lisa A; Spaeth, George L

2015-12-01

To our knowledge, few studies have combined an objective measure of vision-related performance (VRP) and subjective measures of vision-related quality of life (VRQoL) with clinically related visual parameters, particularly in a large, prospective, cohort study setting. To examine the relationships between clinical visual assessments and both a VRP and 2 self-reported VRQoL measurements. Patients (N = 161) with moderate-stage glaucoma recruited from the Glaucoma Service at Wills Eye Hospital, Philadelphia, Pennsylvania, were enrolled from May 2012 to May 2014 in an ongoing prospective, 4-year longitudinal observational study. This report includes cross-sectional results from the baseline visit. Patients received a complete ocular examination, automated visual field (VF) test and Cirrus optical coherence tomographic scan. Contrast sensitivity was measured with the Pelli-Robson and the Spaeth-Richman Contrast Sensitivity (SPARCS) tests. Vision-related performance was assessed by the Compressed Assessment of Ability Related to Vision (CAARV) test. Vision-related QoL was assessed by the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ-25) and a modified Glaucoma Symptom Scale (MGSS). Correlations between clinical measures and CAARV, NEI-VFQ-25, and MGSS scores. A total of 161 patients were enrolled in the study. The strongest correlation was found between SPARCS score in the better eye and total CAARV score (r = 0.398; 95% CI, 0.235-0.537; P < .001). The CAARV score also correlated with the Pelli-Robson score (r = 0.353; 95% CI, 0.186-0.499; P = .001), VF mean deviation (r = 0.366; 95% CI, 0.200-0.510; P < .001), and VA (r = -0.326, 95% CI = -0.476 to -0.157; P = .003) in the better eye. There were more statistically significant correlations between contrast sensitivity tests and VF mean deviation with VRQoL measurements than with other clinical measures (visual acuity, intraocular pressure, Disc Damage Likelihood Scale, and mean retinal nerve fiber layer thickness). The MGSS scores were lower (worse) in women compared with men (P = .03 for binocular, P = .01 for better eye, and P = .05 for the worse eye). Structural measures (eg, Disc Damage Likelihood Scale, and retinal nerve fiber layer thickness) were generally not informative with respect to VRP or VRQoL. Contrast sensitivity tests and VF mean deviation were associated with both objective measures of the ability to act and subjective measurements of VRQoL. The strongest correlation was between SPARCS score (contrast sensitivity) in the better eye and total CAARV score. Therefore, measurement of contrast sensitivity should be considered when evaluating patients' VRQoL. The results of this study were limited by the patient population and apply only within the bounds of the tested cohort.

An RNAi Screen for Genes Involved in Nanoscale Protrusion Formation on Corneal Lens in Drosophila melanogaster.

PubMed

Minami, Ryunosuke; Sato, Chiaki; Yamahama, Yumi; Kubo, Hideo; Hariyama, Takahiko; Kimura, Ken-Ichi

2016-12-01

The "moth-eye" structure, which is observed on the surface of corneal lens in several insects, supports anti-reflective and self-cleaning functions due to nanoscale protrusions known as corneal nipples. Although the morphology and function of the "moth-eye" structure, are relatively well studied, the mechanism of protrusion formation from cell-secreted substances is unknown. In Drosophila melanogaster, a compound eye consists of approximately 800 facets, the surface of which is formed by the corneal lens with nanoscale protrusions. In the present study, we sought to identify genes involved in "moth-eye" structure, formation in order to elucidate the developmental mechanism of the protrusions in Drosophila. We re-examined the aberrant patterns in classical glossy-eye mutants by scanning electron microscope and classified the aberrant patterns into groups. Next, we screened genes encoding putative structural cuticular proteins and genes involved in cuticular formation using eye specific RNAi silencing methods combined with the Gal4/UAS expression system. We identified 12 of 100 candidate genes, such as cuticular proteins family genes (Cuticular protein 23B and Cuticular protein 49Ah), cuticle secretion-related genes (Syntaxin 1A and Sec61 ββ subunit), ecdysone signaling and biosynthesis-related genes (Ecdysone receptor, Blimp-1, and shroud), and genes involved in cell polarity/cell architecture (Actin 5C, shotgun, armadillo, discs large1, and coracle). Although some of the genes we identified may affect corneal protrusion formation indirectly through general patterning defects in eye formation, these initial findings have encouraged us to more systematically explore the precise mechanisms underlying the formation of nanoscale protrusions in Drosophila.

Correlation between eye and ear symptoms and lack of teeth, bruxism and other parafunctions in a population of 1006 patients in 2003-2008.

PubMed

Michalak, Maciej; Wysokińska-Miszczuk, Joanna; Wilczak, Magdalena; Paulo, Michał; Bożyk, Andrzej; Borowicz, Janusz

2012-02-29

Parafunctions (harmful habits) play a crucial role in the formation of temporo-mandibular joint (TMJ) dysfunction syndrome with disc displacement. Disorder symptoms in temporo-mandibular joints manifest themselves in the eye and ear but are usually not associated with the dysfunction of temporo-mandibular joints and that might lead to errors in diagnosis. The aim of the study was to examine the influence of missing teeth and parafunctions on the occurrence of ear and eye symptoms in patients treated in the Department of Prosthodontics of the Medical University of Lublin. The patient group consisted of 753 women and 253 men aged 10 to 82 years who had been treated in the Department of Prosthodontics, Medical University of Lublin in the years 2003-2008 due to various symptoms associated with temporo-mandibular joint dysfunction. Eye (24.84%, n = 785) and ear (33.38%, n = 785) syndromes occur on average more often in patients with parafunctions than without them (15.98%, n = 219 and 23.29%, n = 219). However, only parafunctions involving tooth contact should be taken into consideration when diagnosing eye and ear syndromes. The data presented here show that the number of missing teeth does not have a significant influence on the frequency of occurrence of parafunctions. Parafunctions have become a very important factor in the diagnosis of diseases and pathological symptoms of eye and ear as the rate at which they occur is growing. The kind of parafunction is very important. Only those involving tooth contact should be taken into consideration when diagnosing eye and ear syndromes.

Correlation between eye and ear symptoms and lack of teeth, bruxism and other parafunctions in a population of 1006 patients in 2003-2008

PubMed Central

Michalak, Maciej; Wysokińska-Miszczuk, Joanna; Paulo, Michał; Bożyk, Andrzej; Borowicz, Janusz

2012-01-01

Introduction Parafunctions (harmful habits) play a crucial role in the formation of temporo-mandibular joint (TMJ) dysfunction syndrome with disc displacement. Disorder symptoms in temporo-mandibular joints manifest themselves in the eye and ear but are usually not associated with the dysfunction of temporo-mandibular joints and that might lead to errors in diagnosis. The aim of the study was to examine the influence of missing teeth and parafunctions on the occurrence of ear and eye symptoms in patients treated in the Department of Prosthodontics of the Medical University of Lublin. Material and methods The patient group consisted of 753 women and 253 men aged 10 to 82 years who had been treated in the Department of Prosthodontics, Medical University of Lublin in the years 2003-2008 due to various symptoms associated with temporo-mandibular joint dysfunction. Results Eye (24.84%, n = 785) and ear (33.38%, n = 785) syndromes occur on average more often in patients with parafunctions than without them (15.98%, n = 219 and 23.29%, n = 219). However, only parafunctions involving tooth contact should be taken into consideration when diagnosing eye and ear syndromes. The data presented here show that the number of missing teeth does not have a significant influence on the frequency of occurrence of parafunctions. Parafunctions have become a very important factor in the diagnosis of diseases and pathological symptoms of eye and ear as the rate at which they occur is growing. Conclusions The kind of parafunction is very important. Only those involving tooth contact should be taken into consideration when diagnosing eye and ear syndromes. PMID:22457683

Genetic link between Cabeza, a Drosophila homologue of Fused in Sarcoma (FUS), and the EGFR signaling pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shimamura, Mai; Kyotani, Akane; Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585

2014-08-01

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease that causes progressive muscular weakness. Fused in Sarcoma (FUS) that has been identified in familial ALS is an RNA binding protein that is normally localized in the nucleus. However, its function in vivo is not fully understood. Drosophila has Cabeza (Caz) as a FUS homologue and specific knockdown of Caz in the eye imaginal disc and pupal retina using a GMR-GAL4 driver was here found to induce an abnormal morphology of the adult compound eyes, a rough eye phenotype. This was partially suppressed by expression of the apoptosis inhibitor P35. Knockdownmore » of Caz exerted no apparent effect on differentiation of photoreceptor cells. However, immunostaining with an antibody to Cut that marks cone cells revealed fusion of these and ommatidia of pupal retinae. These results indicate that Caz knockdown induces apoptosis and also inhibits differentiation of cone cells, resulting in abnormal eye morphology in adults. Mutation in EGFR pathway-related genes, such as rhomboid-1, rhomboid-3 and mirror suppressed the rough eye phenotype induced by Caz knockdown. Moreover, the rhomboid-1 mutation rescued the fusion of cone cells and ommatidia observed in Caz knockdown flies. The results suggest that Caz negatively regulates the EGFR signaling pathway required for determination of cone cell fate in Drosophila. - Highlights: • Knockdown of Cabeza induced rough eye phenotype. • Knockdown of Cabeza induced fusion of cone cells in pupal retinae. • Knockdown of Cabeza induced apoptosis in pupal retinae. • Mutation in EGFR pathway-related genes suppressed the rough eye phenotype. • Cabeza may negatively regulate the EGFR pathway.« less

DISC1 Causes Associative Memory and Neurodevelopmental Defects in Fruit Flies

PubMed Central

Furukubo-Tokunaga, Katsuo; Kurita, Kazuki; Honjo, Ken; Pandey, Himani; Ando, Tetsuya; Takayama, Kojiro; Arai, Yuko; Mochizuki, Hiroaki; Ando, Mai; Kamiya, Atsushi; Sawa, Akira

2016-01-01

Originally found in a Scottish family with diverse mental disorders, the DISC1 protein has been characterized as an intracellular scaffold protein that associates with diverse binding partners in neural development. To explore its functions in a genetically tractable system, we expressed the human DISC1 in fruit flies (Drosophila melanogaster). As in mammalian neurons, DISC1 is localized to diverse subcellular domains of developing fly neurons including the nuclei, axons and dendrites. Overexpression of DISC1 impairs associative memory. Experiments with deletion/mutation constructs have revealed the importance of amino terminal domain (46–290) for memory suppression whereas carboxyl domain (598–854) and the amino terminal residues (1–45) including the nuclear localization signal (NLS1) are dispensable. DISC1 overexpression also causes suppression of axonal and dendritic branching of mushroom body neurons, which mediate a variety of cognitive functions in the fly brain. Analyses with deletion constructs reveal that protein domains 598–854 and 349–402 are both required for the suppression of axonal branching while amino-terminal domains including NLS1 are dispensable. In contrast, NLS1 was required for the suppression of dendritic branching, suggesting a mechanism involving gene expression. Moreover, domain 403–596 is also required for the suppression of dendritic branching. We also show that overexpression of DISC1 suppresses glutamatergic synaptogenesis in developing neuromuscular junctions. Deletion/mutation experiments have revealed the importance of protein domains 403–596 and 349–402 for synaptic suppression, while amino terminal domains including NLS1 are dispensable. Finally, we show that DISC1 functionally interacts with the fly homolog of Dysbindin (DTNBP1) via direct protein-protein interaction in developing synapses. PMID:26976042

Glaucoma-Diagnostic Ability of Ganglion Cell-Inner Plexiform Layer Thickness Difference Across Temporal Raphe in Highly Myopic Eyes.

PubMed

Kim, Young Kook; Yoo, Byeong Wook; Jeoung, Jin Wook; Kim, Hee Chan; Kim, Hae Jin; Park, Ki Ho

2016-11-01

To evaluate the glaucoma-diagnostic ability of the ganglion cell-inner plexiform layer (GCIPL) thickness difference across the temporal raphe in highly myopic eyes. We consecutively enrolled a total of 195 highly myopic eyes (axial length [AL] >26.5 mm) of 195 subjects: 93 glaucoma patients along with and 102 nonglaucomatous subjects. Cirrus high-definition optical coherence tomography (OCT) was employed to scan all of the subjects' macular and optic discs. Using a MATLAB-based customized program (the GCIPL hemifield test), a positive test result was automatically declared if the following two conditions were met: (1) the horizontal line is detected for longer than one-half of the distance from the temporal inner elliptical annulus to the outer elliptical annulus, and (2) the average GCIPL thickness difference within 10 pixels of the reference line, both above and below, is 5 μm or more. The glaucoma-diagnostic ability was computed using the area under the receiver operating characteristic curve (AUC). Among the glaucomatous eyes, GCIPL hemifield test positivity was shown in 92.5% (86 of 93), significantly higher than that for the nonglaucomatous eyes (4.90%, 5 of 102; P <0.001). The value of AUC for the GCIPL hemifield test was excellent (0.938; sensitivity 92.50%, specificity 95.10%) and was the best compared with those for any of OCT parameters. In highly myopic eyes, determination of the presence or absence of GCIPL thickness difference across the temporal raphe via OCT macula scan can be a useful means of distinguishing the glaucomatous damage.

Nonmydriatic fundus photography for teleophthalmology diabetic retinopathy screening in rural and urban clinics.

PubMed

Chin, Eric K; Ventura, Bruna V; See, Kai-Yin; Seibles, Joann; Park, Susanna S

2014-02-01

To evaluate the relative diagnostic value of nonmydriatic fundus photography (nFP) among patients screened for diabetic retinopathy in remote rural medical clinics and an urban academic medical center for nonadherence to recommended annual dilated eye examination. A retrospective cross-sectional study was performed among diabetic patients seen in primary outpatient clinics between 2006 and 2011 who were screened for diabetic retinopathy with nFP for history of nonadherence to recommended annual dilated eye examination. A single nonstereoscopic, 45°, 10-megapixel digital image of the disc and macula of both eyes was obtained locally and transmitted electronically to a retinal specialist for remote review. The results from remote rural Native American Indian reservations were compared with those from an urban academic family practice clinic. The proportion of subjects diagnosed with diabetic retinopathy and the quality of fundus images were compared. Among 872 patients (1,744 eyes) screened from rural sites and 517 subjects (1,034 eyes) screened from an urban site, images were of good quality for evaluation in 82.4% and 85.7% of subjects, respectively. Diabetic retinopathy was noted in 12.6% of rural subjects and 29.6% of urban subjects (p<0.001). nFP can be a useful tool in both rural and urban settings to screen for diabetic retinopathy in patients who are nonadherent to the recommended dilated annual eye exam. In our study population, a surprisingly higher percentage of diabetic subjects screened from the urban clinic had retinopathy compared with subjects screened in rural clinics.

Modifications of the falciform process in the eye of beloniformes (Teleostei: Atherinomorpha): evolution of a curtain-like septum in the eye.

PubMed

Reckel, Frank; Melzer, Roland R

2004-04-01

In order to comparatively analyze curtain-like septa in the eyes of visually orientated "close-to-surface-predators" among atherinomorph teleosts, we examined the eyes of 24 atherinomorph species under a binocular microscope with regard to the falciform process and related structures in the vitreous cavity. Additionally, falciform process samples were analyzed by transmission electron microscopy. All the studied representatives of the Cyprinodontiformes and Atheriniformes, and of one of the beloniform suborder, Adrianichthyioidei, possess a "typical" processus falciformis. In the eyes of the representatives of the other beloniform suborder, Belonoidei, however, pigmented structures that originate in the region of the optic disc and protrude into the vitreous cavity were noted. In the Hemiramphidae (halfbeaks) and Exocoetidae (flying fishes) these pigmented structures have a more cone-like shape, whereas in the Belonidae (needlefishes) and Scomberesocidae (sauries) horizontally oriented heavily pigmented curtain-like septa occur that divide the vitreous cavity dorsoventrally. It is suggested that the "typical" processus falciformis represents a plesiomorphic feature within the Atherinomorpha, whereas the pigmented modifications of the falciform process must be seen as a synapomorphic character state of the Belonoidei. The curtain-like septum of the Belonidae and Scomberesocidae might have evolved from the cone-like structures that are found in the Exocoetoidea. The functional significance of the pigmented structures in the eye is as yet not clear, except for the curtain-like septum found in Belonidae. It might play a role in visual orientation near the water surface at Snell's window. Copyright 2004 Wiley-Liss, Inc.

Methodology of the Singapore Indian Chinese Cohort (SICC) eye study: quantifying ethnic variations in the epidemiology of eye diseases in Asians.

PubMed

Lavanya, Raghavan; Jeganathan, V Swetha E; Zheng, Yingfeng; Raju, Prema; Cheung, Ning; Tai, E Shyong; Wang, Jie Jin; Lamoureux, Ecosse; Mitchell, Paul; Young, Terri L; Cajucom-Uy, Howard; Foster, Paul J; Aung, Tin; Saw, Seang Mei; Wong, Tien Y

2009-01-01

Current knowledge of ethnic variability in the epidemiology of major eye diseases in Asia is limited. This report summarizes the rationale and study design of the Singapore Indian Chinese Cohort (SICC) Eye Study, a population-based study of ethnic South Asian (Indians) and East Asian (Chinese) older adults in Singapore. The SICC examined a population-based cross-sectional sample of 3,300 ethnic Indians and 3,300 ethnic Chinese aged 40-80+ years residing in the South-Western part of Singapore. From two lists of 12,000 names of each ethnic group provided by the Ministry of Home Affairs, age-stratified random sampling was used to select 6,350 names in each group, with a target sample size of 3,300. Invitations were sent to attend a central clinic using letters, telephone calls and home visits. Examination procedures included interviews, measurement of blood pressure, anthropometry, presenting and best-corrected visual acuity, subjective refraction, ocular biometry, Goldmann applanation tonometry, slit-lamp biomicroscopy, optic disc imaging and digital photography of the lens and retina, using a standardized protocol. Selected participants underwent gonioscopic examination, visual field testing, and anterior and posterior segment optical coherence tomography. Blood, tear, and urine samples were collected for biochemical analyses, and stored for genetic and proteomic studies. In conjunction with the Singapore Malay Eye Study, the SICC study will permit an in-depth evaluation of the prevalence, risk factors, and impact of major eye diseases in Chinese, Indians and Malays, three distinct Asian ethnic groups, whose combined numbers represent half the world's population.

