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Sample records for postvitrectomy retinal detachment

  1. Retinal Detachment

    MedlinePlus

    ... men more than women and whites more than African Americans. A retinal detachment is also more likely to occur in people who Are extremely nearsighted Have had a retinal detachment in the other eye Have a family history of retinal detachment Have had cataract surgery Have ...

  2. Retinal Detachment

    MedlinePlus

    ... immediately. Treatment How is retinal detachment treated? Small holes and tears are treated with laser surgery or ... laser surgery tiny burns are made around the hole to “weld” the retina back into place. Cryopexy ...

  3. Retinal detachment repair

    MedlinePlus

    Scleral buckling; Vitrectomy; Pneumatic retinopexy; Laser retinopexy; Rhegmatogenous retinal detachment repair ... it meets the hole in the retina. Scleral buckling can be done using numbing medicine while you ...

  4. Retinal detachment in pseudophakia.

    PubMed

    Galin, M A; Poole, T A; Obstbaum, S A

    1979-07-01

    In a series of cataract patients excluding myopic individuals, under age 60 years, and cases in which vitreous loss occurred, retinal detachment was no less frequent after intracapsular cataract extraction and Sputnik iris supported lenses than in controls. Both groups were followed up for a minimum of two years. The detachments predominantly occurred from retinal breaks in areas of the retina that looked normal preoperatively.

  5. Pharmacotherapies for Retinal Detachment.

    PubMed

    Wubben, Thomas J; Besirli, Cagri G; Zacks, David N

    2016-07-01

    Retinal detachment is an important cause of visual loss. Currently, surgical techniques, including vitrectomy, scleral buckle, and pneumatic retinopexy, are the only means to repair retinal detachment and restore vision. However, surgical failure rates may be as high as 20%, and visual outcomes continue to vary secondary to multiple processes, including postoperative cystoid macular edema, epiretinal membrane formation, macular folds, and, ultimately, photoreceptor death. Therefore, pharmacotherapies are being sought to aid the success rates of modern surgical techniques and reduce or slow the degeneration of photoreceptors during retinal detachment. This review discusses potential therapeutic avenues that aid in retinal reattachment, reduce the rate of retinal redetachment by limiting proliferative vitreoretinopathy, and protect against photoreceptor cell death.

  6. PIMASERTIB AND SEROUS RETINAL DETACHMENTS

    PubMed Central

    AlAli, Alaa; Bushehri, Ahmad; Park, Jonathan C.; Krema, Hatem

    2016-01-01

    Purpose: To report a case of multifocal serous retinal detachments associated with pimasertib. Methods: The authors report a 26-year-old patient who developed bilateral multifocal serous retinal detachments appearing 2 days after starting pimasertib (as part of a clinical trial investigating its use in low-grade metastatic ovarian cancer) and rapidly resolving 3 days after stopping it. Conclusion: The mechanism of MEK inhibitor induced visual toxicity remains unclear. The pathophysiology of multifocal serous retinal detachments as a complication of pimasertib is still poorly understood. PMID:26444523

  7. Missed retinal breaks in rhegmatogenous retinal detachment

    PubMed Central

    Takkar, Brijesh; Azad, Shorya; Shashni, Adarsh; Pujari, Amar; Bhatia, Indrish; Azad, Rajvardhan

    2016-01-01

    AIM To evaluate the causes and associations of missed retinal breaks (MRBs) and posterior vitreous detachment (PVD) in patients with rhegmatogenous retinal detachment (RRD). METHODS Case sheets of patients undergoing vitreo retinal surgery for RRD at a tertiary eye care centre were evaluated retrospectively. Out of the 378 records screened, 253 were included for analysis of MRBs and 191 patients were included for analysis of PVD, depending on the inclusion criteria. Features of RRD and retinal breaks noted on examination were compared to the status of MRBs and PVD detected during surgery for possible associations. RESULTS Overall, 27% patients had MRBs. Retinal holes were commonly missed in patients with lattice degeneration while missed retinal tears were associated with presence of complete PVD. Patients operated for cataract surgery were significantly associated with MRBs (P=0.033) with the odds of missing a retinal break being 1.91 as compared to patients with natural lens. Advanced proliferative vitreo retinopathy (PVR) and retinal bullae were the most common reasons for missing a retinal break during examination. PVD was present in 52% of the cases and was wrongly assessed in 16%. Retinal bullae, pseudophakia/aphakia, myopia, and horse shoe retinal tears were strongly associated with presence of PVD. Traumatic RRDs were rarely associated with PVD. CONCLUSION Pseudophakic patients, and patients with retinal bullae or advanced PVR should be carefully screened for MRBs. Though Weiss ring is a good indicator of PVD, it may still be over diagnosed in some cases. PVD is associated with retinal bullae and pseudophakia, and inversely with traumatic RRD. PMID:27990367

  8. Rhegmatogenous retinal detachment treatment guidelines.

    PubMed

    García-Arumí, J; Martínez-Castillo, V; Boixadera, A; Blasco, H; Marticorena, J; Zapata, M Á; Macià, C; Badal, J; Distéfano, L; Rafart, J M; Berrocal, M; Zambrano, A; Ruíz-Moreno, J M; Figueroa, M S

    2013-01-01

    This paper outlines general guidelines following the initial diagnosis of rhegmatogenous retinal detachment. These include preoperative evaluation, treatment, possible intra- and post-operative complications, retinal re-detachment, and all therapeutic options available for each case. Treatment of the traumatic retinal detachment is also described, due to its importance and peculiarities. Treatment or prophylactic guidelines are suggested for the different types of retinal detachment described. These are based on both the experience of the ophthalmologists that have participated in preparing the guidelines, and also on evidence-based grading linked to bibliographical sources. However, these guidelines should not be interpreted as being mandatory. Given that there is a wide spectrum of options for treatment of retinal detachment, the surgeons' experience with one or other surgical technique will be of utmost importance in obtaining the best surgical result. As guidelines, they are intended as an additional aid to the surgeon during the decision-making process, with the expectation that the final choice will still be left to the surgeon's judgment and past experience.

  9. 23-gauge vitrectomy and silicone oil tamponade with and without phacoemulsification in rhegmatogenous retinal detachment.

    PubMed

    Ozkan, Seyhan Sonar; Citirik, Mehmet; Beyazyildiz, Emrullah; Beyazyildiz, Ozlem

    2015-01-01

    The aim of this study is to assess clinical outcomes of 23-gauge vitrectomy and silicone oil (SO) tamponade combined with and without phacoemulsification (PE) in rhegmatogenous retinal detachment (RRD). The study included forty eyes of 40 patients that underwent 23-gauge vitrectomy and SO tamponade combined with and without PE. Twenty eyes of 20 cases, of whom underwent 23-gauge vitrectomy and SO tamponade combined with PE were allocated to the group 1. Likewise, 20 eyes of 20 cases that underwent 23-gauge vitrectomy and SO tamponade alone were allocated to the group 2. Best corrected visual acuity (BCVA) between two groups was compared. There was no significant difference in BCVA between the two groups during the 6 months (P = 0.3). Recurrent retinal detachments were observed in 2 cases (10%) in both groups. There was no statistically significant difference between two groups as a point of recurrent retinal detachments (P = 1). We have found higher rates of post-vitrectomy cataract progression (45%) in the eyes with RRD who underwent 23-gauge vitrectomy and SO tamponade. Combined vitrectomy and PE is safe and effective for the patients with RRD.

  10. A novel episcleral macular buckling: wire-strengthened sponge exoplant for recurrent macular hole and retinal detachment in high myopic eyes.

    PubMed

    Mortada, Hassan A

    2013-01-01

    The purpose would be to describe and evaluate a novel technique of episcleral macular buckling in postvitrectomy recurrent macular hole retinal detachment in highly myopic eyes. A 7mm silicone sponge strengthened with a U-shaped 0.5mm orthodontics stainless steel wire fed along its length and hand-bent to produce L-shaped buckle of appropriate shape and length, is used. The episcleral macular buckling has performed on 15 highly myopic eyes (axial length > 30mm) with recurrent macular hole retinal detachment following silicone oil removal. Buckle localization has been performed by manipulating the long arm of the exoplant, under direct internal visualization, scleral marking and suturing. Successful retinal reattachment with improvement in visual acuity achieved in all 15 eyes. Closure of the macular holes was confirmed by Optical Coherence Tomography. The anatomical and functional outcomes of this new technique of macular buckling appears to provide an effective and feasible means of retinal reattachment and hole closure in postvitrectomy recurrent macular hole detachment in highly myopic eyes.

  11. A Novel Episcleral Macular Buckling: Wire-Strengthened Sponge Exoplant for Recurrent Macular Hole and Retinal Detachment in High Myopic Eyes

    PubMed Central

    Mortada, Hassan A.

    2013-01-01

    The purpose would be to describe and evaluate a novel technique of episcleral macular buckling in postvitrectomy recurrent macular hole retinal detachment in highly myopic eyes. A 7mm silicone sponge strengthened with a U-shaped 0.5mm orthodontics stainless steel wire fed along its length and hand-bent to produce L-shaped buckle of appropriate shape and length, is used. The episcleral macular buckling has performed on 15 highly myopic eyes (axial length > 30mm) with recurrent macular hole retinal detachment following silicone oil removal. Buckle localization has been performed by manipulating the long arm of the exoplant, under direct internal visualization, scleral marking and suturing. Successful retinal reattachment with improvement in visual acuity achieved in all 15 eyes. Closure of the macular holes was confirmed by Optical Coherence Tomography. The anatomical and functional outcomes of this new technique of macular buckling appears to provide an effective and feasible means of retinal reattachment and hole closure in postvitrectomy recurrent macular hole detachment in highly myopic eyes. PMID:24600635

  12. [Ocular hypertension after surgery for retinal detachment].

    PubMed

    Muşat, O; Cristescu, R; Coman, Corina; Asandi, R

    2012-01-01

    This papers presents a case of a patient with retinal detachement, 3 days ago operated (posterior vitrectomy internal tamponament with silicon oil 1000) who develop increased ocular pressure following silicon oil output in the anterior chamber.

  13. [Binocular vision after treatment of retinal detachment].

    PubMed

    Maksymowicz, Małgorzata; Raczyńska, Krystyna; Maksymowicz, Jarosław

    2003-01-01

    The study covered 79 patients after treatment of retinal detachment. Double vision, strabismus and disturbances of eyeballs motility were found. Up to 12 months after intervention, the deterioration of binocular vision was observed in 48.28 to 89.66% of patients, depending on the method used. The majority of disturbances were observed during the first 3 months with tendency to gradual subsidence during consecutive 9 months. A patient, after treatment of retinal detachment, can be qualified to return to work where stereopsis is needed under condition that ophthalmologic examination is done every three months during the first year after operation and than once a year.

  14. Retinal detachment repair - series (image)

    MedlinePlus

    ... scleral buckle is applied. This consists of a silicone patch wrapped around the eye, compressing the globe ... of the eye, and sealing the detachment. The silicone patch is usually left in place permanently, unless ...

  15. [Retinal detachment in various myopic refractions].

    PubMed

    Alimanović-Halilović, Emina

    2009-01-01

    The basic aim of this study was to find the group of "critical" myopic refraction with the highest occurrence of retinal detachment. In the study, 180 myopic eyes were analyzed. Upon the targeted ophthalmological anamnesis, definition of the objective refraction, and indirect binocular ophthalmoscopy, we analyzed the distribution of retinal detachment and the area affected in relation to refraction. All the eyes were divided into groups according to the refraction height. Average age of our patients ranged from 48.43 to 51.60 years with SD from 13.88 to 18.45. We did not find a statistically significant difference for a certain age. The study covered 102 (56.6%) male and 78 (43.3%) female patients. The highest occurrence of retinal detachment was found in Refraction Group from 3.5 to 7.49 dsph, total 21 (11.6%). The retinal detachments usually affected 2/4 or 3/4 of the eye fundus surface respectively.

  16. [Retinal detachment with retinoschisis--case report].

    PubMed

    Cristescu, R; Muşat, O; Toma, Oana; Coma, Corina; Gabej, Ioana; Burcea, M

    2013-01-01

    We present the case of a 43 year old patient diagnosed with rhegmatogenous retinal detachment and retinoschizis, a rare case of disease association. Surgery is recommended and we practice 23 gauge vitrectomy, laser retinopexy, criopexy in the periphery and internal heavy oil tamponade. Postoperatory evolution was favorable.

  17. Retinal detachment: is reparative surgery always mandatory?

    PubMed Central

    Jarrett, W H

    1988-01-01

    The author reports 16 cases of rhegmatogenous retinal detachment in which, for a variety of reasons, immediate reparative surgery was not carried out. To date, one-half of these cases have not been operated, and four have been followed for 6 years or longer. No case suffered visual loss because of the delay in surgery, nor has chronic inflammation, glaucoma, or rubeosis been a problem. The clinical characteristics of this group of cases is defined. PMID:2979020

  18. Axial eye length after retinal detachment surgery.

    PubMed

    Vukojević, Nenad; Sikić, Jakov; Curković, Tihomir; Juratovac, Zlatko; Katusić, Damir; Sarić, Borna; Jukić, Tomislav

    2005-01-01

    Changes in the eye axial diameter were studied to assess the eye globe impact of conventional operation for retinal detachment. The study included 69 eyes in 69 patients operated on for rhegmatogenous retinal detachment. There were 46.4% of men and 53.6% of women, mean age 52.7 (+/- 15.21) years. Results of preoperative and postoperative ultrasonographic measurement of axial diameter are presented. The mean preoperative and postoperative eye axial diameter was 23.69 (+/- 1.84) mm and 24.43 (+/- 1.91) mm, respectively. Postoperative results showed the axial eye length to increase by a mean of 0.74 (+/- 0.44) mm, yielding a statistically significant difference from the preoperative measurement (p < 0.001). The mean myopia induced by this eyeball elongation was 1.77 D. The encircling band with and without segmental buckling used in surgical repair of retinal detachment creates circular and segmental indentation of the eyeball, thus increasing its axial length. The myopia induced by elongation of the eyeball results in considerable myopia, which requires appropriate correction in the early postoperative period to achieve favorable vision rehabilitation.

  19. Management of Giant Retinal Tear Detachments

    PubMed Central

    Berrocal, Maria H.; Chenworth, Megan L.; Acaba, Luis A.

    2017-01-01

    Giant retinal tears (GRTs) are full-thickness circumferential tears of more than 90 degrees of the retina that are associated with vitreous detachment. They are related to ocular trauma, high myopia, aphakia, pseudophakia, genetic mutations involving collagen and young age. GRTs comprise 1.5% of all rhegmatogenous retinal detachments and the average age of incidence is 42 years. GRTs are more common in males, as 72% of all cases occur in males. The incidence of GRTs in the general population is estimated to be 0.05 per 100,000 individuals. Common techniques used in the management of GRTs include fluid-air exchange, pneumatic retinopexy, scleral buckling, primary vitrectomy with gas or silicone oil tamponade, and combined scleral buckle-vitrectomies. However, management of GRTs poses a great challenge to physicians due to the high risk of intra- and post-operative complications and the many technical difficulties involved. The advent of perfluorocarbon liquids (PFCL) and the use of micro-incisional surgery for the treatment of GRTs has provided new opportunities for the management of GTRs. Today, retinal reattachment can be achieved in 94-100% of cases. PMID:28299011

  20. Retinal Detachment due to CrossFit Training Injury

    PubMed Central

    Joondeph, Stephanie A.; Joondeph, Brian C.

    2013-01-01

    The purpose of this paper is to describe a traumatic retinal detachment occurring as a result of CrossFit training using an elastic exercise band. The patient sustained an ocular injury from an elastic band during CrossFit training, resulting in a giant retinal dialysis and retinal detachment, which were successfully repaired. Trainers and athletes need to be aware of the potential for ocular injury from elastic exercise bands and take appropriate precautions. PMID:24106626

  1. Retinal Detachment due to CrossFit Training Injury.

    PubMed

    Joondeph, Stephanie A; Joondeph, Brian C

    2013-01-01

    The purpose of this paper is to describe a traumatic retinal detachment occurring as a result of CrossFit training using an elastic exercise band. The patient sustained an ocular injury from an elastic band during CrossFit training, resulting in a giant retinal dialysis and retinal detachment, which were successfully repaired. Trainers and athletes need to be aware of the potential for ocular injury from elastic exercise bands and take appropriate precautions.

  2. [Vitreo-retinal surgery for complicated retinal detachment].

    PubMed

    Wang, J Z

    1993-07-01

    93 eyes (93 patients) of complicated retinal detachment were treated with vitreo-retinal surgery. Among the series, 75 eyes were rhegmatogenous with PVR C3-D3 in 66 eyes (88.0%), while the remaining 18 eyes were traction induced. None of the cases had giant tears or complicating diabetes. On discharge from the hospital, the operation was effective in 62 cases (66.7%), in whom the retina was totally reattached or only a small amount of subretinal fluid remained. In a group of 40 eyes where the inert gas SF6 was used, the operation was effective in 30 cases (75.0%). 41 cases were followed up postoperatively for over 3 months, averaging 13.7 months, to find the operative results stable in 33 eyes (80.5%), with the visual acuity improved in 22 cases (66.7%), unchanged in 9 cases (27.3%), and decreased in 2 cases (6.0%). The operative procedures, the peeling of pre-retinal membrane, the effect of PVR severity on the operative results, and the promotion of operative efficacy by application of wide encircling buckle and inert gas tamponade were discussed.

  3. Advantages of diabetic tractional retinal detachment repair

    PubMed Central

    Sternfeld, Amir; Axer-Siegel, Ruth; Stiebel-Kalish, Hadas; Weinberger, Dov; Ehrlich, Rita

    2015-01-01

    Purpose To evaluate the outcomes and complications of patients with diabetic tractional retinal detachment (TRD) treated with pars plana vitrectomy (PPV). Patients and methods We retrospectively studied a case series of 24 eyes of 21 patients at a single tertiary, university-affiliated medical center. A review was carried out on patients who underwent PPV for the management of TRD due to proliferative diabetic retinopathy from October 2011 to November 2013. Preoperative and final visual outcomes, intraoperative and postoperative complications, and medical background were evaluated. Results A 23 G instrumentation was used in 23 eyes (95.8%), and a 25 G instrumentation in one (4.2%). Mean postoperative follow-up time was 13.3 months (4–30 months). Visual acuity significantly improved from logarithm of the minimum angle of resolution (LogMAR) 1.48 to LogMAR 1.05 (P<0.05). Visual acuity improved by ≥3 lines in 75% of patients. Intraoperative complications included iatrogenic retinal breaks in seven eyes (22.9%) and vitreal hemorrhage in nine eyes (37.5%). In two eyes, one sclerotomy was enlarged to 20 G (8.3%). Postoperative complications included reoperation in five eyes (20.8%) due to persistent subretinal fluid (n=3), vitreous hemorrhage (n=1), and dislocated intraocular lens (n=1). Thirteen patients (54.2%) had postoperative vitreous hemorrhage that cleared spontaneously, five patients (20.8%) required antiglaucoma medications for increased intraocular pressure, seven patients (29.2%) developed an epiretinal membrane, and two patients (8.3%) developed a macular hole. Conclusion Patients with diabetic TRD can benefit from PPV surgery. Intraoperative and postoperative complications can be attributed to the complexity of this disease. PMID:26604667

  4. Retinal detachment in a patient with extensive myelinated retinal nerve fibers.

    PubMed

    Chen, Muh-Shy; Ho, Tzyy-Chang; Chang, Ching-Chung; Hou, Ping-Kang

    2007-01-01

    We report extensive myelinated retinal nerve fibers in a 42-year-old patient with retinal detachment. Fundus examination revealed a horseshoe-shaped tear near the temporal edge. Pars plana vitrectomy was performed and firm vitreo-retinal adhesion was noticed in the area of extensive myelinated retinal nerve fibers. Following vitrectomy with silicone oil tamponade, the retina was reattached successfully. In conclusion, retinal detachment may develop in patients with extensive myelinated retinal nerve fibers. Vitrectomy may be performed to treat this condition.

  5. Detachments of the retinal pigment epithelium at the posterior pole.

    PubMed

    Noble, K G; Levitzky, M J; Carr, R E

    1976-08-01

    Multiple vitelliform cysts of the retina, a disorder of unknown cause in which there are multiple detachments of the retinal pigment epithelium at the posterior pole, occurred in five patients. In four patients all lesions were located outside the parafoveal area while one patient showed bilateral foveal elevations associated with more eccentric detachments. Several patients showed slow resolution of some of the detachments with mild disturbances of the pigment epithelium.

  6. Rhegmatogenous retinal detachment in morning glory syndrome pathogenesis and treatment.

    PubMed

    Ho, C L; Wei, L C

    2001-01-01

    We report a case of morning glory syndrome with retinal detachment. A slit-like retinal break at the edge of the excavated disc anomaly provided a direct communication between the subretinal space and the vitreous cavity. Retinal reattachment and useful vision was achieved after a single procedure of vitrectomy and gas tamponade. We believe that identification of the retinal break, removal of epipapillary fibroglial tissue and its traction force, the avoidance of perfluorocarbon liquid and the appropriate use of long-acting gas as endotamponade, all contributed to the favorable outcome. This is more evidence supporting the rhegmatogenous theory of retinal detachment in morning glory syndrome. A literature review of the clinical presentations and treatments of similar cases is included.

  7. Risk factors of rhegmatogenous retinal detachment associated with choroidal detachment in Chinese patients

    PubMed Central

    Gu, Yong-Hao; Ke, Gen-Jie; Wang, Lin; Gu, Qi-Hong; Zhou, En-Liang; Pan, Hong-Biao; Wang, Shi-Ying

    2016-01-01

    AIM To comprehensively analyze the risk factors of rhegmatogenous retinal detachment (RRD) associated with choroidal detachment (CD). METHODS A total of 265 eyes of 265 consecutive cases of RRD were retrospectively analyzed. All patients had systemic and ophthalmologic examination. CD was diagnosed by indirect ophthalmoscopy, B-scan ultrasonography, and ultrasound biomicroscope (UBM). Each parameter was compared between patients of RRD and rhegmatogenous retinal detachment associated with choroidal detachment (RRDCD). Logistic regression analysis was used to determine the independent risk factors of CD. RESULTS There were 52 eyes (19.62%) with CD. Pseudophakia was more commonly seen in RRDCD (21.15% vs 6.10%, P=0.002). Intraocular pressure (IOP) was lower (8.60±3.62 vs 12.96±3.55, P<0.001), best-corrected visual acuity was worse [3.00 (2.00 to 3.00) vs 1.92 (1.22 to 3.00), P=0.001], and refractive error was more myopic [-4 (-9 to -2) vs -2 (-6 to 0), P=0.007] in RRDCD. Eyes with RRDCD had larger extent of retinal detachment (P=0.007). In RRDCD, 34.62% of eyes presented with multiple holes (P=0.044) and 25.00% with macular holes (P=0.012), compared with 20.66% and 14.08% in RRD. High myopia (P=0.039), low IOP (P=0.017), and larger extent of retinal detachment (P<0.001) were significant and independent risk factors for developing CD. CONCLUSION For CD in RRD, related factors include BCVA, IOP, lens status, refractive error, extent of retinal detachment, number of holes, and macular hole. Larger extent of retinal detachment, high myopia, and low IOP are significant and independent risk factors. PMID:27500106

  8. Interventions for asymptomatic retinal breaks and lattice degeneration for preventing retinal detachment

    PubMed Central

    Wilkinson, Charles P

    2016-01-01

    Background Asymptomatic retinal breaks and lattice degeneration are visible lesions that are risk factors for later retinal detachment. Retinal detachments occur when fluid in the vitreous cavity passes through tears or holes in the retina and separates the retina from the underlying retinal pigment epithelium. Creation of an adhesion surrounding retinal breaks and lattice degeneration, with laser photocoagulation or cryotherapy, has been recommended as an effective means of preventing retinal detachment. This therapy is of value in the management of retinal tears associated with the symptoms of flashes and floaters and persistent vitreous traction upon the retina in the region of the retinal break, because such symptomatic retinal tears are associated with a high rate of progression to retinal detachment. Retinal tears and holes unassociated with acute symptoms and lattice degeneration are significantly less likely to be the sites of retinal breaks that are responsible for later retinal detachment. Nevertheless, treatment of these problems is frequently recommended, in spite of the fact that the effectiveness of this therapy is unproven. Objectives The purpose of this review was to evaluate the effectiveness of interventions for asymptomatic retinal breaks and lattice degeneration. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 1), MEDLINE (January 1950 to January 2012), EMBASE (January 1980 to January 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 28 January 2012. Textbooks regarding retinal detachment and the reference lists of relevant reports were reviewed for additional

  9. Syphilis presenting as retinal detachment and orchitis in a young man with HIV.

    PubMed

    Yogo, Norihiro; Nichol, Aran Cunningham; Campbell, Thomas B; Erlandson, Kristine M

    2014-02-01

    Retinal detachment and testicular lesions are 2 rare presentations of syphilis. We describe a man with bilateral retinal detachment from ocular syphilis and syphilitic orchitis as a manifestation of syphilis and HIV coinfection.

  10. Spontaneous resolution of optic nerve coloboma-associated retinal detachment.

    PubMed

    Ying, Michelle S; Fuller, Jeff; Young, Joshua; Marcus, Dennis M

    2004-01-01

    We report a congenital neurosensory retinal detachment associated with an optic nerve coloboma with subsequent spontaneous reattachment. This represents the earliest reported case of such a clinical situation. An observation period is recommended for infants with this clinical course to allow for the opportunity of spontaneous reattachment.

  11. Pneumoretinopexy in the treatment of retinal detachment with macular hole.

    PubMed

    Menchini, U; Scialdone, A; Visconti, C; Brancato, R

    1988-01-01

    Nine eyes of nine patients affected by retinal detachment with macular hole were treated with pneumoretinopexy and postoperative positioning. All the eyes were myopic (mean 13.3 d., sd 3.3), two were amblyopic and one was aphakic. The operative technique included eye softening and intravitreal SF6 gas injection only. Barrage laser photocoagulation was carried out after retinal reattachment. In seven eyes (77.8%) the retina reattached in a mean of three days and the visual acuity improved. No recurrences were observed after a mean of 11.6 months. No severe complications occurred. Vitreous flare was present in 44% and increase of floaters in 55% of the eyes. We believe that pneumoretinopexy can be employed as the first treatment in case of myopic retinal detachment with macular hole.

  12. Spectral domain optical coherence tomography imaging of subretinal bands associated with chronic retinal detachments

    PubMed Central

    Kothari, Nikisha; Kuriyan, Ajay E; Flynn, Harry W

    2016-01-01

    We report three patients with subretinal bands associated with retinal detachment in chronic retinal detachments who underwent successful retinal reattachment. Subretinal bands before and after surgery can be identified on clinical examination and spectral domain optical coherence tomography. Removal of subretinal bands is not mandatory to achieve retinal reattachment. PMID:27099457

  13. Retinal Detachment in Down Syndrome: Characteristics and Surgical Outcomes

    PubMed Central

    AlAhmadi, Badr O.; Alsulaiman, Sulaiman M.; Arevalo, J. Fernando

    2016-01-01

    Purpose. To determine the functional and anatomic outcomes of rhegmatogenous retinal detachment (RRD) surgery in patients with Down syndrome. Methods. A retrospective chart review was performed of patients with Down syndrome who had undergone surgery for RRD at King Khalid Eye Specialist Hospital between 1995 and 2014. Results. A total of 245 patients with Down syndrome were evaluated during the study period. Eighteen eyes of 15 patients (6.1%) with RRD were identified. Three out of 15 patients (20%) presented with bilateral retinal detachment. All eyes presented with macula off retinal detachment. The retina was successfully reattached in 16/18 (88.8%) eyes after a mean follow-up of 48 months. The final postoperative visual acuity ranged from light perception to 20/125 (median: hand motion) (11/18 eyes). Conclusions. The anatomic success rate of retinal reattachment surgery in patients with Down syndrome is comparable to the general population. Patients with Down syndrome should undergo regular ophthalmic examinations for early diagnosis. Despite late diagnosis and the presence of proliferative vitreoretinopathy (PVR) in some patients, favorable anatomical outcomes can be achieved. PMID:27123341

  14. Pseudophakic flat anterior chamber following retinal detachment repair.

    PubMed

    Taylor, B C; Winslow, R L

    1981-09-01

    Flat anterior chambers were caused by varying mechanisms in 10 of 70 consecutive pseudophakic eyes operated on for retinal detachment. With iris or capsular implant fixation, three of 46 (7%) developed flat anterior chambers, and with anterior chamber lenses, the occurrence was seven of 24 (29%). Events initiating flat chambers included wound leak, pupillary block, and choroidal detachment. In eyes with flat anterior chambers, the retina could not be reattached in one case, extensive peripheral anterior synechia with persistent intraocular pressure elevation occurred in another case, and bullous keratopathy remained in two additional instances. Endothelial cell densities were obtained in eight eyes and were low on an age-related basis.

  15. Retinal dialysis and detachment in a child after airbag deployment.

    PubMed

    Eliott, Dean; Hauch, Adam; Kim, Rubin W; Fawzi, Amani

    2011-04-01

    A variety of airbag-associated ocular injuries have been reported in children sitting in the front passenger seat during automobile collisions. These injuries range from corneal abrasions to traumatic hyphema with secondary glaucoma and cataract. We report the case of a 5-year-old boy who experienced retinal dialysis and detachment associated with airbag deployment. The patient recovered 20/20 visual acuity after cryopexy and placement of a radial sponge.

  16. Timing and Outcomes of Vitreoretinal Surgery after Traumatic Retinal Detachment

    PubMed Central

    Orban, Molly

    2016-01-01

    Traumatic retinal detachments are a significant cause of morbidity. There are currently no evidence-based guidelines on the appropriate time to perform vitreoretinal surgery to repair a traumatic retinal detachment. Early intervention, within seven days of the inciting trauma, may decrease proliferative vitreoretinopathy and postoperative endophthalmitis. Later intervention may yield a reduced risk of inflammation and hemorrhage, particularly in cases of concomitant open globe injuries. This article reviews the literature on the management of retinal detachments associated with ocular trauma from the years 2006 to 2016. Particular focus was placed on the timing of surgery, concomitant open globe injury, anatomical success rates, visual acuity, and complication rates. In this review, anatomical success was not significantly related to timing of intervention when compared between early and delayed intervention in eyes with and without concomitant open globe injuries. Visual acuities postoperatively varied widely despite timing of intervention due to the large variation in mechanism and extent of ocular injuries. Proliferative vitreoretinopathy was a common complication. Preliminary data indicate that endophthalmitis rates may be lower when early vitreoretinal surgery is performed. There is insufficient data to conclude whether early or delayed surgery leads to improved outcomes, highlighting the need for further research in this domain. PMID:27999681

  17. Choroidal melanoma with massive retinal fibrosis and spontaneous regression of retinal detachment.

    PubMed

    Pitts, R E; Awan, K J; Yanoff, M

    1976-01-01

    An unusual case of choroidal malignant melanoma with heterochromia iridis, massive subretinal hemorrhage and fibrosis, spontaneously resolving retinal detachment, and subretinal seeding is reported. Clinical and pathological findings are presented and discussed. The unusual aspects of the case are further considered by Drs. Andrew Ferry and Mark Tso.

  18. Perfluorocarbon liquids in the management of complicated retinal detachments.

    PubMed

    Comaratta, M R; Chang, S

    1991-06-01

    Low viscosity perfluorocarbon liquids have unique physical properties making them ideal for the temporary tamponade, mechanical fixation, and manipulation of the retina. These substances are optically clear, have a specific gravity greater than that of water, and have interfacial tension properties similar to those of silicone oil. The temporary mechanical fixation of the retina by perfluorocarbon liquids facilitates the removal of epiretinal membranes and release of tractional forces. Intraoperative flattening of the retina under perfluorocarbon liquid eliminates the need for a posterior retinotomy. Perfluorocarbon liquids are being used intraoperatively for hydrokinetic manipulation of the retina during vitrectomy for complicated retinal detachments secondary to proliferative vitreoretinopathy, giant retinal tears, and trauma. Additional indications for the intraoperative utilization of perfluorocarbon liquids in vitreous surgery are discussed.

  19. Macular Hole Formation in Rhegmatogenous Retinal Detachment after Scleral Buckling

    PubMed Central

    Byon, Ik Soo; Kwon, Han Jo; Park, Gun Hyung; Park, Sung Who

    2014-01-01

    Purpose To describe early macular hole (MH) development in rhegmatogenous retinal detachment (RRD) after scleral buckling (SB) based on optical coherence tomography (OCT) findings. Methods The medical records and spectral domain OCT images of patients in whom MH developed after RRD repair were evaluated retrospectively. Results A postoperative MH was detected in five eyes that underwent SB during a 6-year period. All had fovea-off RRD without MH at the time of surgery. OCT showed partial loss of the inner retina with a preserved photoreceptor layer in early postoperative days. On average, 7 days (range,5 to 8 days) after surgery, outer retinal tissues disappeared, resulting in the full-thickness MH. Conclusions Serial OCT findings revealed that partial-thickness lamellar holes progressed to full-thickness MHs, which were formed by the degeneration of the outer retina in eyes with preceding loss of the glial cone in the fovea. PMID:25276077

  20. Tamponade in the surgical management of retinal detachment.

    PubMed

    Vaziri, Kamyar; Schwartz, Stephen G; Kishor, Krishna S; Flynn, Harry W

    2016-01-01

    Despite treatment advances, rhegmatogenous retinal detachment (RD) can have poor visual outcomes even with prompt and appropriate therapy. Pars plana vitrectomy is a leading management modality for the treatment of RD. This procedure is generally accompanied by the use of internal tamponade. Various gases and silicone oils may yield beneficial outcomes. Heavy silicone oils have been approved in some European nations but are not available in the USA. Different tamponade agents have unique benefits and risks, and choice of the agent should be individualized according to the characteristics of the patient and RD, as well as perioperative and postoperative factors.

  1. Tamponade in the surgical management of retinal detachment

    PubMed Central

    Vaziri, Kamyar; Schwartz, Stephen G; Kishor, Krishna S; Flynn, Harry W

    2016-01-01

    Despite treatment advances, rhegmatogenous retinal detachment (RD) can have poor visual outcomes even with prompt and appropriate therapy. Pars plana vitrectomy is a leading management modality for the treatment of RD. This procedure is generally accompanied by the use of internal tamponade. Various gases and silicone oils may yield beneficial outcomes. Heavy silicone oils have been approved in some European nations but are not available in the USA. Different tamponade agents have unique benefits and risks, and choice of the agent should be individualized according to the characteristics of the patient and RD, as well as perioperative and postoperative factors. PMID:27041988

  2. Chorioretinal Coloboma Complications: Retinal Detachment and Choroidal Neovascular Membrane

    PubMed Central

    Hussain, Rehan M.; Abbey, Ashkan M.; Shah, Ankoor R.; Drenser, Kimberly A.; Trese, Michael T.; Capone, Antonio

    2017-01-01

    Purpose: To report the chorioretinal coloboma, and its association with increased risk of retinal detachment (RD) and choroidal neovascularization (CNV). Methods: This retrospective case series included eyes with chorioretinal coloboma diagnosed between 1995 and 2014 with a focus on RD and CNV as related complications. Cases of CNV were managed with laser photocoagulation or intravitreal injection of bevacizumab. For eyes with CNV, therapeutic success was defined as resolution of the subretinal hemorrhage on fundus examination and resolution of the subretinal and intraretinal fluid on optical coherence tomography (OCT). For eyes with RD, anatomic success following surgical intervention was defined as attachment of the retina at the last follow-up visit. Results: Fifty-one eyes of 31 patients with chorioretinal coloboma were identified for review. Bilateral chorioretinal coloboma was present in 64.5% of subjects. RD developed in 15 eyes (29.4%). Among 15 eyes with RD, 4 eyes (27%) had retinal breaks identified within the coloboma, 5 eyes (33%) had retinal breaks outside the coloboma, 2 eyes (13%) showed retinal breaks both inside and outside the coloboma, and in 4 eyes (27%) the causative retinal break was not localized. The overall rate of anatomic success after RD repair was 85.7%. CNV developed in 7 eyes (13.7%) and was located along the margin of the coloboma in all cases. CNV was bilateral in 2 of the 5 affected individuals (40%). Conclusion: RD and CNV were present in a high percentage of eyes with chorioretinal coloboma in these series. The frequent finding of retinal breaks outside the coloboma bed suggests that vitreoretinal interface abnormalities may play a role in development of RD in these eyes. PMID:28299000

  3. Photoreceptor cell death and rescue in retinal detachment and degenerations

    PubMed Central

    Murakami, Yusuke; Notomi, Shoji; Hisatomi, Toshio; Nakazawa, Toru; Ishibashi, Tatsuro; Miller, Joan W.; Vavvas, Demetrios G.

    2013-01-01

    Photoreceptor cell death is the ultimate cause of vision loss in various retinal disorders, including retinal detachment (RD). Photoreceptor cell death has been thought to occur mainly through apoptosis, which is the most characterized form of programmed cell death. The caspase family of cysteine proteases plays a central role for inducing apoptosis, and in experimental models of RD, dying photoreceptor cells exhibit caspase activation; however, there is a paradox that caspase inhibition alone does not provide a sufficient protection against photoreceptor cell loss, suggesting that other mechanisms of cell death are involved. Recent accumulating evidence demonstrates that non-apoptotic forms of cell death, such as autophagy and necrosis, are also regulated by specific molecular machinery, such as those mediated by autophagy-related proteins and receptor-interacting protein kinases, respectively. Here we summarize the current knowledge of cell death signaling and its roles in photoreceptor cell death after RD and other retinal degenerative diseases. A body of studies indicate that not only apoptotic but also autophagic and necrotic signaling are involved in photoreceptor cell death, and that combined targeting of these pathways may be an effective neuroprotective strategy for retinal diseases associated with photoreceptor cell loss. PMID:23994436

  4. Surgical challenges and outcomes of rhegmatogenous retinal detachment in albinism

    PubMed Central

    Sinha, M K; Chhablani, J; Shah, B S; Narayanan, R; Jalali, S

    2016-01-01

    Purpose To report the outcomes and surgical difficulties during rhegmatogenous retinal detachment (RRD) repair in patients with albinism. Methods Retrospective analysis of 10 eyes of 9 patients with albinism that underwent RRD repair was performed. Collected data included demographic details, preoperative examination details, surgical procedure, surgical difficulties, anatomical, and visual outcomes. Outcome measures were retinal reattachment and visual acuity at the last follow-up. Results Mean preoperative best-corrected visual acuity (BCVA) was logMAR (Logarithm of the Minimum Angle of Resolution) 2.15 (range 0.9–3.0) with preoperative localization of causative break in six eyes. One eye had proliferative vitreoretinopathy grade C1 preoperatively. Four eyes underwent scleral buckling (SB) and six underwent 20G pars plana vitrectomy (PPV) with silicone oil injection. Intraoperative complication as iatrogenic retinal break occurred in four eyes. For retinopexy during vitrectomy, endolaser delivery was possible in three out of six eyes, whereas three eyes had cryopexy. The mean follow-up was 12 months in SB group (range 1–12; median 12 months) and 5.33 months (range 1–12; median 3 months) in PPV group. Among vitrectomized eye, two eyes had recurrence at 3 months with oil in situ. Rest of the eyes had attached retina at last follow-up. Mean BCVA at last follow-up was logMAR −1.46 (range 0.7–2.0) with mean improvement of −0.57 logMAR. Conclusions Identification of break, induction of posterior vitreous detachment, and endolaser delivery may be difficult during RRD repair in patients with albinism. The incidence of PVR appeared less in these eyes. Both SB and PPV were efficacious and appear to be good surgical techniques for use in this patient population. PMID:26611845

  5. Experimental retinal detachment causes widespread and multilayered degeneration in rabbit retina.

    PubMed

    Faude, F; Francke, M; Makarov, F; Schuck, J; Gärtner, U; Reichelt, W; Wiedemann, P; Wolburg, H; Reichenbach, A

    2001-05-01

    Retinal detachment remains one of the most frequent causes of visual impairment in humans, even after ophthalmoscopically successful retinal reattachment. This study was aimed at monitoring (ultra-) structural alterations of retinae of rabbits after experimental detachment. A surgical procedure was used to produce local retinal detachments in rabbit eyes similar to the typical lesions in human patients. At various periods after detachment, the detached retinal area as well as neighbouring attached regions were studied by light and electron microscopy. In addition to the well-known degeneration of photoreceptor cells in the detached retina, the following progressive alterations were observed, (i) in both the detached and the attached regions, an incomplete but severe loss of ganglion cell axons occurs; (ii) there is considerable ganglion cell death, particularly in the detached area; (iii) even in the attached retina distant from the detachment, small adherent groups of photoreceptor cells degenerate; (iv) these photoreceptor cells degenerate in an atypical sequence, with severely destructed somata and inner segments but well-maintained outer segments; and (v) the severe loss of retinal neurons is not accompanied by any significant loss of Müller (glial) cells. It is noteworthy that the described progressive (and probably irreparable) retinal destructions occur also in the attached retina, and may account for visual impairment in strikingly large areas of the visual field, even after retinal reattachment.

  6. Success Rates of Vitrectomy in Treatment of Rhegmatogenous Retinal Detachment.

    PubMed

    Mohamed, Yasser Helmy; Ono, Kozue; Kinoshita, Hirofumi; Uematsu, Masafumi; Tsuiki, Eiko; Fujikawa, Azusa; Kitaoka, Takashi

    2016-01-01

    Aim. To investigate the anatomical success rates of pars plana vitrectomy (PPV) after primary rhegmatogenous retinal detachment (RRD). Methods. This retrospective study was conducted between December 2008 and October 2014 at Nagasaki University Hospital. The preoperative data recorded included the lens status, location of the retinal tear, whether a tear was visualized, presence of multiple tears, macula status, presence of peripheral lattice retinal degeneration, and best-corrected visual acuity (BCVA). The primary outcome measures were anatomical (primary and final) and functional success (visual acuity better than 6/60). Results. This study evaluated 422 eyes of 411 patients with a mean age of 57.7 ± 11.2 years. The single-operation reattachment rate (primary anatomical success) was 89.8%. The final anatomical success rate was 100% after 2-6 operations (mean = 3.14 ± 1.03). Functional success rate after the primary reattachment operation was 96.7%, while it was 97.2% at the end of the follow-up. Multiple logistic regression analysis of the possible risk factors for the primary anatomical failure showed a significant relation with the 25 G instruments (P = 0.002) and the presence of multiple tears (P = 0.01). Conclusion. The primary anatomical success of PPV for primary uncomplicated RRD was 89.8% and the final anatomical success rate was 100%.

  7. Success Rates of Vitrectomy in Treatment of Rhegmatogenous Retinal Detachment

    PubMed Central

    Ono, Kozue; Kinoshita, Hirofumi; Uematsu, Masafumi; Tsuiki, Eiko; Fujikawa, Azusa; Kitaoka, Takashi

    2016-01-01

    Aim. To investigate the anatomical success rates of pars plana vitrectomy (PPV) after primary rhegmatogenous retinal detachment (RRD). Methods. This retrospective study was conducted between December 2008 and October 2014 at Nagasaki University Hospital. The preoperative data recorded included the lens status, location of the retinal tear, whether a tear was visualized, presence of multiple tears, macula status, presence of peripheral lattice retinal degeneration, and best-corrected visual acuity (BCVA). The primary outcome measures were anatomical (primary and final) and functional success (visual acuity better than 6/60). Results. This study evaluated 422 eyes of 411 patients with a mean age of 57.7 ± 11.2 years. The single-operation reattachment rate (primary anatomical success) was 89.8%. The final anatomical success rate was 100% after 2–6 operations (mean = 3.14 ± 1.03). Functional success rate after the primary reattachment operation was 96.7%, while it was 97.2% at the end of the follow-up. Multiple logistic regression analysis of the possible risk factors for the primary anatomical failure showed a significant relation with the 25 G instruments (P = 0.002) and the presence of multiple tears (P = 0.01). Conclusion. The primary anatomical success of PPV for primary uncomplicated RRD was 89.8% and the final anatomical success rate was 100%. PMID:27478632

  8. Scleral buckling surgery for rhegmatogenous retinal detachment with subretinal proliferation

    PubMed Central

    Ghasemi Falavarjani, K; Alemzadeh, S A; Modarres, M; Parvaresh, M M; Hashemi, M; Naseripour, M; Nazari Khanamiri, H; Askari, S

    2015-01-01

    Purpose To evaluate the outcome of scleral buckling surgery in patients with rhegmatogenous retinal detachment (RRD) with subretinal proliferation. Methods In this retrospective study, a chart review of all patients with RRD associated with subretinal proliferation who were primarily treated with scleral buckling procedure, from April 2007 to April 2014, was undertaken. Main outcome measures were anatomical retinal reattachment and visual acuity. Results Forty-four eyes of 43 patients including 24 males and 19 females with a mean age of 26.5±13.1 years were evaluated. Immediately after the surgery, retina was reattached in all eyes. However, five eyes (11.3%) needed additional surgery for retinal redetachment. Single surgery anatomical success rate was 88.7%. Four eyes (9.1%), needed pars plana vitrectomy for the treatment of redetachment associated with proliferative vitreoretinopathy and scleral buckle revision surgery was successfully performed in the other eye. Best corrected visual acuity improved from 1.5±0.9 logMAR before surgery to 1.1±0.7 logMAR after surgery (P<0.001). An improvement in BCVA of >2 lines was found in 23 eyes (52.2%) and worsening of best corrected visual acuity of >2 lines was observed in 2 eyes (4.5%). Conclusions Scleral buckling surgery is highly successful in eyes with RRD associated with subretinal proliferation. PMID:25613841

  9. Bietti crystalline retinal dystrophy with subfoveal neurosensory detachment and congenital tortuosity of retinal vessels: case report.

    PubMed

    Padhi, Tapas Ranjan; Kesarwani, Siddharth; Jalali, Subhadra

    2011-06-01

    A 34-year-old man presented with reduction and distortion of vision in both the eyes. The best-corrected vision was 20/20 parts, N6 in either eye. The external and slit lamp examination of both the eyes was unremarkable. The fundus examination showed multiple intraretinal crystalline deposits at the posterior pole, extending up to midperiphery, tortuous retinal blood vessels with S-shaped deflections, and absent foveal reflex in both the eyes. There were no corneal crystals, and the color vision was defective in both the eyes. Fundus autofluorescence and fundus fluorescein angiogram (FFA) were suggestive of geographic areas of retinal pigment epithelium (RPE) and choriocapillary (CC) loss. OCT revealed subfoveal neurosensory detachment. Flash ERG and EOG were normal except for a slight decrease in amplitude and delay in latency of pattern ERG waveforms. The Humphrey's visual field showed paracentral scotoma with reduction in the amplitude of waveforms from the corresponding area in the multifocal ERG in both the eyes. Systemic evaluation for crystalline retinopathy was unremarkable. He was diagnosed to be a case of Bietti crystalline retinopathy (local/regional variant). The subfoveal neurosensory detachment could represent early RPE dysfunction caused by these crystals and could account for the mild visual disturbance in both the eyes. Retinal vascular tortuosity and neurosensory detachment seen in this case is the first time to be reported in literature.

  10. Peripheral Retinal Vascular Patterns in Patients with Rhegmatogenous Retinal Detachment in Taiwan

    PubMed Central

    Chen, San-Ni; Hwang, Jiunn-Feng; Wu, Wen-Chuan

    2016-01-01

    This is an observational study of fluorescein angiography (FA) in consecutive patients with rhegmatogenous retinal detachment (RRD) in Changhua Christian Hospital to investigate the peripheral retinal vascular patterns in those patients. All patients had their age, sex, axial length (AXL), and refraction status (RF) recorded. According to the findings in FA of the peripheral retina, the eyes were divided into 4 groups: in group 1, there was a ramified pattern of peripheral retinal vasculature with gradual tapering; in group 2, there was an abrupt ending of peripheral vasculature with peripheral non-perfusion; in group 3, there was a curving route of peripheral vasculature forming vascular arcades or anastomosis; and in group 4, the same as in group 3, but with one or more wedge-shaped avascular notches. Comparisons of age, sex, AXL, and RF, association of breaks with lattice degeneration and retinal non-perfusion, surgical procedures utilized, and mean numbers of operations were made among the four groups. Of the 73 eyes studied, there were 13 eyes (17.8%) in group 1, 3 eyes (4.1%) in group 2, 40 eyes (54.8%) in group 3 and 17 eyes (23.3%) in group 4. Significant differences in age, AXL and RF, and association of retinal breaks to non-perfusion were noted among the four groups. Patients in group 1 had older ages, while younger ages were noted in groups 3 and 4. Eyes in group 1 had the shortest average AXL and were least myopic in contrast to the eyes in groups 3 and 4. Association of retinal breaks and retinal non-perfusion was significantly higher in groups 2, 3 and 4 than in group 1. In conclusion, peripheral vascular anomalies are common in cases with RRD. Patients with peripheral non-perfusion tend to be younger, with longer axial length and have the breaks associated with retinal non-perfusion. PMID:26909812

  11. Macula-Sparing Rhegmatogenous Retinal Detachment: Is Emergent Surgery Necessary?

    PubMed Central

    Mahmoudi, Sasan; Almony, Arghavan

    2016-01-01

    The status of the macula is a significant factor in determining final visual outcomes in rhegmatogenous retinal detachment (RRD) and should be considered in the timing of surgical repair. Several studies have shown that macula-involving RRDs attain similar visual and anatomic outcomes when surgery is performed within seven days as compared to emergent surgery (within 24 hours). In contrast, surgery prior to macular detachment in macula-sparing RRDs generally yields the best visual outcomes. In the case of macula-sparing RRDs, it is not clear how long the macula may remain attached, therefore, standard practice dictates emergent surgery. Timing of presentation, examination findings, case complexity, co-existing medical conditions, surgeon expertise, and timing and quality of access to operating facilities and staff, however, should all be considered in determining whether a macula-sparing RRD requires immediate intervention or if equivalent visual and possibly better overall outcomes can be achieved with scheduled surgery within an appropriate time frame. PMID:27195093

  12. Aniseikonia and Foveal Microstructure after Retinal Detachment Surgery.

    PubMed

    Okamoto, Fumiki; Sugiura, Yoshimi; Okamoto, Yoshifumi; Hiraoka, Takahiro; Oshika, Tetsuro

    2014-07-17

    Purpose:To quantify aniseikonia after successful surgical repair of rhegmatogenous retinal detachment (RD), and to investigate the relationship between the severity of postoperative aniseikonia and retinal microstructures as well as clinical parameters. Methods:The study included 106 eyes of 106 patients, without any history of ocular disease/surgery and less than 2 diopters of anisometropia, who had undergone successful retinal reattachment surgery. Aniseikonia was measured with New Aniseikonia Test and foveal microstructure was assessed with the spectral-domain optical coherence tomography at 6 months postoperatively. Results:Twenty-eight of 106 patients (26%) had micropsia, 17 patients (16%) had macropsia, and 61 patients (58%) had no aniseikonia. The mean absolute value of aniseikonia was 2.3 ± 2.9% (range; -12.5% - +12.0%). Of 57 eyes with macula-on RD, 3 had micropsia and 12 had macropsia. Of 49 eyes with macula-off RD, 25 had micropsia and 5 had macropsia. Eyes with micropsia mostly exhibited persistent or transient cystoid macular edema, subretinal fluid, hyperreflective or disruption of IS/OS line, while most of the eyes with macropsia presented epiretinal membrane. Stepwise multiple regression analysis revealed that postoperative best-corrected visual acuity and the area of RD were significantly relevant to the mean absolute value of aniseikonia. Conclusions:These results suggested that about half of patients with successful repair of RD had aniseikonia. Eyes with macula-off RD tended to show micropsia, while those with macula-on RD mostly presented macropsia. Micropsia and macropsia were primarily caused by respective specific abnormal structures at the foveal region.

  13. The Development of a Cat Model of Retinal Detachment and Re-attachment.

    PubMed

    Wassmer, Sarah; Leonard, Brian C; Coupland, Stuart G; Baker, Adam; Hamilton, John; Torlone, Renée; Zacks, David N; Tsilfidis, Catherine

    2016-01-01

    We present an optimized surgical technique for feline retinal detachment which allows for natural re-attachment, reduces retinal scarring and vitreal bands, and allows central placement of the detachment in close proximity to the optic nerve. This enables imaging via Optical Coherence Tomography (OCT) and multifocal electroretinography (mfERG) analysis. Ideal detachment conditions involve a lensectomy followed by a three-port pars plana vitrectomy. A 16-20 % retinal detachment is induced by injecting 8 % C3F8 gas into the subretinal space in the central retina with a 42G cannula. The retinal detachment resolves approximately 6 weeks post-surgery. Imaging is enhanced by using a 7.5 and 20 diopter lens for OCT and mfERG fundus imaging, respectively, to compensate for the removed lens.

  14. Massive Bilateral Serous Retinal Detachment in a Case of Hypertensive Chorioretinopathy

    PubMed Central

    Villalba-Pinto, Luis; Hernández-Ortega, M. Ángeles; de los Mozos, F. Javier Lavid; Pascual-Camps, Isabel; Dolz-Marco, Rosa; Arevalo, J. Fernando; Gallego-Pinazo, Roberto

    2014-01-01

    Introduction Systemic high blood pressure is related to a variety of retinal manifestations. We present an atypical case of hypertensive chorioretinopathy with massive bilateral serous retinal detachment. Case Report A 26-year-old male with a genitourinary malformation and secondary grade IV chronic kidney failure as well as high blood pressure complained of acute vision loss. Dilated fundus examination evidenced a bilateral serous retinal detachment with macular involvement. The patient was unresponsive to oral antihypertensive therapy and dialysis treatment. The serous retinal detachment progressively decreased after the restoration of dialysis and antihypertensive therapy. The final visual acuity was 0.50 in both eyes. Discussion In cases of serous macular detachment, it is mandatory to rule out different systemic and ocular diseases. The presence of uncontrolled high blood pressure may produce aggressive bilateral retinal changes, thus hypertension must be under early and strict control in order to improve the visual outcomes. PMID:25120474

  15. Fibulin 2, a Tyrosine O-Sulfated Protein, Is Up-regulated Following Retinal Detachment*

    PubMed Central

    Kanan, Yogita; Brobst, Daniel; Han, Zongchao; Naash, Muna I.; Al-Ubaidi, Muayyad R.

    2014-01-01

    Retinal detachment is the physical separation of the retina from the retinal pigment epithelium. It occurs during aging, trauma, or during a variety of retinal disorders such as age-related macular degeneration, diabetic retinopathy, retinopathy of prematurity, or as a complication following cataract surgery. This report investigates the role of fibulin 2, an extracellular component, in retinal detachment. A major mechanism for detachment resolution is enhancement of cellular adhesion between the retina and the retinal pigment epithelium and prevention of its cellular migration. This report shows that fibulin 2 is mainly present in the retinal pigment epithelium, Bruch membrane, choriocapillary, and to a lesser degree in the retina. In vitro studies revealed the presence of two isoforms for fibulin 2. The small isoform is located inside the cell, and the large isoform is present inside and outside the cells. Furthermore, fibulin 2 is post-translationally modified by tyrosine sulfation, and the sulfated isoform is present outside the cell, whereas the unsulfated pool is internally located. Interestingly, sulfated fibulin 2 significantly reduced the rate of cellular growth and migration. Finally, levels of fibulin 2 dramatically increased in the retinal pigment epithelium following retinal detachment, suggesting a direct role for fibulin 2 in the re-attachment of the retina to the retinal pigment epithelium. Understanding the role of fibulin 2 in enhancing retinal attachment is likely to help improve the current therapies or allow the development of new strategies for the treatment of this sight-threatening condition. PMID:24692557

  16. Mental health measures of anxiety and depression in patients with retinal detachment.

    PubMed

    Mozaffarieh, Maneli; Sacu, Stefan; Benesch, Thomas; Wedrich, Andreas

    2007-07-19

    In this study, the researchers examined anxious and depressive symptoms of patients with rhegmatogenous retinal detachment (RRD) prior to and up to year after retinal detachment surgery. One hundred and thirteen (113) patients with RRD took part in this prospective longitudinal study. Anxiety and depression were evaluated using the Hospital Anxiety and Depression Scale (HADS). Visual acuity (VA) results and HADS scores of all participants were recorded prior to and 3, 6 and 12 months after retinal detachment surgery. Pearson correlation analysis showed a significant association between the patients' VA and HADS psychological scores both prior to and three months after surgery, regardless of the type of surgery performed. Psychological distress is a significant problem associated with retinal detachments that requires more attention.

  17. [Rhegmatogenous retinal detachment in a patient with previous penetrating keratoplasty (clinical case)].

    PubMed

    Burcea, M; Muşat, O; Gheorghe, Andreea; Mahdi, Labib; Colta, Diana; Cernat, Corina; Mansour, Agajani

    2014-01-01

    We present the case of a 54 year old patient diagnosed with rhegmatogenous retinal detachment and perforating keratoplasty. Surgery is recommended and we performed posterior vitrectomy, endolaser, and internal heavy oil tamponade. The post-operative course was favorable.

  18. Visual Recovery after Primary Retinal Detachment Surgery: Biofeedback Rehabilitative Strategy

    PubMed Central

    Vingolo, Enzo M.; Fragiotta, Serena; Domanico, Daniela; Limoli, Paolo G.; Nebbioso, Marcella; Spadea, Leopoldo

    2016-01-01

    Purpose. To evaluate possible speeding up recovery time after retinal detachment (RD) surgery using biofeedback strategy. Methods. A total of 52 eyes were selected. After surgery, patients were divided into two groups: group A, including patients submitted to biofeedback with MP-1 strategy; group B, patients who received common care strategy. Biofeedback strategy was started 15 days after the suspension of cycloplegic eye drops in buckling procedure or after silicone oil removal in the vitrectomized eyes. Controls were scheduled at baseline and 6, 12, and 18 weeks. Results. At baseline, there was no significant difference in BCVA between groups (P = 0.4230). At the end of biofeedback treatment (WK 6) BCVA of group A was significantly better (P < 0.001) than group B and BCVA was still better in group A than group B at WK 12 (P = 0.028) and at WK 18 (P = 0.041). Conclusions. Visual recovery after RD surgery is still unclear, and it does not depend on entity of the RD. Our data demonstrate that in biofeedback group there was a significant recovery in visual performances that still remains evident after 3 months from the baseline. PMID:26998353

  19. Scleral Buckling for Rhegmatogenous Retinal Detachment Associated with Pars Planitis

    PubMed Central

    Ahn, Jae Kyoun

    2016-01-01

    Purpose. To evaluate the surgical outcome of scleral buckling (SB) in rhegmatogenous retinal detachment (RRD) patients associated with pars planitis. Methods. Retrospective review of RRD patients (32 eyes of pars planitis RRD and 180 eyes of primary RRD) who underwent SB. We compared primary and final anatomical success rates and visual outcomes between two groups. Results. Primary and final anatomical success were achieved in 25 (78.1%) and 31 (96.8%) eyes in the pars planitis RRD group and in 167 eyes (92.7%) and 176 eyes (97.7%) in primary RRD group, respectively. Both groups showed significant visual improvement (p < 0.001) and there were no significant differences in final visual acuity. Pars planitis RRD group was associated with higher rate of postoperative proliferative vitreoretinopathy (PVR) development (12.5% versus 2.8%, p = 0.031). Pars planitis and high myopia were significant preoperative risk factors and pseudophakia was borderline risk for primary anatomical failure after adjusting for various clinical factors. Conclusions. Pars planitis associated RRD showed inferior primary anatomical outcome after SB due to postoperative PVR development. However, final anatomical and visual outcomes were favorable. RRD cases associated with pars planitis, high myopia, and pseudophakia might benefit from different surgical approaches, such as combined vitrectomy and SB. PMID:27688907

  20. Anomalous posterior vitreous detachment: a unifying concept in vitreo-retinal disease.

    PubMed

    Sebag, J

    2004-08-01

    Posterior vitreous detachment (PVD) is the consequence of changes in the macromolecular structure of gel vitreous that result in liquefaction, concurrent with alterations in the extracellular matrix at the vitro-retinal interface that allow the posterior vitreous cortex to detach from the internal limiting lamina of the retina. Gel liquefaction that exceeds the degree of vitro-retinal dehiscence results in anomalous PVD (APVD). APVD varies in its clinical manifestations depending upon where in the fundus vitreo-retinal adhesion is strongest. At the periphery, APVD results in retinal tears and detachments. In the macula, APVD causes vitreo-macular traction syndrome, results in vitreoeschisis with macular pucker or macular holes, or contributes to some cases of diabetic macular edema. At the optic disc and retina, APVD causes vitreo-papillary traction and promotes retinal and optic disc neovascularization. Unifying the spectrum of vitreo-retinal diseases into the conceptual frame-work of APVD underscores that to more effectively treat, and ultimately prevent, these disorders it is necessary to replicate the two components of an innocuous PVD, i.e., gel liquefaction and vitreo-retinal dehiscence. Pharmacologic vitreolysis is designed to mitigate against APVD by chemically breaking down vitreous macromolecules and weakening vitro-retinal adhesion to safely detach the posterior vitreous cortex. This would not only facilitate surgery, but if performed early in the natural history of disease, it should prevent progressive disease.

  1. Scleral buckling with a noncontact wide-angle viewing system in the management of retinal detachment with undetected retinal break: a case report

    PubMed Central

    Kita, Mihori; Fujii, Yukiko; Kawagoe, Naoaki; Hama, Sachiyo

    2013-01-01

    A young patient who showed rhegmatogenous retinal detachment with preoperatively undetected retinal break was successfully treated by scleral buckling using a noncontact wide-angle viewing system. PMID:23569352

  2. Management of retinal detachment in block related globe perforation with pneumatic retinopexy.

    PubMed

    Rishi, Karandeep; Venkatesh, Pradeep; Garg, Satpal P

    2013-03-01

    Retinal detachment after ocular perforation related to local anesthesia is a common complication, which is usually associated with a poor prognosis despite complex vitreoretinal surgical procedures. We report a case of 62-year-old male with cataract surgery done 4 weeks back with nasal retinal detachment with a posterior break. Pneumatic retinopexy was performed and laser barrage of the breaks was done the next day when the retina got attached. A vision of 20/30 was achieved at the end of 2 months. To the best of our knowledge, this is a first case report in literature where pneumatic retinopexy was used to manage a retinal detachment caused by block-related perforation.

  3. Repair of retinal detachment associated with proliferative vitreoretinopathy using perfluoroperhydrophenanthrene (Vitreon). Vitreon Study Group.

    PubMed

    Carroll, B F; Peyman, G A; Mehta, N J; Millsap, C M; Greve, M D; Dunlap, W A; Lee, K J; Ma, P E

    1994-04-01

    A total of 140 consecutive patients underwent repair of retinal detachment associated with grade C2 to D3 proliferative vitreoretinopathy with perfluoroperhydrophenanthrene (Vitreon) as an intraoperative hydrokinetic tool. In seven patients the Vitreon was left in the eye for extended tamponade. Intraoperative reattachment was obtained in 98% of patients. At the final follow-up examination (mean 7 months) 84% of retinas remained attached, and 92% of patients had stable or improved visual acuity. Vitreon was found to be safe and effective in the repair of complicated retinal detachments. No complications were directly related to Vitreon when used intraoperatively or when left in the eye for extended tamponade.

  4. Recovery of visual acuity following the repair of pseudophakic retinal detachment.

    PubMed Central

    Isernhagen, R D; Wilkinson, C P

    1988-01-01

    Postoperative visual acuities were evaluated in a series of 100 pseudophakic eyes in which rhegmatogenous retinal detachments involved the macula and in which reattachment surgery was successful. Preoperative visual acuity and duration of macular detachment were directly and indirectly related to visual outcome, respectively. Eyes in which extracapsular surgery had been followed by posterior chamber lens implantation had significantly better postoperative visual acuities than cases in which older iris-fixation IOLs were placed following intracapsular procedures. PMID:2979019

  5. Macrophage- and RIP3-dependent inflammasome activation exacerbates retinal detachment-induced photoreceptor cell death

    PubMed Central

    Kataoka, K; Matsumoto, H; Kaneko, H; Notomi, S; Takeuchi, K; Sweigard, J H; Atik, A; Murakami, Y; Connor, K M; Terasaki, H; Miller, J W; Vavvas, D G

    2015-01-01

    Detachment of photoreceptors from the retinal pigment epithelium is seen in various retinal disorders, resulting in photoreceptor death and subsequent vision loss. Cell death results in the release of endogenous molecules that activate molecular platforms containing caspase-1, termed inflammasomes. Inflammasome activation in retinal diseases has been reported in some cases to be protective and in others to be detrimental, causing neuronal cell death. Moreover, the cellular source of inflammasomes in retinal disorders is not clear. Here, we demonstrate that patients with photoreceptor injury by retinal detachment (RD) have increased levels of cleaved IL-1β, an end product of inflammasome activation. In an animal model of RD, photoreceptor cell death led to activation of endogenous inflammasomes, and this activation was diminished by Rip3 deletion. The major source of Il1b expression was found to be infiltrating macrophages in the subretinal space, rather than dying photoreceptors. Inflammasome inhibition attenuated photoreceptor death after RD. Our data implicate the infiltrating macrophages as a source of damaging inflammasomes after photoreceptor detachment in a RIP3-dependent manner and suggest a novel therapeutic target for treatment of retinal diseases. PMID:25906154

  6. Identification of Potential Biomarkers for Rhegmatogenous Retinal Detachment Associated with Choroidal Detachment by Vitreous iTRAQ-Based Proteomic Profiling

    PubMed Central

    Wu, Zhifeng; Ding, Nannan; Yu, Mengxi; Wang, Ke; Luo, Shasha; Zou, Wenjun; Zhou, Ying; Yan, Biao; Jiang, Qin

    2016-01-01

    Rhegmatogenous retinal detachment associated with choroidal detachment (RRDCD) is a complicated and serious type of rhegmatogenous retinal detachment (RRD). In this study, we identified differentially expressed proteins in the vitreous humors of RRDCD and RRD using isobaric tags for relative and absolute quantitation (iTRAQ) combined with nano-liquid chromatography-electrospray ion trap-mass spectrometry-mass spectrometry (nano-LC-ESI-MS/MS) and bioinformatic analysis. Our result shows that 103 differentially expressed proteins, including 54 up-regulated and 49 down-regulated proteins were identified in RRDCD. Gene ontology (GO) analysis suggested that most of the differentially expressed proteins were extracellular.The Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis suggested that proteins related to complement and coagulation cascades were significantly enriched. iTRAQ-based proteomic profiling reveals that complement and coagulation cascades and inflammation may play important roles in the pathogenesis of RRDCD. This study may provide novel insights into the pathogenesis of RRDCD and offer potential opportunities for the diagnosis and treatment of RRDCD. PMID:27941623

  7. The Genetic Causes of Nonsyndromic Congenital Retinal Detachment: A Genetic and Phenotypic Study of Pakistani Families

    PubMed Central

    Keser, Vafa; Khan, Ayesha; Siddiqui, Sorath; Lopez, Irma; Ren, Huanan; Qamar, Raheel; Nadaf, Javad; Majewski, Jacek; Chen, Rui; Koenekoop, Robert K.

    2017-01-01

    Purpose To evaluate consanguineous pedigrees from Pakistan with a clinical diagnosis of nonsyndromic congenital retinal nonattachment (NCRNA) and identify genes responsible for the disease as currently only one NCRNA gene is known (atonal basic helix-loop-helix transcription factor 7: ATOH7). Methods We implemented a three-step genotyping platform: single nucleotide polymorphism genotyping to identify loss of heterozygosity regions in patients, Retinal Information Network panel screening for mutations in currently known retinal genes. Negative patients were then subjected to whole exome sequencing. Results We evaluated 21 consanguineous NCRNA pedigrees and identified the causal mutations in known retinal genes in 13 out of our 21 families. We found mutations in ATOH7 in three families. Surprisingly, we then found mutations in familial exudative vitreoretinopathy (FEVR) genes; low-density lipoprotein receptor-related protein 5 mutations (six families), tetraspanin 12 mutations (two families), and NDP mutations (two families). Thus, 62% of the patients were successfully genotyped in our study with seven novel and six previously reported mutations in known retinal genes. Conclusions Although the clinical diagnosis of all children was NCRNA with severe congenital fibrotic retinal detachments, the molecular diagnosis determined that the disease process was in fact a very severe form of FEVR in 10 families. Because severe congenital retinal detachment has not been previously associated with all the FEVR genes, we have thus expanded the phenotypic spectrum of FEVR, a highly variable retinal detachment phenotype that has clinical overlap with NCRNA. We identified seven novel mutations. We also established for the first time genetic overlap between the Iranian and Pakistani populations. We identified eight NCRNA families that do not harbor mutations in any known retinal genes, suggesting novel causal genes in these families. PMID:28192794

  8. Scleral buckling for retinal detachment in Ibadan, Sub-Saharan Africa: anatomical and visual outcome

    PubMed Central

    Oluleye, TS; Ibrahim, OA; Olusanya, BA

    2013-01-01

    Background Scleral buckle surgery is not a commonly performed surgical procedure in Sub-Saharan Africa due to a paucity of trained vitreo retinal surgeons. The aim of the study was to review sclera buckle procedures with a view to evaluating the anatomical and visual outcomes. Methods Case records of patients that had scleral buckle surgery at the Retina Unit of the University College Hospital, Ibadan, Nigeria, between 2007 and 2010 were reviewed. Information retrieved included patients’ demographics, duration of symptoms, and presenting vision. Other information included site of retinal break, extent of retinal detachment, involvement of the fellow eye, and macular involvement. Postoperative retina reattachment and postoperative visual acuity were also recorded. Proportions and percentages were used to analyze data. Results Forty five eyes of 42 patients were studied with a male to female ratio of 1.6:1. The mean age was 47.7 years (±17.6 years). The median duration before presentation was 3 months (range: 5 days – 156 months). Subtotal retinal detachment was found in 35 eyes (77.8%) while total retinal detachment occurred in ten eyes (22.2%). Thirty four eyes (75.6%) had “macular off ” detachments. At 6 weeks, there was an improvement in visual acuity in 23 eyes (51.1%), while visual acuity remained the same in nine eyes (20%) and was worse in 13 eyes (28.9%). Anatomical attachment was seen in 43 eyes (95.6%) on the operation table, in 40 eyes (90.9%) at first day postoperatively and in 32 eyes (86.5%) at 6 weeks after surgery. Conclusion Outcome of sclera buckle surgery for rhegmatogenous retinal detachment may be improved in developing countries of Sub Sahara Africa if adequate awareness is created to educate the populace on early presentation. PMID:23754869

  9. Treatment of retinal tears and lattice degenerations in fellow eyes in high risk patients suffering retinal detachment: a prospective study

    PubMed Central

    Mastropasqua, L.; Carpineto, P.; Ciancaglini, M.; Falconio, G.; Gallenga, P.

    1999-01-01

    BACKGROUND/AIMS—Fellow eye prophylaxis for retinal detachment (RD) is still a controversial issue since opinions are not unanimous regarding the kind of lesions to be treated or the method of treatment. This prospective clinical study aimed to follow the course of vitreoretinal conditions in 150 high risk fellow eyes.
METHODS—150 consecutive patients with unilateral rhegmatogenous RD were included in this study. Inclusion criteria were good explorability of fellow eye retinal periphery and one of the following conditions in the fellow eye—aphakia, pseudophakia with capsulotomy, high myopia (>−6D), contralateral eye to a giant retinal tear. Prophylactic treatment (photocoagulation or scleral buckling) was performed in the presence of retinal tears and lattice degenerations. The state of the vitreous body was determined at the beginning of the study and at the end, when RD occurred.
RESULTS—Follow up ranged from 36 to 132 months. 95 fellow eyes were subjected to laser treatment; five eyes underwent prophylactic surgical treatment. Initially, in the treated group posterior vitreous detachment (PVD) was present in 100 eyes (100% of cases), but as a complete PVD only in 42 of them (42%). 10 eyes in the treated group developed RD during the follow up period. In five of these cases the partial PVD had progressed and a retinal tear in a previously healthy area was the cause of the retinal detachment. In the other five eyes RD apparently developed from previously treated lesions. Progression of PVD was evident in four out of these five eyes. The untreated eyes had no visible degenerative lesions. During follow up eight eyes developed RD. These eyes had no PVD at the beginning of the study, but showed a partial PVD at the time of the diagnosis of RD.
CONCLUSION—Fellow eyes with pre-existing retinal tears and PVDs can go on to retinal detachment in spite of laser prophylactic treatment. When PVD is not detectable or a partial PVD is present, the

  10. Visual outcome after removal of silicone oil in patients undergoing retinectomy for complex retinal detachment

    PubMed Central

    Wong, Roger; De Luca, Marco; Shunmugam, Manoharan; Williamson, Tom; Laidlaw, Alistair; Vaccaro, Valeria

    2016-01-01

    AIM To evaluate the functional outcome after removal of silicone oil (ROSO) in patients undergoing retinectomy for complex retinal detachment. METHODS We performed a retrospective case note review of patients who underwent ROSO after retinectomy for complex retinal detachment. Patients with less than 6mo follow up and recurrent retinal detachment following ROSO were excluded. RESULTS Thirty-six patients were included. The mean best corrected visual acuity (BCVA) pre-ROSO was 1.13 logMAR (SD 0.5). The mean BCVA 3mo following ROSO was 1.16 logMAR (SD 0.53), 6mo following ROSO 1.13 (SD 0.63), and 12mo following ROSO 1.18 (SD 0.69). At 12mo after ROSO, the BCVA improved in 38.9% of patients, remained unchanged in 25%, and deteriorated in 36.1%, although there was no statistical significant difference in BCVA after ROSO at 3, 6 and 12mo (P=0.93). The size of retinectomy ranged from 15° to 270° (SD 53) and did not influence the visual outcome (P=0.11). CONCLUSION There was no statistically significanT difference in BCVA between pre- and post- ROSO following retinectomy for complex retinal detachment. There was no statistical difference in visual outcome related to the size of the retinectomy. PMID:26949619

  11. Long-term follow-up of patients after retinal detachment surgery.

    PubMed

    Coakes, R L; Ramsay, J H; Tarbuck, D T

    1978-04-01

    The value of long-term follow-up of patients after retinal detachment surgery depends on the number of further detachments prevented. This in turn depends on the frequency with which predisposing lesions are found and treated and also the risk of leaving them untreated. In a retrospective study of 128 patients who had attended the Retina Clinic at Moorfields, High Holborn, for at least 10 years, the frequency with which asymptomatic retinal breaks were detected was less than two per hundred patients per year of follow-up. The risk of such lesions progressing to detachment if left untreated is estimated to be no more than 12 per cent and on this basis it is likely that no more than four or five detachments were prevented in our series. During the same period 66 new or re-detachments occurred, in spite of regular examination and treatment of predisposing lesions found, and it is concluded that long-term follow-up is of doubtful value in the prevention of further detachments.

  12. Anatomical and functional outcomes of scleral buckling versus primary vitrectomy in pseudophakic retinal detachment

    PubMed Central

    Cankurtaran, Veysel; Citirik, Mehmet; Simsek, Mert; Tekin, Kemal; Teke, Mehmet Yasin

    2017-01-01

    Retinal detachment is the separation of the sensory retina from the retinal pigment epithelium by subretinal fluid. There are several types of retinal re-attachment surgery, including scleral buckling (SB), pneumatic retinopexy, and vitrectomy (with or without SB). The objective of this study was to compare anatomical and visual outcomes between patients with pseudophakic rhegmatogenous retinal detachment (RRD) who underwent pars plana vitrectomy (PPV) with silicone oil (SO) or perfluoropropane (C3F8) gas tamponade and pseudophakic RRD patients who underwent SB surgery. We evaluated retrospectively 101 pseudophakic RRD patients from a single center. The patients were classified into three groups according to the surgical procedure performed: PPV + Silicone - patients who underwent PPV with SO tamponade; PPV + Gas - patients who underwent PPV with perfluoropropane gas tamponade; and SB group - patients who underwent SB surgery. The groups were compared with regard to primary and final anatomical and visual outcomes. The number of patients in PPV + Silicone, PPV + Gas, and SB group was 39 (38.6%), 32 (31.7%), and 30 (29.7%), respectively. The mean follow-up period in PPV + Silicone, PPV + Gas, and SB group was 33.95 ± 23.58, 32.62 ± 10.95, and 33.76 ± 16.62 months, respectively. No significant difference was observed between the groups neither with regard to primary and final anatomical and visual success rates nor in relation to the recurrence rate of retinal detachment. According to our anatomical and visual outcome results, either of the three methods (i.e. PPV + Silicone, PPV + Gas, or SB) can be used in the treatment of pseudophakic retinal detachment. PMID:28135566

  13. Anatomical and functional outcomes of scleral buckling versus primary vitrectomy in pseudophakic retinal detachment.

    PubMed

    Cankurtaran, Veysel; Citirik, Mehmet; Simsek, Mert; Tekin, Kemal; Teke, Mehmet Yasin

    2017-02-21

    Retinal detachment is the separation of the sensory retina from the retinal pigment epithelium by subretinal fluid. There are several types of retinal re-attachment surgery, including scleral buckling (SB), pneumatic retinopexy, and vitrectomy (with or without SB). The objective of this study was to compare anatomical and visual outcomes between patients with pseudophakic rhegmatogenous retinal detachment (RRD) who underwent pars plana vitrectomy (PPV) with silicone oil (SO) or perfluoropropane (C3F8) gas tamponade and pseudophakic RRD patients who underwent SB surgery. We evaluated retrospectively 101 pseudophakic RRD patients from a single center. The patients were classified into three groups according to the surgical procedure performed: PPV + Silicone - patients who underwent PPV with SO tamponade; PPV + Gas - patients who underwent PPV with perfluoropropane gas tamponade; and SB group - patients who underwent SB surgery. The groups were compared with regard to primary and final anatomical and visual outcomes. The number of patients in PPV + Silicone, PPV + Gas, and SB group was 39 (38.6%), 32 (31.7%), and 30 (29.7%), respectively. The mean follow-up period in PPV + Silicone, PPV + Gas, and SB group was 33.95 ± 23.58, 32.62 ± 10.95, and 33.76 ± 16.62 months, respectively. No significant difference was observed between the groups neither with regard to primary and final anatomical and visual success rates nor in relation to the recurrence rate of retinal detachment. According to our anatomical and visual outcome results, either of the three methods (i.e., PPV + Silicone, PPV + Gas, or SB) can be used in the treatment of pseudophakic retinal detachment.

  14. Scleral buckling procedure with chandelier illumination for pediatric rhegmatogenous retinal detachment

    PubMed Central

    Yokoyama, Toshiyuki; Kanbayashi, Koki; Yamaguchi, Tamaki

    2015-01-01

    Purpose To assess the treatment of pediatric patients with rhegmatogenous retinal detachment (RRD) by scleral buckling with chandelier illumination. Methods Three eyes were treated in three patients, healthy boys aged 7 years, 12 years, and 11 years, with RRD, macular involvement, and small retinal holes, of which two were preoperatively undetectable. Conventional scleral buckling with cryoretinopexy was performed under the contact lens for vitreous surgery or noncontact wide-angle viewing system using 27-gauge twin chandelier illumination. Results The only known predisposing factor for retinal detachment was myopia stronger than 3 D with lattice retinal degeneration in two of the three patients. Retinal reattachment was achieved in all cases without intra- or postoperative complications. However, visual recovery was limited in one of the three patients. Conclusion Scleral buckling with chandelier illumination is effective for pediatric RRD, especially if the retinal hole is difficult to detect preoperatively. However, visual recovery was sometimes limited because of macular involvement due to late diagnosis, which is one of the characteristic features of pediatric RRD. PMID:25657577

  15. Early ultrasonographic diagnosis of retinal detachment: multidisciplinary approach and benefit.

    PubMed

    Cabric, Emir; Salihefendic, Nizama; Zildzic, Muharem; Licanin, Zoran; Smajlovic, Fahrudin

    2010-01-01

    Patients with eye problems are often present in family medicine and emergency wards, whether it is isolated disturbances of vision, or as part of other diseases. A large number of pathological entities of the eye require prompt and accurate diagnosis and appropriate therapy before they get to specialized ophthalmological institutions. Ultrasonography of the eye is a simple, non-invasive, painless method that can be done at the first contact with patients and can provide very important information for accurate diagnosis of pathological changes. Early detection of retinal ablation, intra ocular bleeding and tumors by this method can save sight and lives of patients. Sonography of the eye in 667 patients over two years revealed 27 retinal ablation and hemophthalmos in 36 patients. Every fifth patient with retinal ablation was referred by a doctor of family medicine. Knowing the possibilities of ultrasonography in ophthalmology, teamwork at the level of primary health care can open access to ultrasonography of the eye for other specialty physicians which can improve population health and provide a new quality in the prevention of vision loss.

  16. Progression to macula-off tractional retinal detachment after a contralateral intraoperative intravitreal bevacizumab injection for proliferative diabetic retinopathy.

    PubMed

    Zlotcavitch, Leonid; Flynn, Harry W; Avery, Robert L; Rachitskaya, Aleksandra

    2015-01-01

    We report a patient with progression to a macula-off tractional retinal detachment in a fellow eye after a contralateral intraoperative intravitreal bevacizumab injection. A 32-year-old diabetic man noted decreased vision in his left eye 1 week following 25 gauge pars plana vitrectomy, gas tamponade, and intraoperative injection of bevacizumab in his right eye. Left eye visual acuity decreased from 20/80 to 20/200, and macula-off tractional retinal detachment was seen on clinical exam and imaging. Progression of tractional retinal detachment associated with proliferative diabetic retinopathy in a fellow eye after a contralateral intraoperative intravitreal bevacizumab injection may occur.

  17. The changes of ocular axial length and corneal curvatures after scleral buckling for retinal detachment.

    PubMed

    Wang, H Z; Chen, M T; Chang, C H; Tsai, M C; Wu, W C; Chung, C B

    1994-02-01

    As myopia plays an important role in the pathogenesis of retinal detachment, alterations of refractive components after scleral buckling procedures for retinal detachment may be an important factor for retinal redetachment. To find out the refractive change following retinal detachment surgery, we prospectively followed up the alterations of corneal curvature, and axial components (axial length, anterior chamber depth, lens thickness, and vitreous length) of 44 eyes of rhegmatogenous retinal detachment before and after operations. The procedures consisted of encircling scleral buckling (12 eyes) and segmental scleral buckling (32 eyes). All patients were followed for 6 months postoperatively. The corneal curvatures were measured with a keratometer, the axial length and axial components were measured with an A-scan ultrasonography. The methods and materials used in operation were recorded in detail to correlate with the refractive changes. The corneal curvature showed a trend to flatten early after operation (the 1st week), and gradually reversed to steepening. But, the difference was statistically significant only at the K2 (vertical meridian) in the 1st postoperative week and the K1 (horizontal meridian) in the 4th postoperative week. Lengthening of eyeballs were noted in the encircling group (12 eyes), but only the elongation in the 1st postoperative week was statistically significant. While in segmental buckling group, the axial length of the eyeballs was transiently shortened. The shortening was significant in the 2nd, 4th, and 6th week after operation. The reduction of eyeball's axial length was related to the shortening of vitreous length and shallowing of anterior chamber.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Primary Repair of Moderate Severity Rhegmatogenous Retinal Detachment: A Critical Decision-Making Algorithm

    PubMed Central

    VELEZ-MONTOYA, Raul; JACOBO-OCEGUERA, Paola; FLORES-PRECIADO, Javier; DALMA-WEISZHAUSZ, Jose; GUERRERO-NARANJO, Jose; SALCEDO-VILLANUEVA, Guillermo; GARCIA-AGUIRRE, Gerardo; FROMOW-GUERRA, Jans; MORALES-CANTON, Virgilio

    2016-01-01

    We reviewed all the available data regarding the current management of non-complex rhegmatogenous retinal detachment and aimed to propose a new decision-making algorithm aimed to improve the single surgery success rate for mid-severity rhegmatogenous retinal detachment. An online review of the Pubmed database was performed. We searched for all available manuscripts about the anatomical and functional outcomes after the surgical management, by either scleral buckle or primary pars plana vitrectomy, of retinal detachment. The search was limited to articles published from January 1995 to December 2015. All articles obtained from the search were carefully screened and their references were manually reviewed for additional relevant data. Our search specifically focused on preoperative clinical data that were associated with the surgical outcomes. After categorizing the available data according to their level of evidence, with randomized-controlled clinical trials as the highest possible level of evidence, followed by retrospective studies, and retrospective case series as the lowest level of evidence, we proceeded to design a logical decision-making algorithm, enhanced by our experiences as retinal surgeons. A total of 7 randomized-controlled clinical trials, 19 retrospective studies, and 9 case series were considered. Additional articles were also included in order to support the observations further. Rhegmatogenous retinal detachment is a potentially blinding disorder. Its surgical management seems to depend more on a surgeon´s preference than solid scientific data or is based on a good clinical history and examination. The algorithms proposed herein strive to offer a more rational approach to improve both anatomical and functional outcomes after the first surgery. PMID:28289689

  19. [Perfluorodecalin as a hydrokinetic substance in complicated retinal detachment].

    PubMed

    Greber, H

    1991-01-01

    Perfluorodecalin is a clear colourless fluid with high specific gravity. It is immiscible with gas, blood, water, or any other fluid used in vitrectomy. The low viscosity permits easy injection and removal with microsurgical equipment. The high weight displaces subretinal fluid anteriorly through retinal breaks back into the vitreous space. Posterior retinotomies can be avoided. A large bubble of perfluorodecalin in the vitreous cavity stabilizes the retina mechanically during dissection and peeling of epiretinal membranes. Before the procedure is ended the fluid must be completely removed from the eye and replaced by BSS, air, gas, or silicon oil. We present the surgical technique and preliminary results.

  20. [Laser instrument surgery in preventing and treating retinal detachment (communication II)].

    PubMed

    Ivanov, A N

    2002-01-01

    The paper is devoted to the actual problem of ophthalmology--removal of cysts and retinal detachments caused by cystoid retinal lesions. 3 stages of treatment are identified: stage 1 used YAG-laser dissection of the external wall of the retinal cyst with drainage of its contents. Stage 2 involved extrascleral filling reinforced by argon coagulation of the zone of the emptied cyst or by endolaser coagulation. Laser intervention was performed by the laser combine "Visulas-YAG II" produced by the firm "Karl Zeiss" (Germany) and fitted up by endolaser output. Coagulation energy was 0.2-0.7 W, the power of YAG-laser was 0.1-5.7 mJ with impulses of 120. Almost in all of the cases laser action was realized during one session. The laser's action was associated with hemorrhage in 11 cases (57.9%), and within 1 year of observations 2 relapses were noted (10.5%). YAG perforation of the external wall of a retinal cyst brings on its drainage and evacuation that is a perspective factor in subsequent surgical interventions during operations for retinal detachment due to cystoid degeneration.

  1. Elastic stability of silicone ferrofluid internal tamponade (SFIT) in retinal detachment surgery

    NASA Astrophysics Data System (ADS)

    Voltairas, P. A.; Fotiadis, D. I.; Massalas, C. V.

    2001-01-01

    It has been argued that silicone ferrofluid internal tamponade (SFIT) can provide (360°) tamponade of the retina in retinal detachment surgery. Provided that the produced SFIT is biocompatible, exact knowledge is needed of its elastic stability in the magnetic field produced by the semi-solid magnetic silicon band (MSB) used as a scleral buckle. We propose a quantitative, phenomenological model to estimate the critical magnetic field produced by the MSB that 'closes' retinal tears and results in the reattachment of the retina. The magnetic 'deformation' of SFIT is modeled in accordance with the deformation of a ferrofluid droplet in an external magnetic field.

  2. Using surgical microscope for sclera buckling and transscleral cryopexy: an alternative procedure of treatment for rhegmatogenous retinal detachment.

    PubMed

    Zhong, Liu-xue-ying; Du, Yi; Liu, Wen; Huang, Su-Ying; Zhang, Shao-chong

    2014-01-01

    Purpose. To observe the long-term effectiveness of scleral buckling and transscleral cryopexy conducted under a surgical microscope in the treatment of uncomplicated rhegmatogenous retinal detachment. Methods. This was a retrospective analysis in a total of 227 consecutive patients (244 eyes) with uncomplicated rhegmatogenous retinal detachment (proliferative vitreoretinopathy ≤ C2). All patients underwent scleral buckling and transscleral cryopexy under a surgical microscope without using a binocular indirect ophthalmoscope or a contact lens. Results. After initial surgery, complete retinal reattachment was achieved in 226 eyes (92.6%), and retinal redetachment developed in 18 eyes (7.4%). The causes of retinal redetachment included presence of new breaks in eight eyes (44%), failure to completely seal the breaks in five eyes (28%), missed retinal breaks in four eyes (22%), and iatrogenic retinal breaks in one eye (6%). Scleral buckling surgery was performed again in 12 eyes (66%). Four eyes (22%) developed proliferative vitreoretinopathy and then were treated by vitrectomy. The sealing of retinal breaks and complete retinal reattachment were achieved in 241 eyes (98.8%). Conclusion. Probably because of clear visualization of retinal breaks and being controllable under a surgical microscope, the microsurgery of scleral buckling and transscleral cryopexy for uncomplicated retinal detachment exhibits advisable effectiveness.

  3. Using Surgical Microscope for Sclera Buckling and Transscleral Cryopexy: An Alternative Procedure of Treatment for Rhegmatogenous Retinal Detachment

    PubMed Central

    Zhong, Liu-xue-ying; Liu, Wen; Huang, Su-Ying; Zhang, Shao-chong

    2014-01-01

    Purpose. To observe the long-term effectiveness of scleral buckling and transscleral cryopexy conducted under a surgical microscope in the treatment of uncomplicated rhegmatogenous retinal detachment. Methods. This was a retrospective analysis in a total of 227 consecutive patients (244 eyes) with uncomplicated rhegmatogenous retinal detachment (proliferative vitreoretinopathy ≤ C2). All patients underwent scleral buckling and transscleral cryopexy under a surgical microscope without using a binocular indirect ophthalmoscope or a contact lens. Results. After initial surgery, complete retinal reattachment was achieved in 226 eyes (92.6%), and retinal redetachment developed in 18 eyes (7.4%). The causes of retinal redetachment included presence of new breaks in eight eyes (44%), failure to completely seal the breaks in five eyes (28%), missed retinal breaks in four eyes (22%), and iatrogenic retinal breaks in one eye (6%). Scleral buckling surgery was performed again in 12 eyes (66%). Four eyes (22%) developed proliferative vitreoretinopathy and then were treated by vitrectomy. The sealing of retinal breaks and complete retinal reattachment were achieved in 241 eyes (98.8%). Conclusion. Probably because of clear visualization of retinal breaks and being controllable under a surgical microscope, the microsurgery of scleral buckling and transscleral cryopexy for uncomplicated retinal detachment exhibits advisable effectiveness. PMID:24790997

  4. Correlation between miR-148 Expression in Vitreous and Severity of Rhegmatogenous Retinal Detachment

    PubMed Central

    Tsunekawa, Taichi; Hwang, Shiang-Jyi; Oishi, Akio; Nagasaka, Yosuke; Iwase, Takeshi; Nonobe, Norie; Ueno, Shinji; Ito, Yasuki; Yasuda, Shunsuke; Shimizu, Hideyuki; Suzumura, Ayana; Kataoka, Keiko; Terasaki, Hiroko

    2017-01-01

    Purpose. We had earlier reported positive hsa-miR-148a-3p expression in eyes with rhegmatogenous retinal detachment (RRD) and its involvement in the epithelial-mesenchymal transition of retinal pigment epithelium in vitro. Here we investigated the association of hsa-miR-148a-3p expression levels in the vitreous fluid of patients with RRD with severity of RRD. Methods. The hsa-miR-148a-3p expression levels in the vitreous fluid, range (degree) of retinal detachment (RD), and pixels of retinal break were measured in 27 eyes with RRD. The association of hsa-miR-148a-3p expression levels with other factors was evaluated by multiple regression analysis. Results. The hsa-miR-148a-3p expression levels, time from onset of RRD to vitrectomy, range of RD, and pixels of retinal breaks were 23.68 ± 43.00, 12.07 ± 15.36 days, 155.85 ± 86.67 degrees, and 37000 ± 67100 pixels, respectively. Five eyes with RRD had vitreous hemorrhage preoperatively. The hsa-miR-148a-3p expression levels were significantly associated with pixels of retinal breaks (β = 0.699) and the time from onset of RRD to vitrectomy (β = 0.358) but not with the range of RD or presence of vitreous hemorrhage. Conclusion. The hsa-miR-148a-3p expression levels in the vitreous fluid were significantly associated with the size of retinal break and disease duration. PMID:28261609

  5. Endoillumination (chandelier) assisted scleral buckling for a complex case of retinal detachment.

    PubMed

    Temkar, Shreyas; Takkar, Brijesh; Azad, Shorya Vardhan; Venkatesh, Pradeep

    2016-11-01

    Endoilluminator-assisted scleral buckling combines the advantages of scleral buckling for its external approach and pars plana vitrectomy for its better visual visualization in the management of retinal detachment (RD). It has recently been proven to be safe and efficacious in simple cases. This report discusses successful management of a complex case of RD in a patient with the single functioning eye, where vitrectomy was expected to have a complicated course.

  6. Endoillumination (chandelier) assisted scleral buckling for a complex case of retinal detachment

    PubMed Central

    Temkar, Shreyas; Takkar, Brijesh; Azad, Shorya Vardhan; Venkatesh, Pradeep

    2016-01-01

    Endoilluminator-assisted scleral buckling combines the advantages of scleral buckling for its external approach and pars plana vitrectomy for its better visual visualization in the management of retinal detachment (RD). It has recently been proven to be safe and efficacious in simple cases. This report discusses successful management of a complex case of RD in a patient with the single functioning eye, where vitrectomy was expected to have a complicated course. PMID:27958210

  7. Comparison of lesions predisposing to rhegmatogenous retinal detachment by race of subjects.

    PubMed

    Foos, R Y; Simons, K B; Wheeler, N C

    1983-11-01

    Because rhegmatogenous retinal detachments are thought to be much less common in blacks than in whites, we compared the incidence of various lesions known to cause or predispose to this condition (synchysis senilis, posterior vitreous detachment, breaks, tears, and holes of the peripheral fundus, and lattice degeneration of the retina) in a series of postmortem eyes on the basis of race. Our statistical analysis also included trauma, myopia, and chorioretinitis. The series included 322 black subjects and 2,012 white subjects. The subjects ranged in age from 20 to 93 years at the time of death. Although the initial data showed a racial difference in the incidence of synchysis senilis of grade 3 (50% destruction) or higher and posterior vitreous detachment (P = .033 and P = .021, respectively), we found no difference when the data were age-corrected.

  8. Rhegmatogenous retinal detachments associated to Stickler syndrome in a tertiary eye care center in Saudi Arabia

    PubMed Central

    Alshahrani, Saeed T; Ghazi, Nicola G; Al-Rashaed, Saba

    2016-01-01

    Purpose To investigate the clinical findings and outcomes of rhegmatogenous retinal detachment (RRD) in Stickler syndrome on affected and fellow eyes that underwent prophylactic retinopexy. Patients and methods Chart review of 70 eyes (62 patients). Incidence of RRD, postoperative visual acuity, and risk factors were evaluated. Results Twenty-two patients (35%) had RRD in the fellow eye, 37% of the eyes had cataract, 93% had macular detachment, 50% had proliferative vitreoretinopathy, and 41% had posterior vitreous detachment. Success rates were: 60% of patients after scleral buckling; 57.1% after pars plana vitrectomy; and 75% after combined scleral buckling and pars plana vitrectomy. Sixty-one (93.8%) of patients had successful surgery (including second surgery). Silicone oil tamponade was significantly associated with final anatomic outcome, with a protective odds ratio of 0.11 (P=0.027). Visual acuity improved in 54% of eyes and decreased in 5%. Statistically significant associations were present for eyes with final visual acuity ≥20/200, and total retinal detachment (P<0.001); preoperative cataract (P=0.023); and proliferative vitreoretinopathy (P<0.001). RRD developed in 16/44 eyes despite laser prophylaxis. Conclusion Prophylactic retinopexy was not beneficial for Stickler syndrome patients. Success of primary surgery for RRD remains low. The primary surgery should be vitrectomy combined with scleral buckling and silicone oil tamponade. PMID:26730175

  9. Posterior Vitreous Detachment With Microplasmin Alters the Retinal Penetration of Intravitreal Bevacizumab (Avastin) in Rabbit Eyes

    PubMed Central

    Goldenberg, David T.; Giblin, Frank J.; Cheng, Mei; Chintala, Shravan K.; Trese, Michael T.; Drenser, Kimberly A.; Ruby, Alan J.

    2010-01-01

    Purpose Intravitreal bevacizumab (Avastin) is frequently used for the treatment of age-related macular degeneration. Previous studies have demonstrated full thickness retinal penetration. Intravitreal recombinant microplasmin (MP) has been shown to successfully induce a posterior vitreous detachment (PVD) and vitreous liquefaction in animals. It has been suggested that a PVD may alter the retinal penetration of molecules in the vitreous cavity. The aim of this study was to compare bevacizumab (BV) retinal penetration in rabbit eyes with and without a MP-induced PVD. Methods Twelve adult rabbits were injected with 0.1 ml (0.4 mg) of MP into the vitreous cavity of one eye. One week later, the rabbits were injected with 0.05 ml (1.25 mg) of BV into both eyes. Both eyes of three rabbits each were harvested at 6, 12, 24, and 72 hours after the BV injection. Frozen retinal cross sections were prepared, and BV retinal penetration was evaluated with immunohistochemistry using a fluorescence-labeled antibody against BV. Two eyes from one rabbit were not injected with either agent and used as controls to compare the background autofluorescence. Peripapillary retinal sections were recorded with a digital camera, and intra-retinal BV fluorescence-labeled antibody was measured by qualitative photographic interpretation. Two additional rabbits received an intravitreal injection of 0.1 ml of MP in one eye. One week later, both eyes from each rabbit were enucleated and frozen retinal sections were prepared and analyzed with light microscopy to evaluate for histologic damage. Results Full thickness BV retinal penetration was observed throughout the retina in both eyes of each rabbit. All of the MP-injected eyes exhibited increased antibody labeling in retinas evaluated 6, 12, and 24 hours after BV injection when compared with the contralateral non-MP-injected eyes. By three days after BV injection, all eyes demonstrated decreased antibody labeling compared to earlier time periods

  10. Evaluation of Intravitreal Ranibizumab on the Surgical Outcome for Diabetic Retinopathy With Tractional Retinal Detachment

    PubMed Central

    Dong, Feng; Yu, Chenying; Ding, Haiyuan; Shen, Liping; Lou, Dinghua

    2016-01-01

    Abstract This study aims to investigate intravitreal injection of Ranibizumab on the surgical outcome for diabetic patients who had tractional retinal detachment but did not receive any preoperative retinal photocoagulation. Ninety-seven patients (97 eyes) who had diabetic retinopathy with tractional retinal detachment were enrolled to receive 23-G pars plana vitrectomy (PPV). They were assigned to an experimental group (Group I, n = 47 eyes) and a control group (Group II, n = 50 eyes). The patients in Group I were given 1 injection of intravitreal Ranibizumab (Lucentis 0.5 mg/0.05 mL) 1 week before surgery, whereas those in Group II went down to surgery directly. Follow-ups were performed for 6 months to 3 years (16 ± 6 months), and indicators observed included postoperative best-corrected visual acuity, complications, and retinal thickness in the macula measured by optical coherence tomography. In Group I, BCVA improved from logMAR 1.92 ± 0.49 to logMAR 0.81 ± 0.39 following surgery, whereas in Group II, BCVA improved from logMAR 1.91 ± 0.49 to logMAR 0.85 ± 0.41. There was significant postoperative gain in vision, but there was no significant difference between the 2 groups at postoperative follow-up visits. The mean duration of vitrectomy in Group I and Group II was (40 ± 7) minutes and (53 ± 9) minutes, respectively, with significant difference. Iatrogenic breaks were noted in 5 eyes (11%) in the experimental group and 17 eyes (34%) in the control group; the difference was significant. The retinal thickness in the macula measured by OCT was (256 ± 44) μm and (299 ± 84) μm in Group I and Group II respectively with significant difference. Besides, there were significantly more eyes in Group II that required silicone oil tamponade and postoperative retinal photocoagulation. 23-G PPV combined with intravitreal tamponade and panretinal photocoagulation still remains an effective regimen for the

  11. The pathogenesis of retinal detachment with morning glory disc and optic pit.

    PubMed

    Irvine, A R; Crawford, J B; Sullivan, J H

    1986-01-01

    A child with nonrhegmatogenous retinal detachment associated with morning glory disc underwent first a vitrectomy and then, some months later, an optic nerve sheath fenestration. The latter procedure led to retinal reattachment. It also produced a biopsy specimen that confirmed the perineural herniation of poorly differentiated retinal tissue in this condition, similar to that in congenital pit of the optic nerve. It demonstrated continuity of the vitreous cavity with the perineural space, both histologically and by the fact that gas injected through the pars plana into the vitreous cavity bubbled out the window in the optic nerve sheath. The authors suggest that morning glory disc and optic pit share similar anatomic features, differing more in degree than in kind, and that the porous nature of the poorly differentiated tissue herniated around the optic nerve into the subarachnoid space in these conditions makes several sources of subretinal fluid possible.