Prevalence of Split Nerve Fiber Layer Bundles in Healthy People Imaged with Spectral Domain Optical Coherence Tomography.

PubMed

Gür Güngör, Sirel; Akman, Ahmet; Sarıgül Sezenöz, Almila; Tanrıaşıkı, Gülşah

2016-12-01

The presence of retinal nerve fiber layer (RNFL) split bundles was recently described in normal eyes scanned using scanning laser polarimetry and by histologic studies. Split bundles may resemble RNFL loss in healthy eyes. The aim of our study was to determine the prevalence of nerve fiber layer split bundles in healthy people. We imaged 718 eyes of 359 healthy persons with the spectral domain optical coherence tomography in this cross-sectional study. All eyes had intraocular pressure of 21 mmHg or less, normal appearance of the optic nerve head, and normal visual fields (Humphrey Field Analyzer 24-2 full threshold program). In our study, a bundle was defined as 'split' when there is localized defect not resembling a wedge defect in the RNFL deviation map with a symmetrically divided RNFL appearance on the RNFL thickness map. The classification was performed by two independent observers who used an identical set of reference examples to standardize the classification. Inter-observer consensus was reached in all cases. Bilateral superior split bundles were seen in 19 cases (5.29%) and unilateral superior split was observed in 15 cases (4.16%). In 325 cases (90.52%) there was no split bundle. Split nerve fiber layer bundles, in contrast to single nerve fiber layer bundles, are not common findings in healthy eyes. In eyes with normal optic disc appearance, especially when a superior RNFL defect is observed in RNFL deviation map, the RNLF thickness map and graphs should also be examined for split nerve fiber layer bundles.

Nerve Fiber Flux Analysis Using Wide-Field Swept-Source Optical Coherence Tomography.

PubMed

Tan, Ou; Liu, Liang; Liu, Li; Huang, David

2018-02-01

To devise a method to quantify nerve fibers over their arcuate courses over an extended peripapillary area using optical coherence tomography (OCT). Participants were imaged with 8 × 8-mm volumetric OCT scans centered at the optic disc. A new quantity, nerve fiber flux (NFF), represents the cross-sectional area transected perpendicular to the nerve fibers. The peripapillary area was divided into 64 tracks with equal flux. An iterative algorithm traced the trajectory of the tracks assuming that the relative distribution of the NFF was conserved with compensation for fiber connections to ganglion cells on the macular side. Average trajectory was averaged from normal eyes and use to calculate the NFF maps for glaucomatous eyes. The NFF maps were divided into eight sectors that correspond to visual field regions. There were 24 healthy and 10 glaucomatous eyes enrolled. The algorithm converged on similar patterns of NFL tracks for all healthy eyes. In glaucomatous eyes, NFF correlated with visual field sensitivity in the arcuate sectors (Spearman ρ = 0.53-0.62). Focal nerve fiber loss in glaucomatous eyes appeared as uniform tracks of NFF defects that followed the expected arcuate fiber trajectory. Using an algorithm based on the conservation of flux, we derived nerve fiber trajectories in the peripapillary area. The NFF map is useful for the visualization of focal defects and quantification of sector nerve fiber loss from wide-area volumetric OCT scans. NFF provides a cumulative measure of volumetric loss along nerve fiber tracks and could improve the detection of focal glaucoma damage.

Biomaterials for intervertebral disc regeneration and repair.

PubMed

Bowles, Robert D; Setton, Lori A

2017-06-01

The intervertebral disc contributes to motion, weight bearing, and flexibility of the spine, but is susceptible to damage and morphological changes that contribute to pathology with age and injury. Engineering strategies that rely upon synthetic materials or composite implants that do not interface with the biological components of the disc have not met with widespread use or desirable outcomes in the treatment of intervertebral disc pathology. Here we review bioengineering advances to treat disc disorders, using cell-supplemented materials, or acellular, biologically based materials, that provide opportunity for cell-material interactions and remodeling in the treatment of intervertebral disc disorders. While a field still in early development, bioengineering-based strategies employing novel biomaterials are emerging as promising alternatives for clinical treatment of intervertebral disc disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anomalous optic discs in a patient with a Dandy-Walker cyst.

PubMed

Orcutt, J C; Bunt, A H

1982-03-01

A 19-month-old female infant with a Dandy-Walker cyst had anomalous optic discs, each of which appeared to divide to form an accessory optic nerve. The discs probably lie within the spectrum of anomalous discs including optic nerve aplasia and hypoplasia, megallopapillae, morning glory disc, optic disc dysplasia, and optic nerve colobomas. The association of anomalous optic discs with a Dandy-Walker cyst has not been previously recognized. The ocular and brain malformations in this patient likely occurred during the fourth to eighth week of gestation, when the retinal ganglion cell axons were penetrating the optic nerve, and the rhombic lips were enlarging in early cerebellar development. The etiology of these anomalies is not known; however, teratogens, sporadic events, and genetic disorders should be considered.

Optic Nerve Tilt, Crescent, Ovality, and Torsion in a Multi-Ethnic Cohort of Young Adults With and Without Myopia

PubMed Central

Marsh-Tootle, Wendy L.; Harb, Elise; Hou, Wei; Zhang, Qinghua; Anderson, Heather A.; Weise, Katherine; Norton, Thomas T.; Gwiazda, Jane; Hyman, Leslie

2017-01-01

Purpose The purpose of this article is to evaluate optic nerve head (ONH) characteristics in an ethnically diverse cohort of young U.S. adults. Methods In this study, 409 myopes and 206 nonmyopes (median age 22 years) completed measures including biometry and spectral domain optical coherence tomography from enface (ovality and torsion) and cross-sectional (tilt and crescent width) scans. Associated factors were evaluated using multivariable models. Results In myopic versus nonmyopic right eyes, median tilt (6.0° vs. 2.4°; P < 0.0001) and frequency of crescents (49% vs. 10%; P < 0.0001) were higher in myopes. Right eyes with crescents had higher median tilts (8.8° [myopic], 9.0° [nonmyopic]) than those without crescent (2.5° [myopic], 2.1° [nonmyopic]), irrespective of refractive group (both P < 0.0001). Torsion was similar between groups, with a slight difference in ovality (0.89 vs. 0.91; P < 0.03). Data in the left eyes were similar, and modeling was done only for the right myopic eyes. Multivariable models showed that an increased tilt was associated with ethnicity (P < 0.001), the presence of crescent (P < 0.001), and smaller ONH diameter (P < 0.0031), with interactions between ethnicity and crescent (P = 0.002). Specifically, ONH tilt was significantly higher in Asian eyes without crescent (P < 0.0001 for all comparisons), and crescent width was associated with increased tilt in non-Asian eyes (P < 0.02). Crescent width was associated with ethnicity (greatest in Asians) and disc tilt. Interactions were observed between tilt and ethnicity, whereby tilt had a greater effect on crescent width in non-Asian eyes, and crescent width was associated with increased tilt in non-Asian eyes. Conclusions The data clarify the influence of ethnicity and myopia on ONH characteristics in young adults and may inform future studies of biomechanical properties or of retinal pathology of the myopic eye. PMID:28654981

Incipient nonarteritic anterior ischemic optic neuropathy.

PubMed

Hayreh, Sohan Singh; Zimmerman, M Bridget

2007-09-01

To describe the clinical entity of incipient nonarteritic anterior ischemic optic neuropathy (NAION). Cohort study. Fifty-four patients (60 eyes) seen in our clinic from 1973 through 2000. At their first visit to our clinic, all patients gave a detailed ophthalmic and medical history and underwent a comprehensive ophthalmic evaluation, color fundus photography, and fluorescein fundus angiography. At each follow-up visit (of 49 patients [55 eyes]), the same ophthalmic evaluation was performed, except for fluorescein fundus angiography. Clinical features of incipient NAION. Mean age (+/- standard deviation) of the patients was 58.7+/-15.9 years. Median follow-up time was 6.3 years (interquartile range [IQR], 2.1-8.5). At initial visit, all had optic disc edema (ODE) without any visual loss attributable to NAION. In 55%, the fellow eye had classic NAION; in 25%, incipient progressed to classic NAION (after a median time of 5.8 weeks [IQR, 3.2-10.1]); and in 20%, classic NAION developed after resolution of the first episode of incipient NAION. Patients with incipient, compared with classic, NAION had a greater prevalence of diabetes mellitus (P<0.0001) and lower prevalence of ischemic heart disease (P = 0.046). Patients who progressed to classic NAION versus those who did not were significantly younger (P = 0.025), and their visual acuity worsened in 31% and 0%, respectively, and remained stable in 62% and 98%, respectively; in the eyes with progression, central (in 31%) and peripheral (in 77%) visual fields worsened compared with only 1 eye and 2 eyes, respectively, that did not (P = 0.01 and P<0.0001, respectively); and median time to resolution of ODE in the progressed group was 5.8 weeks (IQR, 4.6-8.7) versus 9.6 weeks (IQR, 6.0-17.7) in those who did not progress. The results show that incipient NAION is a distinct clinical entity, with asymptomatic ODE and no visual loss attributable to NAION. When a patient seeks treatment with asymptomatic ODE, incipient NAION must be borne in mind as a strong possibility in those who have had classic NAION in the fellow eye, in diabetics of all ages, and in those with high risk factors for NAION; this can avoid unnecessary and expensive investigations.

Methylphenidate (Ritalin)-associated cataract and glaucoma.

PubMed

Lu, Chao-Kung; Kuang, Tung-Mei; Chou, Joe Ching-Kuang

2006-12-01

Methylphenidate hydrochloride (Ritalin) is the drug of choice for attention deficit hyperactivity disorder (ADHD). However, an association of Ritalin with glaucoma has been reported. We report a case of Ritalin-associated cataract and glaucoma. A 10-year-old boy was diagnosed with ADHD and had received methylphenidate hydrochloride, 60 mg/day for 2 years. He presented with blurred vision. Best-corrected visual acuity was 6/60 in both eyes. Ocular examinations revealed intraocular pressure (IOP) of 30 mmHg under medication, dense posterior subcapsular opacity of lens, pale disc with advanced cupping, and marked constriction of visual field. Despite maximal anti-glaucomatous medication, IOP still could not be controlled. The patient then received combined cataract and glaucoma surgery. Visual acuity improved and IOP was within normal limits in both eyes postoperatively. Large dose of methylphenidate may cause cataract and glaucoma. The mechanism remains unclear. Doctors should be aware of the possible ocular side effects of methylphenidate.

A rare case of toxic optic neuropathy secondary to consumption of neem oil.

PubMed

Suresha, A R; Rajesh, P; Anil Raj, K S; Torgal, Radhika

2014-03-01

A 35-year-old female was referred to our hospital with bilateral loss of vision of two days duration. She gave history of consumption of about 150 ml of neem oil five days back.Examination revealed no perception of light in both eyes. Both pupils were dilated and sluggishly reacting to light. Her fundus examination showed bilateral hyperemic, edematous discs and also edema extending along the superior and inferior temporal vascular arcade. Magnetic resonance imaging (MRI) scan showed bilateral putaminal regions with altered signal, hypointensities in T1-weighted images, hyperintensities on T2-weighted, images and hyperintense on Fluid Attenuation Inversion Recovery (FLAIR) images suggestive of cytotoxic edema due to tissue hypoxia. Her vision improved to 20/200 in both eyes with treatment after two months. This is the first case report of such nature in the literature to the best of our knowledge.

Chorioretinal neovascular membranes complicating contusional eye injuries with indirect choroidal ruptures.

PubMed Central

Wood, C M; Richardson, J

1990-01-01

Chorioretinal neovascular membranes are a recognised but rare cause of late visual loss in eyes suffering contusional injuries. A series of eight cases is presented all with indirect choroidal ruptures involving the perifoveal region. Two main patterns of 'at risk' rupture were noted: a temporally situated rupture passing almost directly through the fovea, and a rupture which curves inferior or superior to the optic disc stopping just short of the fovea. In six of eight cases there was only a partial thickness rupture of the choroid. These neovascular membranes may present at any time after the original injury, either early (within six months of the injury), which could be related to persistence of the normal reparative neovascular response, or late (at least one year after the injury), which are more likely to have resulted from a secondary breakdown of the outer blood-retina barrier. Images PMID:1690025

Roth Spots in Ocular Toxoplasmosis.

PubMed

Furtado, João M; Toscano, Marcelo; Castro, Vinicius; Rodrigues, Murilo W

2016-10-01

To report a case with unilateral preexisting ocular toxoplasmosis (OT) and newly occurred active retinochoroidal inflammation associated with white-centered retinal hemorrhages (Roth spots) in the healthy eye. Case report. A 20 year-old man presented with a decrease of visual acuity in his right eye associated with 2+ cells in the anterior chamber. Ophthalmoscopy revealed an active retinochoroidal lesion on the upper nasal border of the optic disc associated with local hemorrhage and vitritis. The posterior pole presented white-centered flame-shaped retinal hemorrhages. Toxoplasmosis serology showed an IgG titer >300IU/ml and a negative IgM titer. A complete blood count revealed no abnormalities; other serologies were negative. After 2 weeks of treatment with sulfadiazine, pyrimethamine, folinic acid and prednisone, although the peripapillary lesion was still active, the Roth spots disappeared. OT may be one differential diagnosis of patients suffering Roth spots in association with retinochoroidal inflammation.

Cat eye syndrome.

PubMed

Sharma, Deepak; Murki, Srinivas; Pratap, Tejo; Vasikarla, Madhavi

2014-05-19

A full-term female baby, a product of non-consanguineous marriage, was born at 37 weeks of gestation with a birth weight of 2.08 kg. Antenatal scan at 31 weeks revealed complex congenital heart disease with a hypoplastic right ventricle, pulmonary atresia and an intact septum. Immediately after birth, the infant was shifted to the nursery and was started on intravenous fluids and infusion prostaglandin E1 (Alprostidil). On examination, she had microcephaly, periorbital puffiness, a long philtrum, a broad nasal bridge and retrognathia, up slanting palpebral fissures, widely spaced nipples, a sacral dimple and right upper limb postaxial polydactyly. Postnatal echocardiography confirmed a large ostium secundum atrial septal defect with left to right shunt, right ventricle hypoplasia, pulmonary atresia with an intact septum and a large vertical patent ductus arteriosus. Ophthalmological examination showed a bilateral chorioretinal coloboma sparing disc and fovea. Karyotyping showed an extra small marker chromosome suggestive of the Cat eye syndrome. 2014 BMJ Publishing Group Ltd.

Are animal models useful for studying human disc disorders/degeneration?

PubMed Central

Eisenstein, Stephen M.; Ito, Keita; Little, Christopher; Kettler, A. Annette; Masuda, Koichi; Melrose, James; Ralphs, Jim; Stokes, Ian; Wilke, Hans Joachim

2007-01-01

Intervertebral disc (IVD) degeneration is an often investigated pathophysiological condition because of its implication in causing low back pain. As human material for such studies is difficult to obtain because of ethical and government regulatory restriction, animal tissue, organs and in vivo models have often been used for this purpose. However, there are many differences in cell population, tissue composition, disc and spine anatomy, development, physiology and mechanical properties, between animal species and human. Both naturally occurring and induced degenerative changes may differ significantly from those seen in humans. This paper reviews the many animal models developed for the study of IVD degeneration aetiopathogenesis and treatments thereof. In particular, the limitations and relevance of these models to the human condition are examined, and some general consensus guidelines are presented. Although animal models are invaluable to increase our understanding of disc biology, because of the differences between species, care must be taken when used to study human disc degeneration and much more effort is needed to facilitate research on human disc material. PMID:17632738

[The Autocad system for planimetric study of the optic disc in glaucoma: technique and reproducibility study].

PubMed

Sánchez Pérez, A; Honrubia López, F M; Larrosa Poves, J M; Polo Llorens, V; Melcon Sánchez-Frieras, B

2001-09-01

To develop a lens planimetry technique for the optic disc using AutoCAD. To determine variability magnitude of the optic disc morphological measurements. We employed AutoCAD R.14.0 Autodesk: image acquisition, contour delimitation by multiple lines fitting or ellipse adjustment, image sectorialization and measurements quantification (optic disc and excavation, vertical diameters, optic disc area, excavation area, neuroretinal sector area and Beta atrophy area). Intraimage or operator and interimage o total reproducibility was studied by coefficient of variability (CV) (n=10) in normal and myopic optic discs. This technique allows to obtain optic disc measurement in 5 to 10 minutes time. Total or interimage variability of measurements introduced by one observer presents CV range from 1.18-4.42. Operator or intraimage measurement presents CV range from 0.30-4.21. Optic disc contour delimitation by ellipse adjustment achieved better reproducibility results than multiple lines adjustment in all measurements. Computer assisted AutoCAD planimetry is an interactive method to analyse the optic disc, feasible to incorporate to clinical practice. Reproducibility results are comparable to other analyzers in quantification optic disc morphology. Ellipse adjustment improves results in optic disc contours delimitation.