  12. Reassessment of pneumatic retinopexy for primary treatment of rhegmatogenous retinal detachment

    PubMed Central

    Cohen, Eyal; Zerach, Amir; Mimouni, Michael; Barak, Adiel

    2015-01-01

    Background Pneumatic retinopexy (PR) remains a popular technique for the treatment of rhegmatogenous retinal detachment (RRD). Objective To evaluate the single operation and final success rate of PR for primary treatment of RRD and to determine factors associated with anatomical and visual outcomes. Methods This retrospective case review study analyzed the data of patients who underwent PR for primary treatment of RRD. Patients with a follow-up period of <2 months were excluded. Single operation success was defined as successful retinal reattachment following a single PR throughout 2 months of follow-up. Results Eighty-four eyes met the inclusion criteria. Single operation success was achieved in 50 eyes (59.5%), while 82 obtained anatomical success at the final follow-up visit (97.6%). An average of 0.702±1.095 additional retinal detachment operations was necessary to achieve final anatomical success in the entire cohort (n=84) and 1.4±1.3 in the single operation failure group (n=34). Both groups (single operation success vs failure) did not differ significantly in any of the preoperative variables. Multivariate analysis of pseudophakic patients (n=22) revealed that 52.65% of the variation in single operation outcome was explained by the number of clock-hours detached (partial R2=43.76%, P=0.001). The final best-corrected visual acuity was significantly better in the single operation success group (logarithm of minimum angle [logMAR] 0.229±0.249 vs logMAR 0.747±0.567, P<0.001). Conclusion Careful patient selection is warranted before performing PR in RRD, particularly in pseudophakic patients with large detachments. Ultimately 60% of the cases will attach after the procedure with the rest requiring on average 1.4 additional procedures to achieve final anatomical success. PMID:26586932

  13. Surgical audit of outcome of rhegmatogenous retinal detachment repair at Vitreoretinal unit JPMC in year 2014

    PubMed Central

    Tareen, Saifullah; Tahir, Muhammad Ali; Cheema, Alyscia Miriam

    2016-01-01

    Objective: To investigate the outcome of rhegmatogenous retinal detachment repair at Vitreoretinal unit of Jinnah Post Graduate Medical Centre Karachi in year 2014. Methods: One hundred and three eyes of one hundred and three patients, who underwent three ports parsplana vitrectomy + band + silicone oil, three ports pars plana vitrectomy + silicone oil, three ports pars plana vitrectomy + C3F8 for rhegmatogenous retinal detachment (RRD) repair, at Jinnah Post Graduate Medical Centre, were included in this observational prospective study. Parsplana vitrectomy was done using 23G vitrectomy system. Duration of study was one year. Removal of silicone oil (ROSO) was done on the basis of completely flat retina at least for eight weeks or because of complications due to silicone oil. Patients were followed up post operatively on day one and after one week and then at four weekly interval till the end of the study. Results: Anatomical success was achieved in 91 eyes (88.3%). However in 12 eyes (11.7%) retina redetached after removal of silicone oil. Functional success achievement of visual acuity of 3/60 or better was achieved in 85 (82.5%) of eyes post operatively after removal of silicone oil or absorption of gas C3F8 as the case may be. Conclusion: Re-detachment is common after removal of silicone oil and incidence of re-detachment is related to the degree of preoperative PVR and location of breaks. Re-detachment occurs more commonly if the breaks are inferiorly located as compared to the superior ones. PMID:27022354

  14. Hypoxia inducible factor 1α contributes to regulation of autophagy in retinal detachment.

    PubMed

    Shelby, Shameka J; Angadi, Pavan S; Zheng, Qiong-Duon; Yao, Jingyu; Jia, Lin; Zacks, David N

    2015-08-01

    Photoreceptor (PR) cells receive oxygen and nutritional support from the underlying retinal pigment epithelium (RPE). Retinal detachment results in PR hypoxia and their time-dependent death. Detachment also activates autophagy within the PR, which serves to reduce the rate of PR apoptosis. In this study, we test the hypothesis that autophagy activation in the PR results, at least in part, from the detachment-induced activation of hypoxia-inducible factors (HIF). Retina-RPE separation was created in Brown-Norway rats and C57BL/6J mice by injection of 1% hyaluronic acid into the subretinal space. Retinas were harvested and assayed for HIF protein levels. Cultured 661W photoreceptor cells were subjected to hypoxic conditions and assayed for induction of HIF and autophagy. The requirement of HIF-1α and HIF-2α in regulating photoreceptor autophagy was tested using siRNA in vitro and in vivo. We observed increased levels of HIF-1α and HIF-2α within 1 day post-detachment, as well as increased levels of BNIP3, a downstream target of HIF-1α that contributes to autophagy activation. Exposing 661W cells to hypoxia resulted in increased HIF-1α and HIF-2α levels and increase in conversion of LC3-I to LC3-II. Silencing of HIF-1α, but not HIF-2α, reduced the hypoxia-induced increase in LC3-II formation and increased cell death in 661W cells. Silencing of HIF-1α in rat retinas prevented the detachment-induced increase in BNIP3 and LC3-II, resulting in increased PR cell death. Our data support the hypothesis that HIF-1α, but not HIF-2α, serves as an early response signal to induce autophagy and reduce photoreceptor cell death.

  15. The Safety and Efficacy of Adjustable Postoperative Position after Pars Plana Vitrectomy for Rhegmatogenous Retinal Detachment

    PubMed Central

    Lin, Zhong; Sun, Jin Tao; Moonasar, Nived; Zhou, Ye Hui

    2017-01-01

    Purpose. To report the safety and efficacy of adjustable postoperative position for rhegmatogenous retinal detachment (RRD). Methods. Retrospective review of 536 consecutive RRD eyes that underwent vitrectomy surgery for retina repair from year 2008 to 2014. The retinal breaks were divided into superior, lateral (nasal, temporal, and macular), and inferior locations, according to the clock of breaks. Patients with superior and lateral break location were allowed to have facedown position or lateral decubitus position postoperatively, while patients with inferior break location were allowed to have facedown position. Results. 403 eyes of 400 patients were included. The mean follow-up interval was 22.7 ± 21.3 months. The overall primary retinal reattachment rate was 93.3%. There were 24 (6.0%), 273 (67.7%), and 106 (26.3%) patients with superior, lateral, and inferior break location, respectively. The primary reattachment rate was 95.8%, 92.3%, and 95.3% accordingly. After further divided the break location into subgroups as a function of duration of symptom, postoperative lens situation, number of retinal breaks, and different vitreous tamponade, the primary reattachment rates were all higher than 82%. Conclusion. Adjustable postoperative positioning is effective and safe for RRD repair with different break locations. Choosing postoperative position appropriately according to retinal break locations could be recommended.

  16. Corneal Complications During and After Vitrectomy for Retinal Detachment in Photorefractive Keratectomy Treated Eyes

    PubMed Central

    Tosi, Gian Marco; Baiocchi, Stefano; Balestrazzi, Angelo; Martone, Gianluca; Marigliani, Davide; Neri, Giovanni; Caporossi, Tomaso

    2015-01-01

    Abstract To evaluate the occurrence of late-onset corneal haze (LOCH) after vitrectomy for rhegmatogenous retinal detachment (RRD) in photorefractive keratectomy (PRK)-treated eyes. This observational cohort study comprised 13 eyes of 13 patients who underwent vitrectomy for RRD and who had been subjected to PRK years earlier. The occurrence of LOCH was evaluated together with all the preoperative, intraoperative, and postoperative factors that could affect final corneal status. LOCH developed in 2 eyes. Both patients had undergone PRK for high myopia—one 3 years and the other 9 years prior to RRD. Both patients presented with RRD due to giant retinal tear and were subjected to scleral buckle, 20-gauge vitrectomy, and silicone oil tamponade. Three months after vitrectomy and 1 month after silicone oil removal they both developed LOCH. During vitreoretinal surgery neither of the 2 patients needed mechanical epithelial debridement. Intraoperative epithelial debridement was performed in 2 of the other patients of the series, who had undergone previous PRK for high myopia and had clear corneas at presentation; in 1 of them this manoeuvre hampered intraoperative visualization. Follow-up after retinal detachment surgery ranged from 6 to 156 months (mean, 37.5 months). Subepithelial corneal scarring may be reactivated many years after PRK. In our series this happened after vitrectomy. PMID:26683931

  17. Drainage of subretinal fluidduring scleral buckling surgery for rhegmatogenous retinal detachment

    PubMed Central

    MALAGOLA, R.; PANNARALE, L.; TORTORELLA, P.; ARRICO, L.

    2015-01-01

    Background and objective The purpose of the study is to compare the drainage of subretinal fluid (SRF) in a scleral pocket (SP) with incision parallel to the limbus to drainage through a simple radial scleral thinning (ST), during scleral buckling surgery for rhegmatogenous retinal detachment (RRD). Patients and methods Retrospective cohort study of one hundred sixty-nine consecutive buckling surgery for RRD, where a drainage puncture was performed through SP in eighty-five cases and through previous radial ST in eighty-four cases. Results PT shows significant lower complication rate. The incidence of retinal incarceration or formation of a retinal hole at the first drainage site is lower in PT group (p=0.0285). During surgery choroidal detachment have been observed in a higher percentage of cases in the SP group (p=0.0379). At the end of the surgery a certain amount of SRF behind the buckling was significant in ST group (p=0.0026). Conclusion The SP drainage technique appears to be a useful, effective and safe method to drain SRF. PMID:26188754

  18. Risk factors influencing the outcome of strabismus surgery following retinal detachment surgery with scleral buckle

    PubMed Central

    Rabinowitz, Ronen; Velez, Federico G.; Pineles, Stacy L.

    2013-01-01

    Purpose To determine factors associated with surgical success in patients undergoing strabismus surgery after retinal detachment repair with scleral buckle. Methods The medical records of consecutive patients who underwent strabismus surgery after repair of retinal detachment with scleral buckle were retrospectively reviewed. A successful “motor” outcome was defined as horizontal deviation <10Δ and vertical deviation <4Δ in the primary position; successful “sensory” outcome was no diplopia in the primary position. Various factors such as removing the scleral buckle at the time of strabismus surgery, the macula structural status, size of the preoperative deviation, presence of restriction to passive movement, and whether the eye with the scleral buckle was the operated eye were compared among groups based on motor success. Results A total of 25 patients were included. The overall motor success rate was 72% after 1.8 ± 0.9 operations, with 62% of patients diplopia free in the primary position. Horizontal deviation <10Δ (P = 0.005) and minimal restriction on forced duction test were associated with motor success after the first surgery (P = 0.05). Partial or entire scleral buckle removal (n = 15) and fellow-eye surgery were not significantly correlated with motor success in our cohort. There were no retinal redetachments after scleral buckle removal. Conclusions A small preoperative horizontal deviation, and minimally restricted ocular rotations were associated with better results. Removing the scleral buckle did not improve results. PMID:24215808

  19. Perfluorocarbon-perfused 23 gauge three-dimensional vitrectomy for complicated diabetic tractional retinal detachment

    PubMed Central

    Velez-Montoya, Raul; Guerrero-Naranjo, Jose Luis; Garcia-Aguirre, Gerardo; Morales-Cantón, Virgilio; Fromow-Guerra, Jans; Quiroz-Mercado, Hugo

    2011-01-01

    Background Perfluorocarbon liquid (PCL)-perfused vitrectomy has been shown in previous studies to be feasible, safe, and to have advantages in managing complicated cases of tractional retinal detachment. The present study had the objectives of describing the anatomical results and measuring surgical time and PCL consumption when combining PCL-perfused techniques with modern vitrectomy equipment. Methods A prospective, interventional consecutive case series was investigated. We enrolled patients with diabetic tractional retinal detachment, complicated by proliferative vitreoretinopathy and poor vision. A 23 gauge PCL-perfused vitrectomy was done with three-dimensional settings. During the procedure, we assessed the degree of surgical bleeding, visualization quality, and difficulty of membrane dissections. Visual acuity, intraocular pressure, and anatomical success were assessed at one and 3 months of follow-up. Results Twelve patients were enrolled in this study. There were no statistical significant changes in intraocular pressure and visual acuity throughout the follow-up period. Surgery was performed in a hemorrhage-free environment in almost all cases, with good visualization and low technical difficulty. The mean complete surgical time was 94.92 ± 25.03 minutes. The mean effective vitrectomy time was 22.50 ± 19.04 minutes and the mean PCL consumption was 25.08 ± 9.76 mL, with a speed of 1.11 mL/minute. Anatomical success was 67% at 3 months. Conclusion Although the technique proved to have some advantages in managing complicated cases of diabetic tractional retinal detachment, there was a high consumption of PCL. A redesign of the entire system is needed in order to decrease the amount of PCL needed for the technique. PMID:22267907

  20. Use of Internal Limiting Membrane Autograft in Primary Vitrectomy for Rhegmatogenous Retinal Detachment

    PubMed Central

    Hernández-Da Mota, Sergio Eustolio; Béjar-Cornejo, Jorge Francisco

    2016-01-01

    During a pars plana vitrectomy, an unplanned retinotomy in the raphe was performed in a 55-year-old female patient with rhegmatogenous retinal detachment and proliferative vitreoretinopathy. Since diathermy and laser therapy were not available at that moment, it was decided to peel off a small graft of the internal limiting membrane adjacent to the retinotomy site which had been previously stained with Brilliant Blue G. The graft was displaced under perfluorocarbon fluids and placed inside the retinotomy. Three weeks after surgery, the apparent closure of the retinotomy was observed clinically. PMID:28101042

  1. Expression Profiling after Retinal Detachment and Reattachment: A Possible Role for Aquaporin-0

    PubMed Central

    Farjo, Rafal; Peterson, Ward M.; Naash, Muna I.

    2009-01-01

    Purpose Retinal detachment (RD) is associated with acute visual loss caused by anatomic displacement of the photoreceptors and with chronic visual loss/disturbance caused by retinal remodeling and photoreceptor cell death, which may occur even after successful reattachment. The P2Y2 receptor agonist INS37217 improves the rate of retinal reattachment in animal models of induced RD, and has been shown to also significantly enhance the rate of ERG recovery in a mouse model of RD. The identification of genes modulated by INS37217 may allow further drug discovery for treating RD and edema. Methods To identify genes involved in RD and subsequent reattachment, a retinal microarray screen was performed using a mouse model of RD in the presence or absence of INS37217. Results Ninety-two genes were identified as differentially expressed across three time points, most of which were upregulated in the presence of this agonist. Furthermore, it was shown that RD alters the expression of aquaporin-0 (AQP-0), and this modulation is prevented by treatment with INS37217. The presence of AQP-0 in retinal bipolar cells was also demonstrated, whereas it was previously thought to be specific to the lens. Mice lacking functional alleles of AQP-0 had a photo-transduction deficit as assessed by electroretinography; however, their photoreceptor structure was normal, indicative of a problem with signal transmission between neurons. Conclusions This study establishes the genes involved in RD and reattachment, and also demonstrates for the first time a physiologically significant role for AQP-0 in retinal function. PMID:18234993

  2. Biocompatibility of a Synthetic Biopolymer for the Treatment of Rhegmatogenous Retinal Detachment

    PubMed Central

    Sarfare, Shanta; Dacquay, Yann; Askari, Syed; Nusinowitz, Steven; Hubschman, Jean-Pierre

    2015-01-01

    Objective The aim of this study is to evaluate the retinal safety and toxicity of a novel synthetic biopolymer to be used as a patch to treat rhegmatogenous retinal detachment. Methods Thirty one adult wild type albino mice were divided in 2 groups. In Group A (n=9) 0.2 μl balanced salt solution (BSS) and in Group B (n=22), 0.2 μl biopolymer was injected in the subretinal space. Trans-scleral subretinal injection was performed in one eye and the fellow eye was used as control. In both groups, in vivo color fundus photography, electroretinogram (ERG), spectral domain optical coherence tomography (SD-OCT) were performed before injection and at days 7 and 14 post-intervention. Histological analysis was performed following euthanization at days 1, 7 and 21 post-injection. Results The biopolymer was visualized in the subretinal space in vivo by SD-OCT and post-life by histology up to 1 week after the injection. There were no significant differences in ERG parameters between the two groups at 1 and 2 weeks post-injection. Minimal inflammatory response and loss of photoreceptor cells was only observed in the immediate proximity of the site of scleral perforation, which was similar in both groups. Overall integrity of the outer, inner retina and retinal pigment epithelial (RPE) layers was unaffected by the presence of the biopolymer in the subretinal space. Conclusions Functional and histological evaluation suggests that the synthetic biopolymer is non-inflammatory and non-toxic to the eye. It may represent a safe therapeutic agent in the future, for the treatment of rhegmatogenous retinal detachment. PMID:26744635

  3. [C3F8 in the treatment of retinal detachment associated with vitreoretinal proliferation].

    PubMed

    Fleury, J; Bonnet, M

    1989-01-01

    The perfluoropropane gas was used as an adjunct to vitreoretinal microsurgery in 60 eyes of 60 patients with rhegmatogenous retinal detachment complicated by proliferative vitreoretinopathy. 0.3 ml to 1.8 ml (average 0.9 ml) of pure perfluoropropane gas was used. The surgical procedure included vitrectomy and scleral buckling in all patients. The follow-up after complete gas absorption ranged from 6 months to 3 years in the successful eyes. Total retinal reattachment was achieved in 41 eyes (68.3%). The anatomical success rate was 88% (22/25 eyes) in grade C1-C2 PVR cases, 68.7% (11/15 eyes) in grade C3-D1 PVR cases, and 42% (8/19 eyes) in grade D2-D3 PVR cases. Visual acuity of 0.1 or better was achieved in 80% of eyes with grade C PVR and 61% of eyes with grade D PVR. Visual acuity of 0.4 or better was achieved in 26.9% of eyes with grade C PVR. Macular changes were revealed by fluorescein angiography in 53% of successful eyes. We recommend the use of C3F8 rather than SF6 in the management of rhegmatogenous retinal detachment complicated by PVR. In our experience the anatomical success rate achieved with C3F8 is approximately the same as that achieved with SF6. However permanent retinal reattachment was achieved with a single operation in 87.8% of successful eyes of the present series of patients managed with C3F8 as compared to only 12% of successful eyes of a previous series of patients managed with SF6. The anatomical results achieved with a single operation in the C3F8 series are probably related to the greater longevity of C3F8 as compared to that of SF6.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Retinal detachment

    MedlinePlus

    ... gas bubble in the eye. This is called pneumatic retinopexy. It helps the retina float back into ... requires medical attention within 24 hours of the first symptoms of new flashes of light and floaters. ...

  5. Surgical Management of a Patient with Anterior Megalophthalmos, Lens Subluxation, and a High Risk of Retinal Detachment

    PubMed Central

    Guixeres Esteve, María Carmen; Pardo Saiz, Augusto Octavio; Martínez-Costa, Lucía; González-Ocampo Dorta, Samuel; Sanz Solana, Pedro

    2017-01-01

    The early development of lens opacities and lens subluxation are the most common causes of vision loss in patients with anterior megalophthalmos (AM). Cataract surgery in such patients is challenging, however, because of anatomical abnormalities. Intraocular lens dislocation is the most common postoperative complication. Patients with AM also seem to be affected by a type of vitreoretinopathy that predisposes them to retinal detachment. We here present the case of a 36-year-old man with bilateral AM misdiagnosed as simple megalocornea. He had a history of amaurosis in the right eye due to retinal detachment. He presented with vision loss in the left eye due to lens subluxation. Following the removal of the subluxated lens, it was deemed necessary to perform a vitrectomy in order to prevent retinal detachment. Seven months after surgery, an Artisan® Aphakia iris-claw lens was implanted in the anterior chamber. Fifteen months of follow-up data are provided. PMID:28203198

  6. Choroidal Vasculopathy and Retinal Detachment in a Bald Eagle ( Haliaeetus leucocephalus ) With Lead Toxicosis.

    PubMed

    Eid, Ramzi; Guzman, David Sanchez-Migallon; Keller, Krista A; Wiggans, K Tomo; Murphy, Christopher J; LaDouceur, Elise E B; Keel, M Kevin; Reilly, Christopher M

    2016-12-01

    A subadult male bald eagle ( Haliaeetus leucocephalus ) was presented for severe depression and weakness. Physical examination findings included depressed mentation, dehydration, sternal recumbency, poor body condition, and bilateral, whole-head, horizontal nystagmus. A heavy-metal panel was performed, and blood lead levels were 6.1 ppm. Treatment for lead poisoning was initiated, including subcutaneous fluids and parenteral calcium-disodium ethylenediaminetetraacetic acid, ceftiofur, and meloxicam. Ophthalmic examination findings included absent menace response, absent dazzle reflex, slow and incomplete direct pupillary light reflex, mild anterior uveitis, incipient cataracts, multifocal retinal tears, and retinal separation in both eyes. Because of poor prognosis for vision and release to the wild, the eagle was euthanatized. No lesions were observed on gross postmortem examination. Histologically, extensive myocardial necrosis and multisystemic arteriolar vasculopathy were identified. The eyes were examined after tissue processing, and the vasculopathy extended into the choriocapillaris and was associated with a secondary, bilateral, exudative, retinal detachment. This is the first report in avian species characterizing the histopathologic ocular lesions of lead poisoning.

  7. Anatomical and Gene Expression Changes in the Retinal Pigmented Epithelium Atrophy 1 (rpea1) Mouse: A Potential Model of Serous Retinal Detachment

    PubMed Central

    Luna, Gabriel; Lewis, Geoffrey P.; Linberg, Kenneth A.; Chang, Bo; Hu, Quiri; Munson, Peter J.; Maminishkis, Arvydas; Miller, Sheldon S.; Fisher, Steven K.

    2016-01-01

    Purpose The purpose of this study was to examine the rpea1 mouse whose retina spontaneously detaches from the underlying RPE as a potential model for studying the cellular effects of serous retinal detachment (SRD). Methods Optical coherence tomography (OCT) was performed immediately prior to euthanasia; retinal tissue was subsequently prepared for Western blotting, microarray analysis, immunocytochemistry, and light and electron microscopy (LM, EM). Results By postnatal day (P) 30, OCT, LM, and EM revealed the presence of small shallow detachments that increased in number and size over time. By P60 in regions of detachment, there was a dramatic loss of PNA binding around cones in the interphotoreceptor matrix and a concomitant increase in labeling of the outer nuclear layer and rod synaptic terminals. Retinal pigment epithelium wholemounts revealed a patchy loss in immunolabeling for both ezrin and aquaporin 1. Anti-ezrin labeling was lost from small regions of the RPE apical surface underlying detachments at P30. Labeling for tight-junction proteins provided a regular array of profiles outlining the periphery of RPE cells in wild-type tissue, however, this pattern was disrupted in the mutant as early as P30. Microarray analysis revealed a broad range of changes in genes involved in metabolism, signaling, cell polarity, and tight-junction organization. Conclusions These data indicate changes in this mutant mouse that may provide clues to the underlying mechanisms of SRD in humans. Importantly, these changes include the production of multiple spontaneous detachments without the presence of a retinal tear or significant degeneration of outer segments, changes in the expression of proteins involved in adhesion and fluid transport, and a disrupted organization of RPE tight junctions that may contribute to the formation of focal detachments. PMID:27603725

  8. Retinal detachment in hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome: Color vision abnormality as the first and predominant manifestation.

    PubMed

    Morisawa, Hiroyuki; Makino, Shinji; Takahashi, Hironori; Sorita, Mari; Matsubara, Shigeki

    2015-11-01

    Serous retinal detachment is sometimes caused by hypertensive disorders in pregnancy and its associated conditions, in which the predominant eye symptoms are blurred vision, distorted vision, and reduced visual acuity. To our best knowledge, this is the first report of a puerperal woman with hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome in whom color vision abnormality was the first and predominant manifestation of serous retinal detachment. At 32 weeks of gestation, the 34-year-old Japanese woman underwent cesarean section due to HELLP syndrome. She complained of color vision abnormality on day 1 post-partum and ophthalmological examination revealed serous retinal detachment of both eyes. The visual acuity was preserved. With supportive therapy, her color vision abnormality gradually ameliorated and retinal detachment completely resolved on day 34 post-partum without any sequelae. Obstetricians should be aware that color vision abnormality can be the first and predominant symptom of HELLP-related serous retinal detachment.

  9. Inhibition of retinal detachment-induced apoptosis in photoreceptors by a small peptide inhibitor of the fas receptor.

    PubMed

    Besirli, Cagri G; Chinskey, Nicholas D; Zheng, Qiong-Duan; Zacks, David N

    2010-04-01

    Purpose. To test the effect of a small peptide inhibitor (Met12) of the Fas receptor on the activation of extrinsic and intrinsic apoptosis pathways after retinal detachment. Methods. Retinal-RPE separation was created in Brown Norway rats by subretinal injection of 1% hyaluronic acid. Met12, derived from the Fas-binding extracellular domain of the oncoprotein Met, was injected into the subretinal space at the time of separation. A mutant peptide and vehicle administered in a similar fashion acted as inactive controls. The extrinsic apoptotic pathway was induced in 661W cells using a Fas-activating antibody in the presence or absence of Met12. Caspase 3, caspase 8, and caspase 9 activities were measured with calorimetric and luminescent assays in retinal extracts and cell lysates. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) was performed in retinal sections 3 days after separation. Histology was performed in retinal sections 2 months after retinal detachment. Results. Met12 inhibited Fas-induced caspase 8 activation in 661W cells. Similarly, administration of Met12 into the subretinal space inhibited the activation of caspase 3, caspase 8, and caspase 9 after retinal detachment. This corresponded to a decreased level of TUNEL-positive staining of photoreceptors after retinal-RPE separation in animals that received Met12, but not inactive mutant, peptide treatment. After 2 months, the outer nuclear layer was significantly thicker, and the photoreceptor count was higher in animals treated with subretinal Met12. Conclusions. The small peptide Met12 may serve as a photoreceptor-protective agent in the setting of retinal-RPE separation.

  10. RhoA Signaling and Synaptic Damage Occur Within Hours in a Live Pig Model of CNS Injury, Retinal Detachment

    PubMed Central

    Wang, Jianfeng; Zarbin, Marco; Sugino, Ilene; Whitehead, Ian; Townes-Anderson, Ellen

    2016-01-01

    Purpose The RhoA pathway is activated after retinal injury. However, the time of onset and consequences of activation are unknown in vivo. Based on in vitro studies we focused on a period 2 hours after retinal detachment, in pig, an animal whose retina is holangiotic and contains cones. Methods Under anesthesia, retinal detachments were created by subretinal injection of a balanced salt solution. Two hours later, animals were sacrificed and enucleated for GTPase activity assays and quantitative Western blot and confocal microscopy analyses. Results RhoA activity with detachment was increased 1.5-fold compared to that in normal eyes or in eyes that had undergone vitrectomy only. Increased phosphorylation of myosin light chain, a RhoA effector, also occurred. By 2 hours, rod cells had retracted their terminals toward their cell bodies, disrupting the photoreceptor-to-bipolar synapse and producing significant numbers of spherules with SV2 immunolabel in the outer nuclear layer of the retina. In eyes with detachment, distant retina that remained attached also showed significant increases in RhoA activity and synaptic disjunction. Increases in RAC1 activity and glial fibrillary acidic protein (GFAP) were not specific for detachment, and sprouting of bipolar dendrites, reported for longer detachments, was not seen. The RhoA kinase inhibitor Y27632 significantly reduced axonal retraction by rod cells. Conclusions Activation of the RhoA pathway occurs quickly after injury and promotes synaptic damage that can be controlled by RhoA kinase inhibition. We suggest that retinal detachment joins the list of central nervous system injuries, such as stroke and spinal cord injury, that should be considered for rapid therapeutic intervention. PMID:27472075

  11. Predictive factors for postoperative visual function of primary chronic rhegmatogenous retinal detachment after scleral buckling

    PubMed Central

    Fang, Wei; Li, Jiu-Ke; Jin, Xiao-Hong; Dai, Yuan-Min; Li, Yu-Min

    2016-01-01

    AIM To evaluate predictive factors for postoperative visual function of primary chronic rhegmatgenous retinal detachment (RRD) after sclera buckling (SB). METHODS Totally 48 patients (51 eyes) with primary chronic RRD were included in this prospective interventional clinical cases study, which underwent SB alone from June 2008 to December 2014. Age, sex, symptoms duration, detached extension, retinal hole position, size, type, fovea on/off, proliferative vitreoretinopathy (PVR), posterior vitreous detachment (PVD), baseline best corrected visual acuity (BCVA), operative duration, follow up duration, final BCVA were measured. Pearson correlation analysis, Spearman correlation analysis and multivariate linear stepwise regression were used to confirm predictive factors for better final visual acuity. Student's t-test, Wilcoxon two-sample test, Chi-square test and logistic stepwise regression were used to confirm predictive factors for better vision improvement. RESULTS Baseline BCVA was 0.8313±0.6911 logMAR and final BCVA was 0.4761±0.4956 logMAR. Primary surgical success rate was 92.16% (47/51). Correlation analyses revealed shorter symptoms duration (r=0.3850, P=0.0053), less detached area (r=0.5489, P<0.0001), fovea (r=0.4605, P=0.0007), no PVR (r=0.3138, P=0.0250), better baseline BCVA (r=0.7291, P<0.0001), shorter operative duration (r=0.3233, P=0.0207) and longer follow up (r=-0.3358, P=0.0160) were related with better final BCVA, while independent predictive factors were better baseline BCVA [partial R-square (PR2)=0.5316, P<0.0001], shorter symptoms duration (PR2=0.0609, P=0.0101), longer follow up duration (PR2=0.0278, P=0.0477) and shorter operative duration (PR2=0.0338, P=0.0350). Patients with vision improvement took up 49.02% (25/51). Univariate and multivariate analyses both revealed predictive factors for better vision improvement were better baseline vision [odds ratio (OR) =50.369, P=0.0041] and longer follow up duration (OR=1.144, P=0

  12. Intraoperative optical coherence tomography in macula involving rhegmatogenous retinal detachment repair with pars plana vitrectomy and perfluoron

    PubMed Central

    Toygar, O; Riemann, C D

    2016-01-01

    Purpose To investigate microanatomical relationships during surgical repair of macula involving retinal detachment with pars plana vitrectomy (PPV) and perfluoron (PFO) with a microscope-integrated intraoperative optical coherence tomography (iOCT) device. Patients and methods This consecutive case series included nine eyes of nine patients with macula involving retinal detachment operated by a single surgeon at the Cincinnati Eye Institute. All patients underwent PPV, PFO injection, endolaser, and air–fluid exchange. The macula was imaged with iOCT before PFO injection, after PFO injection, and after air–fluid exchange in all eyes. Results iOCT imaging was ergonomically easy to obtain in all eyes. iOCT clearly demonstrated submacular fluid (SMF) at the beginning of the surgery, macular flattening under PFO in all eyes, small residual SMF under PFO in six of nine eyes, and increased occult SMF following air–fluid exchange in all eyes. Conclusion Microscope-integrated iOCT is a versatile and powerful imaging modality that holds a great deal of promise in the future. Its confirmation of persistent occult SMF in this small series of macular involving retinal detachment repair with PFO, may inform surgical decision making, and demonstrates a pathophysiological rationale for initial face-down positioning after retinal detachment repair. PMID:26656086

  13. Progressive keratoconus, retinal detachment, and intracorneal silicone oil with obsessive–compulsive eye rubbing

    PubMed Central

    Panikkar, Kartik; Manayath, George; Rajaraman, Revathi; Saravanan, Veerappan

    2016-01-01

    An 18-year-old boy with an obsessive–compulsive disorder of eye rubbing presented with forme fruste keratoconus (KC) and posterior subcapsular cataracts. After evaluation, he underwent phacoemulsification in his left eye with intraocular lens implantation. The aggressive eye rubbing, however, aggravated the rapid progression to established KC, and further acute corneal hydrops within 3 months. Within the next 3 months, the eye rubbing precipitated rhegmatogenous retinal detachments (RDs) in both eyes. Furthermore, after undergoing a combined cataract and RD surgery with belt buckling and silicone oil endotamponade in his right eye, the repeated eye rubbing caused extrusion of the implanted silicone oil into the subconjunctival space and within the corneal stroma. This is the first report to our knowledge describing this unique complication associated with eye rubbing. It also highlights the need for increased vigilance and care that needs to be directed toward patients predisposed to such complications. PMID:27843234

  14. Toxic effects of extracellular histones and their neutralization by vitreous in retinal detachment.

    PubMed

    Kawano, Hiroki; Ito, Takashi; Yamada, Shingo; Hashiguchi, Teruto; Maruyama, Ikuro; Hisatomi, Toshio; Nakamura, Makoto; Sakamoto, Taiji

    2014-05-01

    Histones are DNA-binding proteins and are involved in chromatin remodeling and regulation of gene expression. Histones can be released after tissue injuries, and the extracellular histones cause cellular damage and organ dysfunction. Regardless of their clinical significance, the role and relevance of histones in ocular diseases are unknown. We studied the role of histones in eyes with retinal detachment (RD). Vitreous samples were collected during vitrectomy, and the concentration of histone H3 was measured by enzyme-linked immunosorbent assay. The location of the histones and related molecules was examined in a rat RD model. The release of histones and their effects on rat retinal progenitor cells R28 and ARPE-19 were evaluated in vitro. In addition, the protective role of the vitreous body against histones was tested. The intravitreal concentration of histones was higher in eyes with RD (mean, 30.9 ± 9.8 ng/ml) than in control eyes (below the limit of detection, P<0.05). In the rat RD model, histone H3 was observed on the outer side of the detached retina and was associated with photoreceptor death. Histone H3 was released from cultured R28 by oxidative stress. Histones at a concentration 10 μg/ml induced the production of interleukin-8 in ARPE-19 cells (2.5-fold increase, P<0.05) that was mediated through the ERK1/2- and p38 MAPK-dependent pathways and Toll-like receptor 4. Histones were toxic to cells at concentrations of ≥ 20 μg/ml. Vitreous body or hyaluronan decreased toxicity of histones by inhibiting diffusion of histones. These results indicate that histones are released from retinas with RD and may modulate the subretinal microenvironment by functioning as damage-associated molecular pattern molecules, thereby inducing proinflammatory cytokines or cell toxicity. In addition, the important role of the vitreous body and hyaluronan in protecting the retina from these toxic effects is suggested.

  15. Episcleral macular buckling for posterior retinal detachment in silicone oil filled eyes associated with myopic macular hole

    PubMed Central

    Tian, Jiao; Tang, Luo-Sheng; Guo, Xiao-Jian; Luo, Yong-Heng

    2013-01-01

    AIM To evaluate anatomical and visual outcomes of episcleral macular buckling (EMB) for posterior retinal detachment in silicone oil filled eyes associated with myopic macular hole. METHODS Five cases of EMB for initial failure of retinal reattachment after internal limiting membrane (ILM) peeling and silicone oil tamponade caused by myopic macular hole were retrospectively reviewed. A silicone sponge sutured directly across the macular region was performed on the silicone oil filled eyes. Silicone oil was removed no sooner than 1 month post-EMB. The duration of follow-up time after removal of silicone oil was more than 3 months. RESULTS Retinas of five eyes were all reattached at the last follow-up. The postoperative vision ranged from counting fingers to 0.08. CONCLUSION Anatomical results improved after EBM for posterior retinal detachment in silicone oil filled eyes associated with myopic macular hole, which was not evident for visual outcome. PMID:23638417

  16. Surgical Management of Traumatic Retinal Detachment with Primary Vitrectomy in Adult Patients.

    PubMed

    Nowomiejska, Katarzyna; Choragiewicz, Tomasz; Borowicz, Dorota; Brzozowska, Agnieszka; Moneta-Wielgos, Joanna; Maciejewski, Ryszard; Jünemann, Anselm G; Rejdak, Robert

    2017-01-01

    Purpose. To evaluate functional and anatomical results of pars plana vitrectomy (PPV) in the retinal detachment (RD) followed by severe eye trauma. Methods. Retrospective analysis of medical records of forty-one consecutive patients treated with 23-gauge PPV due to traumatic RD. Age, gender, timing of PPV, visual acuity, and presence of intraocular foreign body (IOFB) and proliferative vitreoretinopathy (PVR) were included in the analysis. Results. Mean age of patients was 47 years; the majority of patients were men (88%). Closed globe injury was present in 21 eyes and open globe injury in 20 eyes (IOFB in 13 eyes, penetration injury in 4 eyes, and eye rupture in 3 eyes). Mean follow-up period was 14 months; mean timing of PPV was 67 days. Twenty-seven (66%) eyes had a functional success; 32 eyes (78%) had anatomical success. As a tamponade silicone oil was used in 33 cases and SF6 gas in 8 cases. Conclusions. Severe eye injuries are potentially devastating for vision, but vitreoretinal surgery can improve anatomical and functional outcomes. Among analysed pre- and intra- and postoperative factors, absence of PVR, postoperative retinal attachment, and silicone oil as a tamponade were related to significantly improved visual acuity.

  17. Surgical Management of Traumatic Retinal Detachment with Primary Vitrectomy in Adult Patients

    PubMed Central

    Borowicz, Dorota; Brzozowska, Agnieszka; Moneta-Wielgos, Joanna; Maciejewski, Ryszard; Jünemann, Anselm G.

    2017-01-01

    Purpose. To evaluate functional and anatomical results of pars plana vitrectomy (PPV) in the retinal detachment (RD) followed by severe eye trauma. Methods. Retrospective analysis of medical records of forty-one consecutive patients treated with 23-gauge PPV due to traumatic RD. Age, gender, timing of PPV, visual acuity, and presence of intraocular foreign body (IOFB) and proliferative vitreoretinopathy (PVR) were included in the analysis. Results. Mean age of patients was 47 years; the majority of patients were men (88%). Closed globe injury was present in 21 eyes and open globe injury in 20 eyes (IOFB in 13 eyes, penetration injury in 4 eyes, and eye rupture in 3 eyes). Mean follow-up period was 14 months; mean timing of PPV was 67 days. Twenty-seven (66%) eyes had a functional success; 32 eyes (78%) had anatomical success. As a tamponade silicone oil was used in 33 cases and SF6 gas in 8 cases. Conclusions. Severe eye injuries are potentially devastating for vision, but vitreoretinal surgery can improve anatomical and functional outcomes. Among analysed pre- and intra- and postoperative factors, absence of PVR, postoperative retinal attachment, and silicone oil as a tamponade were related to significantly improved visual acuity. PMID:28163930

  18. Outcome of rhegmatogenous retinal detachment repair: Experience of a tertiary center in Oman

    PubMed Central

    Al-Hinai, Ahmed S.; Al-Abri, Mohamed S.

    2013-01-01

    Aim: To study the outcome of repair of rhegmatogenous retinal detachment (RRD) in a tertiary center. Materials and Methods: Review of electronic medical records within a period of 29 months of consecutive patients who underwent surgical repair for RRD in Sultan Qaboos University Hospital (SQUH). Results: We included 33 consecutive patients (36 eyes). Males constituted 70% of them. The average age was 47 years. Seven eyes out of the 36 had macula-on RRD at presentation. The primary success rate with a single procedure was 86%. However, redetachment occurred in five eyes (14%). Visual acuity was either same as preoperative or better in 81% of the eyes. Giant retinal tear was found in three eyes (8%). The average follow-up period for all patients was 10.25 months (range: 3-25 months). Conclusion: Rhegmatogenous RD is not uncommon disorder. It occurs more frequently in males. However, it has a good prognosis if an intervention was performed in early stages. PMID:24379553

  19. Foveal Structure in Macula-off Rhegmatogenous Retinal Detachment after Scleral Buckling or Vitrectomy

    PubMed Central

    Roohipoor, Ramak; Mohammadi, Naseh; Ghassemi, Fariba; Karkhaneh, Reza; Rezaei, Mansour; Nili-Ahmadabadi, Mehdi; Ebrahimiadib, Nazanin

    2015-01-01

    Purpose: To evaluate foveal microstructural changes and to determine its association with visual outcomes after reattachment of rhegmatogenous retinal detachments (RRDs) by scleral buckling (SB) or pars plana vitrectomy (PPV). Methods: Using spectral domain optical coherence tomography (SD-OCT), foveal microstructure in eyes with macula-off RRD were studied 1, 3, 6, 9, 12 and 15 months after PPV or SB and correlated with visual outcomes. Results: Forty-two eyes were included in the final analysis. Even with improved microstructural changes and normalization of retinal structures on OCT, final visual acuity was not correlated with microstructural changes in eyes undergoing PPV. In the SB group, final visual acuity was significantly correlated with an intact inner segment/outer segment (IS/OS) junction (P = 0.013). There was no significant correlation between final visual acuity and presence of subretinal fluid (SRF) in either group. Conclusion: After SB, eyes with an intact IS/OS junction had better final visual acuity. In the PPV group, there was no significant correlation between microstructural changes and visual acuity. The presence of SRF did not influence final visual acuity in both groups. PMID:26425321

  20. Changes of Vision-Related Quality of Life in Retinal Detachment Patients after Cataract Surgery

    PubMed Central

    Zhu, Bijun; Sun, Qian; Xu, Xian; Miao, Yuyu; Zou, Haidong

    2015-01-01

    Rhegmatenous retinal detachment (RRD) is one of the most serious complications after phacoemulsification combined with intraocular lens implantation surgery. It has been reported that vision-related quality of life (VRQoL), as well as visual acuity rapidly decreased when RRD developed. However, little is known of the VRQoL in those RRD patients after anatomical retinal re-attachment, especially whether or not the VRQoL is higher than that before cataract surgery. In this prospective case series study, we use the Chinese-version low vision quality of life questionnaire (CLVQOL) to assess the changes of VRQoL in age-related cataract patients who suffered from RRD after phacoemulsification with intraocular lens (phaco-IOL) implantation. All participants were asked to complete questionnaires in face- to-face interviews one day before and two weeks after cataract surgery, as well as one day before and three months after RRD surgery. A total of 10,127 consecutive age-related cataract patients were followed up to one year after phaco-IOL implantation; among these patients, 17 were diagnosed as RRD. The total CLVQOL scores and subscale scores except “Mobility” decreased significantly when RRD developed. After retinal surgery, only the score of “General vision and lighting” in the CLVQOL questionnaires improved when compared to the scores two weeks after cataract surgery, although the best corrected visual acuity of all patients significantly raised up. However, the mean CLVQOL scores and subscale scores were still considerably higher than the level prior to cataract surgery. Our study suggests that cataract patients at high risk of postoperative RRD should not deny the opportunity to undergo phaco-IOL implantation, even though potential VRQoL impairment induced by RRD exists. PMID:25764367

  1. Changes of vision-related quality of life in retinal detachment patients after cataract surgery.

    PubMed

    Zhu, Mingming; Huang, Jiannan; Zhu, Bijun; Sun, Qian; Xu, Xian; Miao, Yuyu; Zou, Haidong

    2015-01-01

    Rhegmatenous retinal detachment (RRD) is one of the most serious complications after phacoemulsification combined with intraocular lens implantation surgery. It has been reported that vision-related quality of life (VRQoL), as well as visual acuity rapidly decreased when RRD developed. However, little is known of the VRQoL in those RRD patients after anatomical retinal re-attachment, especially whether or not the VRQoL is higher than that before cataract surgery. In this prospective case series study, we use the Chinese-version low vision quality of life questionnaire (CLVQOL) to assess the changes of VRQoL in age-related cataract patients who suffered from RRD after phacoemulsification with intraocular lens (phaco-IOL) implantation. All participants were asked to complete questionnaires in face- to-face interviews one day before and two weeks after cataract surgery, as well as one day before and three months after RRD surgery. A total of 10,127 consecutive age-related cataract patients were followed up to one year after phaco-IOL implantation; among these patients, 17 were diagnosed as RRD. The total CLVQOL scores and subscale scores except "Mobility" decreased significantly when RRD developed. After retinal surgery, only the score of "General vision and lighting" in the CLVQOL questionnaires improved when compared to the scores two weeks after cataract surgery, although the best corrected visual acuity of all patients significantly raised up. However, the mean CLVQOL scores and subscale scores were still considerably higher than the level prior to cataract surgery. Our study suggests that cataract patients at high risk of postoperative RRD should not deny the opportunity to undergo phaco-IOL implantation, even though potential VRQoL impairment induced by RRD exists.

  2. Long-Term Changes in Intraocular Pressure after Vitrectomy for Rhegmatogenous Retinal Detachment, Epi-Retinal Membrane, or Macular Hole

    PubMed Central

    Yamamoto, Kentaro; Iwase, Takeshi; Terasaki, Hiroko

    2016-01-01

    Purpose To determine the long-term changes in the intraocular pressure (IOP) following vitrectomy for rhegmatogenous retinal detachment (RRD), epiretinal membrane (ERM), and macular hole (MH), and to investigate the relationship between the retinal disease and the incidence of late-onset IOP elevation. Methods This was a retrospective, observational, comparative study. We reviewed the medical records of 54 eyes of 54 RRD patients, 117 eyes of 117 ERM patients, and 75 eyes of 75 MH patients who underwent 20-, 23- or 25-gauge vitrectomy. The IOPs before surgery and 1, 3, 6, and 12 months following vitrectomy, and also at the final visit (average, 23.95 months) were evaluated. We defined a significant increase in the IOP as an increase of ≥4 mmHg from the preoperative IOP, and this increase was taken to be a ‘death’ event for the Kaplan-Meier survival analyses. Results The mean follow-up period was not significantly different among the groups. The mean IOP at 3 (P = 0.001) and 12 (P = 0.011) months following the vitrectomy and at the final visit (P = 0.002) were significantly higher than that before the vitrectomy in the RRD group. The mean IOP in the RRD group was significant higher than that in the ERM group at 1 (P = 0.005), 3 (P = 0.009), and 12 (P = 0.013) months following vitrectomy, and at the final visit (P = 0.032). Kaplan-Meier survival analyses showed that the RRD group had a significantly higher risk of an IOP increase following vitrectomy than the other groups (P<0.001 by log-rank test). Multivariate logistic regression analyses showed that a preoperative diagnosis of RRD was the only risk factor that was significantly associated with a postoperative IOP elevation after excluding eyes with a low preoperative IOP (odds ratio, 3.208; P = 0.003). Conclusions A late-onset IOP elevation following vitrectomy was observed only in eyes that underwent RRD surgery. The elevation was probably caused by the specific characteristics and surgical procedures of

  3. A review of techniques employed in 1100 cases of retinal detachment.

    PubMed Central

    Chawla, H B

    1982-01-01

    To produce a flat retina after an operation demands an unrestricted view of the retina during the operation, and to achieve such a view most retinal surgeons would unhesitatingly recommend the binocular indirect ophthalmoscope and scleral depression. Once the retina and all its breaks are clearly in view, the keynote of the ensuing surgery should be simplicity and safety. The former requires that the intended operation should be the least complicated available, and, should the surgical intention be frustrated, that each step should blend with the next in orderly progression, the surgeon exhausting the possibility of one step before moving on to the next and being able to recognise when the possibilities are exhausted. The latter requires experience in deciding which is in fact the least complicated operation. In general the cavity of the globe should not be entered unless the eye stands to lose more than it gains by remaining inviolate. Paracentesis, fluid release, and intravitreal air all have their place, and to avoid them gains us nothing if the retina remains detached. PMID:7115648

  4. A New Sutureless Illuminated Macular Buckle Designed for Myopic Macular Hole Retinal Detachment

    PubMed Central

    Bedda, Ahmed M.; Lolah, Mohamed; Abd Al Shafy, Muhammad S.

    2017-01-01

    Purpose. To report the anatomic and visual results of a new sutureless illuminated macular buckle designed for patients with macular hole retinal detachment related to high myopia (MMHRD). Design. Prospective nonrandomized comparative interventional trial. Methods. Twenty myopic eyes of 20 patients (mean age, 51.4 years; range, 35–65 years) presenting with MMHRD with a posterior staphyloma, in whom the new buckle was used, were evaluated. The buckle used was assembled from a 5 mm wide sponge and a 7 mm wide silicone tire; it was fixed utilizing the sterile topical adhesive Histoacryl Blue (B Braun, TS1050044FP) which polymerizes in seconds upon being exposed to water-containing substances. The primary outcomes measured included aided visual acuity (BCVA) and optical coherence tomography (OCT) findings. The mean follow-up period was 6 months. Results. Postoperatively, the MH closure was identified by OCT in 8 (40%) eyes. The mean BCVA increased from 0.11 to 0.21 (p < 0.005). The axial length of the eyes included decreased from 30.5 mm preoperatively to 29.8 mm (p = 0.002) postoperatively. Conclusion. Preparation of the new sutureless macular buckle is simple and easy. Illumination of the terminal part of the buckle ensures proper placement. Histoacryl Blue is effective in fixing the buckle in its place for at least 6 months with no reported intra- or postoperative complications.

  5. Comparison of scleral buckling using wide-angle viewing systems and indirect ophthalmoscope for rhegmatogenous retinal detachment

    PubMed Central

    Li, Xiu-Juan; Yang, Xiao-Peng; Lyu, Xiao-Bei

    2016-01-01

    AIM To compare the effects of scleral buckling using wide-angle viewing systems (WAVS) with that using indirect ophthalmoscope for the treatment of rhegmatogenous retinal detachment. METHODS The study was a retrospective analyses of the medical records of 94 eyes (94 patients) with rhegmatogenous retinal detachment. Among them, 47 eyes underwent scleral buckling using WAVS with endoilluminator (Group W), and 47 eyes underwent scleral buckling using indirect ophthalmoscope (Group I). Surgical durations, primary success rate, best-corrected visual acuities (BCVA), delayed subretinal fluid absorptions and surgical complications were compared between the two groups. RESULTS At baseline, there were no statistical differences between the two groups in patient's age (P=0.997), gender (P=0.853), symptom duration (P=0.216), BCVA (P=0.389), refractive error (P=0.167), intraocular pressure (P=0.595), the number of retinal breaks (P=0.832), the extent of retinal detachment (P=0.246), subretinal demarcation line (P=0.801), and macular detachment (P=0.811). The follow-up period was 12mo. The surgical durations in Group W (with or without encircling buckling) were significant shorter than those in Group I (P<0.001 respectively). The primary success rate was 94.27% in Group W, which was similar to that in Group I (92.38%, P = 0.931). The BCVA in Group W was better than that in Group I (P<0.001) at 1-month follow-up visit. However, there were no significant differences between the two groups at 3-month (P=0.221), 6-month (P=0.674), and 12-month (P=0.363) follow-up visits respectively. Delayed subretinal fluid absorptions were more common in Group I than in Group W at 1-month (P=0.045) follow-up visit, but there were no significant differences between the two groups at 3-month (P=0.111), 6-month (P=1.000) and 12-month follow-up visits respectively. CONCLUSION Scleral buckling using WAVS can be an alternative choose for rhegmatogenous retinal detachment. PMID:27672597

  6. Photoreceptor Inner and Outer Segment Junction Reflectivity after Vitrectomy for Macula-Off Rhegmatogenous Retinal Detachment

    PubMed Central

    Kaluzny, Jakub J.; Sikorski, Bartosz L.; Czajkowski, Grzegorz; Burduk, Mateusz; Kaluzny, Bartlomiej J.; Stafiej, Joanna; Malukiewicz, Grazyna

    2015-01-01

    Purpose. To evaluate the spatial distribution of photoreceptor inner and outer segment junction (IS/OS) reflectivity changes after successful vitrectomy for macula-off retinal detachment (PPV-mOFF) using spectral domain optical coherence tomography (SdOCT). Methods. Twenty eyes after successful PPV-mOFF were included in the study. During a mean follow-up period of 15.3 months, SdOCT was performed four times. To evaluate the IS/OS reflectivity a four-grade scale was used. Results. At the first follow-up visit the IS/OS had very similar reflectivity in entire length of the central scan with total average value of 1,05. At the second visit the most significant increase of the reflectivity was observed in temporal and nasal parafovea with average values of 2,17 and 2,22, respectively. The third region of increased reflectivity of an average value of 2,33 appeared during the third follow-up visit and was located in the foveola. At the last follow-up visit in entire central cross section the IS/OS reflectivity exceeded grade 2 reaching the highest average values in nasal and temporal parafovea and foveola. Conclusions. A gradual increase of the IS/OS reflectivity was observed in eyes after PPV-mOFF. The process is not random and starts independently in the peripheral and central part of the macula which may be attributed to the variable regenerative potential of cones and rods. PMID:26579234

  7. Point-of-care ultrasonography of the orbit for detection of retinal detachment in a patient with hemolysis, elevated liver enzymes, and low platelet count syndrome

    PubMed Central

    Shrestha, Gentle Sunder; Rajbhandari, Shayuja; Dhungel, Shashwat; Sharma, Nutan; Poudel, Nimesh; Manandhar, Dhiraj N.

    2016-01-01

    Retinal detachment is a rare, but well-known cause of visual impairment in patients with hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome. With supportive care, patients usually improve, with complete recovery of vision. Bedside ultrasonography of the orbit can be helpful for early detection of retinal detachment in these patients. Here, we present a case of HELLP syndrome presenting with severe visual symptoms. Retinal detachment was detected with point-of-care ocular sonography, which was confirmed with ophthalmoscopic examination. The patient was reassured of the favorable prognosis. Early initiation of aggressive supportive care was followed by progressive improvement of vision, which correlated with sonographic evidence of resolution of detachment. Her vision recovered completely in 2 weeks. PMID:27688632

  8. Long-term follow-up of vitrectomy, with or without 360° encircling buckle, for rhegmatogenous retinal detachment due to inferior retinal breaks

    PubMed Central

    Ghoraba, Hamouda Hamdy; Zaky, Adel Galal; Ellakwa, Amin Faisal

    2016-01-01

    Objective The aim of this study was to report and compare the anatomic and functional results of primary vitrectomy with and without 360° encircling scleral buckle (SB) for the treatment of rhegmatogenous retinal detachment (RRD) due to inferior retinal break(s). Background A variety of options, including SB, pars plana vitrectomy (PPV) with or without SB, and pneumatic retinopexy have been described as methods to repair RRDs. The use of additional SB with vitrectomy for RRD associated with inferior breaks has been a recent controversy after the introduction of transconjunctival cannula systems. Patients and methods A retrospective, interventional, comparative case study was performed. In this study, we reviewed 105 consecutive patients who underwent vitrectomy for primary RRD with inferior retinal break(s) at the vitreoretinal center, performed by a single surgeon. Ninety four patients (94 eyes) were followed up for at least 4 months after silicon oil removal (SOR), and were analyzed. They were divided into two groups: group I included 50 patients who underwent PPV alone + silicon oil (SO); and group II included 44 patients who underwent PPV with 360° SB + SO. The essential parameters were single-operation success rate (SOSR) before SOR, incidence of retinal redetachment after SOR, and final visual acuity. Results SOSR was obtained in 89 eyes (47 [94%] in group I and 42 [95.5%] in group II). From overall 59 phakic retinal detachments (RDs), SOSR was obtained in 56 eyes (30 in group I [93.8%] and 26 in group II [96.3%]) while from overall 35 aphakic or pseudophakic RDs, SOSR was obtained in 33 eyes (17 in group I [94.4%] and 16 in group II [94.1%]). Retinal redetachments after SOR occurred in three patients in group I and two patients in group II. Visual acuity improvement was greater in group I than in group II before SOR. Conclusion Both surgical procedures had similar reattachment rates. The addition of 360° SB to PPV + SO might not have additional benefits

  9. Retinal Pigment Epithelium Atrophy 1 (rpea1): A New Mouse Model With Retinal Detachment Caused by a Disruption of Protein Kinase C, θ

    PubMed Central

    Ji, Xiaojie; Liu, Ye; Hurd, Ron; Wang, Jieping; Fitzmaurice, Bernie; Nishina, Patsy M.; Chang, Bo

    2016-01-01

    Purpose Retinal detachments (RDs), a separation of the light-sensitive tissue of the retina from its supporting layers in the posterior eye, isolate retinal cells from their normal supply of nourishment and can lead to their deterioration and death. We identified a new, spontaneous murine model of exudative retinal detachment, nm3342 (new mutant 3342, also referred to as rpea1: retinal pigment epithelium atrophy 1), which we characterize herein. Methods The chromosomal position for the recessive nm3342 mutation was determined by DNA pooling, and the causative mutation was discovered by comparison of whole exome sequences of mutant and wild-type controls. The effects of the mutation were examined in longitudinal studies by clinical evaluation, electroretinography (ERG), light microscopy, and marker and Western blot analyses. Results New mutant 3342, nm3342, also referred to as rpea1, causes an early-onset, complete RD on the ABJ/LeJ strain background, and central exudative RD and late-onset RPE atrophy on the C57BL/6J background. The ERG responses were normal at 2 months of age but deteriorate as mice age, concomitant with progressive pan-retinal photoreceptor loss. Genetic analysis localized rpea1 to mouse chromosome 2. By high-throughput sequencing of a whole exome capture library of an rpea1/rpea1 mutant and subsequent sequence analysis, a splice donor site mutation in the Prkcq (protein kinase C, θ) gene, was identified, leading to a skipping of exon 6, frame shift and premature termination. Homozygotes with a Prkcq-targeted null allele (Prkcqtm1Litt) have similar retinal phenotypes as homozygous rpea1 mice. We determined that the PKCθ protein is abundant in the lateral surfaces of RPE cells and colocalizes with both tight and adherens junction proteins. Phalloidin-stained RPE whole mounts showed abnormal RPE cell morphology with aberrant actin ring formation. Conclusions The homozygous Prkcqrpea1 and the null Prkcqtm1Litt mutants are reliable novel mouse

  10. Change in refraction after lens-sparing vitrectomy for rhegmatogenous retinal detachment and epiretinal membrane.

    PubMed

    Iwase, Takeshi; Yamamoto, Kentaro; Yanagida, Kosei; Kobayashi, Misato; Ra, Eimei; Murotani, Kenta; Terasaki, Hiroko

    2016-08-01

    The aim of this study was to compare changes in refraction following lens-sparing vitrectomy between patients with rhegmatogenous retinal detachment (RRD) and epiretinal membrane (ERM) and to investigate factors associated with the change in refraction.We reviewed medical records of 49 eyes of 49 patients with RRD (53.6 ± 7.8 years, mean ± standard deviation) and 24 eyes of 24 patients with ERM (50.9 ± 15.7 years) who underwent lens-sparing vitrectomy. Spherical equivalent refractive power was evaluated before and up to 18 months after surgery. The relationship between the change in refraction and several parameters was evaluated.A significant progressive myopic shift in refractive power was observed after vitrectomy in operated RRD and ERM eyes (P < 0.001, P = 0.016, respectively), with no significant difference in fellow eyes. The refraction values observed at ≥3 and ≥12 months following vitrectomy were significantly different as compared with those observed at baseline in the RRD group (P < 0.001) and the ERM group (P < 0.05), respectively. The change in refraction between the RRD and ERM groups was significant (P = 0.030). The multiple linear regression analysis showed that only age was significantly correlated with the change in refraction in RRD (P = 0.018) and ERM (P < 0.001) groups. The change in refraction was significantly and positively correlated with age in RRD (r = -0.461, P = 0.001) and ERM (r = -0.687, P < 0.001) groups. Following lens-sparing vitrectomy, cataract surgery was performed on 30 eyes after 0.89 ± 0.26 years in the RRD group and on 10 eyes after 1.11 ± 0.14 years in the ERM group; there was a significant difference in time to cataract surgery between the groups (P = 0.007). Kaplan-Meier survival analysis demonstrated that there was a significant difference in the rate of cataract surgeries between the RRD and ERM groups (P = 0.022).Following lens

  11. Change in refraction after lens-sparing vitrectomy for rhegmatogenous retinal detachment and epiretinal membrane

    PubMed Central

    Iwase, Takeshi; Yamamoto, Kentaro; Yanagida, Kosei; Kobayashi, Misato; Ra, Eimei; Murotani, Kenta; Terasaki, Hiroko

    2016-01-01

    Abstract The aim of this study was to compare changes in refraction following lens-sparing vitrectomy between patients with rhegmatogenous retinal detachment (RRD) and epiretinal membrane (ERM) and to investigate factors associated with the change in refraction. We reviewed medical records of 49 eyes of 49 patients with RRD (53.6 ± 7.8 years, mean ± standard deviation) and 24 eyes of 24 patients with ERM (50.9 ± 15.7 years) who underwent lens-sparing vitrectomy. Spherical equivalent refractive power was evaluated before and up to 18 months after surgery. The relationship between the change in refraction and several parameters was evaluated. A significant progressive myopic shift in refractive power was observed after vitrectomy in operated RRD and ERM eyes (P < 0.001, P = 0.016, respectively), with no significant difference in fellow eyes. The refraction values observed at ≥3 and ≥12 months following vitrectomy were significantly different as compared with those observed at baseline in the RRD group (P < 0.001) and the ERM group (P < 0.05), respectively. The change in refraction between the RRD and ERM groups was significant (P = 0.030). The multiple linear regression analysis showed that only age was significantly correlated with the change in refraction in RRD (P = 0.018) and ERM (P < 0.001) groups. The change in refraction was significantly and positively correlated with age in RRD (r = −0.461, P = 0.001) and ERM (r = −0.687, P < 0.001) groups. Following lens-sparing vitrectomy, cataract surgery was performed on 30 eyes after 0.89 ± 0.26 years in the RRD group and on 10 eyes after 1.11 ± 0.14 years in the ERM group; there was a significant difference in time to cataract surgery between the groups (P = 0.007). Kaplan–Meier survival analysis demonstrated that there was a significant difference in the rate of cataract surgeries between the RRD and ERM groups (P = 0

  12. Quality assessment of cataract surgery in Denmark - risk of retinal detachment and postoperative endophthalmitis.

    PubMed

    Bjerrum, Søren Solborg

    2015-03-01

    The main purpose of this thesis was to examine whether the Danish National Patient Registry (NPR) could be used to monitor and assess the quality of cataract surgery in Denmark by studying the risks of two serious postoperative complications following cataract surgery - retinal detachment (RD) and postoperative endophthalmitis (PE). The thesis consists of four retrospective studies. In the first study (paper I), we used data from the NPR in the calendar period 2000-2010 to investigate the risk of pseudophakic retinal detachment (PRD) using the fellow non-operated eyes of the patients as reference. The study showed that over a 10-year study period, the risk of PRD was increased by a factor of 4.2 irrespective of sex and age. The risk of PRD was highest in the first part of the postoperative period and then gradually decreased but remained statistically significantly higher than the risk of RD in non-operated fellow eyes up to 10 years after cataract surgery. The epidemiology of RD in the non-operated fellow eyes was different from the epidemiology of RD in the background population as young men had the highest risk of RD in the non-operated fellow eyes. This means that the absolute risk of PRD was highest for young men because they had a higher risk of RD before they underwent cataract surgery. In the second study (paper II), we used data from the NPR and reviewed patient charts to assess the risk of PE after cataract surgery performed in public eye departments and private hospitals/clinics in the study period 2002-2010. The overall risk of PE among the seven public eye departments was 0.36 per 1000 registered cataract operations, and the PE risk among the departments was homogeneous. The overall risk of PE among the 28 private hospitals/clinics was 0.73 per 1000 registered cataract operations, and the risk among the private hospitals/clinics was heterogeneous. Most private hospitals/clinics had a risk of PE that was lower than or similar to the risk of PE after

  13. Successful Management in a Case of Traumatic Retinal Detachment due to Open Globe Injury Using Microincisional Vitrectomy

    PubMed Central

    Lai, Wei-Yu; Wu, Tsung-Tien

    2016-01-01

    Background Retinal detachment (RD) following ocular trauma often results in guarded visual prognosis and sometimes leads to loss of the eye. With the advent of microincisional vitrectomy surgery and the development of surgical techniques, the management of ocular trauma has been transformed. Case Presentation A 34-year-old man sustained an open globe injury from fragmented glass at work. He received primary repair and another follow-up surgery 9 days later, including vitrectomy, silicone oil tamponade, and lensectomy for RD and traumatic cataract at another medical center. However, his retina was totally detached and completely curled up in a roll with choroid on display when he was seen by us 1 month later. He was managed with vigilant and patient peeling and unfolding of the retina using a 23-gauge forceps and silicone oil tamponade, and achieved anatomical success and preservation of his eye at 6-month follow-up. Conclusions This report demonstrates that even in cases which appear to be hopeless at presentation, the surgeon's perseverance and surgical technique can salvage an eye that may otherwise be phthisical. It also encourages retinal surgeons to use microincisional vitrectomy to manage severe traumatic RD. PMID:28101038

  14. A retrospective study comparing outcomes of primary rhegmatogenous retinal detachment repair by scleral buckling and pars plana vitrectomy in Finland

    PubMed Central

    Sahanne, Sari; Tuuminen, Raimo; Haukka, Jari; Loukovaara, Sirpa

    2017-01-01

    Background Rhegmatogenous retinal detachment (RRD) is the most common form of retinal detachment and an ophthalmic emergency. Here, we compared outcomes of primary RRD eyes operated with conventional scleral buckling (SB) with cryoretinopexy to those operated with standard pars plana vitrectomy (PPV). Methods This is an institutional, retrospective, register-based, observational, comparative study. Based on the surgical procedure, 319 eyes of 319 patients were divided into two groups: SB plus cryotherapy (n=50) and PPV (n=269). Changes in intraocular pressure (IOP) and best-corrected visual acuity (BCVA) were recorded at 30 days and reoperation rates within 180 days postoperatively. Results Eyes operated with PPV had less reoperations within the first 180 days as compared with SB eyes (P=0.001, log-rank test); however, changes in IOP were more prominent (mean ± standard deviation: +8.1±8.8 vs. +4.4±7.0 mmHg, respectively; P=0.006). Changes in BCVA did not differ between the surgical procedures. Conclusion PPV was associated with higher primary anatomic success rates and lower risk of reoperation but significant IOP elevation when compared to SB. These factors should be case-specifically considered when choosing treatment modality for primary RRD. PMID:28331284

  15. Outcome of primary rhegmatogenous retinal detachment surgery in a tertiary referral centre in Northern Ireland – A regional study

    PubMed Central

    Mikhail, Michael A; Mangioris, George; Casalino, Giuseepe; McGimpsey, Stuart; Sharkey, James; Best, Richard

    2017-01-01

    Purpose To report the primary and final success, functional outcome and complication rates of patients with primary rhegmatogenous retinal detachment (RRD) who underwent retinal detachment surgery in a tertiary referral centre in Northern Ireland. Venue Vitreoretinal service, Royal Victoria Hospital, Belfast, Northern Ireland. Methods This is a retrospective case series of all patients who underwent primary RRD repair between 1st of January 2013 and 31st of December 2013. Charts were reviewed. Patients’ demographics, overall primary and final success, functional outcome, complication rates were identified and recorded. Subgroup analysis according to lens status and foveal attachment was also performed. Results A total of 212 cases of primary RRD were included. Mean age at time of surgery was 56.6 years (range 9-90 years); 175(82.5%) had pars plana vitrectomy (PPV), 27 (12.5%), scleral buckle (SB) repair and 10 (5%) pneumatic retinopexy (PR). Overall primary and final success rate were 86% and 95.6% respectively. Overall mean visual acuity improved from 1.1 to 0.4 LogMAR postoperatively after a mean follow-up of 9 months. There was no significant difference in the primary success rate in relation to the baseline lens status (χ2 = 3.4, P = 0.2) and to the baseline macular status (χ2 = 0.6, P = 0.7). Presence of proliferative vitreoretinopathy (PVR) negatively affected the primary success rate (χ2=7.2, P = 0.03). Poor prognostic factors for success were PVR at presentation, inferior breaks and increasing number of detached quadrants. Conclusions This study demonstrates a success rate comparable with other centres with a low rate of final failure. Despite sub-specialism and the great advances in VR surgery, the biology of RRD dictates a failure rate. New therapies may improve results in the future. PMID:28298707

  16. One "8"-shaped scleral suture to treat rhegmatogenous retinal detachment: a refined procedure of minimal scleral buckling.

    PubMed

    Min, H Y; Chen, D; Chen, Y; Dong, F T

    2014-08-28

    The aim of this study was to investigate the outcomes of one "8"-shaped scleral suture of minimal scleral buckling (MSB) surgery without sub-retinal drainage for rhegmatogenous retinal detachment (RRD) treatment. Thirty patients (30 eyes) with RRD were recruited. Thirty eyes with RRD were repaired by one "8"-shaped scleral suture of minimal buckling without subretinal drainage by one surgeon. The refined MSB procedure is described. Reattachment time and best-corrected visual acuity (BCVA) were observed. The age of the 30 patients ranged from 17 to 65 years (mean, 43.1 ± 8.6 years). The retinas of 19 eyes (63.3%) reattached within 12 h of the operations, and those of 11 eyes (67%) reattached within 72 h. The average time of follow-up was 10.4 ± 2.8 months. BCVAs were increased in 27 eyes (90%), whereas those of 3 eyes did not change. The mean preoperative BCVA was 0.738 ± 0.368 log minimal angle of resolution (MAR), and mean postoperative BCVA was 0.422 ± 0.278 logMAR, and the difference was statistically significant (P < 0.05). The sponge for buckling in only one eye exposed from the conjunctiva was taken out, and the retina remained attached. In conclusion, an "8"-shaped scleral suture of MSB without sub-retinal drainage is an efficient procedure to treat selected RRD cases.

  17. Outcome of rhegmatogenous retinal detachment repair by scleral buckling: The experience of a tertiary referral center in Scotland

    PubMed Central

    Shankar, Vikas; Lim, Lik Thai; Ah-Kee, Elliott Yann; Hammer, Harold

    2014-01-01

    Purpose: The primary aim of this study is to report the outcome of patients with rhegmatogenous retinal detachment (RRD) who underwent scleral buckling (SB) surgery. Methods: This is a retrospective noncomparative case series study of all patients who underwent RRD repair by primary SB between March 2008 and February 2009. Patient demographics, visual outcome, complications, and failure rates were identified and recorded. Results: A total of 65 patients underwent RRD repair by SB, with a mean age of 44.44 years. Results showed that the primary outcome (primary anatomical success following index surgery) was 90.77%, while the secondary outcome (anatomical success following repeat surgery) was 98.46%. Conclusion: The study showed a high-success rate of SB in phakic eyes both in terms of postoperative best-corrected visual acuity and complication rates. We recommend the continued use of this technique in selected cases of RRD. PMID:25378877

  18. Serous Retinal Detachment in Dome-shaped Macula with 7 Years Follow-up

    PubMed Central

    Alakeely, Adel G.; Alrashaed, Saba

    2016-01-01

    Dome-shaped macula (DSM) was first described by Gaucher et al. as a convex protrusion of macula within a staphyloma in highly myopic eyes that cause visual impairment associated with serous foveal detachment (SFD). We describe a patient with persistent SFD in DSM documented by serial spectral domain optical coherence tomography for 7 years with stable vision. PMID:27994399

  19. Perfluoro-n-octane as a temporary intraocular tamponade in a staged approach to manage complex retinal detachments

    PubMed Central

    Barthelmes, Daniel; Chandra, Jay

    2015-01-01

    Purpose To evaluate outcomes in patients with complex retinal detachments (RD) with proliferative vitreoretinopathy (PVR) requiring retinectomy using a staged approach utilizing perfluoro-n-octane (PFO) as a short-term postoperative intraocular tamponade. Methods Retrospective analysis. Patients who underwent 23G pars plana vitrectomy for the management of complicated RD where PFO was used as a primary temporary intraocular tamponade. Only eyes with PVR in rhegmatogenous RD or eyes with penetrating injuries or globe ruptures (ocular trauma) and subsequent RD with PVR were included. Analysis of 17 eyes of 17 consecutive patients with a minimum follow-up of 12 months during a period of 5 years. The primary outcome measure was the reattachment rate after at least 12 months of follow-up after the PFO removal. Secondary outcome measures were changes in visual acuity, complications due to PFO use, and necessity for further surgeries. Results Eight eyes with prior penetrating injuries or globe rupture and nine eyes with rhegmatogenous pathology were included. All eyes had PFO as temporary tamponade for 14 days (median), which was replaced by silicon oil. Sixteen eyes (94%) had complete and one eye partial reattachment. No redetachments occurred. All eyes retained or improved visual acuity. On average, only 2.5 procedures, including silicon oil removal, were performed. Two eyes had long-term intraocular pressure of 5 mmHg and no eye had intraocular pressure of ≥21 mmHg. No long-term inflammation was observed. Conclusion PFO seems to be beneficial in a staged approach to repair complex detachments when used as short-term tamponade. A median period of 14 days allowed for both sufficient retinal support plus a reduction in side effects seen in long-term endotamponades. PMID:25784785

  20. Efficacy of two different thiol-modified crosslinked hyaluronate formulations as vitreous replacement compared to silicone oil in a model of retinal detachment

    PubMed Central

    Schnichels, Sven; Schneider, Nele; Hohenadl, Christine; Hurst, José; Schatz, Andreas; Januschowski, Kai; Spitzer, Martin S.

    2017-01-01

    The efficacy of two novel artificial vitreous body substitutes (VBS) consisting of highly biocompatible thiolated cross-linked hyaluronic acid (HA)-based hydrogels in comparison to silicone oil in a model of retinal detachment was investigated. Pars plana vitrectomy (23G) was performed in the right eye of 24 pigmented rabbits. Retinal detachment of two quadrants was induced by creating a small retinotomy near the vascular arcade and injecting balanced salt solution (BSS) subretinally. The retina was reattached by injecting air, which was followed by increasing the infusion pressure, and the retinal tear was treated by endolaser photocoagulation. At the end of the procedure, the eye was filled either with 5000-cs silicone oil (after fluid air exchange) or the respective hydrogel (with two different viscosities). Follow-up examination included slit lamp examination, funduscopy, intraocular pressure measurements (IOP), optical coherence tomography (OCT) and electroretinogram (ERG) measurements. After a maximum follow-up of four weeks both eyes were removed, examined macroscopically, photographed, and prepared for histology. Of the eight rabbits that received silicone oil, seven (87.5%) developed a recurrent retinal detachment with pronounced proliferative vitreoretinopathy within the first two weeks after surgery. In contrast, in the hydrogel treated eyes, the retina stayed attached in the majority of the cases (73.3%). IOP and retinal morphology were normal as long as the retina remained re-attached. In conclusions, this model of retinal detachment, both thiolated crosslinked hyaluronate hydrogels showed superior efficacy when compared to silicone oil. These hydrogels have a promising potential as novel vitreous body substitutes. PMID:28248989

  1. Profiles of Inflammatory Cytokines in the Vitreous Fluid from Patients with Rhegmatogenous Retinal Detachment and Their Correlations with Clinical Features

    PubMed Central

    Takahashi, Shizuka; Adachi, Kobu; Suzuki, Yukihiko; Maeno, Atsuko

    2016-01-01

    Purpose. To characterize the profiles for inflammatory cytokines in the vitreous fluid from patients with rhegmatogenous retinal detachment (RRD) by comparing those of other vitreoretinal diseases and to analyze the correlation between intravitreal cytokines and clinical features. Materials and Methods. Vitreous fluid was obtained at the time of surgery from 28 RRD eyes. Vitreous fluid was similarly collected from patients with macular hole (MH), epiretinal membrane, proliferative diabetic retinopathy (PDR), and retinal vein occlusion as controls. Twenty-seven cytokines were measured. Intravitreal cytokine profiles in RRD were characterized by comparing these with those in other vitreoretinal diseases. We also analyzed the correlations between vitreous cytokines and clinical features. Results. There were statistical differences in the MCP-1, MIP-1β, and IP-10 between the RRD and MH, while the IL-6 and IL-8 exhibited levels that were between those for the PDR and MH. MIP-1β was significantly correlated to both the extent and duration of the RRD, while IL-8 was significantly correlated to the extent of the RRD. Conclusions. MCP-1, MIP-1β, and IP-10 may modify the pathologic features of RRD. The levels of these cytokines are related in part to the clinical features and the level of photoreceptor damage. PMID:28074184

  2. Loss of Visual Acuity after Successful Surgery for Macula-On Rhegmatogenous Retinal Detachment in a Prospective Multicentre Study

    PubMed Central

    Di Lauro, Salvatore; Castrejón, Melissa; Fernández, Itziar; Rojas, Jimena; Coco, Rosa M.; Sanabria, María R.; Rodríguez de la Rua, Enrique; Pastor, J. Carlos

    2015-01-01

    Purpose. To quantify the frequency of visual loss after successful retinal detachment (RD) surgery in macula-on patients in a multicentric, prospective series of RD. Methods. Clinical variables from consecutive macula-on RD patients were collected in a prospective multicentric study. Visual loss was defined as at least a reduction in one line in best corrected visual acuity (VA) with Snellen chart. The series were divided into 4 subgroups: (1) all macula-on eyes (n = 357); (2) macula-on patients with visual loss at the third month of follow-up (n = 53) which were further subdivided in (3) phakic eyes (n = 39); and (4) pseudophakic eyes (n = 14). Results. Fifty-three eyes (14.9%) had visual loss three months after surgery (n = 39 phakic eyes; n = 14 pseudophakic eyes). There were no statistically significant differences between them regarding their clinical characteristics. Pars plana vitrectomy (PPV) was used in 67.2% of cases, scleral buckle in 57.7%, and scleral explant in 11.9% (36.1% were combined procedures). Conclusions. Around 15% of macula-on RD eyes lose VA after successful surgery. Development of cataracts may be one cause in phakic eyes, but vision loss in pseudophakic eyes could have other explanations such as the effect of released factors produced by retinal ischemia on the macula area. Further investigations are necessary to elucidate this hypothesis. PMID:26640704

  3. Silicone Oil Reinjection without Macular Buckling for Treatment of Recurrent Myopic Macular Hole Retinal Detachment after Silicone Oil Removal

    PubMed Central

    Ghoraba, Hammouda Hamdy; Elgouhary, Sameh Mohamed; Mansour, Hosam Osman

    2014-01-01

    Purpose. To evaluate the efficacy of silicone oil (S.O) reinjection without macular buckling for treatment of recurrent myopic macular hole retinal detachment (MHRD) after silicone oil removal. Methods. A retrospective consecutive interventional study from medical reports on cases of myopic MHRD. Fifty-three eyes of 51 patients underwent silicone oil removal after successful repair of MHRD were reviewed. The main outcomes were the retinal status after silicone oil removal and management of recurrent cases. Results. The rate of recurrent RD (Re RD) after silicone oil removal was 11.3% (6 out of 53 eyes). One case refused any other interference. In the remaining 5 eyes, 4 eyes (80%) could be reattached by S.O re-injection and one eye (20%) developed Re RD after S.O re-injection. Range of followup after management of recurrence was 5–53 months (mean 18.7 months). Conclusions. This case series concluded that the risk factors for recurrent RD after silicone oil removal from cases of myopic MHRD were high myopia, open flat MH, and large posterior staphyloma. Revision of vitrectomy and S.O re-injection can reattach most of recurrent cases. PMID:24672706

  4. Integrating Scleral Buckling, Transscleral Drainage of Subretinal Fluid, Intravitreal Anti-Vascular Endothelial Growth Factor, and Laser Photocoagulation in Stage 3B Coats' Total Retinal Detachment.

    PubMed

    Huang, Ying-Chen; Lai, Chi-Chun; Wu, Wei-Chi

    2016-09-01

    The integration of quadruple therapy in a 13-year-old boy with stage 3B Coats' disease achieved retinal reattachment and visual improvement. Scleral buckling might play a role in retinal detachment in Coats' disease, although it has previously been considered insignificant. Instead of performing vitrectomy and internal drainage with a drainage hole in the retina, less-invasive procedures that do not require retinotomy appear to be beneficial in cases of advanced Coats' disease. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:865-868.].

  5. Unsuccessful vitrectomy without gas tamponade for macular retinal detachment and retinoschisis without optic disc pit.

    PubMed

    Hotta, Kazuki

    2004-01-01

    The mechanism of subretinal fluid accumulation in optic disc pit maculopathy is unknown. A 67-year-old Japanese woman complaining of blurred vision in her right eye presented with a best-corrected visual acuity of 20/200. Slit-lamp biomicroscopy and optical coherence tomography examination showed maculopathy typically associated with optic disc pits, except that the patient had no optic disc pit. Long-acting gas tamponade was required to achieve reattachment of the retina and retinoschisis after initial failure of surgery using surgically induced vitreous detachment without either fluid-air exchange or gas injection. Vitreous traction may not have played a major role in introducing fluid into the submacular space in this case. Gas tamponade may be indispensable to achieve surgical success. This may also pertain to some cases of optic nerve pits.

  6. Comparative Study of 27-Gauge versus 25-Gauge Vitrectomy for the Treatment of Primary Rhegmatogenous Retinal Detachment

    PubMed Central

    Rizzo, Stanislao; Virgili, Gianni

    2017-01-01

    Purpose. To compare the vitrectomy time, clinical outcomes, and complications between 27-gauge (27-G) and 25-gauge (25-G) vitrectomy in patients with primary rhegmatogenous retinal detachment (PRRD). Methods. Prospective, nonrandomized, comparative, interventional study. Forty consecutive patients with PRRD were recruited. Twenty patients underwent the 27-gauge procedure and twenty patients had the 25-gauge procedure. The main outcome measure of the study was the actual vitrectomy time. Results. The mean duration of vitreous removal was 23.2 min (SD 6.5) with 27-G vitrectomy and 19.6 min (SD 7.3) with 25-G vitrectomy, resulting in a difference of 3.6 min (95% confidence interval (95%CI): −8.0 to 0.8 mins, p = 0.11). Mean logMAR visual acuity improved from 1.70 ± 1.18 preoperatively to 0.12 ± 0.14 at final postoperative visit (p < 0.001) in the 27-G group and from 1.52 ± 1.15 preoperatively to 0.22 ± 0.30 at final postoperative visit (p < 0.001) in the 25-G group. The anatomical success rate after a single operation was 90.0% and 85.0% in the 27-G and in the 25-G groups (p = 0.63), respectively. Intraoperative iatrogenic retinal breaks (IRBs) occurred in 2 eyes in the 27-G group and 1 eye in the 25-G group. Conclusions. Twenty-seven-gauge vitrectomy may be a safe and effective surgery for the treatment of PRRD. PMID:28367324

  7. Vitreous advanced glycation endproducts and α-dicarbonyls in retinal detachment patients with type 2 diabetes mellitus and non-diabetic controls

    PubMed Central

    Mulder, Douwe J.; Schalkwijk, Casper G.; Scheijen, Jean L.; Smit, Andries J.; Los, Leonoor I.

    2017-01-01

    Purpose Advanced glycation endproducts (AGEs) and their precursors α-dicarbonyls are implicated in the progression of diabetic retinopathy. The purpose of this study was to assess AGEs and α-dicarbonyls in the vitreous of patients with type 2 diabetes mellitus (T2DM) with early stages or absence of diabetic retinopathy. Methods We examined vitreous samples obtained during vitrectomy from 31 T2DM patients presenting themselves with rhegmatogenous retinal detachment and compared these to 62 non-diabetic rhegmatogenous retinal detachment patients, matched on age, estimated glomerular filtration rate, smoking, intra-ocular lens implantation, and proliferative vitreoretinopathy. AGEs (pentosidine, Nε-(carboxymethyl)lysine, Nε-(carboxyethyl)lysine, and 5-hydro-5-methylimidazolone) and α-dicarbonyls (3-deoxyglucosone, methylglyoxal, and glyoxal) were measured by ultra performance liquid chromatography or high performance liquid chromatography. Skin autofluorescence was measured by the AGE Reader. Results Mean age was 64 ± 7.6 years for T2DM patients and 63 ± 8.1 years for controls. For T2DM patients, median diabetes duration was 2.2 (0.3–7.4) years. Non-proliferative diabetic retinopathy was present in 1 patient and classified as absent or background retinopathy in 30 patients. Vitreous levels of pentosidine (2.20 vs. 1.59 μmol/mol lysine, p = 0.012) and 3-deoxyglucosone (809 vs. 615 nmol/L, p = 0.001) were significantly elevated in T2DM patients compared to controls. Other AGEs and α-dicarbonyls in the vitreous were not significantly different. There was a trend for increased skin autofluorescence in T2DM patients as compared to controls (p = 0.07). Conclusions Pentosidine and 3-deoxyglucosone concentrations were increased in the vitreous of rhegmatogenous retinal detachment patients with a relatively short duration of diabetes compared to non-diabetic rhegmatogenous retinal detachment patients. PMID:28264049

  8. Computational Simulation of Scleral Buckling Surgery for Rhegmatogenous Retinal Detachment: On the Effect of the Band Size on the Myopization.

    PubMed

    Lanchares, Elena; Del Buey, María A; Cristóbal, José A; Calvo, Begoña; Ascaso, Francisco J; Malvè, Mauro

    2016-01-01

    A finite element model (FE) of the eye including cornea, sclera, crystalline lens, and ciliary body was created to analyze the influence of the silicone encircling bandwidth and the tightness degree on the myopia induced by scleral buckling (SB) procedure for rhegmatogenous retinal detachment. Intraocular pressure (IOP) was applied to the reference geometry of the FE model and then SB surgery was simulated with encircling bandwidths of 1, 2, and 2.5 mm. Different levels of tightening and three values of IOP were applied. The anterior segment resulted as unaffected by the surgery. The highest value of Cauchy stress appeared in the surroundings of the implant, whereas no increment of stress was observed either in anterior segment or in the optic nerve head. The initial IOP did not appear to play any role in the induced myopia. The wider the band, the greater the induced myopia: 0.44, 0.88, and 1.07 diopters (D) for the 1, 2, and 2.5 mm bandwidth, respectively. Therefore, patients become more myopic with a wider encircling element. The proposed simulations allow determining the effect of the bandwidth or the tightness degree on the axial lengthening, thus predicting the myopic increment caused by the encircling surgery.

  9. Considerations in Management of Rhegmatogenous Retinal Detachment in One Eyed Pregnant Females: A Report of Two Cases

    PubMed Central

    Ashish, M; Alok, S; Elesh, J; Shubhi, T

    2015-01-01

    The aim of this case report is to discuss issues related to management of one eyed pregnant female. A 26-year-old female (Patient A) and 28-year-old female (Patient B) both in second trimester and one eyed presented to our outpatient department with diminution of vision due to rhegmatogenous retinal detachment (RRD). Retina was attached in Patient A following scleral buckling surgery but Patient B required pars plana vitrectomy with silicon oil tamponade. Best corrected visual acuity in both patients did improve from 1/60 to 6/24 and 6/18, respectively at 6 months follow-up. Exudative RDs are known to occur in pregnancy as a complication of preeclampsia, but RRD in pregnancy although co-incidental poses certain challenge with regard to management of such cases especially if the patient is one-eyed. Things to consider for management include (1) type of anesthesia (2) surgical positioning (3) positioning after surgery (4) anti-glaucoma medication if required (5) corticosteroid treatment in pregnancy (6) to provide them ambulatory vision as early as possible. With proper management and monitoring it is possible to provide them with early ambulatory vision without offering any harm to her pregnancy and fetus. PMID:27057392

  10. Computational Simulation of Scleral Buckling Surgery for Rhegmatogenous Retinal Detachment: On the Effect of the Band Size on the Myopization

    PubMed Central

    Lanchares, Elena; del Buey, María A.; Cristóbal, José A.; Ascaso, Francisco J.

    2016-01-01

    A finite element model (FE) of the eye including cornea, sclera, crystalline lens, and ciliary body was created to analyze the influence of the silicone encircling bandwidth and the tightness degree on the myopia induced by scleral buckling (SB) procedure for rhegmatogenous retinal detachment. Intraocular pressure (IOP) was applied to the reference geometry of the FE model and then SB surgery was simulated with encircling bandwidths of 1, 2, and 2.5 mm. Different levels of tightening and three values of IOP were applied. The anterior segment resulted as unaffected by the surgery. The highest value of Cauchy stress appeared in the surroundings of the implant, whereas no increment of stress was observed either in anterior segment or in the optic nerve head. The initial IOP did not appear to play any role in the induced myopia. The wider the band, the greater the induced myopia: 0.44, 0.88, and 1.07 diopters (D) for the 1, 2, and 2.5 mm bandwidth, respectively. Therefore, patients become more myopic with a wider encircling element. The proposed simulations allow determining the effect of the bandwidth or the tightness degree on the axial lengthening, thus predicting the myopic increment caused by the encircling surgery. PMID:27413542

  11. [Results of a morphological study of the experimental use of polyglycolide fiber explants in the surgery of retinal detachment].

    PubMed

    Kiseleva, O A; Ziangirova, G G; Iomdina, E N; Aliev, T I

    2005-01-01

    The paper presents the results of experimental use of a polyglycolide material-based filling for temporary episcleral filling in retinal detachment. Thorough comparative morphological and biomechanical studies of 120 experimental eyes in different periods after scleroplasty, by using an inflatable balloon catheter, homoscleral and polyglycolide fillings, have indicated that the polyglycolide filling material is completely lysed by ocular tissues within 60-90 days, which rules out a repeated surgical intervention for removal of temporary filling (for example, an inflatable balloon catheter), by preserving the constancy of the depth of scleral pressing-in. The short existence of a chemically indifferent polyglycolide filling in the ocular tissues excludes its negative effect on the surrounding structures of the eye, minimizes the likelihood of the occurrence of early postoperative complications, but thereby leading to a substantial increase in the biochemical stability of the scleral-and-chorioretinal complex in the early postoperative periods and ensuring increased resistance to dynamic loads, by forming a stable scleral-and-chorioretinal adhesion 3 months after surgery. The findings suggest that the designed polyglycolide explant has advantages and that it is expedient to introduce the new Russian resolving polyglycolide fiber explants into clinical practice (for scleroplastic operations).

  12. A Mystery of Bilateral Annular Choroidal and Exudative Retinal Detachment with No Systemic Involvement: Is It Part of Vogt-Koyanagi-Harada Disease Spectrum or a New Entity?

    PubMed

    Elaraoud, Ibrahim; Andreatta, Walter; Jiang, Li; Damer, Kenan; Al-Ibrahim, Jalil

    2017-01-01

    A 65-year-old Caucasian male presented to the eye emergency department with bilateral significant visual loss. He was otherwise healthy with no significant past medical history. Ophthalmic history was significant for chronic open-angle glaucoma, for which the patient was using latanoprost once daily to both eyes. There was no preceding history of trauma or ocular surgery and the patient was emmetropic. Two weeks prior to his presentation, he reported a headache, which settled spontaneously. Slit-lamp examination demonstrated bilateral keratic precipitates, bilateral significantly shallow anterior chamber, and bilaterally normal intraocular pressures of 16 mm Hg. Fundal examination was significant for bilateral 360-degree choroidal detachments with exudative retinal detachment involving the maculae. These findings were confirmed using wide-field fundus photography, B-scan ultrasonography, and optical coherence tomography. Fundus fluorescein angiography did not reveal any evidence of retinal vasculitis. Indocyanine green chorioangiography of the posterior pole showed multiple areas of focal choroidal hypoperfusion. Extensive systemic investigation demonstrated no infectious, neoplastic, or inflammatory cause, and the patient did not complain of any systemic symptoms. Treatment with high-dose intravenous methylprednisolone was administered and this brought about complete resolution of both choroidal and retinal detachments, with partial visual recovery.

  13. A Mystery of Bilateral Annular Choroidal and Exudative Retinal Detachment with No Systemic Involvement: Is It Part of Vogt-Koyanagi-Harada Disease Spectrum or a New Entity?

    PubMed Central

    Elaraoud, Ibrahim; Andreatta, Walter; Jiang, Li; Damer, Kenan; Al-Ibrahim, Jalil

    2017-01-01

    A 65-year-old Caucasian male presented to the eye emergency department with bilateral significant visual loss. He was otherwise healthy with no significant past medical history. Ophthalmic history was significant for chronic open-angle glaucoma, for which the patient was using latanoprost once daily to both eyes. There was no preceding history of trauma or ocular surgery and the patient was emmetropic. Two weeks prior to his presentation, he reported a headache, which settled spontaneously. Slit-lamp examination demonstrated bilateral keratic precipitates, bilateral significantly shallow anterior chamber, and bilaterally normal intraocular pressures of 16 mm Hg. Fundal examination was significant for bilateral 360-degree choroidal detachments with exudative retinal detachment involving the maculae. These findings were confirmed using wide-field fundus photography, B-scan ultrasonography, and optical coherence tomography. Fundus fluorescein angiography did not reveal any evidence of retinal vasculitis. Indocyanine green chorioangiography of the posterior pole showed multiple areas of focal choroidal hypoperfusion. Extensive systemic investigation demonstrated no infectious, neoplastic, or inflammatory cause, and the patient did not complain of any systemic symptoms. Treatment with high-dose intravenous methylprednisolone was administered and this brought about complete resolution of both choroidal and retinal detachments, with partial visual recovery. PMID:28203189

  14. Rhegmatogenous Retinal Detachment with a High Risk of Proliferative Vitreoretinopathy Treated with Episcleral Surgery and an Intravitreal Dexamethasone 0.7-mg Implant

    PubMed Central

    Reibaldi, Michele; Russo, Andrea; Longo, Antonio; Bonfiglio, Vincenza; Uva, Maurizio G.; Gagliano, Caterina; Toro, Mario D.; Avitabile, Teresio

    2013-01-01

    Purpose To report a case of rhegmatogenous retinal detachment with a high risk of proliferative vitreoretinopathy (PVR) effectively treated with episcleral surgery and an intravitreal dexamethasone 0.7-mg implant. Methods A 35-year-old Caucasian man with a macula-off rhegmatogenous subtotal retinal detachment that had persisted for 1 month in his myopic left eye presented several risk factors that could have led to the development of PVR after retinal detachment surgery. His best corrected visual acuity was hand motion. He received an intravitreal dexamethasone 0.7-mg implant (Ozurdex®) after episcleral surgery to prevent this complication. Results At least 9 months after surgery, no sign of PVR or pucker has developed in the treated eye. Visual acuity improved to 0.2, the retina was attached and no complications were observed. Conclusion Intravitreal dexamethasone 0.7-mg implant (Ozurdex) could be considered as off-label treatment following episcleral surgery to prevent PVR. PMID:23687501

  15. Endodrainage, Tumor Photocoagulation, and Silicone Oil Tamponade for Primary Exudative Retinal Detachment due to Choroidal Melanoma Persisting after Proton Beam Therapy

    PubMed Central

    Seibel, Ira; Cordini, Dino; Willerding, Gregor; Riechardt, Aline Isabel; Joussen, Antonia Maria

    2014-01-01

    Background Choroidal melanoma is frequently accompanied by an exudative retinal detachment that can persist after proton beam therapy. This study investigates whether vitrectomy without tumor resection improves the clinical outcome. Methods This is a retrospective interventional case series. Twenty patients with choroidal melanoma with exudative retinal detachment involving the macula were treated by vitrectomy, endodrainage, photocoagulation, and silicone oil tamponade after proton beam therapy. Results The mean follow-up was 38.4 months (median 21.5, range 12.0-122.0). The mean time between proton beam therapy and surgery was 4.5 months (range 0.1-9.2). Reattachment was achieved in 95% of the patients after one vitrectomy. One patient was lost to follow-up because enucleation was performed after 45.9 months due to a secondary glaucoma. Mean visual acuity decreased from 1.1 to 1.8 logMAR before vitrectomy and after 4 years, respectively. No patient showed local tumor recurrence. Metastatic disease was present in 1 patient after 15.2 months, and this patient died after 19.2 months. Conclusion Vitrectomy is indicated after therapeutic proton beam irradiation in patients who present with persisting exudative retinal detachment involving the macula and high local or systemic risk factors for hemorrhagic complications, thus excluding endoresection. PMID:27175359

  16. Scleral buckling versus vitrectomy for macula-off rhegmatogenous retinal detachment as accessed with spectral-domain optical coherence tomography: a retrospective observational case series

    PubMed Central

    2013-01-01

    Background Scleral buckling surgery and pars plana vitrectomy are competing methods in the treatment of retinal detachment. The recent development of spectral-domain optical coherence tomography (SD-OCT) has dramatically improved the visualization of the photoreceptor layer relative to conventional OCT, and offers new opportunities to investigate the discordances between anatomic and functional outcomes after retinal detachment surgery. Hence, the study aim was to use SD-OCT to compare the postoperative macular recovery between scleral buckling and vitrectomy for macular-off rhegmatogenous retinal detachment. Methods In this retrospective observational case series, we observed 32 patients who underwent scleral buckling surgery (group 1) and 26 patients who underwent pars plana vitrectomy (group 2) as the primary surgery for macula-off rhegmatogenous retinal detachment. OCT was used to examine microstructural changes in the macular area. Results The mean visual acuity improvement was 0.4 ± 0.8 logMAR in group 1 and 0.7 ± 0.9 logMAR in group 2. As detected by SD-OCT, subretinal fluid was present in 26 of the group 1 eyes (81.3%) and 5 of the group 2 eyes (19.2%) at 8 weeks postoperatively. This difference was statistically significant (Fisher’s exact test, P < 0.05). Moreover, detection by SD-OCT revealed epiretinal membranes in 5 of the group 1 eyes (15.6%) and 11 of the group 2 eyes (42.3%), a difference that was statistically significant (Fisher’s exact test, P < 0.05). Conclusions Macular recovery and the mean visual acuity differed between the 2 groups of patients. With the help of SD-OCT, we observed that subretinal fluids could persist for a relatively longer period after scleral buckling. Based on our results, we conclude that primary vitrectomy surgery is a better choice for macular recovery of the macula-off rhegmatogenous retinal detachment. PMID:23587195

  17. Heavy lifting at work and risk of retinal detachment: a population-based register study in Denmark

    PubMed Central

    Curti, Stefania; Coggon, David; Hannerz, Harald; Mattioli, Stefano

    2016-01-01

    Objectives To investigate the relationship between rhegmatogenous retinal detachment (RRD) and frequent heavy lifting in a Danish working population through national register data. Methods A dynamic cohort of all men aged 20–59 years in Denmark was followed through the Danish Occupational Hospitalisation Register from 1995 to 2010 for diagnosed RRD. Occupational categories were classified according to their potential for heavy lifting in 4 main groups: heavy lifters, manual workers unlikely to be heavy lifters, other manual workers and non-manual workers unlikely to be heavy lifters. The age-standardised rate of diagnosed RRD for heavy lifting occupations was compared with that experienced by the other 3 occupational categories. Rate ratios (RRs) and 95% CIs were estimated through a Poisson regression model adjusted for calendar period and age group. Results The highest age-standardised rate of diagnosed RRD was recorded among non-manual workers performing occupational activities unlikely to be associated with heavy lifting (18.0 cases per 100 000 person-years). The RR for workers in jobs expected to entail a high frequency of heavy lifting compared with manual workers whose occupation was unlikely to be associated with heavy lifting was 0.91 (95% CI 0.73 to 1.14), while in comparison with other manual workers, it was 0.93 (95% CI 0.78 to 1.11). The RR compared with non-manual workers in occupations unlikely to entail heavy lifting was 0.51 (95% CI 0.43 to 0.60). Conclusions These findings do not support an association of occupational heavy lifting with diagnosed RRD. The epidemiological evidence for this association is still inconclusive. Future studies should use a more specific measure of exposure to resolve the outstanding uncertainties. PMID:26561504

  18. Valved versus nonvalved cannula small-gauge pars plana vitrectomy for repair of retinal detachments with Grade C proliferative vitreoretinopathy

    PubMed Central

    Oellers, Patrick; Stinnett, Sandra; Hahn, Paul

    2016-01-01

    Purpose Valved cannulas are a recent addition to small-gauge pars plana vitrectomy (PPV) and provide stable intraocular fluidics. The goal of this study was to compare outcomes and postoperative complication rates of valved vs nonvalved cannula small-gauge PPV for repair of retinal detachments (RDs) complicated by Grade C proliferative vitreoretinopathy (PVR). Methods A retrospective chart review of 364 consecutive eyes with either valved or nonvalved cannula PPV for RD repair was performed. The primary outcomes were single surgery and final anatomic success and change in best-corrected visual acuity for repair of RDs complicated by Grade C PVR. Results We identified 36 eyes in the valved group and 31 eyes in the nonvalved group with Grade C PVR RD. The single surgery success was 83% vs 77% (P=0.555) and the final anatomic success was 94% vs 87% (P=0.404) in the valved vs nonvalved eyes, respectively. The mean final visual acuity gain was −0.36 logarithm of the minimum angle of resolution (logMAR; approximate Early Treatment Diabetes Retinopathy Study [ETDRS] score =17 letters) in valved eyes vs −0.33 logMAR (approximate ETDRS score =16 letters) in nonvalved eyes (P=0.81). Postoperative complication rates including postoperative day 1 hypotony, hypertony, and anterior chamber fibrin formation; postoperative retention of intraocular or subretinal perfluorocarbon liquid; and subsequent epiretinal membrane peel were not statistically different between groups. Conclusion Valved cannula PPV yields equivalent visual acuity and anatomic outcomes without increased postoperative complication rates compared to traditional nonvalved cannula PPV for Grade C PVR-associated RD repair. PMID:27313445

  19. Comparison of outcomes: scleral buckling and pars plana vitrectomy versus vitrectomy alone for primary repair of rhegmatogenous retinal detachment

    PubMed Central

    Lindsell, Luke B; Sisk, Robert A; Miller, Daniel M; Foster, Robert E; Petersen, Michael R; Riemann, Christopher D; Hutchins, Robert K

    2017-01-01

    Objective To assess the combination of scleral buckling (SB) and pars plana vitrectomy (PPV) versus PPV alone in the primary repair of rhegmatogenous retinal detachments (RRDs). Methods The current study was a retrospective, comparative, interventional, consecutive case series of 179 eyes of 174 patients who underwent primary RRD repair by five surgeons between January 1, 2008 and December 31, 2010, utilizing SB with PPV or PPV. Univariate and multivariate analyses were used to compare the efficacy of the two surgical strategies and assess for risk factors of proliferative vitreoretinopathy (PVR). Results Single surgery anatomic success (SSAS) was similar (P=0.76) between the PPV group (112 of 132 eyes, 85%) and SB with PPV group (39 of 47 eyes, 83%). Final anatomic success was 100% in each group. There was no difference in rates of PVR formation (PPV 16% vs SB with PPV 19%, P=0.70). Final logarithm of the minimum angle of resolution acuity was 0.33 (20/43) in the PPV group and 0.37 (20/47) in the SB with PPV group (P=0.62). Postoperative anterior chamber fibrin was highly correlated with PVR formation (PVR 13% vs no PVR 0.7%, P=0.003; odds ratio =68.37, P=0.007). Separate analysis of medium- to high-complexity cases showed similar SSAS (PPV 86% vs SB with PPV 83%, P=0.45). Conclusion SB with PPV versus PPV alone were similarly efficacious for repair of primary RRDs of varying complexity. SSAS rates, PVR incidence, and final visual acuities were not significantly different. PMID:28053500

  20. Associations Between Retinal Pigment Epithelium and Drusen Volume Changes During the Lifecycle of Large Drusenoid Pigment Epithelial Detachments

    PubMed Central

    Balaratnasingam, Chandrakumar; Yannuzzi, Lawrence A.; Curcio, Christine A.; Morgan, William H.; Querques, Giuseppe; Capuano, Vittorio; Souied, Eric; Jung, Jesse; Freund, K. Bailey

    2016-01-01

    Purpose Drusenoid pigment epithelial detachments (PEDs) are a defined path to atrophy in age-related macular degeneration (AMD). We analyzed the relationships between retinal pigment epithelium (RPE) and drusen volume changes during the PED lifecycle, using spectral-domain optical coherence tomography (SD-OCT). Methods Twenty-one cases of drusenoid PED tracked using SD-OCT through periods of growth and collapse were evaluated. Volumetric calculations and piece-wise linear regression analysis were used to determine the breakpoint between growth and collapse. Spectral-domain OCT scans were independently evaluated for the appearance of intraretinal hyperreflective foci, acquired vitelliform lesions (AVLs), and disruptions to the RPE+basal lamina band. Timing of these events with respect to the breakpoint was statistically evaluated. Morphometric characteristics of drusenoid PEDs were correlated with rate of PED collapse and final visual acuity. Results Mean age of subjects was 75.3 years and mean period of follow up was 4.1 years (median 4.5 years; range, 0.6–6.6 years). The lifecycle of drusenoid PEDs was asymmetric, in that the rate of collapse (0.199 mm3/month) is significantly faster (P < 0.001) than the rate of growth (0.022 mm3/month). Appearance of intraretinal hyperreflective foci and AVLs preceded the breakpoint (both P < 0.001). The timing of disruptions to the RPE+basal lamina band did not differ from the breakpoint (P = 0.510). Maximal height, volume, and diameter of drusenoid PEDs were inversely correlated with final visual acuity (all P < 0.001) and positively correlated with the rate of PED collapse (all P < 0.001). Conclusions Spectral-domain OCT signatures, plausibly attributable to anteriorly migrated RPE and disintegration of the RPE layer, precede or occur simultaneously with changes in volume of drusenoid PED during the lifecycle of this lesion. PMID:27760262

  1. Three-Year Efficacy and Safety of a Silicone Oil-Filled Foldable-Capsular-Vitreous-Body in Three Cases of Severe Retinal Detachment

    PubMed Central

    Lin, Xiaofeng; Sun, Xuyuan; Wang, Zhenfang; Jiang, Zhaoxin; Liu, Yaqin; Wang, Peijuan; Gao, Qianying

    2016-01-01

    Purpose We previously designed a novel foldable capsular vitreous body (FCVB) to treat severe retinal detachment and evaluated its performance in a 1-year follow up study. The purpose of this study was to determine the efficacy and safety of a silicone oil (SO)-filled FCVB in a 3-year follow-up. Methods Standard three-port pars plana vitrectomy was performed, and the FCVB was triple folded and implanted in the vitreous cavity of three eyes. The SO then was injected into the capsule to support the retina. The eyes were examined using Goldmann applanation tonometry, fundus photography, optical coherence tomography (OCT), noncontact specular microscopy, and ultrasound biomicroscopy over a 3-year implantation period. Results At the 3-year follow-up, retinal reattachment was achieved in all three cases, with steady intraocular pressure. The visual acuity showed slight fluctuations, and it was slightly increased compared to baseline. Optical coherence tomography revealed decreased retinal thickness and an altered retinal structure in the implanted eyes compared to the control eyes. No keratopathy, glaucoma, SO leakage, SO emulsification, or other apparent complications occurred during the observation period. Conclusion The SO-filled FCVB was effective and safe as a vitreous substitute in three eyes over a 3-year observation period. Translational Relevance Silicone oil emulsification is a severe complication after retinal detachment surgery. On the basis of animal experiments, we investigated a new strategy and product, the FCVB, to overcome this complication. In this pilot study, FCVB limited SO emulsification and migration. This study could lay the foundation for a further multicenter clinical trial. PMID:26855843

  2. Results of surgical treatment of retinal detachments complicated with proliferative vitreoretinopathies with the use of perfluropropane (C3F8) gas.