Cecocentral scotoma as the initial manifestation of subacute bacterial endocarditis

PubMed Central

Strauss, Danielle Savitsky; Baharestani, Samuel; Nemiroff, Julia; Amesur, Kiran; Howard, David

2011-01-01

Introduction: We report a case of a 67-year-old male who presented with a cecocentral scotoma caused by a septic embolus from subacute bacterial endocarditis (SBE). Methods: A 67-year-old man presented with sudden, painless decreased vision in the left eye. A dilated fundoscopic exam, Humphrey visual field test, transthoracic echocardiogram, abdominal computed tomography (CT), and blood cultures were all performed. Results: A dilated fundoscopic exam revealed temporal segmental optic disc pallor on the left, and Humphrey visual field testing demonstrated a dense left cecocentral scotoma. When the patient developed fever (103. 9°F) and palpitations, transthoracic echocardiogram revealed valvular vegetations, and contrast CT of the abdomen revealed an abscess in the dome of the liver likely due to an infectious thrombus. Blood cultures grew viridians group streptococci in three separate peripheral collections. Conclusion: This case illustrates that a sudden cecocentral scotoma may be the initial manifestation of SBE. PMID:21468335

Cover-layer with High Refractive Index for Near-Field Recording Media

NASA Astrophysics Data System (ADS)

Kim, Jin-Hong; Lee, Jun-Seok

2007-06-01

TiO2 nanoparticles are added into UV-curable resin to increase the refractive index of the cover-layer laminated for cover-layer incident near-field recording media. A high refractive index is required for the cover-layer operating with an optical head with a high numerical aperture. The eye pattern from a cover-layer coated 20 GB read-only memory disc in which the refractive index of the cover-layer is 1.75 is achieved, but the gap servo is unstable owing to the rough surface of the cover-layer. Even though the light loss due to the nanoparticles is negligible, a rough microstructure is developed by adding the nanoparticles into an organic binder material. To achieve a smooth surface for a stable gap servo, the solubility of the nanoparticles should be enhanced by the optimization of the surface of the nanoparticles.

Cover-Layer with High Refractive Index for Near-Field Recording Media

NASA Astrophysics Data System (ADS)

Kim, Jin-Hong; Lee, Jun-Seok

2007-06-01

TiO2 nanoparticles are added into UV-curable resin to increase the refractive index of the cover-layer laminated for cover-layer incident near-field recording media. A high refractive index is required for the cover-layer operating with an optical head with a high numerical aperture. The eye pattern from a cover-layer coated 20 GB read-only memory disc in which the refractive index of the cover-layer is 1.75 is achieved, but the gap servo is unstable owing to the rough surface of the cover-layer. Even though the light loss due to the nanoparticles is negligible, a rough microstructure is developed by adding the nanoparticles into an organic binder material. To achieve a smooth surface for a stable gap servo, the solubility of the nanoparticles should be enhanced by the optimization of the surface of the nanoparticles.

Deletion Analysis of the Tumorous-Head (tuh–3) Gene in DROSOPHILA MELANOGASTER

PubMed Central

Kuhn, David T.; Woods, Daniel F.; Andrew, Deborah J.

1981-01-01

In the presence of the naturally occurring maternal-effect alleles tuh-1h or tuh-1g, the tuh-3 mutant gene can cause the tumorous-head trait or the sac-testis trait. The tuh-3 gene functions as a semidominant in the presence of the tuh-1h maternal effect. Eye-antennal structures are replaced by posterior abdominal tergites and genital structures. If tuh-1h is replaced by its naturally occurring allele tuh-1g, tuh-3 functions as a recessive hypomorph and the defect switches from anterior to posterior structures, with a male genital-disc defect appearing with variable penetrance. Function and regulation of tuh-3+ may better be understood in light of the cytological localization of tuh-3 either adjacent to or as part of the bithorax complex. The tuh-3+ gene product appears to be essential for normal development, at least in the posterior end of the embryo. PMID:6804305

A new species of Scinax from the Purus-Madeira interfluve, Brazilian Amazonia (Anura, Hylidae).

PubMed

Ferrão, Miquéias; Moravec, Jiří; de Fraga, Rafael; de Almeida, Alexandre Pinheiro; Kaefer, Igor Luis; Lima, Albertina Pimentel

2017-01-01

A new tree frog species of the genus Scinax from the interfluve between the Purus and Madeira rivers, Brazilian Amazonia, is described and illustrated. The new species is diagnosed by medium body size, snout truncate in dorsal view, ulnar and tarsal tubercles absent, nuptial pads poorly developed, skin on dorsum shagreen, dorsum light brown with dark brown spots and markings, white groin with black spots, anterior and posterior surfaces of thighs black, and iris bright orange. The advertisement call consists of a single short note, with 16-18 pulses and dominant frequency at 1572-1594 Hz. Tadpoles are characterized by body ovoid in dorsal view and triangular in lateral view, tail higher than body, oral disc located anteroventrally and laterally emarginated, dorsum of body uniformly grey-brown with dark brown eye-snout stripe in preservative, fins translucent with small to large irregular diffuse dark brown spots.

A new species of Scinax from the Purus-Madeira interfluve, Brazilian Amazonia (Anura, Hylidae)

PubMed Central

Ferrão, Miquéias; Moravec, Jiří; de Fraga, Rafael; de Almeida, Alexandre Pinheiro; Kaefer, Igor Luis; Lima, Albertina Pimentel

2017-01-01

Abstract A new tree frog species of the genus Scinax from the interfluve between the Purus and Madeira rivers, Brazilian Amazonia, is described and illustrated. The new species is diagnosed by medium body size, snout truncate in dorsal view, ulnar and tarsal tubercles absent, nuptial pads poorly developed, skin on dorsum shagreen, dorsum light brown with dark brown spots and markings, white groin with black spots, anterior and posterior surfaces of thighs black, and iris bright orange. The advertisement call consists of a single short note, with 16−18 pulses and dominant frequency at 1572−1594 Hz. Tadpoles are characterized by body ovoid in dorsal view and triangular in lateral view, tail higher than body, oral disc located anteroventrally and laterally emarginated, dorsum of body uniformly grey-brown with dark brown eye-snout stripe in preservative, fins translucent with small to large irregular diffuse dark brown spots. PMID:29118625

Characteristics of incident geographic atrophy in the complications of age-related macular degeneration prevention trial.

PubMed

Brader, Hilary Smolen; Ying, Gui-Shuang; Martin, E Revell; Maguire, Maureen G

2013-09-01

To characterize the size, location, conformation, and features of incident geographic atrophy (GA) as detected by annual stereoscopic color photographs and fluorescein angiograms (FAs). Retrospective cohort study within a larger clinical trial. Patients with bilateral large drusen in whom GA developed during the course of the Complications of Age-related Macular Degeneration Prevention Trial (CAPT). Annual stereoscopic color photographs and FAs were reviewed from 114 CAPT patients in whom GA developed in the untreated eye during 5 to 6 years of follow-up. Geographic atrophy was defined according to the Revised GA Criteria for identifying early GA.(23) Color-optimized fundus photographs were viewed concurrently with the FAs during grading. Size and distance from the fovea of individual GA lesions, number of areas of atrophy, and change in visual acuity (VA) when GA first developed in an eye. At presentation, the median total GA area was 0.26 mm(2) (0.1 disc area). Geographic atrophy presented as a single lesion in 89 (78%) eyes. The median distance from the fovea was 395 μm. Twenty percent of incident GA lesions were subfoveal and an additional 18% were within 250 μm of the foveal center. Development of GA was associated with a mean decrease of 7 letters from the baseline VA level compared with 1 letter among matched early age-related macular degeneration eyes without GA. Geographic atrophy that formed in areas previously occupied by drusenoid pigment epithelial detachments on average were larger (0.53 vs. 0.20 mm(2); P = 0.0001), were more central (50 vs. 500 μm from the center of the fovea; P<0.0001), and were associated with significantly worse visual outcome (20/50 vs. 20/25; P = 0.0003) than GA with other drusen types as precursors. Incident GA most often appears on color fundus photographs and FAs as a small, singular, parafoveal lesion, although a large minority of lesions are subfoveal or multifocal at initial detection. The characteristics of incident GA vary with precursor drusen types. These data can facilitate design of future clinical trials of therapies for GA. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Ranges of Cervical Intervertebral Disc Deformation During an In Vivo Dynamic Flexion–Extension of the Neck

PubMed Central

Yu, Yan; Mao, Haiqing; Li, Jing-Sheng; Tsai, Tsung-Yuan; Cheng, Liming; Wood, Kirkham B.; Li, Guoan; Cha, Thomas D.

2017-01-01

While abnormal loading is widely believed to cause cervical spine disc diseases, in vivo cervical disc deformation during dynamic neck motion has not been well delineated. This study investigated the range of cervical disc deformation during an in vivo functional flexion–extension of the neck. Ten asymptomatic human subjects were tested using a combined dual fluoroscopic imaging system (DFIS) and magnetic resonance imaging (MRI)-based three-dimensional (3D) modeling technique. Overall disc deformation was determined using the changes of the space geometry between upper and lower endplates of each intervertebral segment (C3/4, C4/5, C5/6, and C6/7). Five points (anterior, center, posterior, left, and right) of each disc were analyzed to examine the disc deformation distributions. The data indicated that between the functional maximum flexion and extension of the neck, the anterior points of the discs experienced large changes of distraction/compression deformation and shear deformation. The higher level discs experienced higher ranges of disc deformation. No significant difference was found in deformation ranges at posterior points of all the discs. The data indicated that the range of disc deformation is disc level dependent and the anterior region experienced larger changes of deformation than the center and posterior regions, except for the C6/7 disc. The data obtained from this study could serve as baseline knowledge for the understanding of the cervical spine disc biomechanics and for investigation of the biomechanical etiology of disc diseases. These data could also provide insights for development of motion preservation surgeries for cervical spine. PMID:28334358

Ranges of Cervical Intervertebral Disc Deformation During an In Vivo Dynamic Flexion-Extension of the Neck.

PubMed

Yu, Yan; Mao, Haiqing; Li, Jing-Sheng; Tsai, Tsung-Yuan; Cheng, Liming; Wood, Kirkham B; Li, Guoan; Cha, Thomas D

2017-06-01

While abnormal loading is widely believed to cause cervical spine disc diseases, in vivo cervical disc deformation during dynamic neck motion has not been well delineated. This study investigated the range of cervical disc deformation during an in vivo functional flexion-extension of the neck. Ten asymptomatic human subjects were tested using a combined dual fluoroscopic imaging system (DFIS) and magnetic resonance imaging (MRI)-based three-dimensional (3D) modeling technique. Overall disc deformation was determined using the changes of the space geometry between upper and lower endplates of each intervertebral segment (C3/4, C4/5, C5/6, and C6/7). Five points (anterior, center, posterior, left, and right) of each disc were analyzed to examine the disc deformation distributions. The data indicated that between the functional maximum flexion and extension of the neck, the anterior points of the discs experienced large changes of distraction/compression deformation and shear deformation. The higher level discs experienced higher ranges of disc deformation. No significant difference was found in deformation ranges at posterior points of all the discs. The data indicated that the range of disc deformation is disc level dependent and the anterior region experienced larger changes of deformation than the center and posterior regions, except for the C6/7 disc. The data obtained from this study could serve as baseline knowledge for the understanding of the cervical spine disc biomechanics and for investigation of the biomechanical etiology of disc diseases. These data could also provide insights for development of motion preservation surgeries for cervical spine.

VIIP 2017 Clinical Update

NASA Technical Reports Server (NTRS)

Tarver, William

2017-01-01

INTRODUCTION: NASA's Space Medicine community knowledge regarding the "Vision Impairment Intracranial Pressure", or VIIP.has been evolving over time.. Various measures of occupational health related to this condition had to be determined and then plans/processes put into place. The most robust of these processes were inititated in 2010. This presentation will provide a clinic update of the astronaut occupational health data related to VIIP. METHODS: NASA and its international partners require its astronauts to undergo routine health measures deemed important to monitoring VIIP. The concern is that the spaceflight environment aboard ISS could cause some astronauts to have physiologic changes detrimental to either ongoing mission operations or long-term health related to the ocular system and possibly the CNS. Specific medical tests include but are not limited to brain/orbit MRI (NASA unique protocol), OCT, fundoscopy and ocular ultrasound. Measures are taken prior to spaceflight, in-flight and post-flight. Measures to be reported include incidence of disc edema, globe flattening, choroidal folds, ONSD and change in refractive error. RESULTS: 73 ISS astronauts have been evaluated at least partially for VIIP related measures. Of these individuals, approximately 1 in 7 have experienced disc edema. The prevalence of the other findings is more complicated as the medical testing has changed over time. Overall, 26 separate individuals have experienced at least one of the findings NASA has associated with VIIP Another confounding factor is most of the astronauts have prior spaceflight experience at the time of the "pre-flight" testing. DISCUSSION: In 2010 NASA and its US operating segment (USOS) partners (CSA, ESA and JAXA) began routine occupational monitoring and data collection for most VIIP related changes. Interpretation of that data is extremely challenging for several reasons. For example, the determination of disc edema is the most complete finding as we have had highly qualified optometrists routinely and competently performing post-flight funduscopic exams for the entirety of the ISS program. Yet in 2013 NASA added OCT to our in-flight suite of eye exams. Shortly after routine screening with the OCT, a new term appeared within VIIP vernacular - "subclinical disc edema". OCT has much greater ability to measure change within the retina and provides significantly more data to analyze, understand and communicate out. Communicating VIIP data clearly adds even more challenge. Historically we've reported data per eye and not necessarily per person. This has led to difficulty in understanding how many individuals have experienced "VIIP" within the aerospace medicine community. The presenter will attempt to provide clear and concise communication of VIIP findings.

A Population-based survey of the prevalence and types of glaucoma in Nigeria: results from the Nigeria National Blindness and Visual Impairment Survey.

PubMed

Kyari, Fatima; Entekume, Gabriel; Rabiu, Mansur; Spry, Paul; Wormald, Richard; Nolan, Winifred; Murthy, Gudlavalleti V S; Gilbert, Clare E

2015-12-12

Glaucoma is the leading cause of irreversible blindness worldwide. There tends to be a lower reporting of glaucoma in Africa compared to other blinding conditions in global burden data. Research findings of glaucoma in Nigeria will significantly increase our understanding of glaucoma in Nigeria, in people of the West African diaspora and similar population groups. We determined the prevalence and types of glaucoma in Nigeria from the Nigeria National Blindness and Visual Impairment cross-sectional Survey of adults aged ≥40 years. Multistage stratified cluster random sampling with probability-proportional-to-size procedures were used to select a nationally representative sample of 15,027 persons aged ≥40 years. Participants had logMAR visual acuity measurement, FDT visual function testing, autorefraction, A-scan biometry and optic disc assessment. Participants with visual acuity of worse than 6/12 or suspicious optic discs had detailed examination including Goldmann applanation tonometry, gonioscopy and fundus photography. Disc images were graded by Moorfields Eye Hospital Reading Centre. Glaucoma was defined using International Society of Geographical and Epidemiological Ophthalmology criteria; and classified into primary open-angle or primary angle-closure or secondary glaucoma. Diagnosis of glaucoma was based on ISGEO classification. The type of glaucoma was determined by gonioscopy. A total of 13,591 participants in 305 clusters were examined (response rate 90.4 %). Optic disc grading was available for 25,289 (93 %) eyes of 13,081 (96 %) participants. There were 682 participants with glaucoma; a prevalence of 5.02 % (95 % CI 4.60-5.47). Among those with definite primary glaucoma that had gonioscopy (n = 243), open-angle glaucoma was more common (86 %) than angle-closure glaucoma (14 %). 8 % of glaucoma was secondary with the commonest causes being couching (38 %), trauma (21 %) and uveitis (19 %). Only 5.6 % (38/682) of participants with glaucoma knew they had the condition. One in every 5 persons with glaucoma (136;20 %) was blind i.e., visual acuity worse than 3/60. Nigeria has a high prevalence of glaucoma which is largely open-angle glaucoma. A high proportion of those affected are blind. Secondary glaucoma was mostly as a consequence of procedures for cataract. Public health control strategies and high quality glaucoma care service will be required to reduce morbidity and blindness from glaucoma.

Rate and Pattern of Rim Area Loss in Healthy and Progressing Glaucoma Eyes

PubMed Central

Hammel, Na’ama; Belghith, Akram; Bowd, Christopher; Medeiros, Felipe A.; Sharpsten, Lucie; Mendoza, Nadia; Tatham, Andrew J.; Khachatryan, Naira; Liebmann, Jeffrey M.; Girkin, Christopher A.; Weinreb, Robert N.; Zangwill, Linda M.

2015-01-01

Objective To characterize the rate and pattern of age-related and glaucomatous neuroretinal rim area changes in subjects of African descent (AD) and European descent (ED). Design Prospective longitudinal study. Subjects 296 eyes of 157 healthy subjects (88 AD and 69 ED) and 73 progressing glaucoma eyes of 67 subjects (24 AD and 43 ED) from the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES) were included. Methods Global and sectoral rim area was measured using confocal laser scanning ophthalmoscopy (CSLO). Progression of glaucomatous optic disc damage was determined by masked stereophoto review. The rates of absolute rim area loss and percent rim area loss in healthy and progressing glaucomatous eyes were compared using multivariable nested mixed-effects models. Main Outcome Measures Rate of rim area loss over time. Results The median (inter-quartile range) follow-up time was 5.0 years (2.0–7.4) for healthy eyes and 8.3 years (7.5–9.9) for progressing glaucoma eyes. The mean rate of global rim area loss was significantly faster in progressing glaucoma eyes compared with healthy eyes for both rim area loss (−10.2 ×10−3 mm2/year vs. −2.8 ×10−3 mm2/year, respectively, P<.001) and percent rim area loss (−1.1 %/year vs. −0.2 %/year, respectively, P<.001), but there was considerable overlap between the two groups. 63% of progressing glaucoma eyes had a rate of change faster than the 5th quantile of healthy eyes. For both healthy and progressing eyes, the pattern of rim area loss and percent rim area loss was similar; it tended to be fastest in the superior temporal and inferior temporal sectors. The rate of change was similar in AD and ED progressing eyes. Conclusions Compared with healthy eyes, the mean rate of global rim area loss was 3.7 times faster and the mean rate of global percent rim area loss was 5.4 times faster in progressing glaucoma eyes. A reference database of healthy eyes can be used to help clinicians distinguish age-related rim area loss from rim area loss due to glaucoma. PMID:26746597

A Structurally and Functionally Biomimetic Biphasic Scaffold for Intervertebral Disc Tissue Engineering

PubMed Central

Choy, Andrew Tsz Hang; Chan, Barbara Pui

2015-01-01

Tissue engineering offers high hopes for the treatment of intervertebral disc (IVD) degeneration. Whereas scaffolds of the disc nucleus and annulus have been extensively studied, a truly biomimetic and mechanically functional biphasic scaffold using naturally occurring extracellular matrix is yet to be developed. Here, a biphasic scaffold was fabricated with collagen and glycosaminoglycans (GAGs), two of the most abundant extracellular matrix components in the IVD. Following fabrication, the scaffold was characterized and benchmarked against native disc. The biphasic scaffold was composed of a collagen-GAG co-precipitate making up the nucleus pulposus-like core, and this was encapsulated in multiple lamellae of photochemically crosslinked collagen membranes comprising the annulus fibrosus-like lamellae. On mechanical testing, the height of our engineered disc recovered by ~82-89% in an annulus-independent manner, when compared with the 99% recovery exhibited by native disc. The annulus-independent nature of disc height recovery suggests that the fluid replacement function of the engineered nucleus pulposus core might mimic this hitherto unique feature of native disc. Biphasic scaffolds comprised of 10 annulus fibrosus-like lamellae had the best overall mechanical performance among the various designs owing to their similarity to native disc in most aspects, including elastic compliance during creep and recovery, and viscous compliance during recovery. However, the dynamic mechanical performance (including dynamic stiffness and damping factor) of all the biphasic scaffolds was similar to that of the native discs. This study contributes to the rationalized design and development of a biomimetic and mechanically viable biphasic scaffold for IVD tissue engineering. PMID:26115332

Temporal and spatial expression of Drosophila DLGS97 during neural development.

PubMed

Albornoz, Valeria; Mendoza-Topaz, Carolina; Oliva, Carlos; Tello, Judith; Olguín, Patricio; Sierralta, Jimena

2008-07-01

The products of the Drosophila discs-large (dlg) gene are members of the MAGUK family of proteins, a group of proteins involved in localization, transport and recycling of receptors and channels in cell junctions, including the synapse. In vertebrates, four genes with multiple splice variants homologous to dlg are described. dlg originates two main proteins, DLGA, similar to the vertebrate neuronal protein PSD95, and DLGS97, similar to the vertebrate neuronal and epithelial protein SAP97. DLGA is expressed in epithelia, neural tissue and muscle. DLGS97 is expressed in neural tissue and muscle but not in epithelia. The distinctive difference between them is the presence in DLGS97 of an L27 domain. The differential expression between these variants makes the study of DLGS97 of key relevance to understand the in vivo role of synaptic MAGUKs in neurons. Here we present the temporal and spatial expression pattern of DLGS97 during embryonic and larval nervous system development, during eye development and in adult brain. Our results show that DLGS97 is expressed zygotically, in neurons in the embryo, larvae and adult, and is absent at all stages in glial cells. During eye development DLGS97 starts to be expressed in photoreceptor cells at early stages of differentiation and localizes basal to the basolateral junctions. In the brain, DLGS97 is expressed in the mushroom bodies and optic lobes at larval and adult stages; and in the antennal lobe in the adult stage. In addition we show that both, dlgS97 and dlgA transcripts, express during development multiple splice variants with differences in the use of exons in two sites.

Evaluation of Retinal and Choroidal Thickness by Swept-Source Optical Coherence Tomography: Repeatability and Assessment of Artifacts

PubMed Central

Mansouri, Kaweh; Medeiros, Felipe A.; Tatham, Andrew J.; Marchase, Nicholas; Weinreb, Robert N.

2017-01-01

PURPOSE To determine the repeatability of automated retinal and choroidal thickness measurements with swept-source optical coherence tomography (SS OCT) and the frequency and type of scan artifacts. DESIGN Prospective evaluation of new diagnostic technology. METHODS Thirty healthy subjects were recruited prospectively and underwent imaging with a prototype SS OCT instrument. Undilated scans of 54 eyes of 27 subjects (mean age, 35.1 ± 9.3 years) were obtained. Each subject had 4 SS OCT protocols repeated 3 times: 3-dimensional (3D) 6 × 6-mm raster scan of the optic disc and macula, radial, and line scan. Automated measurements were obtained through segmentation software. Interscan repeatability was assessed by intraclass correlation coefficients (ICCs). RESULTS ICCs for choroidal measurements were 0.92, 0.98, 0.80, and 0.91, respectively, for 3D macula, 3D optic disc, radial, and line scans. ICCs for retinal measurements were 0.39, 0.49, 0.71, and 0.69, respectively. Artifacts were present in up to 9% scans. Signal loss because of blinking was the most common artifact on 3D scans (optic disc scan, 7%; macula scan, 9%), whereas segmentation failure occurred in 4% of radial and 3% of line scans. When scans with image artifacts were excluded, ICCs for choroidal thickness increased to 0.95, 0.99, 0.87, and 0.93 for 3D macula, 3D optic disc, radial, and line scans, respectively. ICCs for retinal thickness increased to 0.88, 0.83, 0.89, and 0.76, respectively. CONCLUSIONS Improved repeatability of automated choroidal and retinal thickness measurements was found with the SS OCT after correction of scan artifacts. Recognition of scan artifacts is important for correct interpretation of SS OCT measurements. PMID:24531020

Kozai-Lidov disc instability

NASA Astrophysics Data System (ADS)

Lubow, Stephen H.; Ogilvie, Gordon I.

2017-08-01

Recent results by Martin et al. showed in 3D smoothed particle hydrodynamics simulations that tilted discs in binary systems can be unstable to the development of global, damped Kozai-Lidov (KL) oscillations in which the discs exchange tilt for eccentricity. We investigate the linear stability of KL modes for tilted inviscid discs under the approximations that the disc eccentricity is small and the disc remains flat. By using 1D equations, we are able to probe regimes of large ratios of outer to inner disc edge radii that are realistic for binary systems of hundreds of astronomical unit separations and are not easily probed by multidimensional simulations. For order unity binary mass ratios, KL instability is possible for a window of disc aspect ratios H/r in the outer parts of a disc that roughly scale as (nb/n)2 ≲ H/r ≲ nb/n, for binary orbital frequency nb and orbital frequency n at the disc outer edge. We present a framework for understanding the zones of instability based on the determination of branches of marginally unstable modes. In general, multiple growing eccentric KL modes can be present in a disc. Coplanar apsidal-nodal precession resonances delineate instability branches. We determine the range of tilt angles for unstable modes as a function of disc aspect ratio. Unlike the KL instability for free particles that involves a critical (minimum) tilt angle, disc instability is possible for any non-zero tilt angle depending on the disc aspect ratio.

Syringomyelia presenting with unilateral optic neuropathy: a case report.

PubMed

Ngoo, Qi Zhe; Tai, Evelyn Li Min; Wan Hitam, Wan Hazabbah

2017-01-01

In this case report, we present two cases of syringomyelia with optic neuropathy. In Case 1, a 36-year-old Malay lady presented to our clinic with acute onset of blurring of vision in her left eye that she experienced since past 1 month. She was diagnosed with syringomyelia 12 years ago and was on conservative management. Her visual acuity was 6/6 in the right eye and counting fingers at 1 m in the left. There was a positive relative afferent pupillary defect in her left eye. Optic nerve functions of her left eye were reduced. Visual field showed a left inferior field defect. Her extraocular muscle movements were full. Magnetic resonance imaging of the brain and spine showed syringomyelia at the level of C2-C6 and T2-T9. Both of her optic nerves were normal. Her condition improved with intravenous and oral corticosteroids. In Case 2, a 44-year-old Malay lady presented to our clinic with a progressive central scotoma in her right eye that she experienced since past 1 month. She had previous history of recurrent episodes of weakness in both of her lower limbs from past 8 months. Visual acuity in her right and left eye was 6/9 and 6/6, respectively. The relative afferent pupillary defect in her right eye was positive. Optic nerve functions of her right eye were affected. Visual field showed a central scotoma in her right eye. Her extraocular muscle movements were full. Fundoscopy of her right eye showed a pale optic disc. Her left eye fundus was normal. Magnetic resonance imaging of the brain and spine showed syringomyelia at T3-T6. Both of her optic nerves were normal. A diagnosis of syringomyelia with right optic atrophy was performed. Her condition improved with intravenous and oral corticosteroids. Optic neuropathy is a rare neuro-ophthalmic manifestation in patients with syringomyelia. Prompt diagnosis and timely management are essential to avoid a poor visual outcome. Intravenous corticosteroids are beneficial in the treatment of early optic neuropathy in syringomyelia.

Orbital alignment of circumbinary planets that form in misaligned circumbinary discs: the case of Kepler-413b

NASA Astrophysics Data System (ADS)

Pierens, A.; Nelson, R. P.

2018-06-01

Although most of the circumbinary planets detected by the Kepler spacecraft are on orbits that are closely aligned with the binary orbital plane, the systems Kepler-413 and Kepler-453 exhibit small misalignments of ˜2.5°. One possibility is that these planets formed in a circumbinary disc whose midplane was inclined relative to the binary orbital plane. Such a configuration is expected to lead to a warped and twisted disc, and our aim is to examine the inclination evolution of planets embedded in these discs. We employed 3D hydrodynamical simulations that examine the disc response to the presence of a modestly inclined binary with parameters that match the Kepler-413 system, as a function of disc parameters and binary inclinations. The discs all develop slowly varying warps, and generally display very small amounts of twist. Very slow solid body precession occurs because a large outer disc radius is adopted. Simulations of planets embedded in these discs resulted in the planet aligning with the binary orbit plane for disc masses close to the minimum mass solar nebular, such that nodal precession of the planet was controlled by the binary. For higher disc masses, the planet maintains near coplanarity with the local disc midplane. Our results suggest that circumbinary planets born in tilted circumbinary discs should align with the binary orbit plane as the disc ages and loses mass, even if the circumbinary disc remains misaligned from the binary orbit. This result has important implications for understanding the origins of the known circumbinary planets.

[A clinical study of Leber hereditary optic neuropathy].

PubMed

Wei, Qi-Ping; Sun, Yan-Hong; Zhou, Xiang-tian; Zhou, Jian; Gong, Xiao-hong; Jia, Xiao-yun

2012-12-01

To investigate the clinical characteristics of Leber hereditary optic neurology (LHON) patients with different primary site mutation. Four hundred and fourteen patients with optic neuropathy were divided into three groups: clinically diagnosed LHON group (group A), probable LHON group (group B), optic neuropathy of unknown reason group (group C). Visual acuity (VA), colour vision, Intraocular pressure (IOP), virtual field and visual evoked potential (VEP) were tested for all the patients. Some (64 cases) had optical coherence tomography (OCT) measurement. Mutations of mtDNA were detected for all the groups, and clinical analysis were carried out emphatically in the patients with the 11778 mutation confirmed by gene assessment. T paired test was used to evaluate two group patients of different Mitochondrial DNA mutation. Gene mutations were found in 215 of the 414 patients (52%). Approximately 93% (199/255) of the patients were caused by the common primary mutations (11778, 14484, 3460 mutation), in which 100% mutation (106/106) in group A, 65% (91/139) in group B, and 11% (18/169) in group C. No cases were diagnosed with confirmed LHON in the patients with unilateral optic neuropathy. Fundus examination in 334 eyes of 167 cases showed pseudo papilledema (54 eyes), normal (67 eyes), pale disc or pale on the temporal side of the optic disc (213 eyes). On the basis data of OCT from 64 patients and 84 normal person, RNFL was found thickening at the early stage and thinning gradually at the later stage in the LHON patients. But, the RNFL thickness of patients with 1-2 years history was not significantly different from the patients with over 2 years history(P = 0.051), and there was no difference among the patients with different mitochondrial DNA mutations. The initial mean VA of patients with the 14484 mutation and 11778 mutation were 3.6 ± 0.65, 3.75 ± 0.54 (t = 0.536, P > 0.05), but the follow-up VA were 4.29 ± 0.55 (t = 4.034, P < 0.001) and 3.93 ± 0.49 respectively (t = 1.857, P > 0.05). The symptoms and fundus manifestation were similar in the LHOH patients with different primary site mutation. Gene mutation analysis is helpful to assess the prognosis of visual acuity.

Ganglion cell complex scan in the early prediction of glaucoma.

PubMed

Ganekal, S

2012-01-01

To compare the macular ganglion cell complex (GCC) with peripapillary retinal fiber layer (RNFL) thickness map in glaucoma suspects and patients. Forty participants (20 glaucoma suspects and 20 glaucoma patients) were enrolled. Macular GCC and RNFL thickness maps were performed in both eyes of each participant in the same visit. The sensitivity and specificity of a color code less than 5% (red or yellow) for glaucoma diagnosis were calculated. Standard Automated Perimetry was performed with the Octopus 3.1.1 Dynamic 24-2 program. The statistical analysis was performed with the SPSS 10.1 (SPSS Inc. Chicago, IL, EUA). Results were expressed as mean +/- standard deviation and a p value of 0.05 or less was considered significant. Provide absolute numbers of these findings with their units of measurement. There was a statistically significant difference in average RNFL thickness (p=0.004), superior RNFL thickness (p=0.006), inferior RNFL thickness (p=0.0005) and average GCC (p=0.03) between the suspects and glaucoma patients. There was no difference in optic disc area (p=0.35) and vertical cup/disc ratio (p=0.234) in both groups. While 38% eyes had an abnormal GCC and 13% had an abnormal RNFL thickness in the glaucoma suspect group, 98% had an abnormal GCC and 90% had an abnormal RNFL thickness in the glaucoma group. The ability to diagnose glaucoma with macular GCC thickness is comparable to that with peripapillary RNFL thickness . Macular GCC thickness measurements may be a good alternative or a complementary measurement to RNFL thickness assessment in the clinical evaluation of glaucoma. © NEPjOPH.

Internal retinal layer thickness and macular migration after internal limiting membrane peeling in macular hole surgery.

PubMed

Faria, Mun Y; Ferreira, Nuno P; Mano, Sofia; Cristóvao, Diana M; Sousa, David C; Monteiro-Grillo, Manuel E

2018-05-01

To provide a spectral-domain optical coherence tomography (SD-OCT)-based analysis of retinal layers thickness and nasal displacement of closed macular hole after internal limiting membrane peeling in macular hole surgery. In this nonrandomized prospective interventional study, 36 eyes of 32 patients were subjected to pars plana vitrectomy and 3.5 mm diameter internal limiting membrane (ILM) peeling for idiopathic macular hole (IMH). Nasal and temporal internal retinal layer thickness were assessed with SD-OCT. Each scan included optic disc border so that distance between optic disc border and fovea were measured. Thirty-six eyes had a successful surgery with macular hole closure. Total nasal retinal thickening (p<0.001) and total temporal retinal thinning (p<0.0001) were observed. Outer retinal layers increased thickness after surgery (nasal p<0.05 and temporal p<0.01). Middle part of inner retinal layers (mIRL) had nasal thickening (p<0.001) and temporal thinning (p<0.05). The mIRL was obtained by deducting ganglion cell layer (GCL) and retinal nerve fiber layer (RNFL) thickness from overall thickness of the inner retinal layer. Papillofoveal distance was shorter after ILM peeling in macular hole surgery (3,651 ± 323 μm preoperatively and 3,361 ± 279 μm at 6 months; p<0.0001). Internal limiting membrane peel is associated with important alteration in inner retinal layer architecture, with thickening of mIRL and shortening of papillofoveal distance. These factors may contribute to recovery of disrupted foveal photoreceptor and vision improvement after IMH closure.

Radial Peripapillary Capillary Network Visualized Using Wide-Field Montage Optical Coherence Tomography Angiography.