    PubMed

    Vardanyan, A H; Hovakimyan, A V; Hambartsumyan, A V

    2000-01-01

    The aim of the current study is the efficiency assessment of C3F8 gas usage in posterior vitrectomies in patients having retinal detachment of different etiologies with presence of proliferative vitreoretinopathies and retinal tears. 34 patients have undergone posterior vitrectomy with the usage of perfluoropropane C3F8 gas for providing internal tamponade. Total attachment of retina has been attached in all 34 cases and C3F8 gas has been injected in each eye. The most frequent complications that have been revealed after the usage of C3F8 gas and their management are reflected in the article. Thus, we came to a conclusion that vitrectomy in combination with episcleral buckling, transvitreal drainage of subretinal liquid, diode endolaser coagulation of retina and internal tamponade with C3F8 gas is effective and pathogenetikally proved method for treatment of rhegmatogenous retinal detachments complicated with severe vitreoretinopathies. The achievement of perfect anatomical results depends on manifestation degree of proliferative vitreoretinopathy. This study was supported by grant of the Ministry of Health of Armenia.

  3. Retinal Detachment Vision Simulator

    MedlinePlus

    ... Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Academy Publications EyeNet Ophthalmology Information for: International Ophthalmologists Media Medical Students Patients and Public Technicians and Nurses ...

  4. Scleral buckling for primary rhegmatogenous retinal detachment using noncontact wide-angle viewing system with a cannula-based 25 G chandelier endoilluminator

    PubMed Central

    Imai, Hisanori; Tagami, Mizuki; Azumi, Atsushi

    2015-01-01

    Purpose The aim of this study is to report the result of scleral buckling (SB) using a combination of a noncontact wide-angle viewing system and a cannula-based 25 G chandelier endoilluminator. Methods Retrospective analyses of the medical records of 79 eyes of 79 patients with primary uncomplicated rhegmatogenous retinal detachments who had underwent SB using a combination of a noncontact wide-angle viewing system and a chandelier endoilluminator were performed. Results There were 50 men and 29 women. The mean ± standard deviation age was 43.7±16.0 years. Their preoperative best-corrected visual acuity (BCVA) was 0.31±0.65 logMAR units. The final BCVA was 0.10±0.31 logMAR units, which was significantly better than the preoperative BCVA (P<0.01). The initial and final anatomical success rates were 92.4% and 100%, respectively. Backward logistic multiple regression analysis revealed no relationship between explanatory variables and the primary anatomic success (P=0.104). Conclusion SB using a combination of a noncontact wide-angle viewing system and a chandelier endoilluminator is a modified new technique and may be a valid option for the management of rhegmatogenous retinal detachments. PMID:26635466

  5. Comparison of the Inverted Internal Limiting Membrane Flap Technique and the Internal Limiting Membrane Peeling for Macular Hole with Retinal Detachment

    PubMed Central

    Matsumura, Takehiro; Takamura, Yoshihiro; Tomomatsu, Takeshi; Arimura, Shogo; Gozawa, Makoto; Kobori, Akira; Inatani, Masaru

    2016-01-01

    Purpose To evaluate the efficacy of the inverted internal limiting membrane (ILM) flap technique in vitrectomy for macular hole (MH) with retinal detachment (RD) compared with vitrectomy using ILM peeling. Methods A retrospective case series study was performed. Twenty-two eyes of 22 patients who underwent vitrectomy for MH with RD and followed-up more than 12 months after the surgery were included in this study. We retrospectively reviewed the medical records of patients who underwent vitrectomy with inverted ILM flap technique or vitrectomy with ILM peeling. Ten patients who had been treated vitrectomy with inverted ILM flap technique, and 12 patients who had been treated vitrectomy with ILM peeling were analyzed. We evaluated changes in best-corrected visual acuity (BCVA) before and after surgery, closing rates of MH, and retinal reattachment rates and compared between both groups. Results MH was closed and RD was reattached postoperatively in 9 eyes (90%) in the inverted ILM flap group. In the ILM peeling group, the MH was closed in 4 eyes (33.3%) and the retinas were reattached in 6 eyes (50%) after surgery. Significant improvement in BCVA after surgery (P = 0.0017) was only found in the inverted ILM flap group. Conclusions Higher rates of closed MH and retinal reattachment, and small but significant improvement in BCVA were found in the inverted ILM flap group. Based on our data, the inverted ILM flap technique may be useful in vitrectomy for MH with RD. PMID:27764184

  6. Macular hole formation and spontaneous closure after vitrectomy for rhegmatogenous retinal detachment documented by spectral-domain optical coherence tomography: Case report and literature review

    PubMed Central

    Kim, Jin Young; Park, Sung Pyo

    2015-01-01

    This case report describes macular hole (MH) formation and spontaneous closure after vitrectomy for rhegmatogenous retinal detachment (RRD) repair. A 58-year-old man referred with a macula-off superior RRD, in whom vitrectomy was performed. MH with vitreomacular traction (VMT) caused by the posterior vitreous cortex remnants developed 2 weeks after vitrectomy. Four weeks postoperatively, optical coherence tomography revealed resolution of the VMT and spontaneous closure of MH without providing any treatment. This is the first report of an MH formation and spontaneous closure after vitrectomy for RRD. This suggests that the VMT mediated by the posterior vitreous cortex remnants has an important role in the development of secondary MH. PMID:26655006

  7. Risk of Tractional Retinal Detachment Following Intravitreal Bevacizumab Along with Subretinal Fluid Drainage and Cryotherapy for Stage 3B Coats’ Disease

    PubMed Central

    Bhat, Vishalakshi; D’Souza, Palmeera; Shah, Parag K.; Narendran, V.

    2016-01-01

    Purpose: To review the surgical outcomes of intravitreal bevacizumab (IVB) along with subretinal fluid drainage with cryotherapy in patients with stage 3B Coats’ disease. Materials and Methods: A retrospective study of seven cases of stage 3B Coats’ disease, who underwent subretinal fluid drainage with cryopexy, from May 2011 to March 2014. Five eyes received additional IVB at the end of surgery. Green laser therapy was performed on telangiectatic vessels postoperatively. Results: The mean age was 34 months (range, 10-84 months). Mean follow-up was 19 months. Six patients (85.7%) had an attached retina at final follow-up. Three out of four patients (75%) that received IVB developed tractional retinal detachments (TRDs). Two eyes that did not receive bevacizumab did not develop any traction. None progressed to neovascular glaucoma or phthisis bulbi. Conclusion: Simultaneous injection of bevacizumab along with subretinal drainage and cryotherapy for advanced Coats’ disease could not avoid TRD. PMID:27162454

  8. Retinal Disorders

    MedlinePlus

    ... be serious enough to cause blindness. Examples are Macular degeneration - a disease that destroys your sharp, central vision Diabetic eye disease Retinal detachment - a medical emergency, when the retina is ... children. Macular pucker - scar tissue on the macula Macular hole - ...

  9. An Office-Based Fluid to Fluid Exchange Technique for the Treatment of Postvitrectomy Vitreous Cavity Hemorrhage and Secondary Glaucoma

    PubMed Central

    2017-01-01

    A case of postvitrectomy hemorrhage with secondary glaucoma successfully treated with an office-based fluid to fluid exchange is described. A 25 Ga trocar was placed 3 mm from the sclerocorneal limbus at the 2 o'clock position and connected to a 250 cc elevated bottle of balanced salt solution (BSS) through an intravenous (IV) line and an infusion cannula. Afterward, a 25 Ga needle was inserted 3 mm from the limbus at the 5 o'clock position approximately. The BSS fluid entered the eye through the 25 Ga trocar lavaging the vitreous cavity and the anterior chamber. About 4 to 6 cc of hemorrhagic fluid egressed the eye through the 25 Ga needle. PMID:28321352

  10. Serous Retinal Detachment Associated with Dome-Shaped Macula and Staphyloma Edge in Myopic Patients before and after Treatment with Spironolactone

    PubMed Central

    Fernández-Vega Sanz, Álvaro; Rangel, Carlos Mario; Villota Deleu, Eva; Fernández-Vega Sanz, Beatriz; Sánchez-Ávila, Ronald Mauricio

    2016-01-01

    Objective. Serous retinal detachment (SRD) is a common anatomical complication associated with dome-shaped macula (DSM) and staphyloma margin in myopic patients. Here we described the anatomical and functional outcomes obtained with the use of oral spironolactone, a mineralocorticoid antagonist, in the management of myopic patients with SRD associated with DSM and staphyloma margin. Methods. We evaluated both eyes of twelve myopic patients with long-standing SRD associated with DSM or staphyloma margin. The patients were treated daily for six months with oral spironolactone 50 mg. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT), determined by optical coherence tomography, were evaluated on the first day and on monthly follow-up visits. Results. Pretreatment BCVA (mean ± standard deviation) was 0.406 ± 0.324 LogMAR, and posttreatment BCVA was 0.421 ± 0.354 LogMAR (P = 0.489). Pretreatment CRT was 323.9 ± 78.6 μm, and after six months of treatment it was significantly lower, 291.2 ± 74.5 μm (P = 0.010). There were no treatment-related complications. Conclusions. We evaluated a novel treatment for SRD associated with DSM and staphyloma margin in myopic patients. After six months of treatment with the mineralocorticoid antagonist spironolactone, the subretinal fluid and CRT were significantly reduced; however, there was no improvement in BCVA. PMID:26942003

  11. Persistent subfoveolar fluid following retinal detachment surgery: an SD-OCT guided study on the incidence, aetiological associations, and natural history

    PubMed Central

    Tee, J J L; Veckeneer, M; Laidlaw, D A

    2016-01-01

    Purpose To investigate the incidence and natural history of persistent subfoveolar fluid (PSF) following surgery for macular off rhegmatogenous retinal detachment and the effect of PSF on photoreceptor structure and final visual acuity. Methods Retrospective study of 61 cases with post-operative optical coherence tomography (OCT) performed within 12 weeks of surgery. Based on aetiology, cases were categorized into tractional retinal tears (TRT) group or atrophic round holes and dialyses (RHD) group to investigate the incidence and duration of PSF. A Kaplan–Meier graph was plotted to compare survival time of subfoveolar fluid for both groups. Following secondary reclassification of cases into those with and without PSF, the effect of PSF on final visual acuity and photoreceptor structure was investigated with Mann–Whitney U-test used for comparison. Spearman's correlation testing was used to probe associations between time to recorded resolution of PSF with final visual acuity and photoreceptor structure. Results Incidence of PSF was greater in the RHD group and persisted for longer compared with TRT group. No detectable adverse effect of PSF on final visual acuity was seen however an individual case of severe photoreceptor atrophy was observed. No significant correlation was found between the time to recorded resolution of PSF and the final visual acuity or to photoreceptor grading scores. Conclusions A difference in incidence of PSF was detected between the aetiological groups. PSF was ubiquitous and slow to resolve in the RHD group. Most cases of PSF resolve without adverse sequelae; however, progressive photoreceptor atrophy and sub-optimal visual outcome may result in a minority. PMID:26742870

  12. Retinal Detachment: Torn or Detached Retina Symptoms

    MedlinePlus

    ... Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Academy Publications EyeNet Ophthalmology Information for: International Ophthalmologists Media Medical Students Patients and Public Technicians and Nurses ...

  13. Retinal Detachment: Torn or Detached Retina Diagnosis

    MedlinePlus

    ... Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Academy Publications EyeNet Ophthalmology Information for: International Ophthalmologists Media Medical Students Patients and Public Technicians and Nurses ...

  14. Retinal Detachment: Torn or Detached Retina Treatment

    MedlinePlus

    ... Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Academy Publications EyeNet Ophthalmology Information for: International Ophthalmologists Media Medical Students Patients and Public Technicians and Nurses ...

  15. Disruption of murine Adamtsl4 results in zonular fiber detachment from the lens and in retinal pigment epithelium dedifferentiation

    PubMed Central

    Collin, Gayle B.; Hubmacher, Dirk; Charette, Jeremy R.; Hicks, Wanda L.; Stone, Lisa; Yu, Minzhong; Naggert, Jürgen K.; Krebs, Mark P.; Peachey, Neal S.; Apte, Suneel S.; Nishina, Patsy M.

    2015-01-01

    Human gene mutations have revealed that a significant number of ADAMTS (a disintegrin-like and metalloproteinase (reprolysin type) with thrombospondin type 1 motifs) proteins are necessary for normal ocular development and eye function. Mutations in human ADAMTSL4, encoding an ADAMTS-like protein which has been implicated in fibrillin microfibril biogenesis, cause ectopia lentis (EL) and EL et pupillae. Here, we report the first ADAMTSL4 mouse model, tvrm267, bearing a nonsense mutation in Adamtsl4. Homozygous Adamtsl4tvrm267 mice recapitulate the EL phenotype observed in humans, and our analysis strongly suggests that ADAMTSL4 is required for stable anchorage of zonule fibers to the lens capsule. Unexpectedly, homozygous Adamtsl4tvrm267 mice exhibit focal retinal pigment epithelium (RPE) defects primarily in the inferior eye. RPE dedifferentiation was indicated by reduced pigmentation, altered cellular morphology and a reduction in RPE-specific transcripts. Finally, as with a subset of patients with ADAMTSL4 mutations, increased axial length, relative to age-matched controls, was observed and was associated with the severity of the RPE phenotype. In summary, the Adamtsl4tvrm267 model provides a valuable tool to further elucidate the molecular basis of zonule formation, the pathophysiology of EL and ADAMTSL4 function in the maintenance of the RPE. PMID:26405179

  16. Vitreous Detachment

    MedlinePlus

    ... of vision. Treatment How does vitreous detachment affect vision? Although a vitreous detachment does not threaten sight, ... hole or detached retina can lead to permanent vision loss in the affected eye. Those who experience ...

  17. Spectral-domain optical coherence tomography analysis of persistent subretinal fluid after scleral buckling surgery for macula-off retinal detachment

    PubMed Central

    Gharbiya, M; Malagola, R; Mariotti, C; Parisi, F; De Vico, U; Ganino, C; Grandinetti, F

    2015-01-01

    Purpose To determine the predictive value of markers for persistent subretinal fluid (SRF) absorption and the influence of subfoveal fluid on visual outcome after scleral buckle (SB) surgery for rhegmatogenous retinal detachment (RRD). Patients and methods This was a retrospective, observational study. We reviewed the medical records of 64 eyes of 64 patients who underwent SB surgery for macula-off RRD. Patients underwent clinical examination and spectral-domain optical coherence tomography before surgery, at 1 month and every 3 months postoperatively. The height and width of SRF bleb(s) were measured over time. Results Persistent SRF at 1 month was observed in 40 eyes (62.5%). SRF blebs were first detected 1.7±2.2 months postoperatively. In 29 cases that could be fully followed up, SRF blebs were completely absorbed 7.8±4.4 months postoperatively. Resolution of fluid was associated with an improvement of VA (P=0.003). Serial measurements of SRF bleb size showed that bleb width decreased significantly at all time points during the 12-month follow-up period (P<0.05), while significant bleb height decrease occurred from postoperative sixth month only (P<0.05). There was no correlation between VA outcomes and subfoveal bleb height or width (P>0.05). The cut-off value of the bleb width-to-height ratio level for predicting bleb absorption at 6 months was 7, with 89% sensitivity and 83% specificity. Conclusions Visual improvement may occur with late resolution of residual subfoveal fluid. A bleb width-to-height ratio >7 indicates a higher risk of SRF to persist beyond 6 months after surgery. PMID:26139048

  18. Therapy for acute retinal necrosis.

    PubMed

    Kawaguchi, Tatsushi; Spencer, Doran B; Mochizuki, Manabu

    2008-01-01

    Acute retinal necrosis is a progressive necrotizing retinopathy caused by herpes simplex virus (HSV) or varicella zoster virus (VZV). The mainstay of its treatment is antiviral therapy against these pathogenic organisms, such as intravenous acyclovir or oral valacyclovir. Systemic and topical corticosteroids together with antiviral therapy are used as an anti-inflammatory treatment to minimize damages to the optic nerve and retinal blood vessels. Because the majority of severe cases of the disease show occlusive retinal vasculitis, a low dosage of aspirin is used as anti-thrombotic treatment. Vitreo-retinal surgery is useful to repair rhegmatogenous retinal detachment, one of the main late-stage complications. Moreover, recent articles have reported some encouraging results of prophylactic vitrectomy before rhegmatogenous retinal detachment occurs. The efficacy of laser photocoagulation to prevent the development or extension of rhegmatogenous retinal detachment is controversial. Despite these treatments, the visual prognosis of acute retinal necrosis is still poor, in particular VZV-induced acute retinal necrosis.

  19. Vitrectomy with or without encircling band for pseudophakic retinal detachment: a multi-centre, three-arm, randomised clinical trial. VIPER Study Report No. 1—design and enrolment

    PubMed Central

    Mazinani, B; Baumgarten, S; Schiller, P; Agostini, H; Helbig, H; Limburg, E; Hellmich, M; Walter, P

    2016-01-01

    Purpose Scleral buckling is currently used in addition to vitrectomy for the treatment of pseudophakic retinal detachment (PRD) to better support the vitreous base and better visualisation of the periphery. Aims The aims of this study are to evaluate (1) whether the combination of 20 G vitrectomy and scleral buckling is superior to 20 G vitrectomy alone (control) (confirmatory), and (2) whether transconjunctival 23/25 G vitrectomy is non-inferior to 20 G vitrectomy (both without scleral buckling) regarding operation success (exploratory). Methods The VIPER (Vitrectomy Plus Encircling Band Vs. Vitrectomy Alone For The Treatment Of Pseudophakic Retinal Detachment) study is an unmasked, multi-centre, three-arm randomised trial. Patients with PRD were eligible, excluding complicated retinal detachment or otherwise severe ophthalmologic impairment. Patients were randomised to one of three interventions: 20 G vitrectomy alone (control C), combination of 20 G vitrectomy and circumferential scleral buckling (experimental treatment E1) or 23/25 G vitrectomy alone (experimental treatment E2). The primary endpoint is the absence of any indication for a retina re-attaching procedure during 6 months of follow-up. Secondary endpoints include best corrected visual acuity, retina re-attaching procedures, complications and adverse events. Results From June 2011 to August 2013, 257 patients were enrolled in the study. The internet randomisation service assigned 100 patients each to the treatment arms C and E1, and 57 patients to treatment E2. The imbalance is due to the fact that several retinal surgeons did not qualify for performing E2. The random assignment was stratified and balanced (ie, 1:1 or 1:1:1 ratio) by surgeon. Conclusions The described study represents a methodologically rigorous protocol evaluating the benefits of three different vitrectomy approaches to PRD. The projected results will help to establish their overall efficacy and will permit

  20. Divertor detachment

    NASA Astrophysics Data System (ADS)

    Krasheninnikov, Sergei

    2015-11-01

    The heat exhaust is one of the main conceptual issues of magnetic fusion reactor. In a standard operational regime the large heat flux onto divertor target reaches unacceptable level in any foreseeable reactor design. However, about two decades ago so-called ``detached divertor'' regimes were found. They are characterized by reduced power and plasma flux on divertor targets and look as a promising solution for heat exhaust in future reactors. In particular, it is envisioned that ITER will operate in a partly detached divertor regime. However, even though divertor detachment was studied extensively for two decades, still there are some issues requiring a new look. Among them is the compatibility of detached divertor regime with a good core confinement. For example, ELMy H-mode exhibits a very good core confinement, but large ELMs can ``burn through'' detached divertor and release large amounts of energy on the targets. In addition, detached divertor regimes can be subject to thermal instabilities resulting in the MARFE formation, which, potentially, can cause disruption of the discharge. Finally, often inner and outer divertors detach at different plasma conditions, which can lead to core confinement degradation. Here we discuss basic physics of divertor detachment including different mechanisms of power and momentum loss (ionization, impurity and hydrogen radiation loss, ion-neutral collisions, recombination, and their synergistic effects) and evaluate the roles of different plasma processes in the reduction of the plasma flux; detachment stability; and an impact of ELMs on detachment. We also evaluate an impact of different magnetic and divertor geometries on detachment onset, stability, in- out- asymmetry, and tolerance to the ELMs. Supported by the U.S. Department of Energy Office of Science, Office of Fusion Energy Sciences under Award Number DE-DE-FG02-04ER54739 at UCSD.

  1. Mutation in type II procollagen (COL2A1) that substitutes aspartate for glycine alpha 1-67 and that causes cataracts and retinal detachment: evidence for molecular heterogeneity in the Wagner syndrome and the Stickler syndrome (arthro-ophthalmopathy)

    PubMed Central

    Körkkö, J; Ritvaniemi, P; Haataja, L; Kääriäinen, H; Kivirikko, K I; Prockop, D J; Ala-Kokko, L

    1993-01-01

    A search for mutations in the gene for type II procollagen (COL2A1) was carried out in affected members of a family with early-onset cataracts, lattice degeneration of the retina, and retinal detachment. They had no symptoms suggestive of involvement of nonocular tissues, as is typically found in the Stickler syndrome. The COL2A1 gene was amplified with PCR, and the products were analyzed by denaturing gradient gel electrophoresis. The results suggested a mutation in one allele for exon 10. Sequencing of the fragment demonstrated a single-base mutation that converted the codon for glycine at position alpha 1-67 to aspartate. The mutation was found in three affected members of the family available for study but not in unaffected members or 100 unrelated individuals. Comparison with previously reported mutations suggested that mutations introducing premature termination codons in the COL2A1 gene are a frequent cause of the Stickler syndrome, but mutations in the COL2A1 gene that replace glycine codons with codons for bulkier amino acid can produce a broad spectrum of disorders that range from lethal chondrodysplasias to a syndrome involving only ocular tissues, similar to the syndrome in the family originally described by Wagner in 1938. Images Figure 2 Figure 3 Figure 4 PMID:8317498

  2. Establishment of a recessive mutant small-eye rat with lens involution and retinal detachment associated with partial deletion and rearrangement of the Cryba1 gene.

    PubMed

    Yamada, Toshiyuki; Nanashima, Naoki; Shimizu, Takeshi; Nakazawa, Yosuke; Nakazawa, Mitsuru; Tsuchida, Shigeki

    2015-10-15

    From our stock of SDRs (Sprague-Dawley rats), we established a mutant strain having small opaque eyes and named it HiSER (Hirosaki small-eye rat). The HiSER phenotype is progressive and autosomal recessive. In HiSER eyes, disruption and involution of the lens, thickening of the inner nuclear layer, detachment and aggregation of the retina, rudimentary muscle in the ciliary body and cell infiltration in the vitreous humour were observed. Genetic linkage analysis using crossing with Brown Norway rat suggested that the causative gene(s) is located on chromosome 10. Microarray analysis showed that the expression level of the Cryba1 gene encoding βA3/A1-crystallin on chromosome 10 was markedly decreased in HiSER eyes. Genomic PCR revealed deletion of a 3.6-kb DNA region encompassing exons 4-6 of the gene in HiSERs. In HiSER eyes, a chimaeric transcript of the gene containing exons 1-3 and an approximately 250-bp sequence originating from the 3'-UTR of the Nufip2 gene, located downstream of the breakpoint in the opposite direction, was present. Whereas the chimaeric transcript was expressed in HiSER eyes, neither normal nor chimaeric βA3/A1-crystallin proteins were detected by Western blot analysis. Real-time RT (reverse transcription)-PCR analysis revealed that expression level of the Nufip2 gene in the HiSER eye was 40% of that in the SDR eye. These results suggest that the disappearance of the βA3/A1-crystallin protein and, in addition, down-regulation of the Nufip2 gene as a consequence of gene rearrangement causes the HiSER phenotype.

  3. Transcorneal Electrical Stimulation Therapy for Retinal Disease

    ClinicalTrials.gov

    2012-05-03

    Retinitis Pigmentosa; Macula Off; Primary Open Angle Glaucoma; Hereditary Macular Degeneration; Treated Retina Detachment; Retinal Artery Occlusion; Retinal Vein Occlusion; Non-Arthritic-Anterior-Ischemic Optic-Neuropathy; Hereditary Autosomal Dominant Optic Atrophy; Dry Age Related Macular Degeneration; Ischemic Macula Edema

  4. Progressive outer retinal necrosis-like retinitis in immunocompetent hosts.

    PubMed

    Chawla, Rohan; Tripathy, Koushik; Gogia, Varun; Venkatesh, Pradeep

    2016-08-10

    We describe two young immunocompetent women presenting with bilateral retinitis with outer retinal necrosis involving posterior pole with centrifugal spread and multifocal lesions simulating progressive outer retinal necrosis (PORN) like retinitis. Serology was negative for HIV and CD4 counts were normal; however, both women were on oral steroids at presentation for suspected autoimmune chorioretinitis. The retinitis in both eyes responded well to oral valaciclovir therapy. However, the eye with the more fulminant involvement developed retinal detachment with a loss of vision. Retinal atrophy was seen in the less involved eye with preservation of vision. Through these cases, we aim to describe a unique evolution of PORN-like retinitis in immunocompetent women, which was probably aggravated by a short-term immunosuppression secondary to oral steroids.

  5. Retinitis Pigmentosa

    MedlinePlus

    ... Action You are here Home › Retinal Diseases Listen Retinitis Pigmentosa What is retinitis pigmentosa? What are the symptoms? ... is available? What treatment is available? What is retinitis pigmentosa? Retinitis pigmentosa, also known as RP, refers to ...

  6. Fluid vitreous substitutes in vitreo retinal surgery.

    PubMed

    Saxena, S; Gopal, L

    1996-12-01

    Advances in the surgical instrumentation and vitreoretinal techniques have allowed intraoperative reapproximation of retina to a more normal position. The use of intravitreally injected liquid materials (viscoelastic liquids, liquid perfluorocarbons and silicone oil), as adjunctive agents to vitreo-retinal surgery play an important role in facilitating retinal reattachment. These materials are used as intraoperative instruments to re-establish intraocular volume, assist in separating membranes adherent to the retina, manipulate retinal detachments and mechanically flatten detached retina. Over the longer term, silicone oil maintains intraocular tamponade. One should be cognizant of the potential uses, benefits and risks of each of these vitreous substitutes.

  7. Functional and Behavioral Metrics for Evaluating Laser Retinal Damage

    DTIC Science & Technology

    2006-01-01

    pigmentosa , and retinal detachment10. mfERG response characteristics have been shown to vary depending on the part of the retina that is affected by a...DoD Controlling Office is (insert controlling DoD office). 20100715258 Functional and behavioral metrics for evaluating laser retinal damage Cheryl...potential for and severity of laser eye injury and retinal damage is increasing . Sensitive and accurate methods to evaluate and follow laser retinal

  8. Dynamics of slab detachment

    NASA Astrophysics Data System (ADS)

    Duretz, T.; Schmalholz, S. M.; Gerya, T. V.

    2012-04-01

    Our study investigates the dynamics of slab detachment and evaluates the amount of time necessary for slabs to detach. We combine both the results of two-dimensional numerical modeling with the prediction of a one-dimensional analytical solution for viscous necking under gravity. This tidy suggest that the dominant deformation mechanisms leading to slab detachment is viscous necking, independently of the depth of slab detachment. Localised simple shear may also occur when the slab dip is moderate, especially in the colder parts of the slab. Brittle fracturing, or breaking, plays a minor role during the slab detachment process. 2D thermo-mechanical simulations indicate that the duration of slab detachment is short (< 4 Ma) and can occur in less than 0.5 Ma. No simple correlation between the slab detachment depth and duration was found. Our results suggest that deep slab detachments (> 250 km) can also occur within a short time (< 1 Ma). On the other hand, slab detachments taking place between 35 and 250 km depth may last less than 2 Ma. This aspect has implications for geodynamic interpretations using slab detachment as explanation for processes such as melting, exhumation or surface uplift.

  9. Descemet membrane detachment.

    PubMed

    Mackool, R J; Holtz, S J

    1977-03-01

    Four eyes of three patients had extensive postoperative Descemet membrane (DM) detachment. Blood was present just anterior to the DM in three of the four eyes and later converted to and persisted as pigment. Haziness of the cornea at the level of the DM could be seen with reattachment. Detachments of the DM are classified as planar when there is 1 mm or less separation of the DM from its overlying stroma in all areas. Nonplanar DM detachments exceed 1 mm of separation. Planar detachments have a much better prognosis than nonplanar detachments do, with or without descemetopexy. Repair of DM detachments, when necessary, should include air injection, with the lease possible instrumentation of the DM.

  10. Modeling of Detached Solidification

    NASA Technical Reports Server (NTRS)

    Regel, Liya L.; Wilcox, William R.; Popov, Dmitri

    1997-01-01

    Our long term goal is to develop techniques to achieve detached solidification reliably and reproducibly, in order to produce crystals with fewer defects. To achieve this goal it is necessary to understand thoroughly the physics of detached solidification. It was the primary objective of the current project to make progress toward this complete understanding. 'Me products of this grant are attached. These include 4 papers and a preliminary survey of the observations of detached solidification in space. We have successfully modeled steady state detached solidification, examined the stability of detachment, and determined the influence of buoyancy-driven convection under different conditions. Directional solidification in microgravity has often led to ingots that grew with little or no contact with the ampoule wall. When this occurred, crystallographic perfection was usually greatly improved -- often by several orders of magnitude. Indeed, under the Soviet microgravity program the major objective was to achieve detached solidification with its resulting improvement in perfection and properties. Unfortunately, until recently the true mechanisms underlying detached solidification were unknown. As a consequence, flight experiments yielded erratic results. Within the past three years, we have developed a new theoretical model that explains many of the flight results. This model gives rise to predictions of the conditions required to yield detached solidification.

  11. Retinitis Pigmentosa.

    ERIC Educational Resources Information Center

    Carr, Ronald E.

    1979-01-01

    The author describes the etiology of retinitis pigmentosa, a visual dysfunction which results from progressive loss of the retinal photoreceptors. Sections address signs and symptoms, ancillary findings, heredity, clinical diagnosis, therapy, and research. (SBH)

  12. Retinitis pigmentosa

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/001029.htm Retinitis pigmentosa To use the sharing features on this page, please enable JavaScript. Retinitis pigmentosa is an eye disease in which there is ...

  13. Inhibition of the alternative complement pathway preserves photoreceptors after retinal injury

    PubMed Central

    Sweigard, J. Harry; Matsumoto, Hidetaka; Smith, Kaylee E.; Kim, Leo A.; Paschalis, Eleftherios I.; Okonuki, Yoko; Castillejos, Alexandra; Kataoka, Keiko; Hasegawa, Eiichi; Yanai, Ryoji; Husain, Deeba; Lambris, John D.; Vavvas, Demetrios; Miller, Joan W.; Connor, Kip M.

    2015-01-01

    Degeneration of photoreceptors is a primary cause of vision loss worldwide, making the underlying mechanisms surrounding photoreceptor cell death critical to developing new treatment strategies. Retinal detachment, characterized by the separation of photoreceptors from the underlying retinal pigment epithelium, is a sight-threatening event that can happen in a number of retinal diseases. The detached photoreceptors undergo apoptosis and programmed necrosis. Given that photoreceptors are nondividing cells, their loss leads to irreversible visual impairment even after successful retinal reattachment surgery. To better understand the underlying disease mechanisms, we analyzed innate immune system regulators in the vitreous of human patients with retinal detachment and correlated the results with findings in a mouse model of retinal detachment. We identified the alternative complement pathway as promoting early photoreceptor cell death during retinal detachment. Photoreceptors down-regulate membrane-bound inhibitors of complement, allowing for selective targeting by the alternative complement pathway. When photoreceptors in the detached retina were removed from the primary source of oxygen and nutrients (choroidal vascular bed), the retina became hypoxic, leading to an up-regulation of complement factor B, a key mediator of the alternative pathway. Inhibition of the alternative complement pathway in knockout mice or through pharmacological means ameliorated photoreceptor cell death during retinal detachment. Our current study begins to outline the mechanism by which the alternative complement pathway facilitates photoreceptor cell death in the damaged retina. PMID:26203084

  14. Optimal management of cytomegalovirus retinitis in patients with AIDS

    PubMed Central

    Stewart, Michael W

    2010-01-01

    Cytomegalovirus (CMV) retinitis is the most common cause of vision loss in patients with acquired immunodeficiency syndrome (AIDS). CMV retinitis afflicted 25% to 42% of AIDS patients in the pre-highly active antiretroviral therapy (HAART) era, with most vision loss due to macula-involving retinitis or retinal detachment. The introduction of HAART significantly decreased the incidence and severity of CMV retinitis. Optimal treatment of CMV retinitis requires a thorough evaluation of the patient’s immune status and an accurate classification of the retinal lesions. When retinitis is diagnosed, HAART therapy should be started or improved, and anti-CMV therapy with oral valganciclovir, intravenous ganciclovir, foscarnet, or cidofovir should be administered. Selected patients, especially those with zone 1 retinitis, may receive intravitreal drug injections or surgical implantation of a sustained-release ganciclovir reservoir. Effective anti-CMV therapy coupled with HAART significantly decreases the incidence of vision loss and improves patient survival. Immune recovery uveitis and retinal detachments are important causes of moderate to severe loss of vision. Compared with the early years of the AIDS epidemic, the treatment emphasis in the post- HAART era has changed from short-term control of retinitis to long-term preservation of vision. Developing countries face shortages of health care professionals and inadequate supplies of anti-CMV and anti-HIV medications. Intravitreal ganciclovir injections may be the most cost effective strategy to treat CMV retinitis in these areas. PMID:20463796

  15. [Aging and retinal vascular diseases].

    PubMed

    Takagi, Hitoshi

    2007-03-01

    Ocular vascular diseases such as diabetic retinopathy, retinal vein occlusion, and age-related macular degeneration, whose population increases along with aging, have become leading causes of severe visual disturbance. Macular edema and serous retinal detachment are associated with abnormal vascular leakage and tractional retinal detachment, and neovascular glaucoma is caused by retinal neovascularization. Such ocular vascular diseases are caused by vascular cell aging and vascular damage associated with lifestyle-related diseases including diabetes mellitus, hypertension, hyperlipidemia, and obesity. In the present study, we investigated molecular mechanisms in such vascular deficiencies using vascular cell biology methodology, and we propose novel strategies for the treatment of such vascular diseases. Along with aging, oxidative stress and physical stress, such as mechanical stretch, continuously and directly insult vascular cells. Such stress induces apoptosis by intracellular signaling through stress kinases in cultured retinal vascular cells. Inhibition of such stress kinases could be an effective treatment to protect the vascular cells against age-related damage. In a retinal vascular developmental model, pericyte loss causes pathology mimicking macular edema and proliferative diabetic retinopathy. Angiopoietin 1 (Ang 1) secreted by pericytes suppresses oxidative stress-induced intracellular signaling through stress kinases linked to cell apoptosis and normalizes such retinal pathology. This suggests that the paracrine action of Ang 1 in the pericytes is necessary to sustain normal retinal vasculature, and that Ang 1-triggered intracellular signaling is useful for the treatment of vascular cell pathology associated with pericyte loss. In diabetic retinopathy and retinal vein occlusion, retinal vessels regress along with retinal vascular cell apoptosis, and the retina becomes ischemic followed by pathological retinal neovascularization. VEGF has been

  16. Detached rock evaluation device

    DOEpatents

    Hanson, David R.

    1986-01-01

    A rock detachment evaluation device (10) having an energy transducer unit 1) for sensing vibrations imparted to a subject rock (172) for converting the sensed vibrations into electrical signals, a low band pass filter unit (12) for receiving the electrical signal and transmitting only a low frequency segment thereof, a high band pass filter unit (13) for receiving the electrical signals and for transmitting only a high frequency segment thereof, a comparison unit (14) for receiving the low frequency and high frequency signals and for determining the difference in power between the signals, and a display unit (16) for displaying indicia of the difference, which provides a quantitative measure of rock detachment.

  17. Learning about Retinitis Pigmentosa

    MedlinePlus

    ... genetic terms used on this page Learning About Retinitis Pigmentosa What is retinitis pigmentosa? What are the symptoms ... Pigmentosa Additional Resources for Retinitis Pigmentosa What is retinitis pigmentosa? Retinitis pigmentosa (RP) is the name given to ...

  18. Plasma detachment in linear devices

    NASA Astrophysics Data System (ADS)

    Ohno, N.

    2017-03-01

    Plasma detachment research in linear devices, sometimes called divertor plasma simulators, is reviewed. Pioneering works exploring the concept of plasma detachment were conducted in linear devices. Linear devices have contributed greatly to the basic understanding of plasma detachment such as volume plasma recombination processes, detached plasma structure associated with particle and energy transport, and other related issues including enhancement of convective plasma transport, dynamic response of plasma detachment, plasma flow reversal, and magnetic field effect. The importance of plasma detachment research using linear devices will be highlighted aimed at the design of future DEMO.

  19. Retinal Macroglial Responses in Health and Disease

    PubMed Central

    de Hoz, Rosa; Rojas, Blanca; Ramírez, Ana I.; Salazar, Juan J.; Gallego, Beatriz I.; Triviño, Alberto; Ramírez, José M.

    2016-01-01

    Due to their permanent and close proximity to neurons, glial cells perform essential tasks for the normal physiology of the retina. Astrocytes and Müller cells (retinal macroglia) provide physical support to neurons and supplement them with several metabolites and growth factors. Macroglia are involved in maintaining the homeostasis of extracellular ions and neurotransmitters, are essential for information processing in neural circuits, participate in retinal glucose metabolism and in removing metabolic waste products, regulate local blood flow, induce the blood-retinal barrier (BRB), play fundamental roles in local immune response, and protect neurons from oxidative damage. In response to polyetiological insults, glia cells react with a process called reactive gliosis, seeking to maintain retinal homeostasis. When malfunctioning, macroglial cells can become primary pathogenic elements. A reactive gliosis has been described in different retinal pathologies, including age-related macular degeneration (AMD), diabetes, glaucoma, retinal detachment, or retinitis pigmentosa. A better understanding of the dual, neuroprotective, or cytotoxic effect of macroglial involvement in retinal pathologies would help in treating the physiopathology of these diseases. The extensive participation of the macroglia in retinal diseases points to these cells as innovative targets for new drug therapies. PMID:27294114

  20. The symbol detachment problem.

    PubMed

    Pezzulo, Giovanni; Castelfranchi, Cristiano

    2007-06-01

    In situated and embodied approaches it is commonly assumed that the dynamics of sensorimotor engagement between an adaptive agent and its environment are crucial in understanding natural cognition. This perspective permits to address the symbol grounding problem, since the aboutness of any mental state arising during agent-environment engagement is guaranteed by their continuous coupling. However, cognitive agents are also able to formulate representations that are detached from the current state of affairs, such as expectations and goals. Moreover, they can act on their representations before--or instead of--acting directly on the environment, for example building the plan of a bridge and not directly the bridge. On the basis of representations, actions such as planning, remembering or imagining are possible that are disengaged from the current sensorimotor cycle, and often functional to future-oriented conducts. A new problem thus has to be acknowledged, the symbol detachment problem: how and why do situated agents develop representations that are detached from their current sensorimotor interaction, but nevertheless preserve grounding and aboutness? How do cognitive agents progressively acquire a range of capabilities permitting them to deal not only with the current situation but also with alternative, in particular future states of affairs? How do they develop the capability of acting on their representations instead of acting directly on the world? In a theoretical and developmental perspective, we propose that anticipation plays a crucial role in the detachment process: anticipatory representations, originally detached from the sensorimotor cycle for the sake of action control, are successively exapted for bootstrapping increasingly complex cognitive capabilities.

  1. Bilateral Cytomegalovirus Retinitis in a Patient with Systemic Lupus Erythematosus

    PubMed Central

    Haze, Masaya; Kobayashi, Takatoshi; Kakurai, Keigo; Shoda, Hiromi; Takai, Nanae; Takeda, Sayako; Tada, Rei; Maruyama, Kouichi; Kida, Teruyo; Ikeda, Tsunehiko

    2016-01-01

    Purpose The purpose of this study was to report the case of a patient who underwent vitrectomy for bilateral rhegmatogenous retinal detachment caused by cytomegalovirus (CMV) retinitis while undergoing steroid and immunosuppressant therapy for systemic lupus erythematosus (SLE). Case Report We report on a 29-year-old female who was undergoing steroids and immunosuppressants treatment for SLE at Osaka Medical College Hospital, Takatsuki City, Japan. Examination of the patient due to prolonged and worsening diarrhea revealed positive test results for C7-HRP, and she was diagnosed with CMV colitis. She was subsequently admitted to the hospital and started on intravenous ganciclovir for treatment. Approximately 1.5 months later, her primary complaint was deterioration of the upper visual field in her left eye, and she was then referred to the Department of Ophthalmology. Numerous granular exudative spots were found around the lower retinal area of her left eye with retinal breaks that had developed in an area of retinal necrosis that resulted in retinal detachment. After time was allowed for the patient's general condition to improve, a vitrectomy was performed on that eye. The patient subsequently developed a similar retinal detachment in her right eye, for which she underwent a vitrectomy. Although the patient required multiple surgeries on both eyes, her retinas currently remain reattached and the inflammation has subsided. Conclusion The findings of this study show that strict attention must be paid to SLE patients on immunosuppressive therapy due to the possible association of CMV retinitis. PMID:27462259

  2. Retinal remodeling.

    PubMed

    Jones, B W; Kondo, M; Terasaki, H; Lin, Y; McCall, M; Marc, R E

    2012-07-01

    Retinal photoreceptor degeneration takes many forms. Mutations in rhodopsin genes or disorders of the retinal pigment epithelium, defects in the adenosine triphosphate binding cassette transporter, ABCR gene defects, receptor tyrosine kinase defects, ciliopathies and transport defects, defects in both transducin and arrestin, defects in rod cyclic guanosine 3',5'-monophosphate phosphodiesterase, peripherin defects, defects in metabotropic glutamate receptors, synthetic enzymatic defects, defects in genes associated with signaling, and many more can all result in retinal degenerative disease like retinitis pigmentosa (RP) or RP-like disorders. Age-related macular degeneration (AMD) and AMD-like disorders are possibly due to a constellation of potential gene targets and gene/gene interactions, while other defects result in diabetic retinopathy or glaucoma. However, all of these insults as well as traumatic insults to the retina result in retinal remodeling. Retinal remodeling is a universal finding subsequent to retinal degenerative disease that results in deafferentation of the neural retina from photoreceptor input as downstream neuronal elements respond to loss of input with negative plasticity. This negative plasticity is not passive in the face of photoreceptor degeneration, with a phased revision of retinal structure and function found at the molecular, synaptic, cell, and tissue levels involving all cell classes in the retina, including neurons and glia. Retinal remodeling has direct implications for the rescue of vision loss through bionic or biological approaches, as circuit revision in the retina corrupts any potential surrogate photoreceptor input to a remnant neural retina. However, there are a number of potential opportunities for intervention that are revealed through the study of retinal remodeling, including therapies that are designed to slow down photoreceptor loss, interventions that are designed to limit or arrest remodeling events, and

  3. Retinal Prosthesis

    PubMed Central

    Weiland, James D.; Humayun, Mark S.

    2015-01-01

    Retinal prosthesis have been translated from the laboratory to the clinical over the past two decades. Currently, two devices have regulatory approval for the treatment of retinitis pigmentosa. These devices provide partial sight restoration and patients use this improved vision in their everyday lives. Improved mobility and object detection are some of the more notable findings from the clinical trials. However, significant vision restoration will require both better technology and improved understanding of the interaction between electrical stimulation and the retina. This paper reviews the recent clinical trials, highlights technology breakthroughs that will contribute to next generation of retinal prostheses. PMID:24710817

  4. Stability of Detached Solidification

    NASA Technical Reports Server (NTRS)

    Mazuruk, K.; Volz, M. P.; Croell, A.

    2009-01-01

    Bridgman crystal growth can be conducted in the so-called "detached" solidification regime, where the growing crystal is detached from the crucible wall. A small gap between the growing crystal and the crucible wall, of the order of 100 micrometers or less, can be maintained during the process. A meniscus is formed at the bottom of the melt between the crystal and crucible wall. Under proper conditions, growth can proceed without collapsing the meniscus. The meniscus shape plays a key role in stabilizing the process. Thermal and other process parameters can also affect the geometrical steady-state stability conditions of solidification. The dynamic stability theory of the shaped crystal growth process has been developed by Tatarchenko. It consists of finding a simplified autonomous set of differential equations for the radius, height, and possibly other process parameters. The problem then reduces to analyzing a system of first order linear differential equations for stability. Here we apply a modified version of this theory for a particular case of detached solidification. Approximate analytical formulas as well as accurate numerical values for the capillary stability coefficients are presented. They display an unexpected singularity as a function of pressure differential. A novel approach to study the thermal field effects on the crystal shape stability has been proposed. In essence, it rectifies the unphysical assumption of the model that utilizes a perturbation of the crystal radius along the axis as being instantaneous. It consists of introducing time delay effects into the mathematical description and leads, in general, to stability over a broader parameter range. We believe that this novel treatment can be advantageously implemented in stability analyses of other crystal growth techniques such as Czochralski and float zone methods.

  5. Model of detached plasmas

    SciTech Connect

    Yoshikawa, S.; Chance, M.

    1986-07-01

    Recently a tokamak plasma was observed in TFTR that was not limited by a limiter or a divertor. A model is proposed to explain this equilibrium, which is called a detached plasma. The model consists of (1) the core plasma where ohmic heating power is lost by anomalous heat conduction and (2) the shell plasma where the heat from the core plasma is radiated away by the atomic processes of impurity ions. A simple scaling law is proposed to test the validity of this model.