PubMed

Mase, Tomoko; Ishibazawa, Akihiro; Nagaoka, Taiji; Yokota, Harumasa; Yoshida, Akitoshi

2016-07-01

We quantitatively analyzed the features of a radial peripapillary capillary (RPC) network visualized using wide-field montage optical coherence tomography (OCT) angiography in healthy human eyes. Twenty eyes of 20 healthy subjects were recruited. En face 3 × 3-mm OCT angiograms of multiple locations in the posterior pole were acquired using the RTVue XR Avanti, and wide-field montage images of the RPC were created. To evaluate the RPC density, the montage images were binarized and skeletonized. The correlation between the RPC density and the retinal nerve fiber layer (RNFL) thickness measured by an OCT circle scan was investigated. The RPC at the temporal retina was detected as far as 7.6 ± 0.7 mm from the edge of the optic disc but not around the perifoveal area within 0.9 ± 0.1 mm of the fovea. Capillary-free zones beside the first branches of the arterioles were significantly (P < 0.0001) narrower than those beside the second ones. The RPC densities at 0.5, 2.5, and 5 mm from the optic disc edge were 13.6 ± 0.8, 11.9 ± 0.9, and 10.4 ± 0.9 mm-1. The RPC density also was correlated significantly (r = 0.64, P < 0.0001) with the RNFL thickness, with the greatest density in the inferotemporal region. Montage OCT angiograms can visualize expansion of the RPC network. The RPC is present in the superficial peripapillary retina in proportion to the RNFL thickness, supporting the idea that the RPC may be the vascular network primarily responsible for RNFL nourishment.

On the functional order of binocular rivalry and blind spot filling-in.

PubMed

Qian, Cheng S; Brascamp, Jan W; Liu, Taosheng

2017-07-01

Binocular rivalry is an important phenomenon for understanding the mechanisms of visual awareness. Here we assessed the functional locus of binocular rivalry relative to blind spot filling-in, which is thought to transpire in V1, thus providing a reference point for assessing the locus of rivalry. We conducted two experiments to explore the functional order of binocular rivalry and blind spot filling-in. Experiment 1 examined if the information filled-in at the blind spot can engage in rivalry with a physical stimulus at the corresponding location in the fellow eye. Participants' perceptual reports showed no difference between this condition and a condition where filling-in was precluded by presenting the same stimuli away from the blind spot, suggesting that the rivalry process is not influenced by any filling-in that might occur. In Experiment 2, we presented the fellow eye's stimulus directly in rivalry with the 'inducer' stimulus that surrounds the blind spot, and compared it with two control conditions away from the blind spot: one involving a ring physically identical to the inducer, and one involving a disc that resembled the filled-in percept. Perceptual reports in the blind spot condition resembled those in the 'ring' condition, more than those in the latter, 'disc' condition, indicating that a perceptually suppressed inducer does not engender filling-in. Thus, our behavioral data suggest binocular rivalry functionally precedes blind spot filling-in. We conjecture that the neural substrate of binocular rivalry suppression includes processing stages at or before V1. Copyright © 2017 Elsevier Ltd. All rights reserved.

Structural parameters associated with location of peaks of peripapillary retinal nerve fiber layer thickness in young healthy eyes.

PubMed

Yamashita, Takehiro; Asaoka, Ryo; Kii, Yuya; Terasaki, Hiroto; Murata, Hiroshi; Sakamoto, Taiji

2017-01-01

The location of the peaks of the circumpapillary retinal nerve fiber layer (cpRNFL) thickness is affected by several ocular parameters. In this study, we have generated equations that can determine the peaks of the cpRNFL. This study was a prospective, observational, cross sectional study of 118 healthy right eyes. The axial length, optic disc tilt, superiortemporal (ST)- and inferiortemporal (IT)-peaks of the cpRNFL thickness, and angles of the ST and IT retinal arteries (RA) and veins (RV) were determined. The correlations between the location of the ST- and IT-peaks and ocular structural parameters and the sex, body height and weight were calculated. The best fit equations to generate the location of the ST/IT-peaks were determined using corrected-Akaike Information Criteria. The location of the ST-peak was 0.72+(0.40 x ST-RA)+(0.27 x ST-RV)+(0.14 x height)-(0.47 x papillo-macular-position)-(0.11 x disc tilt) with a coefficient of correlation of 0.61 (P<0.0001). The location of the IT-peak was 21.88+(0.53 x IT-RA)+(0.15 x IT-RV)+(0.041 x corneal thickness)-(1.00 x axial length) with a coefficient of correlation of 0.59 (P<0.0001). The location of ST/IT peaks is determined by different parameters of the ocular structure. These equations allow clinicians to obtain an accurate location of the peaks for a more accurate diagnosis of glaucoma.

Characteristics of Neovascularization in Early Stages of Proliferative Diabetic Retinopathy by Optical Coherence Tomography Angiography.

PubMed

Pan, Jiandong; Chen, Ding; Yang, Xiaoling; Zou, Ruitao; Zhao, Kuo; Cheng, Dan; Huang, Shenghai; Zhou, Tingye; Yang, Ye; Chen, Feng

2018-05-25

To classify retinal neovascularization in untreated early stages of proliferative diabetic retinopathy (PDR) based on optical coherence tomography angiography (OCTA). A cross-sectional study. Thirty-five eyes were included. They underwent color fundus photography, fluorescein angiography (FA), and OCTA examinations. Neovascularizations elsewhere (NVEs), neovascularizations of the optic disc (NVDs), and intraretinal microvascular abnormalities (IRMAs) were scanned by OCTA. The origin and morphology of NVE/NVD/IRMA on OCTA were evaluated. Retinal nonperfusion areas (NPAs) were measured using Image J software. In 35 eyes successfully imaged, 75 NVEs, 35 NVDs and 12 IRMAs were captured. Three proposed subtypes of NVE were indentified based on the origins and morphological features. Type 1 (32 of 75, 42.67%) originated from venous, in a tree-like shape. Type 2 (30 of 75, 40.00%) originated from capillary networks, with an octopus-like appearance. Type 3 (13 of 75, 17.33%) originated from the IRMAs, having a sea fan shape. NVD originated from the retinal artery, the retinal vein, or from the choroid, and arose from the bending vessels near the rim of the optic disc. IRMA originated from and drained into retinal venules, extending in the retina. The initial layer and affiliated NPA were significantly different in the 3 subtypes of NVEs (all P < 0.01). OCTA allowed identification of the origins and morphological patterns of neovascularization in PDR. The new classification of retinal neovascularization may be useful to better understand pathophysiological mechanisms and to guide efficient therapeutic strategies. Copyright © 2018. Published by Elsevier Inc.

Combining functional and structural tests improves the diagnostic accuracy of relevance vector machine classifiers

PubMed Central

Racette, Lyne; Chiou, Christine Y.; Hao, Jiucang; Bowd, Christopher; Goldbaum, Michael H.; Zangwill, Linda M.; Lee, Te-Won; Weinreb, Robert N.; Sample, Pamela A.

2009-01-01

Purpose To investigate whether combining optic disc topography and short-wavelength automated perimetry (SWAP) data improves the diagnostic accuracy of relevance vector machine (RVM) classifiers for detecting glaucomatous eyes compared to using each test alone. Methods One eye of 144 glaucoma patients and 68 healthy controls from the Diagnostic Innovations in Glaucoma Study were included. RVM were trained and tested with cross-validation on optimized (backward elimination) SWAP features (thresholds plus age; pattern deviation (PD); total deviation (TD)) and on Heidelberg Retina Tomograph II (HRT) optic disc topography features, independently and in combination. RVM performance was also compared to two HRT linear discriminant functions (LDF) and to SWAP mean deviation (MD) and pattern standard deviation (PSD). Classifier performance was measured by the area under the receiver operating characteristic curves (AUROCs) generated for each feature set and by the sensitivities at set specificities of 75%, 90% and 96%. Results RVM trained on combined HRT and SWAP thresholds plus age had significantly higher AUROC (0.93) than RVM trained on HRT (0.88) and SWAP (0.76) alone. AUROCs for the SWAP global indices (MD: 0.68; PSD: 0.72) offered no advantage over SWAP thresholds plus age, while the LDF AUROCs were significantly lower than RVM trained on the combined SWAP and HRT feature set and on HRT alone feature set. Conclusions Training RVM on combined optimized HRT and SWAP data improved diagnostic accuracy compared to training on SWAP and HRT parameters alone. Future research may identify other combinations of tests and classifiers that can also improve diagnostic accuracy. PMID:19528827

Doppler optical coherence tomography of retinal circulation.

PubMed

Tan, Ou; Wang, Yimin; Konduru, Ranjith K; Zhang, Xinbo; Sadda, SriniVas R; Huang, David

2012-09-18

Noncontact retinal blood flow measurements are performed with a Fourier domain optical coherence tomography (OCT) system using a circumpapillary double circular scan (CDCS) that scans around the optic nerve head at 3.40 mm and 3.75 mm diameters. The double concentric circles are performed 6 times consecutively over 2 sec. The CDCS scan is saved with Doppler shift information from which flow can be calculated. The standard clinical protocol calls for 3 CDCS scans made with the OCT beam passing through the superonasal edge of the pupil and 3 CDCS scan through the inferonal pupil. This double-angle protocol ensures that acceptable Doppler angle is obtained on each retinal branch vessel in at least 1 scan. The CDCS scan data, a 3-dimensional volumetric OCT scan of the optic disc scan, and a color photograph of the optic disc are used together to obtain retinal blood flow measurement on an eye. We have developed a blood flow measurement software called "Doppler optical coherence tomography of retinal circulation" (DOCTORC). This semi-automated software is used to measure total retinal blood flow, vessel cross section area, and average blood velocity. The flow of each vessel is calculated from the Doppler shift in the vessel cross-sectional area and the Doppler angle between the vessel and the OCT beam. Total retinal blood flow measurement is summed from the veins around the optic disc. The results obtained at our Doppler OCT reading center showed good reproducibility between graders and methods (<10%). Total retinal blood flow could be useful in the management of glaucoma, other retinal diseases, and retinal diseases. In glaucoma patients, OCT retinal blood flow measurement was highly correlated with visual field loss (R(2)>0.57 with visual field pattern deviation). Doppler OCT is a new method to perform rapid, noncontact, and repeatable measurement of total retinal blood flow using widely available Fourier-domain OCT instrumentation. This new technology may improve the practicality of making these measurements in clinical studies and routine clinical practice.

Modeling and optimization of an elastic arthroplastic disc for a degenerated disc

NASA Astrophysics Data System (ADS)

Ghouchani, Azadeh; Ravari, Mohammad; Mahmoudi, Farid

2011-10-01

A three-dimensional finite element model (FEM) of the L3-L4 motion segment using ABAQUS v 6.9 has been developed. The model took into account the material nonlinearities and is imposed different loading conditions. In this study, we validated the model by comparison of its predictions with several sets of experimental data. Disc deformation under compression and segmental rotational motions under moment loads for the normal disc model agreed well with the corresponding in vivo studies. By linking ABAQUS with MATLAB 2010.a, we determined the optimal Young s modulus as well as the Poisson's ratio for the artificial disc under different physiologic loading conditions. The results of the present study confirmed that a well-designed elastic arthroplastic disc preferably has an annulus modulus of 19.1 MPa and 1.24 MPa for nucleus section and Poisson ratio of 0.41 and 0.47 respectively. Elastic artificial disc with such properties can then achieve the goal of restoring the disc height and mechanical function of intact disc under different loading conditions and so can reduce low back pain which is mostly caused due to disc degeneration.

Rock deformation equations and application to the study on slantingly installed disc cutter

NASA Astrophysics Data System (ADS)

Zhang, Zhao-Huang; Meng, Liang; Sun, Fei

2014-08-01

At present the mechanical model of the interaction between a disc cutter and rock mainly concerns indentation experiment, linear cutting experiment and tunnel boring machine (TBM) on-site data. This is not in line with the actual rock-breaking movement of the disc cutter and impedes to some extent the research on the rock-breaking mechanism, wear mechanism and design theory. Therefore, our study focuses on the interaction between the slantingly installed disc cutter and rock, developing a model in accordance with the actual rock-breaking movement. Displacement equations are established through an analysis of the velocity vector at the rock-breaking point of the disc cutter blade; the functional relationship between the displacement parameters at the rock-breaking point and its rectangular coordinates is established through an analysis of micro-displacement vectors at the rock-breaking point, thus leading to the geometric equations of rock deformation caused by the slantingly installed disc cutter. Considering the basically linear relationship between the cutting force of disc cutters and the rock deformation before and after the leap break of rock, we express the constitutive relations of rock deformation as generalized Hooke's law and analyze the effect of the slanting installation angle of disc cutters on the rock-breaking force. This will, as we hope, make groundbreaking contributions to the development of the design theory and installation practice of TBM.

Predicting progression of glaucoma from rates of frequency doubling technology perimetry change.

PubMed

Meira-Freitas, Daniel; Tatham, Andrew J; Lisboa, Renato; Kuang, Tung-Mei; Zangwill, Linda M; Weinreb, Robert N; Girkin, Christopher A; Liebmann, Jeffrey M; Medeiros, Felipe A

2014-02-01

To evaluate the ability of longitudinal frequency doubling technology (FDT) to predict the development of glaucomatous visual field loss on standard automated perimetry (SAP) in glaucoma suspects. Prospective, observational cohort study. The study included 587 eyes of 367 patients with suspected glaucoma at baseline selected from the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES). These eyes had an average of 6.7 ± 1.9 FDT tests during a mean follow-up time of 73.1 ± 28.0 months. Glaucoma suspects had intraocular pressure (IOP) >21 mmHg or an optic disc appearance suspicious of glaucoma. All patients had normal or nonrepeatable abnormal SAP at baseline. Humphrey Matrix FDT (Carl Zeiss Meditec, Inc, Dublin, CA) testing was performed within 6 months of SAP testing. The study end point was the development of 3 consecutive abnormal SAP test results. Joint longitudinal survival models were used to evaluate the ability of rates of FDT pattern standard deviation (PSD) change to predict the development of visual field loss on SAP, adjusting for confounding variables (baseline age, mean IOP, corneal thickness, and follow-up measurements of SAP PSD). The R(2) index was used to evaluate and compare the predictive abilities of the model containing longitudinal FDT PSD data with the model containing only baseline data. Sixty-three of 587 eyes (11%) developed SAP visual field loss during follow-up. The mean rate of FDT PSD change in eyes that developed SAP visual field loss was 0.07 dB/year versus 0.02 dB/year in those that did not (P < 0.001). Baseline FDT PSD and slopes of FDT PSD change were significantly predictive of progression, with hazard ratios of 1.11 per 0.1 dB higher (95% confidence interval [CI], 1.04-1.18; P = 0.002) and 4.40 per 0.1 dB/year faster (95% CI, 1.08-17.96; P = 0.04), respectively. The longitudinal model performed significantly better than the baseline model with an R(2) of 82% (95% CI, 74-89) versus 11% (95% CI, 2-24), respectively. Rates of FDT PSD change were highly predictive of the development of SAP visual field loss in glaucoma suspects. This finding suggests that longitudinal FDT evaluation may be useful for risk stratification of patients with suspected glaucoma. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

On the illumination of neutron star accretion discs

NASA Astrophysics Data System (ADS)

Wilkins, D. R.

2018-03-01

The illumination of the accretion disc in a neutron star X-ray binary by X-rays emitted from (or close to) the neutron star surface is explored through general relativistic ray tracing simulations. The applicability of the canonical suite of relativistically broadened emission line models (developed for black holes) to discs around neutron stars is evaluated. These models were found to describe well emission lines from neutron star accretion discs unless the neutron star radius is larger than the innermost stable orbit of the accretion disc at 6 rg or the disc is viewed at high inclination, above 60° where shadowing of the back side of the disc becomes important. Theoretical emissivity profiles were computed for accretion discs illuminated by hotspots on the neutron star surfaces, bands of emission and emission by the entirety of the hot, spherical star surface and in all cases, the emissivity profile of the accretion disc was found to be well represented by a single power law falling off slightly steeper than r-3. Steepening of the emissivity index was found where the emission is close to the disc plane and the disc can appear truncated when illuminated by a hotspot at high latitude. The emissivity profile of the accretion disc in Serpens X-1 was measured and found to be consistent with a single unbroken power law with index q=3.5_{-0.4}^{+0.3}, suggestive of illumination by the boundary layer between the disc and neutron star surface.

Effect of collagen fibre orientation on intervertebral disc torsion mechanics.

PubMed

Yang, Bo; O'Connell, Grace D

2017-12-01

The intervertebral disc is a complex fibro-cartilaginous material, consisting of a pressurized nucleus pulposus surrounded by the annulus fibrosus, which has an angle-ply structure. Disc injury and degeneration are noted by significant changes in tissue structure and function, which significantly alters stress distribution and disc joint stiffness. Differences in fibre orientation are thought to contribute to changes in disc torsion mechanics. Therefore, the objective of this study was to evaluate the effect of collagen fibre orientation on internal disc mechanics under compression combined with axial rotation. We developed and validated a finite element model (FEM) to delineate changes in disc mechanics due to fibre orientation from differences in material properties. FEM simulations were performed with fibres oriented at [Formula: see text] throughout the disc (uniform by region and fibre layer). The initial model was validated by published experimental results for two load conditions, including [Formula: see text] axial compression and [Formula: see text] axial rotation. Once validated, fibre orientation was rotated by [Formula: see text] or [Formula: see text] towards the horizontal plane, resulting in a decrease in disc joint torsional stiffness. Furthermore, we observed that axial rotation caused a sinusoidal change in disc height and radial bulge, which may be beneficial for nutrient transport. In conclusion, including anatomically relevant fibre angles in disc joint FEMs is important for understanding stress distribution throughout the disc and will be important for understanding potential causes for disc injury. Future models will include regional differences in fibre orientation to better represent the fibre architecture of the native disc.

Compressed 3D and 2D digital images versus standard 3D slide film for the evaluation of glaucomatous optic nerve features.

PubMed

Sandhu, Simrenjeet; Rudnisky, Chris; Arora, Sourabh; Kassam, Faazil; Douglas, Gordon; Edwards, Marianne C; Verstraten, Karin; Wong, Beatrice; Damji, Karim F

2018-03-01

Clinicians can feel confident compressed three-dimensional digital (3DD) and two-dimensional digital (2DD) imaging evaluating important features of glaucomatous disc damage is comparable to the previous gold standard of stereoscopic slide film photography, supporting the use of digital imaging for teleglaucoma applications. To compare the sensitivity and specificity of 3DD and 2DD photography with stereo slide film in detecting glaucomatous optic nerve head features. This prospective, multireader validation study imaged and compressed glaucomatous, suspicious or normal optic nerves using a ratio of 16:1 into 3DD and 2DD (1024×1280 pixels) and compared both to stereo slide film. The primary outcome was vertical cup-to-disc ratio (VCDR) and secondary outcomes, including disc haemorrhage and notching, were also evaluated. Each format was graded randomly by four glaucoma specialists. A protocol was implemented for harmonising data including consensus-based interpretation as needed. There were 192 eyes imaged with each format. The mean VCDR for slide, 3DD and 2DD was 0.59±0.20, 0.60±0.18 and 0.62±0.17, respectively. The agreement of VCDR for 3DD versus film was κ=0.781 and for 2DD versus film was κ=0.69. Sensitivity (95.2%), specificity (95.2%) and area under the curve (AUC; 0.953) of 3DD imaging to detect notching were better (p=0.03) than for 2DD (90.5%; 88.6%; AUC=0.895). Similarly, sensitivity (77.8%), specificity (98.9%) and AUC (0.883) of 3DD to detect disc haemorrhage were better (p=0.049) than for 2DD (44.4%; 99.5%; AUC=0.72). There was no difference between 3DD and 2DD imaging in detecting disc tilt (p=0.7), peripapillary atrophy (p=0.16), grey crescent (p=0.1) or pallor (p=0.43), although 3D detected sloping better (p=0.013). Both 3DD and 2DD imaging demonstrates excellent reproducibility in comparison to stereo slide film with experts evaluating VCDR, notching and disc haemorrhage. 3DD in this study was slightly more accurate than 2DD for evaluating disc haemorrhage, notching and sloping. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The Reading Disc: Learning to Read Using Interactive CD.

ERIC Educational Resources Information Center

Shaw, Simon

1991-01-01

Describes the development of an interactive compact disc on CD-ROM XA that was designed to help adults learn to read. The application of technology to learning is discussed, differences in learner control in computer-based systems are considered, virtual writing is described, and assessment activities available on the disc are explained. (five…

Interplay between DISC1 and GABA signaling regulates neurogenesis in mice and risk for schizophrenia.

PubMed

Kim, Ju Young; Liu, Cindy Y; Zhang, Fengyu; Duan, Xin; Wen, Zhexing; Song, Juan; Feighery, Emer; Lu, Bai; Rujescu, Dan; St Clair, David; Christian, Kimberly; Callicott, Joseph H; Weinberger, Daniel R; Song, Hongjun; Ming, Guo-li

2012-03-02

How extrinsic stimuli and intrinsic factors interact to regulate continuous neurogenesis in the postnatal mammalian brain is unknown. Here we show that regulation of dendritic development of newborn neurons by Disrupted-in-Schizophrenia 1 (DISC1) during adult hippocampal neurogenesis requires neurotransmitter GABA-induced, NKCC1-dependent depolarization through a convergence onto the AKT-mTOR pathway. In contrast, DISC1 fails to modulate early-postnatal hippocampal neurogenesis when conversion of GABA-induced depolarization to hyperpolarization is accelerated. Extending the period of GABA-induced depolarization or maternal deprivation stress restores DISC1-dependent dendritic regulation through mTOR pathway during early-postnatal hippocampal neurogenesis. Furthermore, DISC1 and NKCC1 interact epistatically to affect risk for schizophrenia in two independent case control studies. Our study uncovers an interplay between intrinsic DISC1 and extrinsic GABA signaling, two schizophrenia susceptibility pathways, in controlling neurogenesis and suggests critical roles of developmental tempo and experience in manifesting the impact of susceptibility genes on neuronal development and risk for mental disorders. Copyright © 2012 Elsevier Inc. All rights reserved.

Ocular Outcomes Comparison Between 14- and 70-day Head-down Tilt Bed Rest

NASA Technical Reports Server (NTRS)

Cromwell, R.L.; Taibbi, G.; Zanello, S.B.; Yarbough, P.O.; Ploutz-Snyder, R.J.; Vizzen, G.

2015-01-01

INTRODUCTION: Ophthalmological changes, including optic disc edema with optic nerve sheath distension, posterior globe flattening with hyperopic shift, choroidal folds and cotton wool spots have been detected in some astronauts involved in long-duration spaceflights. (sup 1) It is hypothesized that elevated intracranial pressure resulting from microgravity-induced cephalad fluid shifts may be responsible for most of these findings. Head-down tilt bed rest (HTDBR) is a ground-based microgravity analog which also produces cephalad fluid shifts. It is conceivable that prolonged HDTBR exposure may induce ocular changes similar to those experienced in microgravity. Therefore, the purpose of the present study was to compare structural and functional ocular outcomes between 14- and 70-day HDTBR in healthy human subjects. It is hypothesized that 70-d HDTBR induced ocular changes of greater magnitude as compared to 14-d HDTBR. METHODS: Two HDTBR studies were conducted at the NASA Flight Analogs Research Unit, located at The University of Texas Medical Branch at Galveston, TX. Identical NASA standard screening procedures and BR conditions (e.g., strict sleep-wake cycle, standardized diet, continuous video monitoring) were implemented in both studies. Participants spent 14 and/or 70 consecutive days in a 6deg HDT position and did not engage in exercise. Subjects received weekly ocular examinations before, during, and after HDTBR. Ocular testing included: distance and near best-corrected visual acuity (BCVA), cycloplegic refraction, intraocular pressure (IOP) measurement, color vision, red dot test, modified Amsler grid test, confrontational visual field, color fundus photography and Spectral-domain OCT scans of the macula and the optic disc. Pre/post HDTBR differences between the two studies will be evaluated for BCVA, spherical equivalent, IOP, retinal nerve fiber layer (RNFL) thickness and macular OCT parameters. RESULTS: 16 (12 males and 4 females) and 6 (5 males and 1 female) subjects participated in the 14 and 70-day HDTBR studies, respectively. One subject participated in both studies. The demographic and ophthalmological characteristics of the 14-day HDTBR study have been presented elsewhere.2 In the 70- day study, subjects age averaged 39.5 +/- 7.8 years; pre- and post-HDTBR Goldmann IOP were, on average, 15.4 and 14.6 mmHg in the right eye, and 15.3 and 14.4 mmHg in the left eye, respectively; preand post-HDTBR Spectralis OCT (Heidelberg Engineering, GmbH, Heidelberg, Germany) average RNFL thickness were 103.8 and 106 µm in the right eye, and 103 and 104.3 µm in the left eye, respectively. In both studies, color vision, red dot test, modified Amsler grid test and confrontational visual field were within normal limits at all time points; no changes were detected on stereoscopic color optic disc photography. For the above outcomes, preliminary results of the pre/post HDTBR differences between the two studies will be presented at the 2015 Human Research Program Investigators' Workshop. CONCLUSIONS: Although 14-day HDTBR did not seem to induce clinically relevant ocular changes, (sup 2) a systematic evaluation and comparison with the 70-day HDTBR study results will elucidate whether the magnitude of ocular structural and functional changes is affected by the time spent in the recumbent position. Further research will also address the effects of integrated resistance and aerobic training during HDTBR on the ocular outcomes. REFERENCES: 1. Mader TH et al. Optic disc edema, globe flattening, choroidal folds, and hyperopic shifts observed in astronauts after long-duration space flight. Ophthalmology. 2011;118(10):2058-69. 2. Taibbi G et al. Ocular outcomes evaluation in a 14-day head-down bed rest study. Aviat Space Environ Med. 2014;85(10):983-92.

Semiautomatic computer-aided classification of degenerative lumbar spine disease in magnetic resonance imaging.

PubMed

Ruiz-España, Silvia; Arana, Estanislao; Moratal, David

2015-07-01

Computer-aided diagnosis (CAD) methods for detecting and classifying lumbar spine disease in Magnetic Resonance imaging (MRI) can assist radiologists to perform their decision-making tasks. In this paper, a CAD software has been developed able to classify and quantify spine disease (disc degeneration, herniation and spinal stenosis) in two-dimensional MRI. A set of 52 lumbar discs from 14 patients was used for training and 243 lumbar discs from 53 patients for testing in conventional two-dimensional MRI of the lumbar spine. To classify disc degeneration according to the gold standard, Pfirrmann classification, a method based on the measurement of disc signal intensity and structure was developed. A gradient Vector Flow algorithm was used to extract disc shape features and for detecting contour abnormalities. Also, a signal intensity method was used for segmenting and detecting spinal stenosis. Novel algorithms have also been developed to quantify the severity of these pathologies. Variability was evaluated by kappa (k) and intra-class correlation (ICC) statistics. Segmentation inaccuracy was below 1%. Almost perfect agreement, as measured by the k and ICC statistics, was obtained for all the analyzed pathologies: disc degeneration (k=0.81 with 95% CI=[0.75..0.88]) with a sensitivity of 95.8% and a specificity of 92.6%, disc herniation (k=0.94 with 95% CI=[0.87..1]) with a sensitivity of 60% and a specificity of 87.1%, categorical stenosis (k=0.94 with 95% CI=[0.90..0.98]) and quantitative stenosis (ICC=0.98 with 95% CI=[0.97..0.98]) with a sensitivity of 70% and a specificity of 81.7%. The proposed methods are reproducible and should be considered as a possible alternative when compared to reference standards. Copyright © 2015 Elsevier Ltd. All rights reserved.

On the evolution of vortices in massive protoplanetary discs

NASA Astrophysics Data System (ADS)

Pierens, Arnaud; Lin, Min-Kai

2018-05-01

It is expected that a pressure bump can be formed at the inner edge of a dead-zone, and where vortices can develop through the Rossby Wave Instability (RWI). It has been suggested that self-gravity can significantly affect the evolution of such vortices. We present the results of 2D hydrodynamical simulations of the evolution of vortices forming at a pressure bump in self-gravitating discs with Toomre parameter in the range 4 - 30. We consider isothermal plus non-isothermal disc models that employ either the classical β prescription or a more realistic treatment for cooling. The main aim is to investigate whether the condensating effect of self-gravity can stabilize vortices in sufficiently massive discs. We confirm that in isothermal disc models with Q ≳ 15, vortex decay occurs due to the vortex self-gravitational torque. For discs with 3≲ Q ≲ 7, the vortex develops gravitational instabilities within its core and undergoes gravitational collapse, whereas more massive discs give rise to the formation of global eccentric modes. In non-isothermal discs with β cooling, the vortex maintains a turbulent core prior to undergoing gravitational collapse for β ≲ 0.1, whereas it decays if β ≥ 1. In models that incorpore both self-gravity and a better treatment for cooling, however, a stable vortex is formed with aspect ratio χ ˜ 3 - 4. Our results indicate that self-gravity significantly impacts the evolution of vortices forming in protoplanetary discs, although the thermodynamical structure of the vortex is equally important for determining its long-term dynamics.

System modeling with the DISC framework: evidence from safety-critical domains.

PubMed

Reiman, Teemu; Pietikäinen, Elina; Oedewald, Pia; Gotcheva, Nadezhda

2012-01-01

The objective of this paper is to illustrate the development and application of the Design for Integrated Safety Culture (DISC) framework for system modeling by evaluating organizational potential for safety in nuclear and healthcare domains. The DISC framework includes criteria for good safety culture and a description of functions that the organization needs to implement in order to orient the organization toward the criteria. Three case studies will be used to illustrate the utilization of the DISC framework in practice.

Prize of the best thesis 2015: Study of debris discs through state-of-the-art numerical modelling

NASA Astrophysics Data System (ADS)

Kral, Q.; Thébault, P.

2015-12-01

This proceeding summarises the thesis entitled ``Study of debris discs with a new generation numerical model'' by Quentin Kral, for which he obtained the prize of the best thesis in 2015. The thesis brought major contributions to the field of debris disc modelling. The main achievement is to have created, almost ex-nihilo, the first truly self-consistent numerical model able to simultaneously follow the coupled collisional and dynamical evolutions of debris discs. Such a code has been thought as being the ``Holy Grail'' of disc modellers for the past decade, and while several codes with partial dynamics/collisions coupling have been presented, the code developed in this thesis, called ``LIDT-DD'' is the first to achieve a full coupling. The LIDT-DD model, which is the first of a new-generation of fully self-consistent debris disc models is able to handle both planetesimals and dust and create new fragments after each collision. The main idea of LIDT-DD development was to merge into one code two approaches that were so far used separately in disc modelling, that is, an N-body algorithm to investigate the dynamics, and a statistical scheme to explore the collisional evolution. This complex scheme is not straightforward to develop as there are major difficulties to overcome: 1) collisions in debris discs are highly destructive and produce clouds of small fragments after each single impact, 2) the smallest (and most numerous) of these fragments have a strongly size-dependent dynamics because of the radiation pressure, and 3) the dust usually observed in discs is precisely these smallest grains. These extreme constraints had so far prevented all previous attempts at developing self-consistent disc models to succeed. The thesis contains many examples of the use of LIDT-DD that are not yet published but the case of the collision between two asteroid-like bodies is studied in detail. In particular, LIDT-DD is able to predict the different stages that should be observed after such massive collisions that happen mainly in the latest stages of planetary formation. Some giant impact signatures and observability predictions for VLT/SPHERE and JWST/MIRI are given. JWST should be able to detect many of such impacts and would enable to see on-going planetary formation in dozens of planetary systems.

Automated analysis of heidelberg retina tomograph optic disc images by glaucoma probability score.

PubMed

Coops, Annemiek; Henson, David Barry; Kwartz, Anna J; Artes, Paul Habib

2006-12-01

To compare the diagnostic performance of the Heidelberg Retinal Tomograph's (HRT; Heidelberg Engineering GmbH, Dossenheim, Germany) glaucoma probability score (GPS), an automated, contour line-independent method of optic disc analysis with that of the Moorfields regression analysis (MRA). HRT images were obtained from one eye of 121 patients with glaucoma (median age, 70.2 years; median mean deviation [MD], -3.6 dB, range, +2.0 to -9.9 dB) and 95 healthy control subjects (median age, 59.7 years; median MD -0.1 dB, range +2.5 to -3.7). The diagnostic performances of GPS and MRA were evaluated by including borderline classifications, either as test negatives (most specific criteria) or as test positives (least specific criteria). Agreement between global and sectoral data of both analyses was established. Logistic regression analyses were performed to evaluate the effect of covariates such as optic disc size and age on the classification outcomes of both the GPS and the MRA. In 8 (7%) patients with glaucoma and 10 (11%) control subjects, the GPS failed to provide a complete global and sectoral optic disc classification. Although we could not identify a single distinct cause of this failure in the glaucoma group, failures in the control subjects occurred most often (7/10) with small and crowded optic discs. In subjects who were successfully classified at least globally by the GPS (117 patients with glaucoma, 88 control subjects), the diagnostic performances of GPS and MRA were similar (areas under the receiver operating characteristic [ROC] curve of 0.78 and 0.77, respectively; P > 0.1). With the GPS, sensitivity and specificity were 59% and 91% (most specific criteria) and 78% and 63% (least specific criteria), respectively. Combining GPS and MRA did not increase diagnostic performance significantly (ROC area of combined classifiers, 0.81). Both GPS and MRA were affected by disc size. In patients with glaucoma as well as healthy control subjects, the odds of a positive GPS classification (borderline or outside normal limits) increased by 21% (95% confidence interval [CI], 12%-30%) for each 0.1 mm2 increase in optic disc area. With the MRA, the corresponding increase was 15% (95% CI, 7%-23%). Optic disc area alone accounted for approximately 30% and 22% of the explained variance with the GPS and MRA, respectively (P < 0.001). The proportional-odds logistic regression confirmed that optic disc size affected mainly the tradeoff between true- and false-positive classifications (criterion) rather than the absolute performance of the analyses (area under the ROC curve). There was some evidence of an age effect with the MRA, which showed a 53% (95% CI, 16%-102%) increase in the odds of a positive test (borderline or outside normal limits) associated with each decade of age (P = 0.002), but no age effects were observed with the GPS (P > 0.1). The diagnostic performance of the contour line-independent GPS analysis is similar to that of the MRA. However, clinicians should be aware of the strong size dependence of both GPS and MRA. In large optic discs, both GPS and MRA are likely to produce many false-positive classifications. Correspondingly, the sensitivity to early damage is likely to be low in small optic discs. There is a need for automated classification systems that explicitly address the size dependence of current analyses.

Assessment and diagnosis of suspected glaucoma in patients with mucopolysaccharidosis.