  6. Digital tracking and control of retinal images

    NASA Astrophysics Data System (ADS)

    Barrett, Steven F.; Jerath, Maya R.; Rylander, Henry G., III; Welch, Ashley J.

    1993-06-01

    Laser induced retinal lesions are used to treat a variety of eye diseases such as diabetic retinopathy and retinal detachment. An instrumentation system has been developed to track a specific lesion coordinate on the retinal surface and provide corrective signals to maintain laser position on the coordinate. High resolution retinal images are acquired via a CCD camera coupled to a fundus camera and video frame grabber. Optical filtering and histogram modification are used to enhance the retinal vessel network against the lighter retinal background. Six distinct retinal landmarks are tracked on the high contrast image obtained from the frame grabber using two-dimensional blood vessel templates. The frame grabber is hosted on a 486 PC. The PC performs correction signal calculations using an exhaustive search on selected image portions. An X and Y laser correction signal is derived from the landmark tracking information and provided to a pair of galvanometer steered mirrors via a data acquisition and control subsystem. This subsystem also responds to patient inputs and the system monitoring lesion growth. This paper begins with an overview of the robotic laser system design followed by implementation and testing of a development system for proof of concept. The paper concludes with specifications for a real time system.

  7. Retine revisited.

    PubMed

    Douglas, D E

    2002-10-01

    Retine, so named by Albert Szent-Györgyi, an inhibitor of the growth of transplanted malignant tumours in animals, is present in all mammalian tissues and in urine. Its inhibitory activity was extensively investigated by Szent-Györgyi, but its exact chemical identity was not determined. Details of the reported physical and chemical properties of retine and its ubiquitous occurrence identify it as being identical to a complex mixture of lipid 2,4-diketones of similar ubiquitous occurrence. This lipid mixture has been extensively studied, and individual members have been synthesized.

  8. New Therapeutic Modalities of Retinal Laser Injury.

    DTIC Science & Technology

    1992-03-31

    Management of traumatic hemorrhagic retinal detachment with pars plana vitrectomy . Arch. Ophthalmol. 1990; 108:1281-1286 46. Hanscom TA, Diddle KR. Early... plana vitrectomy and internal drainage. Arch. Ophthalmol. 1990;108:973-978 44. Vander JF, Federman JL, Greven C et al. Surgical removal of massive...hotocoagulation. A. Periphery of the lesion. The inner par of the OPL was replaced by processes of the Muller cells (Mu). Degenerated synaptic terminals

  9. A selected review of current retinal research and study.

    PubMed

    Cohen, J

    1976-06-01

    The present paper reviews recent studies of retinal pathology from the American and British Journals of Ophthalmology during a one-year period (1973-1974). Selection is on the basis of potential value to clinical optometrists. Certain underlying factors in several types of retinal degeneration are first discussed, followed by characteristics of diabetic maculopathy and of other types of macular degeneration including that due to aging. Some material is presented on retinopathies related to sickle cell traits, to viral and worm infections, and to injury. Following a review of certain recent studies of retinoschisis, retinoblastoma, and retrolental fibroplasia, a concluding section deals with retinal detachments and breaks.

  10. Shock detachment from curved wedges

    NASA Astrophysics Data System (ADS)

    Mölder, S.

    2017-03-01

    Curved shock theory is used to show that the flow behind attached shocks on doubly curved wedges can have either positive or negative post-shock pressure gradients depending on the freestream Mach number, the wedge angle and the two wedge curvatures. Given enough wedge length, the flow near the leading edge can choke to force the shock to detach from the wedge. This local choking can preempt both the maximum deflection and the sonic criteria for shock detachment. Analytical predictions for detachment by local choking are supported by CFD results.

  11. Retinitis pigmentosa

    PubMed Central

    Hamel, Christian

    2006-01-01

    Retinitis pigmentosa (RP) is an inherited retinal dystrophy caused by the loss of photoreceptors and characterized by retinal pigment deposits visible on fundus examination. Prevalence of non syndromic RP is approximately 1/4,000. The most common form of RP is a rod-cone dystrophy, in which the first symptom is night blindness, followed by the progressive loss in the peripheral visual field in daylight, and eventually leading to blindness after several decades. Some extreme cases may have a rapid evolution over two decades or a slow progression that never leads to blindness. In some cases, the clinical presentation is a cone-rod dystrophy, in which the decrease in visual acuity predominates over the visual field loss. RP is usually non syndromic but there are also many syndromic forms, the most frequent being Usher syndrome. To date, 45 causative genes/loci have been identified in non syndromic RP (for the autosomal dominant, autosomal recessive, X-linked, and digenic forms). Clinical diagnosis is based on the presence of night blindness and peripheral visual field defects, lesions in the fundus, hypovolted electroretinogram traces, and progressive worsening of these signs. Molecular diagnosis can be made for some genes, but is not usually performed due to the tremendous genetic heterogeneity of the disease. Genetic counseling is always advised. Currently, there is no therapy that stops the evolution of the disease or restores the vision, so the visual prognosis is poor. The therapeutic approach is restricted to slowing down the degenerative process by sunlight protection and vitaminotherapy, treating the complications (cataract and macular edema), and helping patients to cope with the social and psychological impact of blindness. However, new therapeutic strategies are emerging from intensive research (gene therapy, neuroprotection, retinal prosthesis). PMID:17032466

  12. Retinal toxicity of intravitreal tenecteplase in the rabbit

    PubMed Central

    Rowley, S A; Vijayasekaran, S; Yu, P K; McAllister, I L; Yu, D-Yi

    2004-01-01

    Aim: To investigate the retinal toxicity of intravitreal injection of a novel fibrinolytic tenecteplase in rabbit eyes. Methods: Tenecteplase (25–350 μg in 0.1 ml BSS) was injected into the vitreous cavity of normal rabbit eyes. Control (fellow) eyes received 0.1 ml of BSS. One day, 1 week, and 2 months post-injection, the eyes were examined by slit lamp biomicroscopy, indirect ophthalmoscopy, and electroretinography, and then harvested for histopathological examination. Results: No evidence of retinal toxicity was seen with tenecteplase doses up to and including 50 μg. At a dose of 150 μg ophthalmoscopy was normal, but histology showed mild retinal damage in the inner nuclear layer and electroretinography showed a temporary reduction in B-wave amplitude. At doses of 200 μg and above, there was evidence of retinal toxicity on electroretinography, ophthalmoscopy, and histology. Ophthalmoscopic findings included vitreal fibrosis, retinal necrosis and tractional retinal detachment and light microscopy revealed necrosis of retinal pigment epithelium and other retinal layers. Damage was centred around the injection site but was more widespread with the higher doses. Conclusion: A dose of 50 μg tenecteplase appears safe for intravitreal injection in the rabbit. Tenecteplase could have potential applications in the treatment of submacular haemorrhage and retinal vein occlusion. PMID:15031179

  13. Retinitis pigmentosa: clinical observations and correlations.

    PubMed Central

    Pruett, R C

    1983-01-01

    This thesis presents the results of a study of 384 eyes of 192 patients with a mean age of 39.1 years who presented with typical retinitis pigmentosa. The major findings are outlined below, together with suggested hypotheses: Cataract was found in 46.4% of the eyes. Among these, 93.6% showed posterior subcapsular opacification. The incidence of cataract increased with age. The vitreous degeneration that is characteristic of the RP syndrome and begins in childhood was described as showing dust-like, particulate matter throughout the gel; posterior vitreous separation; formation of a posterior matrix of coarse, white, interconnected strands and opacities; and final collapse of the residual gel. Ultrastructural studies of vitreous material from eight eyes revealed that the particles were isolated pigment granules and the coarse strands were composed of condensed collagen fibers. Notwithstanding the vitreous degeneration and prevalence of myopia in RP, neurosensory retinal breaks and/or rhegmatogenous detachment were found in only 7 (1.8%) of the 384 eyes studied. Premature separation of the vitreous from the retina, absence of lattice retinal degeneration, and perhaps a stronger than normal RPE-neurosensory retinal bond are thought to be possible protective factors. Rather than searching for a "toxin," elaborated by diseased retina, that causes vitreous degeneration and cataract formation, it is suggested that the ocular media be studied for an absence of moieties that are normally produced by healthy retina for vitreous and lens maintenance. The classic criteria for diagnosis of RP were met by 96.3% of eyes that showed retinal vascular attenuation and by 52.0% that showed pallor of the optic disc. Less frequent manifestations included solitary retinal hemorrhage, peripheral microaneurysms, telangiectasia, and fluorescein leakage at the macula and disc. Seven additional cases with a Coats'-like retinal detachment were added to the 14 already presented in the

  14. Hypotony and ciliochoroidal detachment following pharmacologic aqueous suppressant therapy in previously filtered patients.

    PubMed

    Vela, M A; Campbell, D G

    1985-01-01

    This is the first report describing the syndrome of hypotony and ciliochoroidal detachment following pharmacologic aqueous suppressant therapy in previously filtered eyes. Four patients had a history of advanced primary open-angle glaucoma treated with multiple medical therapies, including timolol for 11 to 36 months. They then underwent filtration surgery, which failed in two cases. Timolol and/or acetazolamide therapy was instituted 1 to 18 months following surgery. The patients then developed hypotony and ciliochoroidal detachment, which resolved spontaneously after cessation of the pharmacologic aqueous suppressant therapy. In three of the cases, the episode of hypotony and ciliochoroidal detachment recurred after a second challenge with timolol and/or acetazolamide therapy. Inflammation, tumor, wound leakage, retinal detachment and cyclodialysis cleft were excluded. A mechanism of formation of ciliochoroidal detachment in this syndrome is proposed. Long-term timolol therapy followed by filtration surgery and its attendant postoperative hypotony and ciliochoroidal detachment sensitizes the ciliary epithelium. Subsequent pharmacologic aqueous suppressant therapy results in almost total reduction of aqueous production, causing hypotony and ciliochoroidal detachment.

  15. The North Cycladic Detachment System

    NASA Astrophysics Data System (ADS)

    Jolivet, Laurent; Lecomte, Emmanuel; Huet, Benjamin; Denèle, Yoann; Lacombe, Olivier; Labrousse, Loïc; Le Pourhiet, Laetitia; Mehl, Caroline

    2010-01-01

    Low-angle normal faults accommodate a large part of continental post-orogenic extension. Besides the intrinsic rheological characteristics of the continental crust that may lead to the formation of shallow-dipping shear zones at the brittle-ductile transition, the role of pre-existing low-angle structures such as large thrusts has been proposed by several authors. We explore this question with the example of the North Cycladic Detachment System (NCDS) that is composed of a series of distinct detachments cropping out on the islands of Andros, Tinos and Mykonos, separating the Cycladic Blueschists in the footwall from the Upper Cycladic Nappe in the hanging wall. We show that these extensional structures are part of a single large-scale structure (more than 200 km along strike) that reactivates the Vardar suture zone. It extends eastward on Ikaria and westward offshore Evia and Thessalia where it probably connects to recent shallow-dipping normal faults evidenced on published seismic reflection profiles. The NCDS started its activity in the Oligocene concommitantly with the Aegean extension, and was still active in the Late Miocene. It has exhumed a series of metamorphic domes from southern Evia to Mykonos below low-angle detachment systems, made of low-angle normal faults and low-angle ductile shear zones. The ductile shear zones and the faults were created with a low dip and they kept the same attitude throughout their exhumation. We identify three main detachments that are part of a continuum of extension on the NCDS : Tinos detachment, Livada detachment and Mykonos detachment. A fourth detachment (Vari detachment) is the reactivation of an Eocene exhumation-related structure. Deformation in the footwall is characterized by intense stretching and flattening. Using the spatial evolution observed along strike from Andros to Mykonos we construct a history of formation of the NCDS starting with the reactivation of former thrusts leading to the exhumation of high

  16. Sector mapping method for 3D detached retina visualization.

    PubMed

    Zhai, Yi-Ran; Zhao, Yong; Zhong, Jie; Li, Ke; Lu, Cui-Xin; Zhang, Bing

    2016-10-01

    A new sphere-mapping algorithm called sector mapping is introduced to map sector images to the sphere of an eyeball. The proposed sector-mapping algorithm is evaluated and compared with the plane-mapping algorithm adopted in previous work. A simulation that maps an image of concentric circles to the sphere of the eyeball and an analysis of the difference in distance between neighboring points in a plane and sector were used to compare the two mapping algorithms. A three-dimensional model of a whole retina with clear retinal detachment was generated using the Visualization Toolkit software. A comparison of the mapping results shows that the central part of the retina near the optic disc is stretched and its edges are compressed when the plane-mapping algorithm is used. A better mapping result is obtained by the sector-mapping algorithm than by the plane-mapping algorithm in both the simulation results and real clinical retinal detachment three-dimensional reconstruction.

  17. Plasma Detachment Study in VASIMR

    NASA Astrophysics Data System (ADS)

    Ilin, A. V.; Díaz, F. R. Chang; Squire, J. P.; Breizman, B. N.; Novakovski, S. V.; Sagdeev, R. Z.

    2000-10-01

    We present kinetic and MHD simulations of plasma detachment in the exhaust of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR). The detachment is associated with a transition from subalfvenic to superalfvenic plasma flow in the magnetic nozzle. As a result, the kinetic energy of the outgoing plasma flow is greater than the magnetic field energy in the exhaust area, so that the plasma is no longer confined by the magnetic field. We model the outgoing plasma flow under the assumptions that the plasma is collisionless and has a constant electron temperature. Particle simulations show that the ion motion may become nonadiabatic in the exhaust area as the magnetic field decreases downstream. This effect should facilitate the detachment.

  18. Progressive outer retinal necrosis (PORN) in AIDS patients: a different appearance of varicella-zoster retinitis.

    PubMed

    Pavesio, C E; Mitchell, S M; Barton, K; Schwartz, S D; Towler, H M; Lightman, S

    1995-01-01

    Retinal infections caused by the varicella-zoster virus (VZV) have been reported in immunocompetent and immunocompromised individuals. Two cases of a VZV-related retinitis are described with the characteristic features of the recently described progressive outer retinal necrosis (PORN) syndrome. Both patients suffered from the acquired immunodeficiency syndrome (AIDS) with greatly reduced peripheral blood CD4+ T lymphocyte counts, and presented with macular retinitis without vitritis. The disease was bilateral in one case and unilateral in the other. The clinical course was rapidly progressive with widespread retinal involvement and the development of rhegmatogenous retinal detachment with complete loss of vision in the affected eyes despite intensive intravenous antiviral therapy. VZV DNA was identified in vitreous biopsies, by molecular techniques based on the polymerase chain reaction (PCR), in both patients. At present, the use of very high-dose intravenous acyclovir may be the best therapeutic option in these patients for whom the visual prognosis is poor. Intravitreal antiviral drugs could also contribute to the management of these cases.

  19. United Kingdom National Ophthalmology Database Study of Vitreoretinal Surgery: Report 1; Case mix, complications, and cataract

    PubMed Central

    Jackson, T L; Donachie, P H J; Sparrow, J M; Johnston, R L

    2013-01-01

    Aim To report the vitreoretinal (VR) surgical case mix in the United Kingdom, the intraoperative complication rate of pars plana vitrectomy (PPV), and the incidence of post-vitrectomy cataract extraction. Methods Participating hospitals prospectively collected ophthalmic data using a single electronic medical record system, with automatic extraction of anonymised data to a national database. This study included the subset of 11 618 VR operations undertaken on 9619 eyes, of 8741 patients, over 8 years, from 27 sites. Surgical data included the indication for surgery, all procedure elements, and whether or not an intraoperative complication occurred. Post-vitrectomy cataract data were also analysed. The main outcome measures were a description of the indications for surgery, intraoperative PPV complication rate, and percentage of eyes undergoing post-vitrectomy cataract surgery (PVCS). Results The most common indications for VR intervention were retinal breaks and rhegmatogenous retinal detachment (48.5%), macular hole (9.8%), epiretinal membrane (9.6%), and diabetic eye disease (7.3%). Overall, 7.8% of PPVs had at least one intraoperative complication—the most common were iatrogenic retinal breaks (3.2%), and lens touch (1.2–1.6% of phakic eyes). PVCS occurred in 50.2, 68.7, and 74.0% of eyes at 1, 2, and 3 years, respectively. Conclusion VR surgery is undertaken for a wide range of conditions, but a small number of diagnoses encompass the majority of cases. Intraoperative PPV complications are not uncommon, and post-vitrectomy cataract is to be expected in most phakic eyes. PMID:23449509

  20. Choroidal detachment and ocular hypotony: CT evaluation

    SciTech Connect

    Mafee, M.F.; Peyman, G.A.

    1984-12-01

    The computed tomographic (CT) findings in 20 patients with hemorrhagic choroidal detachment, serous choroidal detachment and/or ocular hypotony are described. Hemorrhagic choroidal detachment appeared as an area of high attenuation that was usually localized, uniformly hyperdense, and not position-dependent. Serous choroidal detachment appeared as a convex, thick line of increased density within the vitreous cavity. Inflammatory choroidal detachment produces a diffuse intrauveal and suprachoroidal accumulation of high-density, position-dependent fluid, and uveoscleral thickening and enhancement, which in cross section resembles a ring. CT has proved valuable in localizing and differentiating serous or hemorrhagic choroidal detachment and uveoscleral infolding.

  1. Vitreo-retinal interface: diagnosis and medical-surgical treatment

    NASA Astrophysics Data System (ADS)

    Fortunato, P.; La Torre, A.

    2003-12-01

    Despite insightful studies of various researchers, vitreous physiophathology is still only partially explored as a field of study for modern ophthalmology. There is much to be learned about the mechanisms that maintain the integrity of vitreo-retinal interface and, more deeply, about the biochemical relationship between retinal pigment epithelium and Bruchs membrane; an imbalance between the physical and biological homeostasis at these levels may determine the onset of vitreo-retinal interface disease. Despite the unclear relationship between internal limiting membrane (ILM) and hyaloid, and between pathogenesis and effect of vitreous detachment, surgical techniques are being developed that promise a resolution of most diseases associated with vitreous and retinal anomalies. Optical coherence tomography (OCT) is the main diagnostic technique supporting this advances. The authors, after briefly introducing vitreous physiology and pathology, will discuss the main indications to this type of surgery, which is guided by OCT.

  2. Detached Growth of Germanium by Directional Solidification

    NASA Technical Reports Server (NTRS)

    Palosz, W.; Volz, M. P.; Cobb, S.; Motakef, S.; Szofran, F. R.

    2004-01-01

    The conditions of detached solidification under controlled pressure differential across the meniscus were investigated. Uncoated and graphite- or BN-coated silica and pBN crucibles were used. Detached and partly detached growth was achieved in pBN and BN-coated crucibles, respectively. The results of the experiments are discussed based on the theory of Duffar et al.

  3. Kinematic Fitting of Detached Vertices

    SciTech Connect

    Mattione, Paul

    2007-05-01

    The eg3 experiment at the Jefferson Lab CLAS detector aims to determine the existence of the $\\Xi_{5}$ pentaquarks and investigate the excited $\\Xi$ states. Specifically, the exotic $\\Xi_{5}^{--}$ pentaquark will be sought by first reconstructing the $\\Xi^{-}$ particle through its weak decays, $\\Xi^{-}\\to\\pi^{-}\\Lambda$ and $\\Lambda\\to\\pi^{-}$. A kinematic fitting routine was developed to reconstruct the detached vertices of these decays, where confidence level cuts on the fits are used to remove background events. Prior to fitting these decays, the exclusive reaction $\\gamma D\\rightarrow pp\\pi^{-}$ was studied in order to correct the track measurements and covariance matrices of the charged particles. The $\\Lambda\\rightarrow p\\pi^{-}$ and $\\Xi^{-}\\to\\pi^{-}\\Lambda$ decays were then investigated to demonstrate that the kinematic fitting routine reconstructs the decaying particles and their detached vertices correctly.

  4. Transcriptomic Analysis of Human Retinal Surgical Specimens Using jouRNAl

    PubMed Central

    Delyfer, Marie-Noëlle; Aït-Ali, Najate; Camara, Hawa; Clérin, Emmanuelle; Korobelnik, Jean-François; Sahel, José-Alain; Léveillard, Thierry

    2013-01-01

    Retinal detachment (RD) describes a separation of the neurosensory retina from the retinal pigmented epithelium (RPE). The RPE is essential for normal function of the light sensitive neurons, the photoreceptors. Detachment of the retina from the RPE creates a physical gap that is filled with extracellular fluid. RD initiates cellular and molecular adverse events that affect both the neurosensory retina and the RPE since the physiological exchange of ions and metabolites is severely perturbed. The consequence for vision is related to the duration of the detachment since a rapid reapposition of the two tissues results in the restoration of vision 1. The treatment of RD is exclusively surgical. Removal of vitreous gel (vitrectomy) is followed by the removal non essential part of the retina around the detached area to favor retinal detachment. The removed retinal specimens are res nullius (nothing) and consequently normally discarded. To recover RNA from these surgical specimens, we developed the procedure jouRNAl that allows RNA conservation during the transfer from the surgical block to the laboratory. We also standardized a protocol to purify RNA by cesium chloride ultracentrifugation to assure that the purified RNAs are suitable for global gene expression analysis. The quality of the RNA was validated both by RT-PCR and microarray analysis. Analysis of the data shows a simultaneous involvement of inflammation and photoreceptor degeneration during RD. PMID:23979175

  5. Screening retinal transplants with Fourier-domain OCT

    NASA Astrophysics Data System (ADS)

    Rao, Bin

    2009-02-01

    Transplant technologies have been studied for the recovery of vision loss from retinitis pigmentosa (RP) and age-related macular degeneration (AMD). In several rodent retinal degeneration models and in patients, retinal progenitor cells transplanted as layers to the subretinal space have been shown to restore or preserve vision. The methods for evaluation of transplants are expensive considering the large amount of animals. Alternatively, time-domain Stratus OCT was previously shown to be able to image the morphological structure of transplants to some extent, but could not clearly identify laminated transplants. The efficacy of screening retinal transplants with Fourier-domain OCT was studied on 37 S334ter line 3 rats with retinal degeneration 6-67 days after transplant surgery. The transplants were morphologically categorized as no transplant, detachment, rosettes, small laminated area and larger laminated area with both Fourier-domain OCT and histology. The efficacy of Fourier-domain OCT in screening retinal transplants was evaluated by comparing the categorization results with OCT and histology. Additionally, 4 rats were randomly selected for multiple OCT examinations (1, 5, 9, 14 and 21days post surgery) in order to determine the earliest image time of OCT examination since the transplanted tissue may need some time to show its tendency of growing. Finally, we demonstrated the efficacy of Fourier-domain OCT in screening retinal transplants in early stages and determined the earliest imaging time for OCT. Fourier-domain OCT makes itself valuable in saving resource spent on animals with unsuccessful transplants.

  6. Development of Animal Models of Local Retinal Degeneration

    PubMed Central

    Lorach, Henri; Kung, Jennifer; Beier, Corinne; Mandel, Yossi; Dalal, Roopa; Huie, Philip; Wang, Jenny; Lee, Seungjun; Sher, Alexander; Jones, Bryan William; Palanker, Daniel

    2015-01-01

    Purpose Development of nongenetic animal models of local retinal degeneration is essential for studies of retinal pathologies, such as chronic retinal detachment or age-related macular degeneration. We present two different methods to induce a highly localized retinal degeneration with precise onset time, that can be applied to a broad range of species in laboratory use. Methods A 30-μm thin polymer sheet was implanted subretinally in wild-type (WT) rats. The effects of chronic retinal separation from the RPE were studied using histology and immunohistochemistry. Another approach is applicable to species with avascular retina, such as rabbits, where the photoreceptors and RPE were thermally ablated over large areas, using a high power scanning laser. Results Photoreceptors above the subretinal implant in rats degenerated over time, with 80% of the outer nuclear layer disappearing within a month, and the rest by 3 months. Similar loss was obtained by selective photocoagulation with a scanning laser. Cells in the inner nuclear layer and ganglion cell layer were preserved in both cases. However, there were signs of rewiring and decrease in the size of the bipolar cell terminals in the damaged areas. Conclusions Both methods induce highly reproducible degeneration of photoreceptors over a defined area, with complete preservation of the inner retinal neurons during the 3-month follow-up. They provide a reliable platform for studies of local retinal degeneration and development of therapeutic strategies in a wide variety of species. PMID:26207299

  7. Review: Retinal degeneration: Focus on the unfolded protein response

    PubMed Central

    Gorbatyuk, Oleg

    2013-01-01

    Recently published literature has provided evidence that the unfolded protein response (UPR) is involved in the development of retinal degeneration. The scope of these studies encompassed diabetic retinopathy, retinopathy of prematurity, glaucoma, retinal detachment, light-induced retinal degeneration, age-related macular degeneration, and inherited retinal degeneration. Subsequent studies investigating the role of individual UPR markers in retinal pathogenesis and examining the therapeutic potential of reprogramming the UPR as a method for modulating the rate of retinal degeneration have been initiated. Manipulation of UPR markers has been made possible by the use of knockout mice, pharmacological agents, and viral vector-mediated augmentation of gene expression. Future research will aim at identifying specific inhibitors and/or inducers of UPR regulatory markers as well as expand the list of UPR-related animal models. Additionally, adeno-associated virus-mediated gene delivery is a safe and effective method for modulating gene expression, and thus is a useful research tool for manipulating individual UPR markers in affected retinas and a promising delivery vector for gene therapy in retinal degenerative disorders. PMID:24068865

  8. Hyperoxia-Induced Proliferative Retinopathy: Early Interruption of Retinal Vascular Development with Severe and Irreversible Neurovascular Disruption

    PubMed Central

    Lajko, Michelle; Cardona, Herminio J.; Taylor, Joann M.; Shah, Ronil S.; Farrow, Kathryn N.; Fawzi, Amani A.

    2016-01-01

    Bronchopulmonary dysplasia (BPD) is a major cause of neonatal morbidity in premature infants, occurring as a result of arrested lung development combined with multiple postnatal insults. Infants with BPD exposed to supplemental oxygen are at risk of retinopathy of prematurity as well. Thus, we studied the effects of hyperoxia on the retinal vasculature in a murine model of BPD. The retinal phenotype of this model, which we termed hyperoxia-induced proliferative retinopathy (HIPR), shows severe disruption of retinal vasculature and loss of vascular patterning, disorganized intra-retinal angiogenesis, inflammation and retinal detachment. Neonatal mice were subjected to 75% oxygen exposure from postnatal day (P)0 to P14 to model BPD, then allowed to recover in room air for 1 (P15), 7 (P21), or 14 days (P28). We quantified retinal thickness, protein levels of HIF-1α, NOX2, and VEGF, and examined the cellular locations of these proteins by immunohistochemistry. We examined the retinal blood vessel integrity and inflammatory markers, including macrophages (F4/80) and lymphocytes (CD45R). Compared to controls, normal retinal vascular development was severely disrupted and replaced by a disorganized sheet of intra-retinal angiogenesis in the HIPR mice. At all time-points, HIPR showed persistent hyaloidal vasculature and a significantly thinner central retina compared to controls. HIF-1α protein levels were increased at P15, while VEGF levels continued to increase until P21. Intra-retinal fibrinogen was observed at P21 followed by sub-retinal deposition in at P28. Inflammatory lymphocytes and macrophages were observed at P21 and P28, respectively. This model presents a severe phenotype of disrupted retinal vascular development, intra-retinal angiogenesis inflammation and retinal detachment. PMID:27861592

  9. Influence of Cell Detachment on the Respiration Rate of Tumor and Endothelial Cells

    PubMed Central

    Danhier, Pierre; Copetti, Tamara; De Preter, Géraldine; Leveque, Philippe; Feron, Olivier; Jordan, Bénédicte F.; Sonveaux, Pierre; Gallez, Bernard

    2013-01-01

    Cell detachment is a procedure routinely performed in cell culture and a necessary step in many biochemical assays including the determination of oxygen consumption rates (OCR) in vitro. In vivo, cell detachment has been shown to exert profound metabolic influences notably in cancer but also in other pathologies, such as retinal detachment for example. In the present study, we developed and validated a new technique combining electron paramagnetic resonance (EPR) oximetry and the use of cytodex 1 and collagen-coated cytodex 3 dextran microbeads, which allowed the unprecedented comparison of the OCR of adherent and detached cells with high sensitivity. Hence, we demonstrated that both B16F10 melanoma cells and human umbilical vein endothelial cells (HUVEC) experience strong OCR decrease upon trypsin or collagenase treatments. The reduction of cell oxygen consumption was more pronounced with a trypsin compared to a collagenase treatment. Cells remaining in suspension also encounter a marked intracellular ATP depletion and an increase in the lactate production/glucose uptake ratio. These findings highlight the important influence exerted by cell adhesion/detachment on cell respiration, which can be probed with the unprecedented experimental assay that was developed and validated in this study. PMID:23382841

  10. Influence of cell detachment on the respiration rate of tumor and endothelial cells.

    PubMed

    Danhier, Pierre; Copetti, Tamara; De Preter, Géraldine; Leveque, Philippe; Feron, Olivier; Jordan, Bénédicte F; Sonveaux, Pierre; Gallez, Bernard

    2013-01-01

    Cell detachment is a procedure routinely performed in cell culture and a necessary step in many biochemical assays including the determination of oxygen consumption rates (OCR) in vitro. In vivo, cell detachment has been shown to exert profound metabolic influences notably in cancer but also in other pathologies, such as retinal detachment for example. In the present study, we developed and validated a new technique combining electron paramagnetic resonance (EPR) oximetry and the use of cytodex 1 and collagen-coated cytodex 3 dextran microbeads, which allowed the unprecedented comparison of the OCR of adherent and detached cells with high sensitivity. Hence, we demonstrated that both B16F10 melanoma cells and human umbilical vein endothelial cells (HUVEC) experience strong OCR decrease upon trypsin or collagenase treatments. The reduction of cell oxygen consumption was more pronounced with a trypsin compared to a collagenase treatment. Cells remaining in suspension also encounter a marked intracellular ATP depletion and an increase in the lactate production/glucose uptake ratio. These findings highlight the important influence exerted by cell adhesion/detachment on cell respiration, which can be probed with the unprecedented experimental assay that was developed and validated in this study.

  11. Dealings between Cataract and Retinal Reattachment Surgery in PVR

    PubMed Central

    Deuchler, Svenja; Singh, Pankaj; Müller, Michael; Kohnen, Thomas; Ackermann, Hanns; Iwanczuk, Joerg; Benjilali, Rachid; Koch, Frank

    2016-01-01

    Introduction. To evaluate the impact of the eye lens status and oil side effects on the outcome of vitreoretinal surgery in retinal detachment with proliferative vitreoretinopathy (PVR) and a temporary silicone oil tamponade (SOT). Methods. 101 eyes were analyzed retrospectively and 103 eyes prospectively in regard to their retinal reattachment success rate and key factors for the outcome. Subgroup analysis of 27 eyes with Scheimpflug lens photography (SLP) before and after retinal reattachment service with SOT was performed. For SLP (65% phakic eyes) a Pentacam densitometry reference body with 3 mm diameter was chosen and 3 segments (anterior/mid/posterior) were evaluated separately after a quality check. Results. The retinal reattachment rate was highest in the prospective pseudophakic group (p = 0.039). Lens transparency loss occurred earlier in middle aged patients than in younger patients. Besides the nucleus, layers posterior and anterior to it showed specific transparency changes. The emulsification rate was higher when eyes had been operated on in the anterior chamber before retinal reattachment service. Conclusions. Retinal reattachment surgery seems to benefit from preoperative cataract removal. We found significant lens changes in the nucleus as well as in the layers anterior and posterior to it. This corresponds to the histology of the lens epithelium published before. PMID:27034821

  12. Retinal remodeling in human retinitis pigmentosa.

    PubMed

    Jones, B W; Pfeiffer, R L; Ferrell, W D; Watt, C B; Marmor, M; Marc, R E

    2016-09-01

    Retinitis Pigmentosa (RP) in the human is a progressive, currently irreversible neural degenerative disease usually caused by gene defects that disrupt the function or architecture of the photoreceptors. While RP can initially be a disease of photoreceptors, there is increasing evidence that the inner retina becomes progressively disorganized as the outer retina degenerates. These alterations have been extensively described in animal models, but remodeling in humans has not been as well characterized. This study, using computational molecular phenotyping (CMP) seeks to advance our understanding of the retinal remodeling process in humans. We describe cone mediated preservation of overall topology, retinal reprogramming in the earliest stages of the disease in retinal bipolar cells, and alterations in both small molecule and protein signatures of neurons and glia. Furthermore, while Müller glia appear to be some of the last cells left in the degenerate retina, they are also one of the first cell classes in the neural retina to respond to stress which may reveal mechanisms related to remodeling and cell death in other retinal cell classes. Also fundamentally important is the finding that retinal network topologies are altered. Our results suggest interventions that presume substantial preservation of the neural retina will likely fail in late stages of the disease. Even early intervention offers no guarantee that the interventions will be immune to progressive remodeling. Fundamental work in the biology and mechanisms of disease progression are needed to support vision rescue strategies.

  13. [Atypical case of acute retinal necrosis secondary to the primary herpes simplex infection].

    PubMed

    Terelak-Borys, Barbara; Krzyźewska-Niedzialek, Aldona; Jamrozy-Witkowska, Agnieszka; Borkowski, Piotr K; Ulińska, Magdalena; Grabska-Liberek, Iwona

    2015-01-01

    Acute retinal necrosis is a rare manifestation of viral chorioretinitis, accompanied by occlusive vasculitis, which is associated with poor visual prognosis. The main causal factors include varicella-zoster virus in older patients and herpes simplex in younger ones. The disease typically manifests as a reactivation of latent infections. We present a case of a 57-year-old female with atypical clinical manifestation of acute retinal necrosis secondary to the primary viral infection with herpes simplex. The serology panel of vitreous tap and blood sample confirmed viral aetiology (H. simplex). The initial clinical signs included optic disc edema with retinitis presenting as self-limiting, slowly progressing, peripheral lesions, later followed by uveitis. The antiviral therapy resolved the symptoms of uveitis and enabled healing of retinal lesions, however the natural course of disease was later complicated with retinal detachment. It was successfully treated with vitreoretinal surgery. Despite aggressive treatment, the final visual outcome was unfavourable, due to optic nerve atrophy.

  14. Genetics Home Reference: retinitis pigmentosa

    MedlinePlus

    ... Me Understand Genetics Home Health Conditions retinitis pigmentosa retinitis pigmentosa Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Retinitis pigmentosa is a group of related eye disorders that ...

  15. Dynamic stability of detached solidification

    NASA Astrophysics Data System (ADS)

    Mazuruk, K.; Volz, M. P.

    2016-06-01

    A dynamic stability analysis model is developed for meniscus-defined crystal growth processes. The Young-Laplace equation is used to analyze the response of a growing crystal to perturbations to its radius and a thermal transport model is used to analyze the effect of perturbations on the evolution of the crystal-melt interface. A linearized differential equation is used to analyze radius perturbations but a linear integro-differential equation is required for the height perturbations. The stability model is applied to detached solidification under zero-gravity and terrestrial conditions. A numerical analysis is supplemented with an approximate analytical analysis, valid in the limit of small Bond numbers. For terrestrial conditions, a singularity is found to exist in the capillary stability coefficients where, at a critical value of the pressure differential across the meniscus, there is a transition from stability to instability. For the zero-gravity condition, exact formulas for the capillary stability coefficients are derived.

  16. Experimental results from detached plasmas in TFTR

    SciTech Connect

    Strachan, J.D.; Boody, F.P.; Bush, C.E.; Cohen, S.A.; Grek, B.; Grisham, L.; Jobes, F.C.; Johnson, D.W.; Mansfield, D.K.; Medley, S.S.

    1986-10-01

    Detached plasmas are formed in TFTR which have the principal property of the boundary to the high temperature plasma core being defined by a radiating layer. This paper documents the properties of TFTR ohmic-detached plasmas with a range of plasma densities at two different plasma currents.

  17. Evolving techniques in the treatment of macular detachment caused by optic nerve pits.

    PubMed

    Cox, M S; Witherspoon, C D; Morris, R E; Flynn, H W

    1988-07-01

    Fourteen patients with macular detachments caused by optic nerve pits were treated for progressive visual loss, cystoid macular changes, or atrophy of the macular retinal pigment epithelium. Photocoagulation of the temporal disc border alone was unsuccessful in two cases but promptly reattached the macula of two patients immobilized after laser surgery. Vitrectomy and gas tamponade improved vision and flattened the macula of three patients over various periods. The detachment recurred in one patient. Prompt and sustained macular reattachment with improved vision was noted after photocoagulation, vitrectomy, and gas tamponade in eight patients, although four required second operations. The prompt reattachment and visual recovery noted in these eight patients surpasses the reported 25% rate of spontaneous resolution.

  18. Stability of Detached Grown Germanium Single Crystals

    NASA Technical Reports Server (NTRS)

    Schweizer, M.; Volz, M. P.; Cobb, S. D.; Vujisic, L.; Szofran, F. R.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Detachment of the melt meniscus from the crucible during semiconductor Bridgman growth experiments has been observed in recent years, especially under microgravity experiments. Under earth conditions, the hydrostatic pressure counteracts the mechanism, whereby it is more difficult to achieve detached Bridgman growth. Attempts to get stable detached growth under terrestrial conditions have been discussed in the literature and have been the subject of recent experiments in our own group. The advantage of crystals grown without wall contact is obvious: In general, they possess a higher crystal quality than conventional Bridgman grown crystals with wall contact. However, due to the interaction of different parameters such as the wetting behavior of the melt with the crucible, and the dependence of the growth angle with the shape of the melt meniscus, the mechanism leading to detachment is very complicated and not completely understood. We have grown several doped and undoped Germanium crystals with the detached Bridgman and the normal Bridgman growth technique. Pyrolytic boron nitride containers were used for all growth experiments. In the detached grown crystals the typical gap thickness between the pBN crucible and the crystal is in the range of 10 to 100 micrometers, which was determined by performing profilometer measurements. Etch pit density measurements were also performed and a comparison between detached and attached grown crystals will be given. An interesting feature was detected on the surface of a detached grown crystal. Strong surface striations with an average axial distance of 0.5 mm were observed around the whole circumference. The maximum fluctuation of the gap thickness is in the range of 5-10 micrometers. These variations of the detached gap along the crystal axis can be explained by a kind of stiction of the melt/crucible interface and thus by a variation of the meniscus shape. This phenomenon leading to the fluctuation of the gap thickness will be

  19. Stability of Detached Grown Germanium Single Crystals

    NASA Technical Reports Server (NTRS)

    Schweizer, M.; Volz, M. P.; Cobb, S. D.; Motakef, S.; Szofran, F. R.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Detachment of the melt meniscus from the crucible during semiconductor Bridgman growth experiments has been observed in recent years especially, under microgravity experiments. Under earth conditions, the hydrostatic pressure counteracts the mechanism, whereby it is more difficult to achieve detached Bridgman growth. Attempts to get stable detached growth under terrestrial conditions have been discussed in the literature and have been the subject of recent experiments in our own group. The advantage of crystals grown without wall contact is obvious: In general, they possess a higher crystal quality than conventional Bridgman grown crystals with wall contact. However, due to the interaction of different parameters such as the wetting behavior of the melt with the crucible, and the dependence of the growth angle with the shape of the melt meniscus, the mechanism leading to detachment is very complicated and not completely understood. We have grown several doped and undoped Germanium crystals with the detached Bridgman and the normal Bridgman growth technique. Pyrolytic boron nitride containers were used for all growth experiments. In the detached grown crystals the typical gap thickness between the pBN crucible and the crystal is in the range of 10 to 100 microns, which was determined by performing profilometer measurements. Etch pit density measurements were also performed and a comparison between detached and attached grown crystals will be given. An interesting feature was detected on the surface of a detached grown crystal. Strong surface striations with an average axial distance of 0.5mm were observed around the whole circumference. The maximum fluctuation of the gap thickness is in the range of 5-10 microns. These variations of the detached gap along the crystal axis can be explained by a kind of stiction of the melt/crucible interface and thus by a variation of the meniscus shape. This phenomenon leading to the fluctuation of the gap thickness will be

  20. Particle Simulations of Plasma Detachment in VASIMR

    NASA Technical Reports Server (NTRS)

    Ilin, A. V.; ChangDiaz, F. R.; Squire, J. P.; Breizman, B. N.; Carter, M. D.; Novakovski, S. V.

    1999-01-01

    The particle simulations in a Variable Specific Impulse Magnetoplasma Rocket (VASIMR) currently include self-consistent calculation of. 1) stationary magnetic field in plasma, 2) ion density and velocity, 3) ion-cyclotron radio-frequency heating, 4) ambipolar electric field. The assumptions of quasineutral and collissionless plasma are based on the range of operating VASIMR parameters. The main motivation for the particle simulation in VASIMR is plasma detachment from the magnetic field in the exhaust area. The plasma detachment is caused mainly by the Larmor radius increase. The plasma beta effect on detachment is observed and investigated as well. The results of particle simulations are compared with those from MHD simulations.

  1. [Development of all-silicone detachable balloons].

    PubMed

    Machida, T; Aoki, S; Sasaki, Y; Sasaki, Y; Iio, M; Matsuno, A; Yoshida, S; Basugi, N

    1990-11-25

    Treatment of cerebral vascular lesions such as carotid cavernous sinus fistulas and giant aneurysms is now being performed with intravascular detachable balloon embolization techniques. We have developed several types of all-silicone detachable balloons. Our balloons have self-sealing valves (with or without collars) and detach with simple traction. The self-sealing valve is smaller than 0.6 mm and the balloon can easily be placed through a 7-F catheter. We started clinical trials and a representative case was reported.

  2. Automated segmentation of serous pigment epithelium detachment in SD-OCT images

    NASA Astrophysics Data System (ADS)

    Sun, Zhuli; Shi, Fei; Xiang, Dehui; Chen, Haoyu; Chen, Xinjian

    2015-03-01

    Pigment epithelium detachment (PED) is an important clinical manifestation of multiple chorio-retinal disease processes, which can cause the loss of central vision. A 3-D method is proposed to automatically segment serous PED in SD-OCT images. The proposed method consists of five steps: first, a curvature anisotropic diffusion filter is applied to remove speckle noise. Second, the graph search method is applied for abnormal retinal layer segmentation associated with retinal pigment epithelium (RPE) deformation. During this process, Bruch's membrane, which doesn't show in the SD-OCT images, is estimated with the convex hull algorithm. Third, the foreground and background seeds are automatically obtained from retinal layer segmentation result. Fourth, the serous PED is segmented based on the graph cut method. Finally, a post-processing step is applied to remove false positive regions based on mathematical morphology. The proposed method was tested on 20 SD-OCT volumes from 20 patients diagnosed with serous PED. The average true positive volume fraction (TPVF), false positive volume fraction (FPVF), dice similarity coefficient (DSC) and positive predictive value (PPV) are 97.19%, 0.03%, 96.34% and 95.59%, respectively. Linear regression analysis shows a strong correlation (r = 0.975) comparing the segmented PED volumes with the ground truth labeled by an ophthalmology expert. The proposed method can provide clinicians with accurate quantitative information, including shape, size and position of the PED regions, which can assist diagnose and treatment.

  3. P2Y2 Receptor Agonist INS37217 Enhances Functional Recovery after Detachment Caused by Subretinal Injection in Normal and rds Mice

    PubMed Central

    Nour, May; Quiambao, Alexander B.; Peterson, Ward M.; Al-Ubaidi, Muayyad R.; Naash, Muna I.

    2010-01-01

    Purpose To evaluate the effects of INS37217 on the recovery of retinal function after experimental retinal detachment induced by subretinal injection. Methods Subretinal injections of 1 μL of fluorescent microbeads, saline, or INS37217 (1–200 μM) were made by the transvitreal method in normal (C57BL/6) mice and in mice heterozygous for the retinal degeneration slow (rds) gene. Control, mock-injected animals underwent corneal puncture without injection. Histologic and ERG evaluations were made at 0 to 1 and 8 hours, and 1, 3, 7, 10, 14, and 60 days post injection (PI). DNA fragmentation was evaluated by terminal deoxynucleotidyl transferase–mediated uridine 5′-triphosphate-biotin nick end labeling (TUNEL). Results A single subretinal injection of saline solution containing fluorescent beads caused a histologically evident retinal detachment and distributed the microbeads to almost all the subretinal space. Spontaneous reattachment occurred within 24 hours after injection and was accompanied by evident retinal folding that appeared largely resolved by 6 days later. Relative to controls, injection of saline resulted in approximately 40% recovery of dark-adapted a-wave amplitude at 24 hours PI and gradually improved to approximately 90% of controls at 2 months PI. Subretinal injection of saline containing INS37217 (10 μM) significantly increased rod and cone ERG of normal and rds+/− mice at 1 and 10 days PI, when compared with injection of saline alone. Additionally, INS37217 reduced the number of TUNEL-positive photoreceptors and the enhanced rate of reattachment. Conclusions Enhancement of ERG recovery by INS37217 is likely due to reduced retinal folding and cell death associated with detachment. These results support the use of INS37217 to help restore function after therapies that involve subretinal administration of drugs in animal models of retinal diseases. PMID:14507899

  4. Detached plasma in Saturn's front side magnetosphere

    NASA Technical Reports Server (NTRS)

    Goertz, C. K.

    1983-01-01

    Plasma observations in the outer front side Saturnian magnetosphere are discussed which indicate the existence of dense flux tubes outside the plasma sheets. It is suggested that flux tubes are detached from the plasma sheet by a centifugally driven flute instability. The same instability leads to a dispersal of Titan-injected plasma. It is shown that the detached flux tubes will probably break open as they convect into the nightside magnetotail and lose their content in the form of a planetary wind.

  5. Retinal vascular regeneration.

    PubMed

    Otani, Atsushi; Friedlander, Martin

    2005-01-01

    We discuss the potential use of stem cells for therapeutic angiogenesis in the treatment of retinal diseases. We demonstrate that the clinical utility of these EPC may be not limited in the treatment of ischemic retinal diseases but may also have application for the treatment of retinal degenerative disorders and for a form of cell-based gene therapy. One of the greatest potential benefits of bone marrow derived EPC therapy is the possible use of autologous grafts. Nonetheless, potential toxicities and unregulated cell growth will need to be carefully evaluated before this approach is brought to the clinics.

  6. Retinal Changes Induced by Epiretinal Tangential Forces

    PubMed Central

    Romano, Mario R.; Comune, Chiara; Ferrara, Mariantonia; Cennamo, Gilda; De Cillà, Stefano; Toto, Lisa; Cennamo, Giovanni

    2015-01-01

    Two kinds of forces are active in vitreoretinal traction diseases: tangential and anterior-posterior forces. However, tangential forces are less characterized and classified in literature compared to the anterior-posterior ones. Tangential epiretinal forces are mainly due to anomalous posterior vitreous detachment (PVD), vitreoschisis, vitreopapillary adhesion (VPA), and epiretinal membranes (ERMs). Anomalous PVD plays a key role in the formation of the tangential vectorial forces on the retinal surface as consequence of gel liquefaction (synchysis) without sufficient and fast vitreous dehiscence at the vitreoretinal interface. The anomalous and persistent adherence of the posterior hyaloid to the retina can lead to vitreomacular/vitreopapillary adhesion or to a formation of avascular fibrocellular tissue (ERM) resulting from the proliferation and transdifferentiation of hyalocytes resident in the cortical vitreous remnants after vitreoschisis. The right interpretation of the forces involved in the epiretinal tangential tractions helps in a better definition of diagnosis, progression, prognosis, and surgical outcomes of vitreomacular interfaces. PMID:26421183

  7. Retinal oximetry in patients with ischaemic retinal diseases.

    PubMed

    Rilvén, Sandra; Torp, Thomas Lee; Grauslund, Jakob

    2017-03-01

    The retinal oximeter is a new tool for non-invasive measurement of retinal oxygen saturation in humans. Several studies have investigated the associations between retinal oxygen saturation and retinal diseases. In the present systematic review, we examine whether there are associations between retinal oxygen saturation and retinal ischaemic diseases. We used PubMed and Embase to search for retinal oxygen saturation and retinal ischaemic diseases. Three separate searches identified a total of 79 publications. After two levels of manual screening, 10 studies were included: six about diabetic retinopathy (DR) and four about retinal vein occlusion. No studies about retinal artery occlusion were included. In diabetes, all studies found that increases in retinal venous oxygen saturation (rvSatO2 ) were associated with present as well as increasing levels of DR. Four of six studies also found increased retinal arterial oxygen saturation (raSatO2 ) in patients with DR. In patients with central retinal vein occlusion (CRVO), all studies found that rvSatO2 was reduced, but raSatO2 remained unchanged. Branch retinal vein occlusion was not associated with changes in retinal oxygen saturation, but this was based on a single study. In conclusion, DR is associated with increased rvSatO2 and might also be related to increased raSatO2 . Central retinal vein occlusion (CRVO) is correlated with increased rvSatO2 but unrelated to raSatO2 . Prospective studies are needed to expand these findings. These would tell whether retinal oximetry could be a potential tool for screening or a biomarker of treatment outcome in patients with ischaemic retinal diseases.

  8. Retinal dysplasia of holoprosencephaly.

    PubMed

    Gorovoy, Ian R; Layer, Noelle; de Alba Campomanes, Alejandra G

    2014-03-04

    Retinal dysplasia occurs in the setting of sporadic and syndromic holoprosencephaly, which often has associated ocular malformations. The pathology of this dysplasia, which includes rosettes, has been previously described. However, its funduscopic findings have not been well documented. The authors present the fundus images of a patient with severe holoprosencephaly with retinal dysplasia and bilateral optic nerve colobomas that resulted in death 2 weeks after birth.

  9. Acute retinal necrosis results in low vision in a young patient with a history of herpes simplex virus encephalitis.

    PubMed

    Shahi, Sanjeet K

    2016-08-31

    Acute retinal necrosis (ARN), secondary to herpes simplex encephalitis, is a rare syndrome that can present in healthy individuals, as well as immuno-compromised patients. Most cases are caused by a secondary infection from the herpes virus family, with varicella zoster virus being the leading cause of this syndrome. Potential symptoms include blurry vision, floaters, ocular pain and photophobia. Ocular findings may consist of severe uveitis, retinal vasculitis, retinal necrosis, papillitis and retinal detachment. Clinical manifestations of this disease may include increased intraocular pressure, optic disc oedema, optic neuropathy and sheathed retinal arterioles. A complete work up is essential to rule out cytomegalovirus retinitis, herpes simplex encephalitis, herpes virus, syphilis, posterior uveitis and other conditions. Depending on the severity of the disease, the treatment options consist of anticoagulation therapy, cycloplegia, intravenous acyclovir, systemic steroids, prophylactic laser photocoagulation and pars plana vitrectomy with silicon oil for retinal detachment. An extensive history and clinical examination is crucial in making the correct diagnosis. Also, it is very important to be aware of low vision needs and refer the patients, if expressing any sort of functional issues with completing daily living skills, especially reading. In this article, we report one case of unilateral ARN 20 years after herpetic encephalitis.