PubMed

Ashworth, Jane; Flaherty, Maree; Pitz, Susanne; Ramlee, Azura

2015-03-01

The mucopolysaccharidoses (MPS) are a group of rare lysosomal storage disorders, characterized by the accumulation of glycosaminoglycans within multiple organ systems including the eye. This study aimed to determine the prevalence of glaucoma in patients with MPS, as well as the characteristics, diagnosis and management of patients with MPS and glaucoma. A multicentre retrospective case-note review was carried out by ophthalmologists from four tertiary referral centres to identify patients with MPS who had been treated for glaucoma. Clinical ophthalmological data were collected using standardized data collection forms. Fourteen patients were identified (27 eyes) of 294 patients with MPS. The prevalence of glaucoma ranged from 2.1% to 12.5%. The median age at diagnosis of glaucoma was 8 years. Diagnostic evaluation of glaucoma was incomplete in many patients: intraocular pressure was documented in all eyes, but optic disc appearance was only assessed in 67%, central corneal thickness in 26%, visual fields in 19% and iridocorneal angle in 15%. Patients with MPS need regular assessment for possible glaucoma including during childhood. Multiple factors contribute to the challenges of assessment, diagnosis and monitoring of glaucoma in these patients. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Periarterial Plaques (Kyrieleis' Arteriolitis) in a Case of Bilateral Acute Retinal Necrosis.

PubMed

Chawla, Rohan; Tripathy, Koushik; Sharma, Yog Raj; Venkatesh, Pradeep; Vohra, Rajpal

2017-01-01

To describe unilateral periarterial plaque in a case of bilateral acute retinal necrosis (BARN) due to varicella zoster virus (VZV). Case report. A 43-year-old diabetic male presented to us with dimness of vision in the left eye for three months. He was already on oral steroids and anti-viral therapy. Best-corrected visual acuity was 6/6 OD and hand movements close to face OS. The right eye showed inferior and temporal retinal thinning and pigmentation and periarterial whitish focal Kyrieleis' plaques, specifically along arterioles. Left eye had mild vitritis, optic disc pallor, arteriolar attenuation, with retinal whitening and areas of pigmentation involving 360° of peripheral retina along with some involvement of the posterior pole. Serology for human immunodeficiency virus (HIV), herpes simplex virus (HSV), and cytomegalo virus (CMV) was negative. IgM for VZV was positive. Oral Valacyclovir 1 g thrice daily was continued and a slow taper of oral steroids was instituted. ARN should be considered as a differential diagnosis in cases with Kyrieleis' plaques and a peripheral retinal examination must be done to rule out patches of healed retinitis and vasculitis.

[Neuroretinitis. Clinical cases].

PubMed

Valverde-Gubianas, M; Ramos-López, J F; López-Torres, J A; Toribio-García, M; Milla-Peñalver, C; Gálvez Torres-Puchol, J; Medialdea-Marcos, S

2009-08-01

Evaluate the etiology and the most frequent funduscopic alterations of the neuroretinitis. We present the case of a woman 24 years old with a bilateral decrease of visual sharpness (AV), painless and progressive, the funduscopic examination of which reveals a bilateral optical disc edema, with no hemorrhages or exudates, retina edema of the posterior pole and phlebitic areas. The systematic study was normal except for the hemogram (18,000/mm(3) leucocytes with 79% neutrophils) and the positive serology next to a Chlamydia. We also present the case of a 64 years old woman with a decrease of AV at the right eye of one week duration. At the back of the eye a macular star can be seen, and papilla edema. A systematic study gave normal results and positive serology at Bartonella henselae. The illness produced by a cat scratch is the most common cause of neuroretinitis. The customary findings are a loss of AV, discromatopsia, afferent papillary defects and abnormality on the visual field. Other frequent findings at the back of the eye are hemorrhagic nerve fibers, cotton-like exudates, papilla edema, macular star and glassy inflammation. The roll of antibiotic therapy is questionable. Oral ciprofloxacine seems to give good results.

Beta-zone parapapillary atrophy and multifocal visual evoked potentials in eyes with glaucomatous optic neuropathy.

PubMed

De Moraes, Carlos Gustavo; Ketner, Scott; Teng, Christopher C; Ehrlich, Joshua R; Raza, Ali S; Liebmann, Jeffrey M; Ritch, Robert; Hood, Donald C

2011-08-01

We investigated changes in multifocal visual evoked potential (mfVEP) responses due to beta-zone parapapillary atrophy (ßPPA). Patients with glaucomatous optic neuropathy (GON) with or without standard achromatic perimetry (SAP) abnormalities were referred for mfVEP testing during a 2-year period. Eyes with good quality optic disc stereophotographs and reliable SAP results were included. The mfVEP monocular mean latency delays (ms) and amplitudes (SNR) were analyzed. Age, SAP mean deviation (MD), pattern standard deviation (PSD), and spherical equivalent (SE) were analyzed in the multivariate model. Generalized estimated equations were used for comparisons between groups after adjusting for inter-eye associations. Of 394 eyes of 200 patients, 223 (57%) had ßPPA. The ßPPA eyes were older (59.6 ± 13.7 vs. 56.5 ± 13.7 year, P = 0.02), more myopic (-4.0 ± 3.5 vs. -1.3 ± 3.5 D, P < 0.01), and had poorer SAP scores (MD: -4.9 ± 5.2 vs. -2.6 ± 5.2 dB, P < 0.01; PSD: 4.3 ± 2.9 vs. 2.5 ± 3.0 dB, P < 0.01). By univariate analysis, mean latencies were longer in ßPPA eyes (6.1 ± 5.3 vs. 4.0 ± 5.5 ms, P < 0.01). After adjusting for differences in SE, age, and SAP MD, there was no significant difference between the two groups (P = 0.09). ßPPA eyes had lower amplitude log SNR (0.49 ± 0.16 vs. 0.56 ± 0.15, P < 0.01), which lost significance (P = 0.51) after adjusting for MD and PSD. Although eyes with ßPPA had significantly lower amplitudes and prolonged latencies than eyes without ßPPA, these differences were attributable to differences in SAP severity, age, and refractive error. Thus, ßPPA does not appear to be an independent factor affecting mfVEP responses in eyes with GON.

Beta-zone parapapillary atrophy and multifocal visual evoked potentials in eyes with glaucomatous optic neuropathy

PubMed Central

Ketner, Scott; Teng, Christopher C.; Ehrlich, Joshua R.; Raza, Ali S.; Liebmann, Jeffrey M.; Ritch, Robert; Hood, Donald C.

2015-01-01

We investigated changes in multifocal visual evoked potential (mfVEP) responses due to beta-zone parapapillary atrophy (βPPA). Patients with glaucomatous optic neuropathy (GON) with or without standard achromatic perimetry (SAP) abnormalities were referred for mfVEP testing during a 2-year period. Eyes with good quality optic disc stereophotographs and reliable SAP results were included. The mfVEP monocular mean latency delays (ms) and amplitudes (SNR) were analyzed. Age, SAP mean deviation (MD), pattern standard deviation (PSD), and spherical equivalent (SE) were analyzed in the multivariate model. Generalized estimated equations were used for comparisons between groups after adjusting for inter-eye associations. Of 394 eyes of 200 patients, 223 (57%) had βPPA. The βPPA eyes were older (59.6 ± 13.7 vs. 56.5 ± 13.7 year, P = 0.02), more myopic (−4.0 ± 3.5 vs. −1.3 ± 3.5 D, P < 0.01), and had poorer SAP scores (MD: −4.9 ± 5.2 vs. −2.6 ± 5.2 dB, P < 0.01; PSD: 4.3 ± 2.9 vs. 2.5 ± 3.0 dB, P < 0.01). By univariate analysis, mean latencies were longer in βPPA eyes (6.1 ± 5.3 vs. 4.0 ± 5.5 ms, P < 0.01). After adjusting for differences in SE, age, and SAP MD, there was no significant difference between the two groups (P = 0.09). βPPA eyes had lower amplitude log SNR (0.49 ± 0.16 vs. 0.56 ± 0.15, P < 0.01), which lost significance (P = 0.51) after adjusting for MD and PSD. Although eyes with βPPA had significantly lower amplitudes and prolonged latencies than eyes without βPPA, these differences were attributable to differences in SAP severity, age, and refractive error. Thus, βPPA does not appear to be an independent factor affecting mfVEP responses in eyes with GON. PMID:21735265

MRI signal distribution within the intervertebral disc as a biomarker of adolescent idiopathic scoliosis and spondylolisthesis.

PubMed

Gervais, Julien; Périé, Delphine; Parent, Stefan; Labelle, Hubert; Aubin, Carl-Eric

2012-12-03

Early stages of scoliosis and spondylolisthesis entail changes in the intervertebral disc (IVD) structure and biochemistry. The current clinical use of MR T2-weighted images is limited to visual inspection. Our hypothesis is that the distribution of the MRI signal intensity within the IVD in T2-weighted images depends on the spinal pathology and on its severity. Therefore, this study aims to develop the AMRSID (analysis of MR signal intensity distribution) method to analyze the 3D distribution of the MR signal intensity within the IVD and to evaluate their sensitivity to scoliosis and spondylolisthesis and their severities. This study was realized on 79 adolescents who underwent a MRI acquisition (sagittal T2-weighted images) before their orthopedic or surgical treatment. Five groups were considered: low severity scoliosis (Cobb angle ≤50°), high severity scoliosis (Cobb angles >50°), low severity spondylolisthesis (Meyerding grades I and II), high severity spondylolisthesis (Meyerding grades III, IV and V) and control. The distribution of the MRI signal intensity within the IVD was analyzed using the descriptive statistics of histograms normalized by either cerebrospinal fluid or bone signal intensity, weighted centers and volume ratios. Differences between pathology and severity groups were assessed using one- and two-way ANOVAs. There were significant (p < 0.05) variations of indices between scoliosis, spondylolithesis and control groups and between low and high severity groups. The cerebrospinal fluid normalization was able to detect differences between healthy and pathologic IVDs whereas the bone normalization, which reflects both bone and IVD health, detected more differences between the severities of these pathologies. This study proves for the first time that changes in the intervertebral disc, non visible to the naked eye on sagittal T2-weighted MR images of the spine, can be detected from specific indices describing the distribution of the MR signal intensity. Moreover, these indices are able to discriminate between scoliosis and spondylolisthesis and their severities, and provide essential information on the composition and structure of the discs whatever the pathology considered. The AMRSID method may have the potential to complement the current diagnostic tools available in clinics to improve the diagnostic with earlier biomarkers, the prognosis of evolution and the treatment options of scoliosis and spondylolisthesis.

Olfactory Neuroblastoma: A Rare Cause of External Ophthalmoplegia, Proptosis and Compressive Optic Neuropathy.

PubMed

Kartı, Ömer; Zengin, Mehmet Özgür; Çelik, Ozan; Tokat, Taşkın; Küsbeci, Tuncay

2018-04-01

Olfactory neuroblastoma (ONB), which is a neuroectodermal tumor of the nasal cavity, is a rare and locally aggressive malignancy that may invade the orbit via local destruction. In this study, we report a patient with proptosis, external ophthalmoplegia, and compressive optic neuropathy caused by ONB. A detailed clinical examination including ocular imaging and histopathological studies were performed. The 62-year-old female patient presented to our clinic with complaints of proptosis and visual deterioration in the left eye. Her complaints started 2 months prior to admission. Visual acuity in the left eye was counting fingers from 2 meters. There was relative afferent pupillary defect. She had 6 mm of proptosis and limitation of motility. Fundus examination was normal in the right eye, but there was a hyperemic disc, and increased vascular tortuosity and dilation of the retinal veins in the left eye. Computerized tomography and magnetic resonance imaging of the brain and orbits demonstrated a large heterogeneous mass in the left superior nasal cavity with extensions into the ethmoidal sinuses as well as into the left orbit, compressing the medial rectus muscle and optic nerve. Endoscopic biopsy of the lesion was consistent with an ONB (Hyams' grade III). Orbital invasion may occur in patients with ONB. Therefore, it is important to be aware of this malignancy because some patients present with ophthalmic signs such as external ophthalmoplegia, proptosis, or compressive optic neuropathy.

Bilateral vision loss due to Leber's hereditary optic neuropathy after long-term alcohol, nicotine and drug abuse.

PubMed

Maass, Johanna; Matthé, Egbert

2018-04-01

Leber's hereditary optic neuropathy is relatively rare, and no clinical pathognomonic signs exist. We present a rare case of bilateral vision loss of a patient with multiple drug abuse in the history. A 31-year-old man presented with a history of progressive, decreased vision in both eyes for 6 month. On examination, his visual acuity was hand motion in both eyes. Funduscopy demonstrated a temporal pallor of the optic disc. Goldmann visual field perimetry showed a crescent visual field in the right eye and a circular decrease to less than 50 ° in the left eye. Electroretinogram showed a scotopic b-wave amplitude reduction. Optical coherence tomographies, Heidelberg Retina tomography, visual evoked potentials, and magnetic resonance imaging with contrast as well as blood tests were normal. The patient reported to consume various kinds of drugs as well as recreational drug use and alcohol consumption since he was 16 years old. We started a hemodilution therapy, believing the patient suffered from a bilateral, toxic optic neuropathy due to his lifestyle. Laboratory results later on showed Leber's hereditary optic neuropathy. Leber's hereditary optic neuropathy is a rare disease without a typical, pathognomonic presentation. Even though the patient gave good reasons for a toxic optic neuropathy, one should never stop to test for other diseases.

Comparison of mean deviation with AGIS and CIGTS scores in association with structural parameters in glaucomatous eyes.

PubMed

Naka, Maiko; Kanamori, Akiyasu; Tatsumi, Yasuko; Fujioka, Miyuki; Nagai-Kusuhara, Azusa; Nakamura, Makoto; Negi, Akira

2009-01-01

To evaluate which of the 3 clinically used visual field indices including mean deviation (MD), Advanced Glaucoma Intervention Study (AGIS) score, and Collaborative Initial Glaucoma Treatment Study (CIGTS) score are best in evaluating functional damage of glaucomatous optic neuropathy. In 213 glaucomatous eyes, peripapillary retinal nerve fiber layer thickness (RNFLT) and optic disc configuration were measured with Stratus optical coherence tomography and Heidelberg Retina Tomograph-2, respectively. Visual field was measured with standard automated perimetry 30-2. Correlations of the structural parameters compared with the 3 VF indices using second polynomial regression were calculated. In addition, these correlations were analyzed among eyes of 3 different stages of glaucoma, as defined by MD score (early, MD> or =-6 dB; moderate, -12 dB< or =MD<-6 dB; advanced, MD<-12 dB). Among structure-function relationships in all subjects, the highest correlation determination (R) was MD with RNFLT (=0.298). CIGTS score showed better R than MD or AGIS score with rim area, but these values were not higher than any R with RNFLT. In analyses of 3 groups depending on MD, statistically significant structure-function correlations were observed only in patients with an advanced stage. No clear difference was found among MD and AGIS/CIGTS scores in expressing functional damage of glaucomatous eyes. MD is suggested to be no worse than others in monitoring glaucoma in clinical setting.

Development of collagen fibers and vasculature of the fetal TMJ.

PubMed

Yang, L; Wang, H; Wang, M; Ohta, Y; Suwa, F

1992-10-01

Using 12 human fetuses, histological development and changes in connective fiber structure and fine vascular patterns have been investigated in various fetal gestational stages by light and scanning electron microscopy. The main arterial supply of the articular disc was from the bilaminar region and pterygoideus lateralis muscle. The vascular network on the disc surface was related with fluid secretion. When the bilaminar region was compressed, it caused ischemia and fibrosis as the main pathological changes in TMJ derangement. A decrease in fluid from blood vessels might occur in TMJ degeneration. Collagen fibers in the disc passed mainly anteroposteriorly. In the anterior and posterior bands, muscular tendon fibers came from the pterygoideus lateralis muscle and superior stratum of the bilaminar region. In the posterior band three-dimensional structures of collagen fibers suitable for load bearing were observed. The compass network and process on the disc showed the normal structure that is formed gradually and has functions including dispersion, pressure bearing, friction-proofing and storage of the synovial fluid. Attachments of the disc were suitable for disc function. Large elastic fibers in the posterolateral part of the superior stratum of the bilaminar region may be antagonistic to the upper head of the pterygoideus lateralis muscle fibers passing medioanteriorly, indicating that this antagonism is available for disc function.

Scanning laser polarimetry in eyes with exfoliation syndrome.

PubMed

Dimopoulos, Antonios T; Katsanos, Andreas; Mikropoulos, Dimitrios G; Giannopoulos, Theodoros; Empeslidis, Theodoros; Teus, Miguel A; Holló, Gábor; Konstas, Anastasios G P

2013-01-01

To compare retinal nerve fiber layer thickness (RNFLT) of normotensive eyes with exfoliation syndrome (XFS) and healthy eyes.
 Sixty-four consecutive individuals with XFS and normal office-time intraocular pressure (IOP) and 72 consecutive healthy controls were prospectively enrolled for a cross-sectional analysis in this hospital-based observational study. The GDx-VCC parameters (temporal-superior-nasal-inferior-temporal [TSNIT] average, superior average, inferior average, TSNIT standard deviation (SD), and nerve fiber indicator [NFI]) were compared between groups. Correlation between various clinical parameters and RNFLT parameters was investigated with Spearman coefficient. 
 The NFI, although within normal limits for both groups, was significantly greater in the XFS group compared to controls: the respective median and interquartile range (IQR) values were 25.1 (22.0-29.0) vs 15.0 (12.0-20.0), p<0.001. In the XFS group, all RNFLT values were significantly lower compared to controls (p<0.001). However, they were all within the normal clinical ranges for both groups: TSNIT average median (IQR): 52.8 (49.7-55.7) vs 56.0 (53.0-59.3) µm; superior average mean (SD): 62.3 (6.7) vs 68.8 (8.2) µm; inferior average mean (SD): 58.0 (7.2) vs 64.8 (7.7) µm, respectively. TSNIT SD was significantly lower in the XFS group, median (IQR): 18.1 (15.4-20.4) vs 21.0 (18.4-23.8), p<0.001. There was no systematic relationship between RNFLT and visual acuity, cup-to-disc ratio, IOP, central corneal thickness, Humphrey mean deviation, and pattern standard deviation in either group. 
 Compared to control eyes, polarimetry-determined RNFLT was lower in XFS eyes with normal IOP. Therefore, close monitoring of RNFLT may facilitate early identification of those XFS eyes that convert to exfoliative glaucoma.