  10. Folding of a detachment and fault - Modified detachment folding along a lateral ramp, southwestern Montana, USA

    NASA Astrophysics Data System (ADS)

    Schmidt, Christopher; Whisner, S. Christopher; Whisner, Jennifer B.

    2014-12-01

    The inversion of the Middle Proterozoic Belt sedimentary basin during Late Cretaceous thrusting in Montana produced a large eastwardly-convex salient, the southern boundary of which is a 200 km-long oblique to lateral ramp subtended by a detachment between the Belt rocks and Archean basement. A 10 km-long lateral ramp segment exposes the upper levels of the detachment where hanging wall Belt rocks have moved out over the Paleozoic and Mesozoic section. The hanging wall structure consists of a train of high amplitude, faulted, asymmetrical detachment folds. Initial west-east shortening produced layer parallel shortening fabrics and dominantly strike slip faulting followed by symmetrical detachment folding. 'Lock-up' of movement on the detachment surface produced regional simple shear and caused the detachment folds to become asymmetrical and faulted. Folding of the detachment surface after lock-up modified the easternmost detachment folds further into a southeast-verging, overturned fold pair with a ramp-related fault along the base of the stretched mutual limb.

  11. The Detached Haze Layer in Titan's Mesosphere

    NASA Astrophysics Data System (ADS)

    Lavvas, P.; Yelle, R. V.; Vuitton, V.

    2008-12-01

    The Cassini observations reveal the presence of a detached haze layer in Titan's mesosphere at an altitude of 520 km, well above the stratosphere. Observations of scattered light made by the Imaging Science Subsystem (ISS) reveal a clearly defined layer encircling low and mid-latitude regions. The aerosol layer is also detected in stellar occultation measurements of UV extinction by the UltraViolet Imaging Spectrometer (UVIS). The haze is a global and permanent feature of Titan's atmosphere. Furthermore the location of the detached haze layer is coincident with and the likely cause of a local maximum in the temperature profile measured by the Huygens Atmospheric Structure Instrument (HASI). This temperature inversion is also permanent and global, having been detected in ground-based stellar occultations. The correlation between the extinction profile and the temperature maximum imply that the detached haze cannot be due to condensation, as previously suggested. Previously, Voyager high phase angle images at 500 nm revealed a detached haze layer near 350 km, more than 150 km lower than the Cassini layer. Close examination of the Voyager images suggests that the Cassini detached layer at 520 km is a separate phenomenon rather than a change in the Voyager detached layer. Analysis of the observed optical properties suggests that the average size of particles in the Cassini detached layer is < 45 nm, with an imaginary index k < 0.3 at 187.5 nm, while Non-LTE calculations of the temperature perturbation induced by the detached haze show that the average particle size must be greater than 35 nm for reproducing the heating rate implied by the HASI temperature profile. Calculation of the sedimentation velocity of the particles, coupled with the derived number density, imply a mass flux of 1.9-3.2 × 10-14 g cm-2 s-1. This is approximately equal to the mass flux required to explain the main haze layer and suggests that the stratospheric haze is formed primarily by

  12. Photovoltaic retinal prosthesis

    NASA Astrophysics Data System (ADS)

    Loudin, James; Mathieson, Keith; Kamins, Ted; Wang, Lele; Galambos, Ludwig; Huie, Philip; Sher, Alexander; Harris, James; Palanker, Daniel

    2011-03-01

    Electronic retinal prostheses seek to restore sight to patients suffering from retinal degenerative disorders. Implanted electrode arrays apply patterned electrical stimulation to surviving retinal neurons, producing visual sensations. All current designs employ inductively coupled coils to transmit power and/or data to the implant. We present here the design and initial testing of a photovoltaic retinal prosthesis fabricated with a pixel density of up to 177 pixels/mm2. Photodiodes within each pixel of the subretinal array directly convert light to stimulation current, avoiding the use of bulky coil implants, decoding electronics, and wiring, and thereby reducing surgical complexity. A goggles-mounted camera captures the visual scene and transmits the data stream to a pocket processor. The resulting images are projected into the eyes by video goggles using pulsed, near infrared (~900 nm) light. Prostheses with three pixel densities (15, 55, and 177 pix/mm2) are being fabricated, and tests indicate a charge injection limit of 1.62 mC/cm2 at 25Hz. In vitro tests of the photovoltaic retinal stimulation using a 512-element microelectrode array have recorded stimulated spikes from the ganglion cells, with latencies in the 1-100ms range, and with peak irradiance stimulation thresholds varying from 0.1 to 1 mW/mm2. With 1ms pulses at 25Hz the average irradiance is more than 100 times below the IR retinal safety limit. Elicited retinal response disappeared upon the addition of synaptic blockers, indicating that the inner retina is stimulated rather than the ganglion cells directly, and raising hopes that the prosthesis will preserve some of the retina's natural signal processing.

  13. Update on wide- and ultra-widefield retinal imaging

    PubMed Central

    Shoughy, Samir S; Arevalo, J Fernando; Kozak, Igor

    2015-01-01

    The peripheral retina is the site of pathology in many ocular diseases and ultra-widefield (UWF) imaging is one of the new technologies available to ophthalmologists to manage some of these diseases. Currently, there are several imaging systems used in practice for the purpose of diagnostic, monitoring disease progression or response to therapy, and telemedicine. These include modalities for both adults and pediatric patients. The current systems are capable of producing wide- and UWF color fundus photographs, fluorescein and indocyanine green angiograms, and autofluorescence images. Using this technology, important clinical observations have been made in diseases such as diabetic retinopathy, uveitides, retinal vascular occlusions and tumors, intraocular tumors, retinopathy of prematurity, and age-related macular degeneration. Widefield imaging offers excellent postoperative documentation of retinal detachment surgery. New applications will soon be available to integrate this technology into large volume routine clinical practice. PMID:26458474

  14. Retinal Pigment Epithelium Tears: Risk Factors, Mechanism and Therapeutic Monitoring.

    PubMed

    Clemens, Christoph R; Eter, Nicole

    2016-01-01

    Tears of the retinal pigment epithelium (RPE) are most commonly associated with vascularised RPE detachment due to age-related macular degeneration (AMD), and they usually involve a deleterious loss in visual acuity. Recent studies suggest an increase in RPE tear incidences since the introduction of anti-vascular endothelial growth factor (anti-VEGF) therapies as well as a temporal association between the tear event and the intravitreal injection. As the number of AMD patients and the number of administered anti-VEGF injections increase, both the challenge of RPE tear prevention and the treatment after RPE tear formation have become more important. At the same time, the evolution of retinal imaging has significantly contributed to a better understanding of RPE tear development in recent years. This review summarises the current knowledge on RPE tear development, predictive factors, and treatment strategies before and after RPE tear formation.

  15. Techniques for processing eyes implanted with a retinal prosthesis for localized histopathological analysis.

    PubMed

    Nayagam, David A X; McGowan, Ceara; Villalobos, Joel; Williams, Richard A; Salinas-LaRosa, Cesar; McKelvie, Penny; Lo, Irene; Basa, Meri; Tan, Justin; Williams, Chris E

    2013-08-02

    With the recent development of retinal prostheses, it is important to develop reliable techniques for assessing the safety of these devices in preclinical studies. However, the standard fixation, preparation, and automated histology procedures are not ideal. Here we describe new procedures for evaluating the health of the retina directly adjacent to an implant. Retinal prostheses feature electrode arrays in contact with eye tissue. Previous methods have not been able to spatially localize the ocular tissue adjacent to individual electrodes within the array. In addition, standard histological processing often results in gross artifactual detachment of the retinal layers when assessing implanted eyes. Consequently, it has been difficult to assess localized damage, if present, caused by implantation and stimulation of an implanted electrode array. Therefore, we developed a method for identifying and localizing the ocular tissue adjacent to implanted electrodes using a (color-coded) dye marking scheme, and we modified an eye fixation technique to minimize artifactual retinal detachment. This method also rendered the sclera translucent, enabling localization of individual electrodes and specific parts of an implant. Finally, we used a matched control to increase the power of the histopathological assessments. In summary, this method enables reliable and efficient discrimination and assessment of the retinal cytoarchitecture in an implanted eye.

  16. Quantitative analysis of retinal OCT.

    PubMed

    Sonka, Milan; Abràmoff, Michael D

    2016-10-01

    Clinical acceptance of 3-D OCT retinal imaging brought rapid development of quantitative 3-D analysis of retinal layers, vasculature, retinal lesions as well as facilitated new research in retinal diseases. One of the cornerstones of many such analyses is segmentation and thickness quantification of retinal layers and the choroid, with an inherently 3-D simultaneous multi-layer LOGISMOS (Layered Optimal Graph Image Segmentation for Multiple Objects and Surfaces) segmentation approach being extremely well suited for the task. Once retinal layers are segmented, regional thickness, brightness, or texture-based indices of individual layers can be easily determined and thus contribute to our understanding of retinal or optic nerve head (ONH) disease processes and can be employed for determination of disease status, treatment responses, visual function, etc. Out of many applications, examples provided in this paper focus on image-guided therapy and outcome prediction in age-related macular degeneration and on assessing visual function from retinal layer structure in glaucoma.

  17. Electronic retinal implant surgery.

    PubMed

    MacLaren, R E

    2017-02-01

    Blindness due to outer retinal degeneration still remains largely untreatable. Photoreceptor loss removes light sensitivity, but the remaining inner retinal layers, the optic nerve, and indeed the physical structure of the eye itself may be unaffected by the degenerative processes. This provides the opportunity to restore some degree of vision with an electronic device in the subretinal space. In this lecture I will provide an overview of our experiences with the first-generation retinal implant Alpha IMS, developed by Retina Implant AG and based on the technology developed by Eberhart Zrenner as part of a multicentre clinical trial (NCT01024803). We are currently in the process of running a second NIHR-funded clinical trial to assess the next-generation device. The positive results from both studies to date indicate that the retinal implant should be included as a potential treatment for patients who are completely blind from retinitis pigmentosa. Evolution of the technology in future may provide further opportunities for earlier intervention or for other diseases.

  18. Retinal diseases in a reference center from a Western Amazon capital city

    PubMed Central

    Malerbi, Fernando Korn; Matsudo, Nilson Hideo; Carneiro, Adriano Biondi Monteiro; Lottenberg, Claudio Luiz

    2015-01-01

    ABSTRACT Objective To describe retinal diseases found in patients who were waiting for treatment at a tertiary care hospital in Rio Branco, Acre, Brazil. Methods Patients underwent slit lamp biomicroscopy, dilated fundus exam and ocular ultrasound. Patients were classified according to phakic status and retinal disease of the most severely affected eye. Results A total of 138 patients were examined. The mean age was 51.3 years. Diabetes was present in 35.3% and hypertension in 45.4% of these patients. Cataract was found in 23.2% of patients, in at least one eye. Retinal examination was possible in 129 patients. The main retinal diseases identified were rhegmatogenous retinal detachment (n=23; 17.8%) and diabetic retinopathy (n=32; 24.8%). Out of 40 patients evaluated due to diabetes, 13 (32.5%) had absent or mild forms of diabetic retinopathy and did not need further treatment, only observation. Conclusion Diabetic retinopathy was the main retinal disease in this population. It is an avoidable cause of blindness and can be remotely evaluated, in its initial stages, by telemedicine strategies. In remote Brazilian areas, telemedicine may be an important tool for retinal diseases diagnosis and follow-up. PMID:26761550

  19. A simple analytical solution for slab detachment

    NASA Astrophysics Data System (ADS)

    Schmalholz, Stefan M.

    2011-04-01

    An analytical solution is presented for the nonlinear dynamics of high amplitude necking in a free layer of power-law fluid extended in layer-parallel direction due to buoyancy stress. The solution is one-dimensional (1-D) and contains three dimensionless parameters: the thinning factor (i.e. ratio of current to initial layer thickness), the power-law stress exponent, n, and the ratio of time to the characteristic deformation time of a viscous layer under buoyancy stress, t/ tc. tc is the ratio of the layer's effective viscosity to the applied buoyancy stress. The value of tc/ n specifies the time for detachment, i.e. the time it takes until the layer thickness has thinned to zero. The first-order accuracy of the 1-D solution is confirmed with 2-D finite element simulations of buoyancy-driven necking in a layer of power-law fluid embedded in a linear or power-law viscous medium. The analytical solution is accurate within a factor about 2 if the effective viscosity ratio between the layer and the medium is larger than about 100 and if the medium is a power-law fluid. The analytical solution is applied to slab detachment using dislocation creep laws for dry and wet olivine. Results show that one of the most important parameters controlling the dynamics of slab detachment is the strength of the slab which strongly depends on temperature and rheological parameters. The fundamental conclusions concerning slab detachment resulting from both the analytical solution and from earlier published thermo-mechanical numerical simulations agree well, indicating the usefulness of the highly simplified analytical solution for better understanding slab detachment. Slab detachment resulting from viscous necking is a combination of inhomogeneous thinning due to varying buoyancy stress within the slab and a necking instability due to the power-law viscous rheology ( n > 1). Application of the analytical solution to the Hindu Kush slab provides no "order-of-magnitude argument" against

  20. Detachable microsphere scalpel tips for potential use in ophthalmic surgery with the erbium:YAG laser.

    PubMed

    Hutchens, Thomas C; Darafsheh, Arash; Fardad, Amir; Antoszyk, Andrew N; Ying, Howard S; Astratov, Vasily N; Fried, Nathaniel M

    2014-01-01

    Vitreoretinal surgery is performed using mechanical dissection that sometimes results in iatrogenic complications, including vitreous hemorrhage, retinal breaks, incomplete membrane delamination, retinal distortion, microscopic damage, etc. An ultraprecise laser probe would be an ideal tool for cutting away pathologic membranes; however, the depth of surgery should be precisely controlled to protect the sensitive underlying retina. The ultraprecise surgical microprobe formed by chains of dielectric spheres for use with the erbium:YAG laser source (λ=2940  nm), with extremely short optical penetration depth in tissue, was optimized. Numerical modeling demonstrated a potential advantage of five-sphere focusing chains of sapphire spheres with index n=1.71 for ablating the tissue with self-limited depth around 10 to 20 μm. Novel detachable microsphere scalpel tips formed by chains of 300 μm sapphire (or ruby) spheres were tested on ophthalmic tissues, ex vivo. Detachable scalpel tips could allow for reusability of expensive mid-infrared trunk fibers between procedures, and offer more surgical customization by interchanging various scalpel tip configurations. An innovative method for aiming beam integration into the microsphere scalpel to improve the illumination of the surgical site was also shown. Single Er:YAG pulses of 0.2 mJ and 75-μs duration produced ablation craters in cornea epithelium for one, three, and five sphere structures with the latter generating the smallest crater depth (10 μm) with the least amount of thermal damage depth (30 μm). Detachable microsphere laser scalpel tips may allow surgeons better precision and safety compared to mechanical scalpels when operating on delicate or sensitive areas like the retina.

  1. Distribution of S- and M-cones in normal and experimentally detached cat retina.

    PubMed

    Linberg, K A; Lewis, G P; Shaaw, C; Rex, T S; Fisher, S K

    2001-02-12

    The lectin peanut agglutinin (PNA) and antibodies to short (S)- and medium to long wavelength (M/L)-sensitive cones were utilized in order to define the relative distributions of the two spectral types of cone across the domestic cat's retina. These values, in turn, were compared to those from retinas that had been experimentally detached from the retinal pigment epithelium. The pattern of cone distribution in the normal cat's retina is established by the preponderance of M-cones that constitute between 80% and 90% of all cones. Their peak density of over 26,000 cells/mm(2) resides at the area centralis. Though M-cone density decreases smoothly to the ora serrata where they have densities as low as 2,200 cells/mm(2), the density decrease along the nasotemporal axis is slower,creating a horizontal region of higher cone density. S-cones constitute between 10% and 20% of all cones, the number being quite variable even between individual animals of similar age. The highest S-cone densities are found in three distinct locations: at the superior far periphery near the ora serrata, immediately at the area centralis itself, and in a broad zone comprising the central and lower half of the inferior hemiretina. S-cones in the cat retina do not form a regular geometrical array at any eccentricity. As for the detached cat retina, the density of labeled S-cone outer segments (OS) decreases rapidly as early as 1 day postdetachment and continues decreasing to day 28 when the density of cones labeling with anti-S opsin has dropped to less than 10% of normal. This response points to a profound difference between rods and cones; essentially all rods, including those without OS, continue to express their opsin even in long-term detachments. The implications of these results for visual recovery after retinal reattachment are discussed.

  2. Detachable microsphere scalpel tips for potential use in ophthalmic surgery with the erbium:YAG laser

    NASA Astrophysics Data System (ADS)

    Hutchens, Thomas C.; Darafsheh, Arash; Fardad, Amir; Antoszyk, Andrew N.; Ying, Howard S.; Astratov, Vasily N.; Fried, Nathaniel M.

    2014-01-01

    Vitreoretinal surgery is performed using mechanical dissection that sometimes results in iatrogenic complications, including vitreous hemorrhage, retinal breaks, incomplete membrane delamination, retinal distortion, microscopic damage, etc. An ultraprecise laser probe would be an ideal tool for cutting away pathologic membranes; however, the depth of surgery should be precisely controlled to protect the sensitive underlying retina. The ultraprecise surgical microprobe formed by chains of dielectric spheres for use with the erbium:YAG laser source (λ=2940 nm), with extremely short optical penetration depth in tissue, was optimized. Numerical modeling demonstrated a potential advantage of five-sphere focusing chains of sapphire spheres with index n=1.71 for ablating the tissue with self-limited depth around 10 to 20 μm. Novel detachable microsphere scalpel tips formed by chains of 300 μm sapphire (or ruby) spheres were tested on ophthalmic tissues, ex vivo. Detachable scalpel tips could allow for reusability of expensive mid-infrared trunk fibers between procedures, and offer more surgical customization by interchanging various scalpel tip configurations. An innovative method for aiming beam integration into the microsphere scalpel to improve the illumination of the surgical site was also shown. Single Er:YAG pulses of 0.2 mJ and 75-μs duration produced ablation craters in cornea epithelium for one, three, and five sphere structures with the latter generating the smallest crater depth (10 μm) with the least amount of thermal damage depth (30 μm). Detachable microsphere laser scalpel tips may allow surgeons better precision and safety compared to mechanical scalpels when operating on delicate or sensitive areas like the retina.

  3. [Depth of retinal vessels and electroretinogram changes in stage 3 and 4 cicatricial retinopathy of prematurity].

    PubMed

    Katargina, L A; Riabtsev, D I; Kogoleva, L V

    2013-01-01

    The article presents the results of a study on retinal vessels in stage 3 and 4 cicatricial retinopathy of prematurity (ROP) by means of spectral-domain optical coherence tomography (SD OCT). The study comprised 29 children (40 eyes) aged from 6 month to 12 years with stage 3 and 4 cicatricial ROP, of which 17 children (21 eyes) under 6 and 12 children (19 eyes) over 6 years of age. SD OCT was used to approach the depth of retinal vessels and the caliber of the first-order vessels. Only in 8 eyes (20%) proper retinal vessels were located in the ganglion cell layer. In 12 eyes (30%) the vessels occurred in the nerve fiber layer and in other 20 eyes (50%) they appeared to have extraretinal growth. Thus, physiological depth of retinal vessels (i.e. in the ganglion cell layer) was seen in only 20% of cases. A relationship between the degree of retinal vascular system displacement and the presence of extraretinal tissue was established (p < 0.01). No correlation was found between gestational age and birth weight and the location of retinal vessels (p > 0.05). Location of retinal vessels can serve as a severity criterion, an important test to reveal preclinical negative changes, and a risk factor for late complications (tractional retinoschisis, detachment and tears). A tendency to smaller diameter of retinal vessels and higher artheriovenous index in children with ROP in comparison with healthy full-term children of the same age might indicate a decrease of retinal blood filling which might later cause development of retinal dystrophies.

  4. Intracellular Signalling in Retinal Ischemia

    DTIC Science & Technology

    1990-07-01

    36) However, vascularization of the RPE is not known to occur in human diseases of photoreceptor degeneration, such as retinitis pigmentosa ...A.C. (1986) Retinitis pigmentosa and retinal neovascularization. Ophthalmology 91, 1599- 1603. Figure la: Control rat retina, 8 weeks of age, central...TITLE (Include Security Classification) Intracellular Signalling in Retinal Ischemia 12. PERSONAL AUTHOR(S) Burns, Margaret Sue; Bellhorn, Roy William

  5. Probabilistic retinal vessel segmentation

    NASA Astrophysics Data System (ADS)

    Wu, Chang-Hua; Agam, Gady

    2007-03-01

    Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.

  6. Retinoids and Retinal Diseases

    PubMed Central

    Kiser, Philip D.; Palczewski, Krzysztof

    2016-01-01

    Recent progress in molecular understanding of the retinoid cycle in mammalian retina stems from painstaking biochemical reconstitution studies supported by natural or engineered animal models with known genetic lesions and studies of humans with specific genetic blinding diseases. Structural and membrane biology have been used to detect critical retinal enzymes and proteins and their substrates and ligands, placing them in a cellular context. These studies have been supplemented by analytical chemistry methods that have identified small molecules by their spectral characteristics, often in conjunction with the evaluation of models of animal retinal disease. It is from this background that rational therapeutic interventions to correct genetic defects or environmental insults are identified. Thus, most presently accepted modulators of the retinoid cycle already have demonstrated promising results in animal models of retinal degeneration. These encouraging signs indicate that some human blinding diseases can be alleviated by pharmacological interventions. PMID:27917399

  7. Bioelectronic retinal prosthesis

    NASA Astrophysics Data System (ADS)

    Weiland, James D.

    2016-05-01

    Retinal prosthesis have been translated to clinical use over the past two decades. Currently, two devices have regulatory approval for the treatment of retinitis pigmentosa and one device is in clinical trials for treatment of age-related macular degeneration. These devices provide partial sight restoration and patients use this improved vision in their everyday lives to navigate and to detect large objects. However, significant vision restoration will require both better technology and improved understanding of the interaction between electrical stimulation and the retina. In particular, current retinal prostheses do not provide peripheral visions due to technical and surgical limitations, thus limiting the effectiveness of the treatment. This paper reviews recent results from human implant patients and presents technical approaches for peripheral vision.

  8. Automatic Retinal Oximetry

    NASA Astrophysics Data System (ADS)

    Halldorsson, G. H.; Karlsson, R. A.; Hardarson, S. H.; Mura, M. Dalla; Eysteinsson, T.; Beach, J. M.; Stefansson, E.; Benediktsson, J. A.

    2007-10-01

    This paper presents a method for automating the evaluation of hemoglobin oxygen saturation in the retina. This method should prove useful for monitoring ischemic retinal diseases and the effect of treatment. In order to obtain saturation values automatically, spectral images must be registered in pairs, the vessels of the retina located and measurement points must be selected. The registration algorithm is based on a data driven approach that circumvents many of the problems that have plagued previous methods. The vessels are extracted using an algorithm based on morphological profiles and supervised classifiers. Measurement points on retinal arterioles and venules as well as reference points on the adjacent fundus are automatically selected. Oxygen saturation values along vessels are averaged to arrive at a more accurate estimate of the retinal vessel oxygen saturation. The system yields reproducible results as well as being sensitive to changes in oxygen saturation.

  9. Retinal Failure in Diabetes: a Feature of Retinal Sensory Neuropathy.

    PubMed

    Gray, Ellyn J; Gardner, Thomas W

    2015-12-01

    Physiologic adaptations mediate normal responses to short-term and long-term stresses to ensure organ function. Organ failure results if adaptive responses fail to resolve persistent stresses or maladaptive reactions develop. The retinal neurovascular unit likewise undergoes adaptive responses to diabetes resulting in a retinal sensory neuropathy analogous to other sensory neuropathies. Vision-threatening diabetic retinal neuropathy results from unremitting metabolic and inflammatory stresses, leading to macular edema and proliferative diabetic retinopathy, states of "retinal failure." Current regulatory strategies focus primarily on the retinal failure stages, but new diagnostic modalities and understanding of the pathophysiology of diabetic retinopathy may facilitate earlier treatment to maintain vision in persons with diabetes.

  10. Pathway to Retinal Oximetry

    PubMed Central

    Beach, James

    2014-01-01

    Events and discoveries in oxygen monitoring over the past two centuries are presented as the background from which oximetry of the human retina evolved. Achievements and the people behind them are discussed, showing parallels between the work in tissue measurements and later in the eye. Developments in the two-wavelength technique for oxygen saturation measurements in retinal vessels are shown to exploit the forms of imaging technology available over time. The last section provides a short summary of the recent research in retinal diseases using vessel oximetry. PMID:25237591

  11. Hereditary Retinal Dystrophy.

    PubMed

    Hohman, Thomas C

    2016-12-30

    As our understanding of the genetic basis for inherited retinal disease has expanded, gene therapy has advanced into clinical development. When the gene mutations associated with inherited retinal dystrophies were identified, it became possible to create animal models in which individual gene were altered to match the human mutations. The retina of these animals were then characterized to assess whether the mutated genes produced retinal phenotypes characteristic of disease-affected patients. Following the identification of a subpopulation of patients with the affected gene and the development of techniques for the viral gene transduction of retinal cells, it has become possible to deliver a copy of the normal gene into the retinal sites of the mutated genes. When this was performed in animal models of monogenic diseases, at an early stage of retinal degeneration when the affected cells remained viable, successful gene augmentation corrected the structural and functional lesions characteristic of the specific diseases in the areas of the retina that were successfully transduced. These studies provided the essential proof-of-concept needed to advance monogenic gene therapies into clinic development; these therapies include treatments for: Leber's congenital amaurosis type 2, caused by mutations to RPE65, retinoid isomerohydrolase; choroideremia, caused by mutations to REP1, Rab escort protein 1; autosomal recessive Stargardt disease, caused by mutations to ABCA4, the photoreceptor-specific ATP-binding transporter; Usher 1B disease caused by mutations to MYO7A, myosin heavy chain 7; X-linked juvenile retinoschisis caused by mutations to RS1, retinoschisin; autosomal recessive retinitis pigmentosa caused by mutations to MERTK, the proto-oncogene tyrosine-protein kinase MER; Leber's hereditary optic neuropathy caused by mutations to ND4, mitochondrial nicotinamide adenine dinucleotide ubiquinone oxidoreductase (complex I) subunit 4 and achromatopsia, caused by

  12. Pathway to Retinal Oximetry.

    PubMed

    Beach, James

    2014-09-01

    Events and discoveries in oxygen monitoring over the past two centuries are presented as the background from which oximetry of the human retina evolved. Achievements and the people behind them are discussed, showing parallels between the work in tissue measurements and later in the eye. Developments in the two-wavelength technique for oxygen saturation measurements in retinal vessels are shown to exploit the forms of imaging technology available over time. The last section provides a short summary of the recent research in retinal diseases using vessel oximetry.

  13. Cilio-retinal arterial circulation in central retinal vein occlusion.

    PubMed Central

    McLeod, D

    1975-01-01

    The hypothesis that an occlusion of the central retinal artery is an essential prerequisite for haemorrhage formation after central retinal vein obstruction has been investigated by examining the fundus changes in patients with a cilio-retinal arterial circulation; the findings are at variance with the 'combined occlusion hypothesis'. Comparisons were made between the pathological features in two retinal capillary beds with independent sources of arterial supply--namely, the central retinal and cilio-retinal arteries--but with an obstructed venous drainage channel common to both--namely, the central retinal vein. The importance of intraluminal pressure changes (as distinct from perfusion changes) in the causation of haemorrhages and oedema after venous occlusion is stressed, and the role of arterial disease in the pathogenesis of venous occlusions is distinguished from its role in determining the sequelae of such occlusions. Images PMID:1203235

  14. Electron-impact detachment from B-

    NASA Astrophysics Data System (ADS)

    Andersen, L. H.; Jensen, M. J.; Pedersen, H. B.; Vejby-Christensen, L.; Djurić, N.

    1998-10-01

    Cross sections for electron-impact single and double detachment from B- have been measured from 0 to 200 eV. The single-detachment cross section peaks at 4-5 eV with a cross-section maximum of about 10-14 cm2. A (2p3) 4S state has recently been predicted to give rise to a resonance state in the H2- dianion [T. Sommerfeld et al., Phys. Rev. A 55 1903 (1997)]. We observe no resonances in the detachment cross section of B- and hence no sign of an equivalent shortlived B2-(2p3) state. The ratio of the double- to single-detachment cross section reaches a constant value of 3% at energies above 50 eV. A simple model relates this number to a shake-off probability of about 90%. The ratio between double and single ionization of neutral atomic targets at high energy is also discussed, and the model relates this ratio to the shake-off probability in the sudden approximation.

  15. Progressive outer retinal necrosis syndrome: a comprehensive review of its clinical presentation, relationship to immune system status, and management.

    PubMed

    Austin

    2000-12-01

    Progressive outer retinal necrosis (PORN) syndrome is a form of the Varicella zoster virus (VZV) chorioretinitis found almost exclusively in people with the acquired immunodeficiency syndrome (AIDS). This destructive infection has an extremely rapid course that may lead to no light perception in affected eyes within days or weeks. Attempts at its treatment have had limited success. Rhegmatogenous retinal detachments often occur after the development of atrophic retinal holes, and silicone oil temponade has been found to be the most successful reattachment procedure. Unfortunately, cataract formation is common after such surgery. PORN needs to be differentiated from acute retinal necrosis (ARN) syndrome, a necrotizing retinitis that can also be caused by VZV. PORN and ARN are found at opposite ends of the spectrum of necrotizing herpetic retinopathies (NHR), where its clinical presentation depends upon immune system status. After a brief case presentation, the distinguishing clinical characteristics of PORN, its differentiation from ARN, attempts at its treatment, the role of the immune system status on its clinical appearance and treatment, and management of complications such as retinal detachment and subsequent cataracts are discussed.

  16. Retinal locus for scanning text.

    PubMed

    Timberlake, George T; Sharma, Manoj K; Grose, Susan A; Maino, Joseph H

    2006-01-01

    A method of mapping the retinal location of text during reading is described in which text position is plotted cumulatively on scanning laser ophthalmoscope retinal images. Retinal locations that contain text most often are the brightest in the cumulative plot, and locations that contain text least often are the darkest. In this way, the retinal area that most often contains text is determined. Text maps were plotted for eight control subjects without vision loss and eight subjects with central scotomas from macular degeneration. Control subjects' text maps showed that the fovea contained text most often. Text maps of five of the subjects with scotomas showed that they used the same peripheral retinal area to scan text and fixate. Text maps of the other three subjects with scotomas showed that they used separate areas to scan text and fixate. Retinal text maps may help evaluate rehabilitative strategies for training individuals with central scotomas to use a particular retinal area to scan text.

  17. Nanomaterials and Retinal Toxicity

    EPA Science Inventory

    The neuroretina should be considered as a potential site of nanomaterial toxicity. Engineered nanomaterials may reach the retina through three potential routes of exposure including; intra­ vitreal injection of therapeutics; blood-borne delivery in the retinal vasculature an...

  18. Symptoms of detachment from the self or from the environment in patients with an acquired deficiency of the special senses.

    PubMed

    Jáuregui-Renaud, Kathrine; Ramos-Toledo, Verónica; Aguilar-Bolaños, Miriam; Montaño-Velázquez, Bertha; Pliego-Maldonado, Alejandro

    2008-01-01

    To compare the frequency of symptoms of detachment from the self or from the environment (DD) in patients with an acquired deficiency of the special senses, a questionnaire for DD symptoms [12] and the GHQ12 questionnaire for common mental disorders [16] were auto-administered to patients with hearing-loss (N = 40), peripheral vestibular disease (N = 40) or bilateral retinal disease (N = 40), and to 80 healthy subjects. Patients with retinal disease and patients with vestibular disease reported DD symptoms more frequently & severe than patients with hearing loss and healthy subjects. DD scores were related to the GHQ12 scores and to the type of sensory dysfunction. DD symptoms are more frequent & severe in patients with an acquired deficiency of the special senses, associated to symptoms of common mental disorders.

  19. Detached Growth of Germanium by Directional Solidification

    NASA Technical Reports Server (NTRS)

    Palosz, W.; Volz, M.; Cobb, S.; Motakef, S.; Szofran, F. R.

    2004-01-01

    Detached crystal growth technique (dewetting) offers improvement in the quality of the grown crystals by preventing sticking to the walls of the crucible and thus reducing the possibility of parasitic nucleation and formation of lattice defects upon cooling. One of the factors relevant for the phenomena is the pressure differential across the meniscus at the crystal-melt interface. We investigated this effect experimentally. The growth took place in closed ampoules under the pressure of an inert gas (forming gas: 96% Ar + 4% H2). The pressure above the melt was adjustable and allowed for a control of the pressure difference between the top and bottom menisci. The crystals were characterized, particularly by taking profilometer measurements along the grown crystals surface. The effects of the experimental conditions on the detachment were compared with those predicted based on the theory of Duffar et al.

  20. Controlled Detachment of Chemically Glued Cells.

    PubMed

    Koo, Heebeom; Hahn, Sei Kwang; Yun, Seok Hyun

    2016-11-16

    We demonstrate a chemically detachable cell-glue system based on linkers containing disulfide bonds as well as functional groups for metabolic glycoengineering and bioorthogonal click chemistry. Azide groups are generated on the cell surface by metabolic glycoengineering, and they are further modified into tetrazine (Tz) or trans-cyclooctene (TCO) using rationally designed cross-linkers. When the Tz-modified and TCO-modified cells are mixed together, cell gluing between these two cell groups is established by Tz-TCO click chemistry. This artificial cell-cell adhesion can be broken by the administration of glutathione (5 mM), which triggers the degradation of disulfide bonds. Both the gluing and detachment processes are rapid (<10 min) and minimally cytotoxic.

  1. Responsive systems for cell sheet detachment.

    PubMed

    Patel, Nikul G; Zhang, Ge

    2013-01-01

    Cell sheet engineering has been progressing rapidly during the past few years and has emerged as a novel approach for cell based therapy. Cell sheet harvest technology enables fabrication of viable, transplantable cell sheets for various tissue engineering applications. Currently, the majority of cell sheet studies use thermo-responsive systems for cell sheet detachment. However, other responsive systems began showing their potentials for cell sheet harvest. This review provides an overview of current techniques in creating cell sheets using different types of responsive systems including thermo-responsive, electro-responsive, photo-responsive, pH-responsive and magnetic systems. Their mechanism, approach, as well as applications for cell detachment have been introduced. Further development of these responsive systems will allow efficient cell sheet harvesting and patterning of cells to reconstruct complex tissue for broad clinical applications.

  2. Plasma Detachment Mechanisms in Propulsive Magnetic Nozzles

    DTIC Science & Technology

    2013-03-07

    a marginal fraction of the beam flows back and the divergence angle of the 95%-mass tube measures the effectiveness of detachment, allowing...propellants1,15; and high throttlability, based on the capability of actuating, at constant power, on both the gas flow and the magnetic nozzle16. However...unlimited. Thus, central to our model will be to include the 2D depletion of the injected gas flow , which is governed by the competition between plasma

  3. Extinguishing ELMs in detached radiative divertor plasmas

    NASA Astrophysics Data System (ADS)

    Pigarov, Alexander; Krasheninnikov, Sergei; Rognlien, Thomas

    2016-10-01

    In order to avoid deleterious effects of ELMs on PFCs in next-step fusion devices it has been suggested to operate with small-sized ELMs naturally extinguishing in the divertor. Our modeling effort is focusing at extinguishing type-I ELMs: conditions for expelled plasma dissipation; efficiency of ELM power handling by detached radiative divertors; and the ELM impact on detachment state. Here time-dependent modeling of a sequence of many ELMs was performed with 2-D edge plasma transport code UEDGE-MB-W which incorporates the Macro-Blob (MB) approach to simulate non-diffusive filamentary transport and various ``Wall'' (W) models for time-dependent hydrogen wall inventory and recycling. Three cases were modeled, in which extinguishing ELMs are achieved due to: (i) intrinsic impurities via graphite sputtering, (ii) extrinsic impurity gas puff (Ne), and (iii) =(i) +(ii). For each case, we performed a series of UEDGE-MB-W runs scanning the deuterium and impurity inventories, pedestal losses and ELM frequency. Temporal variations of the degree of detachment, ionization front shape, recombination sink strength, radiated fraction, peak power loads, OSP, impurity charge states, and in/out asymmetries were analyzed. We discuss the onset of extinguishing ELMs, conditions for not burning through and enhanced plasma recombination as functions of scanned parameters. Efficiencies of intrinsic and extrinsic impurities in ELM extinguishing are compared.

  4. Detached Growth of Germanium and Germaniumsilicon

    NASA Technical Reports Server (NTRS)

    Dold, P.; Schweizer, M.; Szofran, F.; Benz, K. W.

    1999-01-01

    Up to now, detached growth was observed mainly under microgravity, i.e. under the absence of hydrostatic pressure that hinders the formation of a free melt meniscus. the detached growth of germanium doped with gallium was obtained under 1 g conditions, the growth was performed in quartz-glass ampoule. Part of the crystal grew without wall contact, the detached growth was observed in-situ with a CCD-camera as well as after the growth process in form of growth lines and the formation of <111> facets on the crystal surface. GeSi crystal (oriientation: <111>, maximum silicon content: 4 at%, seed material: Ge) was grown in a pBN crucible (excluding the possibility of in-situ monitoring of the growth process). The grown crystal exhibits three growth facets, indicating also wall free growth. Surface analysis of the crystals (NDIC, SEM) and characterization of crystal segregation (EDAX, resistivity measurement) and defect structure (EPD, x-ray diffraction measurements) will be presented.

  5. Preliminary Study on Retinal Vascular and Oxygen-related Changes after Long-term Silicone Oil and Foldable Capsular Vitreous Body Tamponade

    PubMed Central

    Yang, Wei; Yuan, Yongguang; Zong, Yao; Huang, Zhen; Mai, Shuyi; Li, Yujie; Qian, Xiaobing; Liu, Yaqin; Gao, Qianying

    2014-01-01

    Silicone oil has been the only long-term vitreous substitute used in the treatment of retinal detachment since 1962 by Cibis. Nevertheless, its effects on retinal vascular morphology and oxygen supply to the retina are ambiguous in current research. We previously invented a foldable capsular vitreous body (FCVB) to use as a new vitreous substitute in the treatment of severe retinal detachment, but its effects on the retinal vessel were unknown. Therefore, in this study, a standard three-port pars plana vitrectomy (PPV) was performed on the right eye of each rabbit and then silicone oil and FCVB were injected into the vitreous cavity as vitreous substitutes. After 180 days of retention, the retinal vascular morphology did not display any distinct abnormalities, and hypoxia-induced factor-1alpha (HIF-1α) and vascular endothelial growth factor (VEGF) did not vary markedly during the observation period in silicone oil tamponade- and FCVB-implanted eyes. This study may suggest that silicone oil and FCVB tamponade in rabbit eyes did not cause retinal vascular pathologic changes or retinal hypoxia for 180 days. PMID:24920425

  6. Preliminary study on retinal vascular and oxygen-related changes after long-term silicone oil and foldable capsular vitreous body tamponade.

    PubMed

    Yang, Wei; Yuan, Yongguang; Zong, Yao; Huang, Zhen; Mai, Shuyi; Li, Yujie; Qian, Xiaobing; Liu, Yaqin; Gao, Qianying

    2014-06-12

    Silicone oil has been the only long-term vitreous substitute used in the treatment of retinal detachment since 1962 by Cibis. Nevertheless, its effects on retinal vascular morphology and oxygen supply to the retina are ambiguous in current research. We previously invented a foldable capsular vitreous body (FCVB) to use as a new vitreous substitute in the treatment of severe retinal detachment, but its effects on the retinal vessel were unknown. Therefore, in this study, a standard three-port pars plana vitrectomy (PPV) was performed on the right eye of each rabbit and then silicone oil and FCVB were injected into the vitreous cavity as vitreous substitutes. After 180 days of retention, the retinal vascular morphology did not display any distinct abnormalities, and hypoxia-induced factor-1alpha (HIF-1α) and vascular endothelial growth factor (VEGF) did not vary markedly during the observation period in silicone oil tamponade- and FCVB-implanted eyes. This study may suggest that silicone oil and FCVB tamponade in rabbit eyes did not cause retinal vascular pathologic changes or retinal hypoxia for 180 days.

  7. Small Animal Retinal Imaging

    NASA Astrophysics Data System (ADS)

    Choi, WooJhon; Drexler, Wolfgang; Fujimoto, James G.

    Developing and validating new techniques and methods for small animal imaging is an important research area because there are many small animal models of retinal diseases such as diabetic retinopathy, age-related macular degeneration, and glaucoma [1-6]. Because the retina is a multilayered structure with distinct abnormalities occurring in different intraretinal layers at different stages of disease progression, there is a need for imaging techniques that enable visualization of these layers individually at different time points. Although postmortem histology and ultrastructural analysis can be performed for investigating microscopic changes in the retina in small animal models, this requires sacrificing animals, which makes repeated assessment of the same animal at different time points impossible and increases the number of animals required. Furthermore, some retinal processes such as neurovascular coupling cannot be fully characterized postmortem.

  8. Inherited Retinal Degenerative Disease Registry

    ClinicalTrials.gov

    2016-03-21

    Eye Diseases Hereditary; Retinal Disease; Achromatopsia; Bardet-Biedl Syndrome; Bassen-Kornzweig Syndrome; Batten Disease; Best Disease; Choroidal Dystrophy; Choroideremia; Cone Dystrophy; Cone-Rod Dystrophy; Congenital Stationary Night Blindness; Enhanced S-Cone Syndrome; Fundus Albipunctatus; Goldmann-Favre Syndrome; Gyrate Atrophy; Juvenile Macular Degeneration; Kearns-Sayre Syndrome; Leber Congenital Amaurosis; Refsum Syndrome; Retinitis Pigmentosa; Retinitis Punctata Albescens; Retinoschisis; Rod-Cone Dystrophy; Rod Dystrophy; Rod Monochromacy; Stargardt Disease; Usher Syndrome

  9. Glutamatergic Retinal Waves

    PubMed Central

    Kerschensteiner, Daniel

    2016-01-01

    Spontaneous activity patterns propagate through many parts of the developing nervous system and shape the wiring of emerging circuits. Prior to vision, waves of activity originating in the retina propagate through the lateral geniculate nucleus (LGN) of the thalamus to primary visual cortex (V1). Retinal waves have been shown to instruct the wiring of ganglion cell axons in LGN and of thalamocortical axons in V1 via correlation-based plasticity rules. Across species, retinal waves mature in three stereotypic stages (I–III), in which distinct circuit mechanisms give rise to unique activity patterns that serve specific functions in visual system refinement. Here, I review insights into the patterns, mechanisms, and functions of stage III retinal waves, which rely on glutamatergic signaling. As glutamatergic waves spread across the retina, neighboring ganglion cells with opposite light responses (ON vs. OFF) are activated sequentially. Recent studies identified lateral excitatory networks in the inner retina that generate and propagate glutamatergic waves, and vertical inhibitory networks that desynchronize the activity of ON and OFF cells in the wavefront. Stage III wave activity patterns may help segregate axons of ON and OFF ganglion cells in the LGN, and could contribute to the emergence of orientation selectivity in V1. PMID:27242446

  10. [Bilateral spontaneously reattached rhegmatogenous retinal detachment. Case report and differential diagnosis with pigmentary retinopathies].

    PubMed

    García-Guzmán, Jorge Guillermo; Franco-Yáñez, Yasmín; Lima-Gómez, Virgilio

    2014-01-01

    Antecedentes: la pigmentación oscura en el fondo del ojo aparece en enfermedades degenerativas, como la retinosis pigmentaria; para poder estimar el pronóstico funcional del paciente esta afección debe distinguirse de otras de evolución no progresiva. En el desprendimiento de retina regmatógeno con resolución espontánea puede existir pigmentación oscura, pero es infrecuente que sea bilateral. Objetivo: analizar las características que distinguen al desprendimiento de la retina con resolución espontánea de otras causas de pigmentación en el fondo del ojo, para poder identificarlo también en casos bilaterales. Caso clínico: paciente femenina con baja visual crónica, referida para evaluación por una retinopatía pigmentaria bilateral. En la exploración clínica se descartaron causas como: retinosis pigmentaria, enfermedades inflamatorias de la retina y traumatismo. Por las características clínicas, la localización de la pigmentación y la información del electrorretinograma se integró el diagnóstico de desprendimiento de la retina regmatógeno, con resolución espontánea bilateral. Se discuten las características clínicas de esta enfermedad y el abordaje diagnóstico para distinguirlo de otras retinopatía pigmentarias. Conclusiones: las características clínicas del desprendimiento de retina con resolución espontánea permiten diferenciarlo de otras causas de pigmentación retiniana, aunque la presentación sea bilateral. El pronóstico de la retina no desprendida es mejor que en una enfermedad degenerativa, por lo que el diagnóstico correcto facilita la rehabilitación.

  11. An Ocular Protein Triad Can Classify Four Complex Retinal Diseases

    PubMed Central

    Kuiper, J. J. W.; Beretta, L.; Nierkens, S.; van Leeuwen, R.; ten Dam-van Loon, N. H.; Ossewaarde-van Norel, J.; Bartels, M. C.; de Groot-Mijnes, J. D. F.; Schellekens, P.; de Boer, J. H.; Radstake, T. R. D. J.

    2017-01-01

    Retinal diseases generally are vision-threatening conditions that warrant appropriate clinical decision-making which currently solely dependents upon extensive clinical screening by specialized ophthalmologists. In the era where molecular assessment has improved dramatically, we aimed at the identification of biomarkers in 175 ocular fluids to classify four archetypical ocular conditions affecting the retina (age-related macular degeneration, idiopathic non-infectious uveitis, primary vitreoretinal lymphoma, and rhegmatogenous retinal detachment) with one single test. Unsupervised clustering of ocular proteins revealed a classification strikingly similar to the clinical phenotypes of each disease group studied. We developed and independently validated a parsimonious model based merely on three proteins; interleukin (IL)-10, IL-21, and angiotensin converting enzyme (ACE) that could correctly classify patients with an overall accuracy, sensitivity and specificity of respectively, 86.7%, 79.4% and 92.5%. Here, we provide proof-of-concept for molecular profiling as a diagnostic aid for ophthalmologists in the care for patients with retinal conditions. PMID:28128370

  12. An Ocular Protein Triad Can Classify Four Complex Retinal Diseases

    NASA Astrophysics Data System (ADS)

    Kuiper, J. J. W.; Beretta, L.; Nierkens, S.; van Leeuwen, R.; Ten Dam-van Loon, N. H.; Ossewaarde-van Norel, J.; Bartels, M. C.; de Groot-Mijnes, J. D. F.; Schellekens, P.; de Boer, J. H.; Radstake, T. R. D. J.

    2017-01-01

    Retinal diseases generally are vision-threatening conditions that warrant appropriate clinical decision-making which currently solely dependents upon extensive clinical screening by specialized ophthalmologists. In the era where molecular assessment has improved dramatically, we aimed at the identification of biomarkers in 175 ocular fluids to classify four archetypical ocular conditions affecting the retina (age-related macular degeneration, idiopathic non-infectious uveitis, primary vitreoretinal lymphoma, and rhegmatogenous retinal detachment) with one single test. Unsupervised clustering of ocular proteins revealed a classification strikingly similar to the clinical phenotypes of each disease group studied. We developed and independently validated a parsimonious model based merely on three proteins; interleukin (IL)-10, IL-21, and angiotensin converting enzyme (ACE) that could correctly classify patients with an overall accuracy, sensitivity and specificity of respectively, 86.7%, 79.4% and 92.5%. Here, we provide proof-of-concept for molecular profiling as a diagnostic aid for ophthalmologists in the care for patients with retinal conditions.

  13. [Application of retinal oximeter in ophthalmology].

    PubMed

    Li, Jing; Ma, Jianmin; Wang, Ningli

    2015-11-01

    Retinal oximeter is a new machine which has been used in the diagnose, treatment and research of several ophthalmic diseases for recent years. It allows ophthalmologists to gain retinal oxygen saturation directly. Therefore, retinal oximeter might be useful for ophthalmologists to understand ophthalmic diseases more deeper and clarify the impact of ischemia on retinal function. It has been reported in the literatures that retinal oximeter has potentially useful diagnostic and therapeutic indications in various eye diseases such as diabetic retinopathy, central retinal vein and artery occlusion, retinitis pigmentosa, glaucomatous optic neuropathy, et al. In this thesis, the application of retinal oximeter in ophthalmology is reviewed.

  14. Intraocular retinal prosthesis.

    PubMed Central

    Humayun, M S

    2001-01-01

    PURPOSE: An electronic implant that can bypass the damaged photoreceptors and electrically stimulate the remaining retinal neurons to restore useful vision has been proposed. A number of key questions remain to make this approach feasible. The goal of this thesis is to address the following 2 specific null hypotheses: (1) Stimulus parameters make no difference in the electrically elicited retinal responses. (2) Just as we have millions of photoreceptors, so it will take a device that can generate millions of pixels/light points to create useful vision. METHODS: For electrophysiologic experiments, 2 different setups were used. In the first setup, charge-balanced pulses were delivered to the retinal surface via electrodes inserted through an open sky approach in normal or blind retinal degenerate (rd) mice. In the second setup, the rabbit retina was removed under red light conditions from an enucleated eye and then maintained in a chamber while being superfused with oxygenated, heated Ames media. In both setups, stimulating electrodes and recording electrodes were positioned on the retinal surface to evaluate the effect of varying stimulation parameters on the orthodromic retinal responses (i.e., recording electrode placed between stimulating electrodes and optic nerve head). For psychophysical experiments, visual images were divided into pixels of light that could be projected in a pattern on the retina in up to 8 sighted volunteers. Subjects were asked to perform various tasks ranging from reading and face recognition to various activities of daily living. RESULTS: Electrophysiologic experiments: In a normal mouse, a single cycle of a 1-kHz sine wave was significantly more efficient than a 1-kHz square wave (P < .05), but no such difference was noted in either of the 8- or 16-week-old rd mouse groups (8-week-old, P = .426; 16-week-old, P = .078). Charge threshold was significantly higher in 16-week-old rd mouse versus both 8-week-old rd and normal mouse for every

  15. ``Detached'' deep earthquakes: are they really?

    NASA Astrophysics Data System (ADS)

    Okal, Emile A.