[Clinical feature of chronic compressive optic neuropathy without optic atrophy].

PubMed

Jiang, Libin; Shi, Jitong; Liu, Wendong; Kang, Jun; Wang, Ningli

2014-12-01

To investigate the clinical feature of the chronic compressive optic neuropathy without optic atrophy. Retrospective cases series study. The clinical data of 25 patients (37 eyes) with chronic compressive optic neuropathy without optic atrophy, treated in Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, from October, 2005 to March, 2014, were collected. Those patients had been showing visual symptoms for 6 months or longer, but missed diagnosed or misdiagnosed as other eye diseases due to their normal or slightly changed fundi. The collected data including visual acuities, visual fields, neuroimaging and/or pathologic diagnosis were analyzed. Among the 25 patients, there were 5 males and 20 females, and their ages range from 9 to 74 years [average (47.5 ± 13.4) years]. All patients suffered progressive impaired vision in single eye or both eyes, without exophthalmos or abnormal eye movements. Except one patient had a headache, other patients did not show systemic symptoms. The corrected visual acuities were between HM to 1.0, and their appearances of optic discs and colors of fundi were normal. After neuroimaging and/or pathological examination, it was proven that 14 patients suffered tuberculum sellae meningiomas, 5 patients with hypophysoma, 3 patient with optic nerve sheath meningioma in orbital apex, 1 patient with cavernous hemangioma, 1 patient with vascular malformation in orbital apex and 1 patient with optic nerve glioma. Among the 19 patients whose suffered occupied lesions of saddle area, 14 patients underwent visual field examinations, and only 4 patients showed classic visual field defects caused by optic chiasmal lesions. Occult progressive visual loss was the most important clinical feature of the disease.

Measurements of donor endothelial keratoplasty lenticules prepared from fresh donated whole eyes by using ultrasound and optical coherence tomography.

PubMed

Kanavi, Mozhgan Rezaei; Nemati, Farzan; Chamani, Tahereh; Kheiri, Bahar; Javadi, Mohammad Ali

2017-03-01

This study was conducted to analyze the profile and thickness of endothelial keratoplasty lenticules prepared from fresh donated whole eyes with Visante optical coherence tomography (V-OCT) compared to measurements obtained from ultrasound pachymetry (USP) at the Central Eye Bank of Iran. Microkeratome-assisted precut corneas were prepared for Descemet stripping automated endothelial keratoplasty by using standard eye bank protocol. Central posterior lenticule thickness (CPLT) on fresh whole eye, before excising corneoscleral disc and transferring to Optisol-GS, was measured by USP. V-OCT was used to measure central, paracentral, and midperipheral thicknesses of lenticules after transferring the tissue to Optisol-GS. Chi Square and Bonferroni tests were respectively used to uncover the differences between the USP and V-OCT measurements and also the thickness profile of lenticules. Postoperative reports for the entire transplanted lenticules were recorded. Accordingly, on evaluation of 312 enrolled precut corneas, CPLT measurements by V-OCT versus USP were statistically different (mean: 136 µm vs 165 µm, respectively; P = 0.008). Thickness profile of the posterior lenticules revealed increased thickness from the central to the peripheral parts of the cornea (mean increase of 16 µm at the pericentral and 64.2 µm at the peripheral locations, respectively); however, the increase in the thickness was relatively symmetrical. Postoperative reports of transplanted lenticules were unremarkable, since there were no posterior flap detachments. In essence, V-OCT measurements of microkeratome-assisted precut lenticules prepared from fresh donated whole eyes averaged 29 μm thinner than USP measurements and revealed a significant but symmetric increase of thickness towards the peripheral parts of the corneas. However, the variation in the thickness profile did not affect the attachment or the clarity of transplanted precut lenticlues.

The Montrachet Study: study design, methodology and analysis of visual acuity and refractive errors in an elderly population.

PubMed

Creuzot-Garcher, Catherine; Binquet, Christine; Daniel, Sandrine; Bretillon, Lionel; Acar, Nyiazi; de Lazzer, Aurélie; Arnould, Laurent; Tzourio, Christophe; Bron, Alain M; Delcourt, Cécile

2016-03-01

To describe the design of the Montrachet Study (Maculopathy Optic Nerve nuTRition neurovAsCular and HEarT diseases) and to report visual acuity and refractive errors in this elderly population. Participants were recruited in Dijon (France), from the ongoing population-based 3C Study. In 2009-2011, 1153 participants from the 3 Cities Study, aged 75 years or more, had an initial eye examination and were scheduled for eye examinations. The eye examination comprised visual acuity, refraction, visual field, ocular surface assessment, photographs and OCT of the macula and the optic disc, measurement of intra-ocular pressure, central corneal thickness and macular pigment assessment. Information on cardiovascular and neurologic diseases and a large comprehensive database (blood samples, genetic testing, cognitive tests, MRI) were available from the 3C Study. Presenting visual acuity <20/60 in the better eye was found in 2.3% (95% CI 1.5-3.2) of the participants with no gender differences. Visual impairment increased with age from 1.5% (95% CI 0.3-2.7) for those aged 75-79 years to 5.6% (95% CI 2.9-8.4) for patients 85 years and older (p = 0.0003). Spherical equivalent did not differ between men and women (p = 0.8) and decreased with age whatever the lens status. Despite the high prevalence of self-reported eye diseases in this elderly population, visual impairment was low and increased with age. The Montrachet Study may help to better estimate the prevalence of eye diseases in people over 75 years of age and to seek associations with cardiovascular and neurologic diseases and their potential risk factors. © 2015 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.

Fabrication of read-only type triple-layered disc

NASA Astrophysics Data System (ADS)

Yang, Huei Wen; Jeng, Tzuan Ren; Yen, Wen Hsin; Chan, Rong Po; Shin, Kuo Ding; Huang, Der Ray

2003-06-01

The approach to increase optical recording density has become very popular research subject in these years. One direct and effective method is to increase the recording layer stack number. That is to say, to add one more recording layer can get one more recording capacity. In this paper, we will propose a new method for manufacturing read only type multi-layered disc. The process is described in the following. This first recorded data layer (called L0) still follows the traditional DVD disc manufacturing process. We obtain the polycarbonate substrate by replicating from Ni stamper. Then polycarbonate substrate is sputtered thin silicon film for semi-reflection layer. As for second layer (L1) and even more layer (Ln-1) producing, one special kind of duplication (called SKD) method is proposed. The duplication (or replication) source of second or nth recorded data is not only limited from Ni stamper. Even polycarbonate or PMMA substrate has recording data are also acceptable sources. At next step, the duplication source is deposited by thin gold film. Then we apply spin coating to bond the first layer (L0) substrate and second layer (L1) duplication source by choosing suitable UV curing glue. After being emitted by UV lamp for several seconds, we can easily separate the duplication source of second layer (L1) from (L0) substrate. Then we find the thin second data layer (L1) is replicated and stacks upon the first layer. On the same way, we sputter thin AgTi layer on the thin second data layer for another semi- reflective layer. By following the above manufacture step, we can produce more layers. In our experimental, we prepare triple layered read-only type disc. The total capacity is almost 12GB for one side of disc, and 24GB for two side of disc. The read-out intensity of laser from each data layer is expected to be similar. Thus we have designed particular reflectance and transmittance for each data layer by controlling the thickness of thin silicon film. We can verify our design by checking the focusing error signal in S-curve search of optical pickup head. The signal quality for each layer can be found from the signal eye pattern and jitter. For compatibility with present drive system, the requirement of the readout signal from each layer should be same as DVD or CD specification

Tau excess impairs mitosis and kinesin-5 function, leading to aneuploidy and cell death.

PubMed

Bougé, Anne-Laure; Parmentier, Marie-Laure

2016-03-01

In neurodegenerative diseases such as Alzheimer's disease (AD), cell cycle defects and associated aneuploidy have been described. However, the importance of these defects in the physiopathology of AD and the underlying mechanistic processes are largely unknown, in particular with respect to the microtubule (MT)-binding protein Tau, which is found in excess in the brain and cerebrospinal fluid of affected individuals. Although it has long been known that Tau is phosphorylated during mitosis to generate a lower affinity for MTs, there is, to our knowledge, no indication that an excess of this protein could affect mitosis. Here, we studied the effect of an excess of human Tau (hTau) protein on cell mitosis in vivo. Using the Drosophila developing wing disc epithelium as a model, we show that an excess of hTau induces a mitotic arrest, with the presence of monopolar spindles. This mitotic defect leads to aneuploidy and apoptotic cell death. We studied the mechanism of action of hTau and found that the MT-binding domain of hTau is responsible for these defects. We also demonstrate that the effects of hTau occur via the inhibition of the function of the kinesin Klp61F, the Drosophila homologue of kinesin-5 (also called Eg5 or KIF11). We finally show that this deleterious effect of hTau is also found in other Drosophila cell types (neuroblasts) and tissues (the developing eye disc), as well as in human HeLa cells. By demonstrating that MT-bound Tau inhibits the Eg5 kinesin and cell mitosis, our work provides a new framework to consider the role of Tau in neurodegenerative diseases. © 2016. Published by The Company of Biologists Ltd.

En Face Doppler Optical Coherence Tomography Measurement of Total Retinal Blood Flow in Diabetic Retinopathy and Diabetic Macular Edema

PubMed Central

Lee, ByungKun; Novais, Eduardo A.; Waheed, Nadia K.; Adhi, Mehreen; de Carlo, Talisa E.; Cole, Emily D.; Moult, Eric M.; Choi, WooJhon; Lane, Mark; Baumal, Caroline R.; Duker, Jay S.; Fujimoto, James G.

2018-01-01

IMPORTANCE Alterations in ocular blood flow play an important role in the pathogenesis and progression of diabetic retinopathy (DR). However, the measurement of retinal blood flow in clinical studies has been challenging. En face Doppler optical coherence tomography (OCT) provides an effective method for measuring total retinal blood flow (TRBF) in the clinic. OBJECTIVE To investigate TRBF in eyes with DR of varying severity, with or without diabetic macular edema (DME), using en face Doppler OCT. DESIGN, SETTING, AND PARTICIPANTS This was a cross-sectional study conducted from May 23, 2014, to January 11, 2016, which analyzed 41 eyes with DR from 31 diabetic patients, 20 eyes without DR from 11 diabetic patients, and 16 eyes from 12 healthy age-matched controls, all at the New England Eye Center in Boston, Massachusetts. MAIN OUTCOMES AND MEASURES Participants were imaged with a high-speed, swept-source OCT prototype at 1050-nm wavelength using repeated en face Doppler OCT raster scans, comprising 600 × 80 axial scans and covering a 1.5 × 2-mm2 area centered at the optic disc. The TRBF was automatically calculated using custom Matlab software. RESULTS This study included 41 eyes with DR from 31 diabetic patients (mean [SD] age, 62.8 [13.4] years; 12 were female patients), 20 eyes without DR from 11 diabetic patients (mean [SD] age, 58.8 [10.1] years; 5 were female patients), and 16 eyes from 12 healthy age-matched controls (mean [SD] age, 57.9 [8.1] years; 8 were female participants). The mean (SD) TRBF was 28.0 (8.5) μL/min in the eyes with DME, 48.8 (13.4) μL/min in the eyes with DR but without DME, 40.1 (7.7) μL/min in the diabetic eyes without retinopathy, and 44.4 (8.3) μL/min in age-matched healthy eyes. A difference in TRBF between the eyes with DME that were treated and the eyes with DME that were not treated was not identified. The TRBF was consistently low in the eyes with DME regardless of DR severity. The eyes with moderate nonproliferative DR but without DME exhibited a wide range of TRBF from 31.1 to 75.0 μL/min, with the distribution being highly skewed. CONCLUSIONS AND RELEVANCE High-speed en face Doppler OCT can measure TRBF in healthy and diabetic eyes. Diabetic eyes with DME exhibited lower TRBF than healthy eyes (P ≤ .001). Further longitudinal studies of TRBF in eyes with DR would be helpful to determine whether reduced TRBF is a risk factor for DME. PMID:28196198

DISC1 Protein Regulates γ-Aminobutyric Acid, Type A (GABAA) Receptor Trafficking and Inhibitory Synaptic Transmission in Cortical Neurons.

PubMed

Wei, Jing; Graziane, Nicholas M; Gu, Zhenglin; Yan, Zhen

2015-11-13

Association studies have suggested that Disrupted-in-Schizophrenia 1 (DISC1) confers a genetic risk at the level of endophenotypes that underlies many major mental disorders. Despite the progress in understanding the significance of DISC1 at neural development, the mechanisms underlying DISC1 regulation of synaptic functions remain elusive. Because alterations in the cortical GABA system have been strongly linked to the pathophysiology of schizophrenia, one potential target of DISC1 that is critically involved in the regulation of cognition and emotion is the GABAA receptor (GABAAR). We found that cellular knockdown of DISC1 significantly reduced GABAAR-mediated synaptic and whole-cell current, whereas overexpression of wild-type DISC1, but not the C-terminal-truncated DISC1 (a schizophrenia-related mutant), significantly increased GABAAR currents in pyramidal neurons of the prefrontal cortex. These effects were accompanied by DISC1-induced changes in surface GABAAR expression. Moreover, the regulation of GABAARs by DISC1 knockdown or overexpression depends on the microtubule motor protein kinesin 1 (KIF5). Our results suggest that DISC1 exerts an important effect on GABAergic inhibitory transmission by regulating KIF5/microtubule-based GABAAR trafficking in the cortex. The knowledge gained from this study would shed light on how DISC1 and the GABA system are linked mechanistically and how their interactions are critical for maintaining a normal mental state. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Novel Human Intervertebral Disc Strain Template to Quantify Regional Three-Dimensional Strains in a Population and Compare to Internal Strains Predicted by a Finite Element Model

PubMed Central

Showalter, Brent L.; DeLucca, John F.; Peloquin, John M.; Cortes, Daniel H.; Yoder, Jonathon H.; Jacobs, Nathan T.; Wright, Alexander C.; Gee, James C.; Vresilovic, Edward J.; Elliott, Dawn M.

2017-01-01

Tissue strain is an important indicator of mechanical function, but is difficult to noninvasively measure in the intervertebral disc. The objective of this study was to generate a disc strain template, a 3D average of disc strain, of a group of human L4–L5 discs loaded in axial compression. To do so, magnetic resonance images of uncompressed discs were used to create an average disc shape. Next, the strain tensors were calculated pixel-wise by using a previously developed registration algorithm. Individual disc strain tensor components were then transformed to the template space and averaged to create the disc strain template. The strain template reduced individual variability while highlighting group trends. For example, higher axial and circumferential strains were present in the lateral and posterolateral regions of the disc, which may lead to annular tears. This quantification of group-level trends in local 3D strain is a significant step forward in the study of disc biomechanics. These trends were compared to a finite element model that had been previously validated against the disc-level mechanical response. Depending on the strain component, 81–99% of the regions within the finite element model had calculated strains within one standard deviation of the template strain results. The template creation technique provides a new measurement technique useful for a wide range of studies, including more complex loading conditions, the effect of disc pathologies and degeneration, damage mechanisms, and design and evaluation of treatments. PMID:26694516

The role of disc self-gravity in circumbinary planet systems - I. Disc structure and evolution

NASA Astrophysics Data System (ADS)

Mutter, Matthew M.; Pierens, Arnaud; Nelson, Richard P.

2017-03-01

We present the results of two-dimensional hydrodynamic simulations of self-gravitating circumbinary discs around binaries whose parameters match those of the circumbinary planet-hosting systems Kepler-16, Kepler-34 and Kepler-35. Previous work has shown that non-self-gravitating discs in these systems form an eccentric precessing inner cavity due to tidal truncation by the binary, and planets which form at large radii migrate until stalling at this cavity. Whilst this scenario appears to provide a natural explanation for the observed orbital locations of the circumbinary planets, previous simulations have failed to match the observed planet orbital parameters. The aim of this work is to examine the role of self-gravity in modifying circumbinary disc structure as a function of disc mass, prior to considering the evolution of embedded circumbinary planets. In agreement with previous work, we find that for disc masses between one and five times the minimum mass solar nebula (MMSN), disc self-gravity affects modest changes in the structure and evolution of circumbinary discs. Increasing the disc mass to 10 or 20 MMSN leads to two dramatic changes in disc structure. First, the scale of the inner cavity shrinks substantially, bringing its outer edge closer to the binary. Secondly, in addition to the eccentric inner cavity, additional precessing eccentric ring-like features develop in the outer regions of the discs. If planet formation starts early in the disc lifetime, these changes will have a significant impact on the formation and evolution of planets and precursor material.