    2001-12-01

    We use primarily the generation of acoustic T waves into the ocean by deep seismic sources to investigate the propagation of high-frequency seismic energy from the bottom of subduction zones to the shoreline at the earth's surface. Conversion from shear waves to oceanic acoustic waves can be used as a proxy for the existence of a continuous slab featuring low anelastic attenuation. With the help of other techniques, such as the estimation of Q from S-to- P spectral amplitude ratios, we examine systematically a number of regions where earthquakes have been described as "detached". We establish the mechanical continuity of the slab to the hypocenters of the 1990 Sakhalin and 1982 Bonin events, which occurred several hundred kilometers in front of the mainstream seismic zone. The study of the 1989 Paraguay shock is inconclusive, probably due to its much smaller size. The vertical continuity of the South American slab through its aseismic depth range is verified, and a similar situation probably exists in Java. Attenuation data suggests that the deep Spanish earthquakes occur within a vertically large segment of colder material, and a similar situation may exist in Colombia. The only clearly detached deep events with no mechanical connection to the surface make up the Vityaz cluster, under the North Fiji Basin. Based on a variety of geophysical evidence, the small deep earthquakes under New Zealand are likely to take place in a detached blob at least 350 km below the termination of mainstream seismicity. These results support a model integrating buoyancy forces over a long continuous slab as the source of the down-dip compressional stresses observed in large earthquakes at the bottom of the transition zone.

  16. High resolution optoelectronic retinal prosthesis

    NASA Astrophysics Data System (ADS)

    Loudin, Jim; Dinyari, Rostam; Huie, Phil; Butterwick, Alex; Peumans, Peter; Palanker, Daniel

    2009-02-01

    Electronic retinal prostheses seek to restore sight in patients with retinal degeneration by delivering pulsed electric currents to retinal neurons via an array of microelectrodes. Most implants use inductive or optical transmission of information and power to an intraocular receiver, with decoded signals subsequently distributed to retinal electrodes through an intraocular cable. Surgical complexity could be minimized by an "integrated" prosthesis, in which both power and data are delivered directly to the stimulating array without any discrete components or cables. We present here an integrated retinal prosthesis system based on a photodiode array implant. Video frames are processed and imaged onto the retinal implant by a video goggle projection system operating at near-infrared wavelengths (~ 900 nm). Photodiodes convert light into pulsed electric current, with charge injection maximized by specially optimized series photodiode circuits. Prostheses of three different pixel densities (16 pix/mm2, 64 pix/mm2, and 256 pix/mm2) have been designed, simulated, and prototyped. Retinal tissue response to subretinal implants made of various materials has been investigated in RCS rats. The resulting prosthesis can provide sufficient charge injection for high resolution retinal stimulation without the need for implantation of any bulky discrete elements such as coils or tethers. In addition, since every pixel functions independently, pixel arrays may be placed separately in the subretinal space, providing visual stimulation to a larger field of view.

  17. Retinal Imaging and Image Analysis

    PubMed Central

    Abràmoff, Michael D.; Garvin, Mona K.; Sonka, Milan

    2011-01-01

    Many important eye diseases as well as systemic diseases manifest themselves in the retina. While a number of other anatomical structures contribute to the process of vision, this review focuses on retinal imaging and image analysis. Following a brief overview of the most prevalent causes of blindness in the industrialized world that includes age-related macular degeneration, diabetic retinopathy, and glaucoma, the review is devoted to retinal imaging and image analysis methods and their clinical implications. Methods for 2-D fundus imaging and techniques for 3-D optical coherence tomography (OCT) imaging are reviewed. Special attention is given to quantitative techniques for analysis of fundus photographs with a focus on clinically relevant assessment of retinal vasculature, identification of retinal lesions, assessment of optic nerve head (ONH) shape, building retinal atlases, and to automated methods for population screening for retinal diseases. A separate section is devoted to 3-D analysis of OCT images, describing methods for segmentation and analysis of retinal layers, retinal vasculature, and 2-D/3-D detection of symptomatic exudate-associated derangements, as well as to OCT-based analysis of ONH morphology and shape. Throughout the paper, aspects of image acquisition, image analysis, and clinical relevance are treated together considering their mutually interlinked relationships. PMID:21743764

  18. Will Retinal Implants Restore Vision?

    NASA Astrophysics Data System (ADS)

    Zrenner, Eberhart

    2002-02-01

    A number of research groups are developing electrical implants that can be attached directly to the retina in an attempt to restore vision to patients suffering from retinal degeneration. However, despite promising results in animal experiments, there are still several major obstacles to overcome before retinal prostheses can be used clinically.

  19. Low Level Laser Retinal Damage

    DTIC Science & Technology

    1990-03-01

    18 Related Projects ........................ . . ....... 20 References . . . . .......................... 22 2 INTRODUCTION The objectives of...fluorescein is a potent phototoxic agent in the retina.26 The damage threshold for blue light retinal damage is lowered by a factor of ten after an... Related to the Probiem of Retinal Light Damage 1. Corneal Holography 2. Hematoporphyrin Studies 3. Fluorescein Fluorescence Measurements 7 EQUIPMENT

  20. Perceptual Fading without Retinal Adaptation

    ERIC Educational Resources Information Center

    Hsieh, Po-Jang; Colas, Jaron T.

    2012-01-01

    A retinally stabilized object readily undergoes perceptual fading and disappears from consciousness. This startling phenomenon is commonly believed to arise from local bottom-up sensory adaptation to edge information that occurs early in the visual pathway, such as in the lateral geniculate nucleus of the thalamus or retinal ganglion cells. Here…

  1. Electron-impact detachment and dissociation of C4- ions

    NASA Astrophysics Data System (ADS)

    Le Padellec, A.; Rabilloud, F.; Pegg, D.; Neau, A.; Hellberg, F.; Thomas, R.; Schmidt, H. T.; Larsson, M.; Danared, H.; Källberg, A.; Andersson, K.; Hanstorp, D.

    2001-12-01

    CRYRING was used to study collision processes between an electron and a negative ion cluster C4-. The total detachment cross sections for the production of the neutral 4C, 3C, 2C, and C fragments were measured. The cross sections for pure detachment, and for detachment plus dissociation leading to the production of C3+C, 2C2, and C2+2C were extracted using a grid. It was found that the pure detachment process overwhelmingly dominates all other fragmentation processes. The threshold location for the detachment channel is found to be around 6.0 eV. Although the doubly charged negative ion C42- has received little previous attention, a defined near-threshold resonance observed in the detachment cross section curve, has been associated with the short-lived state C42- (0.7 fs lifetime).

  2. A Sensitivity Analysis of SOLPS Plasma Detachment

    NASA Astrophysics Data System (ADS)

    Green, D. L.; Canik, J. M.; Eldon, D.; Meneghini, O.; AToM SciDAC Collaboration

    2016-10-01

    Predicting the scrape off layer plasma conditions required for the ITER plasma to achieve detachment is an important issue when considering divertor heat load management options that are compatible with desired core plasma operational scenarios. Given the complexity of the scrape off layer, such predictions often rely on an integrated model of plasma transport with many free parameters. However, the sensitivity of any given prediction to the choices made by the modeler is often overlooked due to the logistical difficulties in completing such a study. Here we utilize an OMFIT workflow to enable a sensitivity analysis of the midplane density at which detachment occurs within the SOLPS model. The workflow leverages the TaskFarmer technology developed at NERSC to launch many instances of the SOLPS integrated model in parallel to probe the high dimensional parameter space of SOLPS inputs. We examine both predictive and interpretive models where the plasma diffusion coefficients are chosen to match an empirical scaling for divertor heat flux width or experimental profiles respectively. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility, and is supported under Contracts DE-AC02-05CH11231, DE-AC05-00OR22725 and DE-SC0012656.

  3. Meniscus Shapes in Detached Bridgman Growth

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Mazuruk, K

    2010-01-01

    In detached Bridgman crystal growth, most of the melt is in contact with the ampoule wall, but the crystal is separated from the wall by a small gap, typically 1-100 micrometers. A liquid free surface, or meniscus, bridges across this gap at the position of the melt-crystal interface. Meniscus shapes have been calculated for the case of detached Bridgman growth in cylindrical ampoules by solving the Young-Laplace equation. Key parameters affecting meniscus shapes are the growth angle, contact angle of the meniscus to the ampoule wall, the pressure differential across the meniscus, and the Bond number, a measure of the ratio of gravitational to capillary forces. In general, for specified values of growth and contact angles, solutions exist only over a finite range of pressure differentials. For intermediate values of the Bond number, there are multiple solutions to the Young-Laplace equations. There are also cases where, as a function of pressure differential, existence intervals alternate with intervals where no solutions exist. The implications of the meniscus shape calculations on meniscus stability are discussed.

  4. Photometric orbits of seven detached eclipsing binaries

    NASA Astrophysics Data System (ADS)

    Popper, D. M.; Etzel, P. B.

    1981-01-01

    Photoelectric light curves of the detached eclipsing binaries V805 Aql, TV Cet, MY Cyg, V478 Cyg, V1143 Cyg, BS Dra, and BK Peg are analyzed. The systems are among those with good spectrographic orbits of both components that are in need of good photometric solutions in order to obtain the absolute properties of the components. The analyses are carried out with a computer program valid for detached systems of spherical or slightly oblate stars in orbits of arbitrary eccentricity. A range of solutions much greater than implied by the internal mean errors of the parameters, is found to give satisfactory fits to the observations. Some of the fits are displayed for a variety of solutions for each system. For the three systems with measurable light variation between eclipses - V478 Cyg, V805 Aql, and MY Cyg - the effect of reflection appears to be substantially less than predicted. Very small, but nonzero, orbital eccentricities are found for four of the systems. The variations of limb darkening with wavelength and with spectral type are found to be in reasonable agreement with predictions from atmospheric theory.

  5. Detection of detachments and inhomogeneities in frescos by Compton scattering

    NASA Astrophysics Data System (ADS)

    Castellano, A.; Cesareo, R.; Buccolieri, G.; Donativi, M.; Palamà, F.; Quarta, S.; De Nunzio, G.; Brunetti, A.; Marabelli, M.; Santamaria, U.

    2005-07-01

    A mobile instrument has been developed for the detection and mapping of detachments in frescos by using Compton back scattered photons. The instrument is mainly composed of a high energy X-ray tube, an X-ray detection system and a translation table. The instrument was first applied to samples simulating various detachment situations, and then transferred to the Vatican Museum to detect detachments and inhomogeneities in the stanza di Eliodoro, one of the "Raphael's stanze".

  6. Evolution of the combat and operational stress control detachment.

    PubMed

    Dailey, Jason I; Ijames, Victoria L

    2014-01-01

    Medical units designed to provide combat and operational stress control services have evolved since World War II into the current Combat and Operational Stress Control (COSC) detachments. Yet the structure of these COSC detachments differ greatly between what is authorized in the table of organization and equipment (TO&E) and what is doctrinally described in the current field manual guiding combat and operational stress control operations. We therefore explore the evolution of the COSC detachment, compare the organizations found in current doctrine with that currently authorized on the TO&E, and conclude with a proposed structure of a modern COSC detachment that is functionally modular with more clear chains of command.

  7. Herpetic (non-cytomegalovirus) retinal infections in patients with the acquired immunodeficiency syndrome.

    PubMed

    Stewart, Michael W

    2013-04-01

    Human herpes viruses cause significant morbidity in patients with the acquired immunodeficiency syndrome. Even after the introduction of highly active anti-retroviral therapy (HAART), herpes viruses remain the leading causes of blindness in AIDS patients. Cytomegalovirus (CMV) retinitis and the closely-related immune reconstitution uveitis syndrome are the most common causes of blindness, but progressive outer retinal necrosis and acute retinal necrosis due to varicella zoster and herpes simplex are also important causes of vision loss. Successful treatment of these conditions requires an aggressive approach with multi-drug intravenous therapy or repeated intravitreal antiviral injections. Since the rate of retinal detachment is alarmingly high despite successful antiviral therapy, internists and ophthalmologists must work closely together to recognize and treat complications as they arise. Fortunately, Epstein-Barr virus is a rare cause of retinal infection and human herpes virus (HHV)-6, HHV-7, and HHV-8 do not appear to be primary pathogens. However, increasing evidence suggests that HHV-6 and HHV-7 play important roles in modulating the immune system and potentiating infection by CMV.

  8. Changes in spectral properties of detached leaves

    NASA Technical Reports Server (NTRS)

    Daughtry, C. S. T.; Biehl, L. L.

    1984-01-01

    If leaf senescence can be delayed for several days without significant changes in spectral properties, then samples of leaves at remote test sites could be prepared and shipped to laboratories to measure spectral properties. The changes in spectral properties of detached leaves were determined. Leaves from red birch and red pine were immersed in water or 0.001 M benzylaminopurine (BAP) and stored in plastic bags in the dark at either 5 or 25 C. Total directional-hemispherical reflectance and transmittance of the adaxial surface of birch leaves were measured over the 400 to 1100 nm wavelength region with a spectroradiometer and integrating sphere. Pine needles were taped together and reflectance of the mat of needles was measured. Spectral properties changed less than 5% of initial values during the first week when leaves were stored at 5 C. Storage at 25 C promoted rapid senescence and large changes in spectral properties. BAP delayed, but did not stop, senescence at 25 C.

  9. Crystal Shape Evolution in Detached Bridgman Growth

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Mazuruk, K.

    2013-01-01

    Detached (or dewetted) Bridgman crystal growth defines that process in which a gap exists between a growing crystal and the crucible wall. Existence of the gap provides several advantages, including no sticking of the crystal to the crucible wall, reduced thermal and mechanical stresses, reduced dislocations, and no heterogeneous nucleation by the crucible. Numerical calculations are used to determine the conditions in which a gap can exist. According to crystal shape stability theory, only some of these gap widths will be dynamically stable. Beginning with a crystal diameter that differs from stable conditions, the transient crystal growth process is analyzed. In microgravity, dynamic stability depends only on capillary effects and is decoupled from heat transfer. Depending on the initial conditions and growth parameters, the crystal shape will evolve towards the crucible wall, towards a stable gap width, or towards the center of the crucible, collapsing the meniscus. The effect of a tapered crucible on dynamic stability is also described

  10. Crystal Shape Evolution in Detached Bridgman Growth

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Mazuruk, K.

    2013-01-01

    Detached (or dewetted) Bridgman crystal growth defines that process in which a gap exists between a growing crystal and the crucible wall. Existence of the gap provides several advantages, including no sticking of the crystal to the crucible wall, reduced thermal and mechanical stresses, reduced dislocations, and no heterogeneous nucleation by the crucible. Numerical calculations are used to determine the conditions in which a gap can exist. According to crystal shape stability theory, only some of these gap widths will be dynamically stable. Beginning with a crystal diameter that differs from stable conditions, the transient crystal growth process is analyzed. In microgravity, dynamic stability depends only on capillary effects and is decoupled from heat transfer. Depending on the initial conditions and growth parameters, the crystal shape will evolve towards the crucible wall, towards a stable gap width, or towards the center of the crucible, collapsing the meniscus. The effect of a tapered crucible on dynamic stability is also described.

  11. A detached binary system BK Pegasi

    NASA Astrophysics Data System (ADS)

    Demircan, Osman; Kaya, Yalcin; Tufekcioglu, Zeki

    1994-12-01

    The UBV photometry of the detached F-type eclipsing binary BK Pegasi is presented. The light curve solution by a simple spherical model assumption suggests that a slightly hotter, larger and more luminous primary was eclipsed during the primary minimum. Combined with the radial velocity curves in Popper (1983), it was used to determine anew the system's parameters. The age and the metal abundance of the system were estimated as (3.3 +/- 0.2) x 109 yr and z = 0.028 +/- 0.003 from a comparison with the new grids of stellar models and the isochrones by Schaller et al. (1993). The distance of the system was estimated as 290 pc.

  12. Post-fever retinitis: a single center experience from south India.

    PubMed

    Vishwanath, Srilatha; Badami, Kalpana; Sriprakash, K S; Sujatha, B L; Shashidhar, S D; Shilpa, Y D

    2014-08-01

    Various retinal manifestations can occur following a febrile illness due to viral, bacterial or protozoal etiology. As there are limited data in the literature, we undertook this study to analyse the clinical presentation of post-fever retinitis due to various etiologies, as well as its course and management. This was a retrospective study of 14 consecutive cases who presented to the Vitreo Retina Department of our hospital over a 1-year period between January 2010 and December 2010. All patients underwent detailed ophthalmic examination and relevant investigations including fundus fluorescein angiography and optical coherence tomography (OCT). Basic and specific investigations were performed as necessary. All patients were given systemic steroids which were tapered based on clinical response. Twenty-one eyes of 14 patients (7 bilateral, 7 unilateral) were studied. Onset of ocular symptoms was approximately 3 weeks after fever. Four patients had specific etiology-one each of chikungunya, enteric fever, malaria and abdominal abscess with pneumococcal pneumonia. The presenting visual acuity of the affected eyes averaged 2/60. Six eyes had relative afferent pupillary defect. All patients had solitary or multiple patches of retinitis at the posterior pole and exudation at the macula. OCT through the lesions revealed inner retinal hyperreflectivity and thickening with after-shadowing. All patients showed improvement in vision with unilateral cases improving to an average of 6/12 and bilateral cases improving to an average of 6/24. Patients also showed resolution of retinitis, macular edema and serous detachment. Post-fever retinitis as a condition manifested approximately 3 weeks after onset of fever. Irrespective of the cause of the fever, clinical presentation of cases was similar with inner retinitis at the posterior pole and a favourable response to steroids, suggesting a possible immunological basis for this condition.

  13. Retinal pseudoangiitis after intravitreal triamcinolone

    PubMed Central

    García-Campos, Jose Manuel; García-Basterra, Ignacio; Kamal-Salah, Radua; Baquero-Aranda, Isabel

    2015-01-01

    We present a case of a 40-year-old woman with a fundus image similar to frosted retinal angiitis after undergoing pars plana vitrectomy and intravitreal triamcinolone injection. The patient with diabetic retinopathy was referred to our hospital with vision loss in her right eye secondary to vitreous haemorrhage. After pars plana vitrectomy and injection of triamcinolone acetonide a funduscopy examination revealed deposits of triamcinolone along the retinal vessels simulating a frosted retinal angiitis. Triamcinolone deposits along blood vessels could be the result of the reabsorption process of these crystals by the perivascular macrophages. Further studies are needed. PMID:25678611

  14. Misfolded Proteins and Retinal Dystrophies

    PubMed Central

    Lin, Jonathan H.; LaVail, Matthew M.

    2010-01-01

    Many mutations associated with retinal degeneration lead to the production of misfolded proteins by cells of the retina. Emerging evidence suggests that these abnormal proteins cause cell death by activating the Unfolded Protein Response, a set of conserved intracellular signaling pathways that detect protein misfolding within the endoplasmic reticulum and control protective and proapoptotic signal transduction pathways. Here, we review the misfolded proteins associated with select types of retinitis pigmentosa, Stargadt-like macular degeneration, and Doyne Honeycomb Retinal Dystrophy and discuss the role that endoplasmic reticulum stress and UPR signaling play in their pathogenesis. Last, we review new therapies for these diseases based on preventing protein misfolding in the retina. PMID:20238009

  15. Resveratrol inhibits epithelial-mesenchymal transition of retinal pigment epithelium and development of proliferative vitreoretinopathy

    PubMed Central

    Ishikawa, Keijiro; He, Shikun; Terasaki, Hiroto; Nazari, Hossein; Zhang, Huiming; Spee, Christine; Kannan, Ram; Hinton, David R

    2015-01-01

    Proliferative vitreoretinopathy (PVR) is a serious complication of retinal detachment and ocular trauma, and its recurrence may lead to irreversible vision loss. Epithelial to mesenchymal transition (EMT) of retinal pigment epithelial (RPE) cells is a critical step in the pathogenesis of PVR, which is characterized by fibrotic membrane formation and traction retinal detachment. In this study, we investigated the potential impact of resveratrol (RESV) on EMT and the fibrotic process in cultured RPE cells and further examined the preventive effect of RESV on PVR development using a rabbit model of PVR. We found that RESV induces mesenchymal to epithelial transition (MET) and inhibits transforming growth factor-β2(TGF-β2)-induced EMT of RPE cells by deacetylating SMAD4. The effect of RESV on MET was dependent on sirtuin1 activation. RESV suppressed proliferation, migration and fibronectin synthesis induced by platelet-derived growth factor-BB or TGF-β2. In vivo, RESV inhibited the progression of experimental PVR in rabbit eyes. Histological findings showed that RESV reduced fibrotic membrane formation and decreased α-SMA expression in the epiretinal membranes. These results suggest the potential use of RESV as a therapeutic agent to prevent the development of PVR by targeting EMT of RPE. PMID:26552368

  16. Flexible retinal electrode array

    DOEpatents

    Okandan, Murat; Wessendorf, Kurt O.; Christenson, Todd R.

    2006-10-24

    An electrode array which has applications for neural stimulation and sensing. The electrode array can include a large number of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. The electrode array can be formed from a combination of bulk and surface micromachining, with electrode tips that can include an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis where the electrodes can be tailored to provide a uniform gentle contact pressure with optional sensing of this contact pressure at one or more of the electrodes.

  17. Intravitreal Injection of Bevacizumab in Primary Vitrectomy to Decrease the Rate of Retinal Redetachment: A Randomized Pilot Study

    PubMed Central

    Tousi, Adib; Hasanpour, Hossein; Soheilian, Masoud

    2016-01-01

    Purpose: To evaluate the effect of intravitreal bevacizumab (IVB) as a surgical adjunct in prevention of proliferative vitreoretinopathy (PVR) after retinal detachment surgery. Methods: In this controlled, randomized pilot study, 27 patients with primary retinal detachment undergoing pars plana deep vitrectomy were included. Of these, 12 received IVB at the end of procedure. The anatomic success and best corrected visual acuity (BCVA) were compared to the control group at months 3 and 6 postoperatively. Results: At three month follow-up, 3 of 11 eyes (27.3%) had detached retinas in the IVB group versus 6 of 12 (50.0%) in the control group (P = 0.40). At six-month follow-up, 3 of 10 eyes (30%) had detached retinas in the IVB group versus 3 in 8 (37.5%) in the control group (P > 0.99). Mean logMAR BCVA improved significantly in both groups relative to baseline, but did not show a significant difference at three-and six-month follow-ups between the two groups. Conclusion: Our preliminary results show neither a benefit nor any harm from intervention in both anatomic and visual outcomes. Our results support conducting additional studies to evaluate the effect of intravitreal bevacizumab on postoperative PVR. PMID:27621784

  18. Spontaneous Solitaire™ AB Thrombectomy Stent Detachment During Stroke Treatment

    SciTech Connect

    Akpinar, Suha Yilmaz, Guliz

    2015-04-15

    Spontaneous Solitaire™ stent retriever detachment is a rarely defined entity seen during stroke treatment, which can result in a disastrous clinical outcome if it cannot be solved within a critical stroke treatment time window. Two solutions to this problem are presented in the literature. The first is to leave the stent in place and apply angioplasty to the detached stent, while the second involves surgically removing the stent from the location at which it detached. Here, we present a case of inadvertent stent detachment during stroke treatment for a middle cerebral artery M1 occlusion resulting in progressive thrombosis. The detached stent was removed endovascularly by another Solitaire stent, resulting in the recanalization of the occluded middle cerebral artery.

  19. Retinal Flip in Rhodopsin Activation?

    PubMed Central

    Feng, Jun; Brown, Michael F.; Mertz, Blake

    2015-01-01

    Rhodopsin is a well-characterized structural model of a G protein-coupled receptor. Photoisomerization of the covalently bound retinal triggers activation. Surprisingly, the x-ray crystal structure of the active Meta-II state has a 180° rotation about the long-axis of the retinal polyene chain. Unbiased microsecond-timescale all-atom molecular dynamics simulations show that the retinal cofactor can flip back to the orientation observed in the inactive state of rhodopsin under conditions favoring the Meta-I state. Our results provide, to our knowledge, the first evidence from molecular dynamics simulations showing how rotation of the retinal ligand within its binding pocket can occur in the activation mechanism of rhodopsin. PMID:26083914

  20. Protein Misfolding and Retinal Degeneration

    PubMed Central

    Tzekov, Radouil; Stein, Linda; Kaushal, Shalesh

    2011-01-01

    The retina is a highly complex and specialized organ that performs preliminary analysis of visual information. Composed of highly metabolically active tissue, the retina requires a precise and well-balanced means of maintaining its functional activity during extended periods of time. Maintenance and regulation of a vast array of different structural and functional proteins is required for normal function of the retina. This process is referred to as protein homeostasis and involves a variety of activities, including protein synthesis, folding, transport, degradation, elimination, and recycling. Deregulation of any of these activities can lead to malfunctioning of the retina, from subtle subclinical signs to severe retinal degenerative diseases leading to blindness. Examples of retinal degenerative diseases caused by disruption of protein homeostasis include retinitis pigmentosa and Stargardt’s disease. A detailed discussion of the role of disruption in protein homeostasis in these and other retinal diseases is presented, followed by examples of some existing and potential treatments. PMID:21825021

  1. Microsystems Technology for Retinal Implants

    NASA Astrophysics Data System (ADS)

    Weiland, James

    2005-03-01

    The retinal prosthesis is targeted to treat age-related macular degeneration, retinitis pigmentosa, and other outer retinal degenerations. Simulations of artificial vision have predicted that 600-1000 individual pixels will be needed if a retinal prosthesis is to restore function such as reading large print and face recognition. An implantable device with this many electrode contacts will require microsystems technology as part of its design. An implantable retinal prosthesis will consist of several subsystems including an electrode array and hermetic packaging. Microsystems and microtechnology approaches are being investigated as possible solutions for these design problems. Flexible polydimethylsiloxane (PDMS) substrate electrode arrays and silicon micromachined electrode arrays are under development. Inactive PDMS electrodes have been implanted in 3 dogs to assess mechanical biocompatibility. 3 dogs were followed for 6 months. The implanted was securely fastened to the retina with a single retinal tack. No post-operative complications were evident. The array remained within 100 microns of the retinal surface. Histological evaluation showed a well preserved retina underneath the electrode array. A silicon device with electrodes suspended on micromachined springs has been implanted in 4 dogs (2 acute implants, 2 chronic implants). The device, though large, could be inserted into the eye and positioned on the retina. Histological analysis of the retina from the spring electrode implants showed that spring mounted posts penetrated the retina, thus the device will be redesigned to reduce the strength of the springs. These initial implants will provide information for the designers to make the next generation silicon device. We conclude that microsystems technology has the potential to make possible a retinal prosthesis with 1000 individual contacts in close proximity to the retina.

  2. General Pathophysiology in Retinal Degeneration

    PubMed Central

    Wert, Katherine J.; Lin, Jonathan H.; Tsang, Stephen H.

    2015-01-01

    Retinal degeneration, including that seen in age-related macular degeneration and retinitis pigmentosa (RP), is the most common form of neural degenerative disease in the world. There is great genetic and allelic heterogeneity of the various retinal dystrophies. Classifications of these diseases can be ambiguous, as there are similar clinical presentations in retinal degenerations arising from different genetic mechanisms. As would be expected, alterations in the activity of the phototransduction cascade, such as changes affecting the renewal and shedding of the photoreceptor OS, visual transduction, and/ or retinol metabolism have a great impact on the health of the retina. Mutations within any of the molecules responsible for these visual processes cause several types of retinal and retinal pigment epithelium degenerative diseases. Apoptosis has been implicated in the rod cell loss seen in a mouse model of RP, but the precise mechanisms that connect the activation of these pathways to the loss of phosphodiesterase (PDE6β) function has yet to be defined. Additionally, the activation of apoptosis by CCAAT/-enhancer-binding protein homologous protein (CHOP), after activation of the unfolded protein response pathway, may be responsible for cell death, although the mechanism remains unknown. However, the mechanisms of cell death after loss of function of PDE6, which is a commonly studied mammalian model in research, may be generalizable to loss of function of different key proteins involved in the phototransduction cascade. PMID:24732759

  3. Filling in the retinal image

    NASA Technical Reports Server (NTRS)

    Larimer, James; Piantanida, Thomas

    1990-01-01

    The optics of the eye form an image on a surface at the back of the eyeball called the retina. The retina contains the photoreceptors that sample the image and convert it into a neural signal. The spacing of the photoreceptors in the retina is not uniform and varies with retinal locus. The central retinal field, called the macula, is densely packed with photoreceptors. The packing density falls off rapidly as a function of retinal eccentricity with respect to the macular region and there are regions in which there are no photoreceptors at all. The retinal regions without photoreceptors are called blind spots or scotomas. The neural transformations which convert retinal image signals into percepts fills in the gaps and regularizes the inhomogeneities of the retinal photoreceptor sampling mosaic. The filling-in mechamism plays an important role in understanding visual performance. The filling-in mechanism is not well understood. A systematic collaborative research program at the Ames Research Center and SRI in Menlo Park, California, was designed to explore this mechanism. It was shown that the perceived fields which are in fact different from the image on the retina due to filling-in, control some aspects of performance and not others. Researchers have linked these mechanisms to putative mechanisms of color coding and color constancy.

  4. Retinal implants: a systematic review.

    PubMed

    Chuang, Alice T; Margo, Curtis E; Greenberg, Paul B

    2014-07-01

    Retinal implants present an innovative way of restoring sight in degenerative retinal diseases. Previous reviews of research progress were written by groups developing their own devices. This systematic review objectively compares selected models by examining publications describing five representative retinal prostheses: Argus II, Boston Retinal Implant Project, Epi-Ret 3, Intelligent Medical Implants (IMI) and Alpha-IMS (Retina Implant AG). Publications were analysed using three criteria for interim success: clinical availability, vision restoration potential and long-term biocompatibility. Clinical availability: Argus II is the only device with FDA approval. Argus II and Alpha-IMS have both received the European CE Marking. All others are in clinical trials, except the Boston Retinal Implant, which is in animal studies. Vision restoration: resolution theoretically correlates with electrode number. Among devices with external cameras, the Boston Retinal Implant leads with 100 electrodes, followed by Argus II with 60 electrodes and visual acuity of 20/1262. Instead of an external camera, Alpha-IMS uses a photodiode system dependent on natural eye movements and can deliver visual acuity up to 20/546. Long-term compatibility: IMI offers iterative learning; Epi-Ret 3 is a fully intraocular device; Alpha-IMS uses intraocular photosensitive elements. Merging the results of these three criteria, Alpha-IMS is the most likely to achieve long-term success decades later, beyond current clinical availability.

  5. Retinal oxygen extraction in humans

    NASA Astrophysics Data System (ADS)

    Werkmeister, René M.; Schmidl, Doreen; Aschinger, Gerold; Doblhoff-Dier, Veronika; Palkovits, Stefan; Wirth, Magdalena; Garhöfer, Gerhard; Linsenmeier, Robert A.; Leitgeb, Rainer A.; Schmetterer, Leopold

    2015-10-01

    Adequate function of the retina is dependent on proper oxygen supply. In humans, the inner retina is oxygenated via the retinal circulation. We present a method to calculate total retinal oxygen extraction based on measurement of total retinal blood flow using dual-beam bidirectional Doppler optical coherence tomography and measurement of oxygen saturation by spectrophotometry. These measurements were done on 8 healthy subjects while breathing ambient room air and 100% oxygen. Total retinal blood flow was 44.3 ± 9.0 μl/min during baseline and decreased to 18.7 ± 4.2 μl/min during 100% oxygen breathing (P < 0.001) resulting in a pronounced decrease in retinal oxygen extraction from 2.33 ± 0.51 μl(O2)/min to 0.88 ± 0.14 μl(O2)/min during breathing of 100% oxygen. The method presented in this paper may have significant potential to study oxygen metabolism in hypoxic retinal diseases such as diabetic retinopathy.

  6. Retinal oxygen extraction in humans

    PubMed Central

    Werkmeister, René M.; Schmidl, Doreen; Aschinger, Gerold; Doblhoff-Dier, Veronika; Palkovits, Stefan; Wirth, Magdalena; Garhöfer, Gerhard; Linsenmeier, Robert A.; Leitgeb, Rainer A.; Schmetterer, Leopold

    2015-01-01

    Adequate function of the retina is dependent on proper oxygen supply. In humans, the inner retina is oxygenated via the retinal circulation. We present a method to calculate total retinal oxygen extraction based on measurement of total retinal blood flow using dual-beam bidirectional Doppler optical coherence tomography and measurement of oxygen saturation by spectrophotometry. These measurements were done on 8 healthy subjects while breathing ambient room air and 100% oxygen. Total retinal blood flow was 44.3 ± 9.0 μl/min during baseline and decreased to 18.7 ± 4.2 μl/min during 100% oxygen breathing (P < 0.001) resulting in a pronounced decrease in retinal oxygen extraction from 2.33 ± 0.51 μl(O2)/min to 0.88 ± 0.14 μl(O2)/min during breathing of 100% oxygen. The method presented in this paper may have significant potential to study oxygen metabolism in hypoxic retinal diseases such as diabetic retinopathy. PMID:26503332

  7. A novel platform for minimally invasive delivery of cellular therapy as a thin layer across the subretina for treatment of retinal degeneration

    NASA Astrophysics Data System (ADS)

    Rotenstreich, Ygal; Tzameret, Adi; Kalish, Sapir E.; Belkin, Michael; Meir, Amilia; Treves, Avraham J.; Nagler, Arnon; Sher, Ifat

    2015-03-01

    Incurable retinal degenerations affect millions worldwide. Stem cell transplantation rescued visual functions in animal models of retinal degeneration. In those studies cells were transplanted in subretinal "blebs", limited number of cells could be injected and photoreceptor rescue was restricted to areas in proximity to the injection sites. We developed a minimally-invasive surgical platform for drug and cell delivery in a thin layer across the subretina and extravascular spaces of the choroid. The novel system is comprised of a syringe with a blunt-tipped needle and an adjustable separator. Human bone marrow mesenchymal stem cells (hBM-MSCs) were transplanted in eyes of RCS rats and NZW rabbits through a longitudinal triangular scleral incision. No immunosuppressants were used. Retinal function was determined by electroretinogram analysis and retinal structure was determined by histological analysis and OCT. Transplanted cells were identified as a thin layer across the subretina and extravascular spaces of the choroid. In RCS rats, cell transplantation delayed photoreceptor degeneration across the entire retina and significantly enhanced retinal functions. No retinal detachment or choroidal hemorrhages were observed in rabbits following transplantation. This novel platform opens a new avenue for drug and cell delivery, placing the transplanted cells in close proximity to the damaged RPE and retina as a thin layer, across the subretina and thereby slowing down cell death and photoreceptor degeneration, without retinal detachment or choroidal hemorrhage. This new transplantation system may increase the therapeutic effect of other cell-based therapies and therapeutic agents. This study is expected to directly lead to phase I/II clinical trials for autologous hBM-MSCs transplantation in retinal degeneration patients.

  8. Ruptured retinal arterial macroaneurysm: diagnosis and management.

    PubMed

    Speilburg, Ashley M; Klemencic, Stephanie A

    2014-01-01

    Retinal arterial macroaneurysm is an acquired, focal dilation of a retinal artery, typically occurring within the first three bifurcations of the central retinal artery. The clinical presentation of a retinal arterial macroaneurysm is highly variable, making initial diagnosis difficult and differentials many. Identification of retinal arterial macroaneurysms is crucial to appropriately co-manage with the primary care physician for hypertension control. Prognosis is generally good and observation is often an adequate treatment. However, in cases of macular threat or involvement, some treatment options are available and referral to a retinal specialist is indicated.

  9. Effect of sodium fluoride, ampicillin, and chlorhexidine on Streptococcus mutans biofilm detachment.

    PubMed

    Liu, Jia; Ling, Jun-Qi; Zhang, Kai; Huo, Li-Jun; Ning, Yang

    2012-08-01

    We examined the effect of three clinically used antimicrobials on Streptococcus mutans UA159 biofilm detachment under flow conditions. Sodium fluoride (NaF) and chlorhexidine at MIC levels promoted biofilm detachment and inhibited detachment when concentrations were higher than the MIC and reduced detached-cell viability only at high concentrations. Ampicillin at all concentrations tested inhibited detachment and reduced the percentage of viable biofilm-detached cells. All the three antimicrobial treatments reduced biofilm live/dead cell ratios.

  10. An improved method of isolating fetal human retinal pigment epithelium.

    PubMed

    Castillo, B V; Little, C W; del Cerro, C; del Cerro, M

    1995-08-01

    The purpose of this study was to develop an improved method of isolating fetal human retinal pigment epithelium (RPE) for tissue culture or transplantation. Fetal human eyes ranging from 8 to 20 wks of gestation were collected and stored in Optisol solution. Under a dissecting microscope, an incision was made behind the ora serrata and extended circumferentially to remove the anterior segment. The vitreous was withdrawn, and the neural retina was carefully detached from the RPE. The sclera then was teased away from the choroid-RPE. The choroid-RPE was treated with 2% dispase in DMEM + 20 mM HEPES at 37 degrees C for 25 min. While still in dispase, the RPE was separated from the choroid using a pair of fine tipped jeweler's forceps under dark-field. An intact sheet of RPE could be separated from the choroid after treatment with dispase. No choroidal contamination was present as determined by light microscopy or cell culture. In vitro, the isolated RPE cells demonstrated classic cobblestone phenotype and expressed cytokeratin. This technique provides an easy and reliable method for isolating pure sheets of fetal human RPE. It also allows utilization of the neural retina of the same eye for other purposes, as the neural retina is not exposed to the enzymatic digestion. These features make this method especially useful for RPE and retinal transplantation; such an application is already underway.

  11. Magnetic Nozzle and Plasma Detachment Experiment

    NASA Technical Reports Server (NTRS)

    Chavers, Gregory; Dobson, Chris; Jones, Jonathan; Martin, Adam; Bengtson, Roger D.; Briezman, Boris; Arefiev, Alexey; Cassibry, Jason; Shuttpelz, Branwen; Deline, Christopher

    2006-01-01

    High power plasma propulsion can move large payloads for orbit transfer (such as the ISS), lunar missions, and beyond with large savings in fuel consumption owing to the high specific impulse. At high power, lifetime of the thruster becomes an issue. Electrodeless devices with magnetically guided plasma offer the advantage of long life since magnetic fields confine the plasma radially and keep it from impacting the material surfaces. For decades, concerns have been raised about the plasma remaining attached to the magnetic field and returning to the vehicle along the closed magnetic field lines. Recent analysis suggests that this may not be an issue of the magnetic field is properly shaped in the nozzle region and the plasma has sufficient energy density to stretch the magnetic field downstream. An experiment was performed to test the theory regarding the Magneto-hydrodynamic (MHD) detachment scenario. Data from this experiment will be presented. The Variable Specific Impulse Magnetoplasma Rocket (VASIMR) being developed by the Ad Astra Rocket Company uses a magnetic nozzle as described above. The VASIMR is also a leading candidate for exploiting an electric propulsion test platform being considered for the ISS.

  12. Observation of mutual neutralization in detached plasma

    NASA Astrophysics Data System (ADS)

    Akira, Tonegawa; Isao, Shirota; Ken'ichi, Yoshida; Masataka, Ono; Kazutaka, Kawamura; Tuguhiro, Watanabe; Nobuyoshi, Ohyabu; Hajime, Suzuki; Kazuo, Takayama

    2001-10-01

    Mutual neutralization in collisions between negative ions and positive ions in molecular activated recombination (MAR) has been observed in a high density magnetized sheet plasma source TPDSHEET-IV(Test Plasma produced by Directed current for SHEET plasma) device. Measurements of the negative ion density of hydrogen atom, the electron density, electron temperature, and the heat load to the target plate were carried out in hydrogen high density plasma with hydrogen gas puff. A cylindrical probe made of tungsten ( 0.4 x 2 cm) was used to measure the spatial profiles of H- by a probe-assisted laser photodetachment The Balmer spectra of visible light emission from hydrogen or helium atoms were detected in front of the target plate. A small amount of secondary hydrogen gas puffing into a hydrogen plasma reduced strongly the heat flux to the target and increased rapidly the density of negative ions of hydrogen atom in the circumference of the plasma, while the conventional radiative and three-body recombination processes were disappeared. These results can be well explained by taking the charge exchange recombination of MAR in the detached plasma into account.

  13. Bubble Growth and Detachment from a Needle

    NASA Astrophysics Data System (ADS)

    Shusser, Michael; Rambod, Edmond; Gharib, Morteza

    1999-11-01

    The release of bubbles from an underwater nozzle or orifice occurs in large number of applications, such as perforated plate columns, blood oxygenators and various methods of water treatment. It is also a widely used method in laboratory research on multiphase flow and acoustics for generating small bubbles in a controlled fashion. We studied experimentally the growth and pinch-off of air bubbles released from a submerged needle into a quiescent liquid or a liquid flowing parallel to the needle. Micron-sized bubbles were generated by an air-liquid dispenser. High-speed imaging was performed to study the formation and detachment of bubbles from the tip of the needle. The impact of the needle diameter was investigated and the size and number of produced bubbles were assessed for different flow rates of air and for different velocities of the imposed upward liquid flow. The results were compared with available theoretical models and numerical computations. The existence of a critical gas flow rate and two regimes of bubble growth were verified.

  14. Stability of Menisci in Detached Bridgman Growth

    NASA Technical Reports Server (NTRS)

    Mazuruk, Konstantin; Volz, Martin P.

    2013-01-01

    Detached growth, also referred to as dewetted growth, is a Bridgman crystal growth process in which the melt is in contact with the crucible wall but the crystal is not. A meniscus bridges the gap between the top of the crystal and the crucible wall. The meniscus shape depends on the contact angle of the melt with the crucible wall, the growth angle of the melt with respect to the solidifying crystal, the gas pressure differential, the Weber number describing the rotation rate of the crucible, and the Bond number. Only some of the meniscus shapes are stable and the stability criterion is the sign of the second variation of the potential energy upon admissible meniscus shape perturbations. The effects of confined gas volumes above and below the melt and crucible rotation are evaluated. The analysis is applicable to the non-stationary case where the crystal radius changes during growth. Static stability maps (crystal radius versus pressure differential) are obtained for a series of Bond numbers, growth angles and Weber numbers. Also, the specific cases of Ge and InSb, in both terrestrial and microgravity conditions, are analyzed. Stability was found to depend significantly on whether the interior surface was considered to be microscopically rough or smooth, corresponding to pinned or unpinned states. It was also found that all meniscus shapes are statically stable in a microgravity environment.

  15. Descemet's Membrane Detachment Management Following Trabeculectomy

    PubMed Central

    Sharifipour, Farideh; Nassiri, Saman; Idan, Aida

    2016-01-01

    Purpose: To present a case of total Descemet's membrane detachment (DMD) after trabeculectomy and its surgical management. Case Report: A 68-year-old woman presented with large DMD and corneal edema one day after trabeculectomy. Intracameral air injection on day 3 was not effective. Choroidal effusion complicated the clinical picture with Descemet's membrane (DM) touching the lens. Choroidal tap with air injection on day 6 resulted in DM attachment and totally clear cornea on the next day. However, on day 12 the same scenario was repeated with choroidal effusion, shallow anterior chamber (AC), and DM touching the lens. The third surgery included transconjunctival closure of the scleral flap with 10/0 nylon sutures, choroidal tap, and intracameral injection of 20% sulfur hexafluoride. After the third surgery, DM remained attached with clear cornea. Suture removal and needling bleb revision preserved bleb function. Lens opacity progressed, and the patient underwent uneventful cataract surgery 4 months later. Conclusion: Scleral flap closure using transconjunctival sutures can be used for DMD after trabeculectomy to make the eye a closed system. Surgical drainage of choroidal effusions should be considered to increase the AC depth. PMID:27621793

  16. Shape Evolution of Detached Bridgman Crystals Grown in Microgravity

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Mazuruk, K.

    2015-01-01

    A theory describing the shape evolution of detached Bridgman crystals in microgravity has been developed. A starting crystal of initial radius r0 will evolve to one of the following states: Stable detached gap; Attachment to the crucible wall; Meniscus collapse. Only crystals where alpha plus omega is great than 180 degrees will achieve stable detached growth in microgravity. Results of the crystal shape evolution theory are consistent with predictions of the dynamic stability of crystallization (Tatarchenko, Shaped Crystal Growth, Kluwer, 1993). Tests of transient crystal evolution are planned for ICESAGE, a series of Ge and GeSi crystal growth experiments planned to be conducted on the International Space Station (ISS).

  17. Improved Crystal Quality by Detached Solidification in Microgravity

    NASA Technical Reports Server (NTRS)

    Regel, Liya L.; Wilcox, William R.

    1999-01-01

    Directional solidification in microgravity has often led to ingots that grew with little or no contact with the ampoule wall. When this occurred, crystallographic perfection was usually greatly improved -- often by several orders of magnitude. Unfortunately, until recently the true mechanisms underlying detached solidification were unknown. As a consequence, flight experiments yielded erratic results. Within the past four years, we have developed a new theoretical model that explains many of the flight results. This model gives rise to predictions of the conditions required to yield detached solidification, both in microgravity and on earth. A discussion of models of detachment, the meniscus models and results of theoretical modeling, and future plans are presented.

  18. Cytomegalovirus retinitis in Good syndrome: case report and review of literature

    PubMed Central

    Popiela, Magdalena; Varikkara, Mohan; Koshy, Zachariah

    2009-01-01

    This report describes the case of a 59-year-old woman diagnosed with cytomegalovirus (CMV) retinitis. The diagnosis was suggested by a typical fundus appearance, and confirmed by a positive PCR for CMV of both serum and vitreous biopsy. HIV status was negative. The patient’s medical history included thymoma followed by a thymectomy, recent multiple oral thrush infections, lower respiratory tract infections, urinary tract infections and severe weight loss. She had previously been treated for toxoplasma chorioretinitis and had vitrectomies for retinal detachment in the right eye. Immunological investigations revealed low T cells, almost absent B cells with reduced immunoglobulins consistent with the diagnosis of Good syndrome. The patient received treatment with intravenous ganciclovir, followed by maintenance valganciclovir, resulting in resolution of the ocular pathology. Immunoglobulin replacement therapy to boost the humoral immunity has been commenced. PMID:21691402

  19. Retinal AO OCT

    NASA Astrophysics Data System (ADS)

    Zawadzki, Robert J.; Miller, Donald T.

    The last two decades have witnessed extraordinary advances in optical technology to image noninvasively and at high resolution the posterior segment of the eye. Two of the most impactful technological advancements over this period have arguably been optical coherence tomography (OCT) and adaptive optics (AO). The strengths of these technologies complement each other and when combined have been shown to provide unprecedented, micron-scale resolution (<3 μm) in all three dimensions and sensitivity to image the cellular retina in the living eye. This powerful extension of OCT, that is AO-OCT, is the focus of this chapter. It presents key aspects of designing and implementing AO-OCT systems. Particular attention is devoted to the relevant optical properties of the eye that ultimately define these systems, AO componentry and operation tailored for ophthalmic use, and of course use of the latest technologies and methods in OCT for ocular imaging. It surveys the wide range of AO-OCT designs that have been developed for retinal imaging, with AO integrated into every major OCT design configuration. Finally, it reviews the scientific and clinical studies reported to date that show the exciting potential of AO-OCT to image the microscopic retina and fundus in ways not previously possible with other noninvasive methods and a look to future developments in this rapidly growing field.

  20. Posterior vitreous wick syndrome: a potential cause of endophthalmitis following vitreo-retinal surgery.

    PubMed

    Venkatesh, P; Verma, L; Tewari, H

    2002-06-01

    Endophthalmitis following pars-plana procedures such as a vitrectomy vitreo-retinal procedures has been infrequently reported in literature. The cited incidence is about 0.1% to 0.2%. In the 8 cases of endophthalmitis that have been reported in literature, the prognosis has been indicated as very poor due to a delay in diagnosis (1-3). Also, no possible source of an inoculum of the pathogenic organism reaching the vitreous cavity has been considered in these reports. We have encountered a few cases of endophthalmitis following vitreo-retinal surgeries at our tertiary eye care centre. Here again not being able to identify the possible source of infectious spread, we now report for the first time in literature, a new entity, the 'posterior vitreous wick syndrome'. This potential source of infectious spread, to the best of our knowledge, has not been considered earlier. We describe the patho-mechanism of the 'posterior vitreous wick syndrome' and also suggest methods of reducing its occurrence during vitreo-retinal procedures. This could also be the patho-mechanism of endophthalmitis following inadvertent loss of scleral integrity during extraocular surgeries like retinal detachment surgery and strabismus surgery (4,5).

  1. Optical coherence tomography imaging of retinal damage in real time under a stimulus electrode

    NASA Astrophysics Data System (ADS)

    Cohen, Ethan; Agrawal, Anant; Connors, Megan; Hansen, Barry; Charkhkar, Hamid; Pfefer, Joshua

    2011-10-01

    We have developed a novel method to study the effects of electrical stimulation of the local retina directly under an epiretinal stimulus electrode in real time. Using optical coherence tomography (OCT) and a superfused retinal eyecup preparation, we obtained high-resolution images of the rabbit retina directly under an optically transparent saline-filled fluoropolymer stimulation tube electrode. During OCT imaging, 50 Hz trains of biphasic current pulses 1 ms/phase (23-749 µC cm-2 ph-1) were applied to the retinal surface for 5 min. After imaging, the stimulated regions were stained with the dye propidium iodide (PI) to reveal cytotoxic damage. Pulse train stimulation at 44-133 µC cm-2 ph-1 had little effect on the retina; however, trains >=442 µC cm-2 ph-1 caused increases in the reflectance of the inner plexiform layer (IPL) and edema. The damage seen in retinal OCT images matched the pattern observed in histological sections, and in the PI staining. With pulse trains >=442 µC cm-2 ph-1, rapid increases in the reflectivity of the IPL could be observed under the stimulus electrode. Below the electrode, we observed a ring-like pattern of retinal detachment in the subretinal space. The OCT imaging method may be useful for analyzing overstimulation of neuronal tissue by electrodes in many brain regions. This paper was originally submitted for the special issue containing contributions from the Sixth Biennial Research Congress of The Eye and the Chip.

  2. Carbon dioxide fixation by detached cereal caryopses

    SciTech Connect

    Watson, P.A.; Duffus, C.M. )

    1988-06-01

    Immature detached cereal caryposes from barley (Hordeum vulgare L. var distichum cv Midas) and wheat (Triticum aestivum L. cv Sicco) were shown to be capable of fixing externally supplied {sup 14}CO{sub 2} in the light or dark. Green cross cells and the testa contained the majority of the {sup 14}C-labeled material. Some {sup 14}C-labeled material was also found in the outer, or transparent, layer and in the endosperm/embryo fraction. More {sup 14}C was recovered from caryopses when they were incubated in {sup 14}CO{sub 2} without the transparent layer, thus suggesting that this layer is a barrier to the uptake of CO{sub 2}. In all cases, significant amounts of {sup 14}C-labeled material were found in caryopses after dark incubation with {sup 14}CO{sub 2}. Interestingly, CO{sub 2} fixation in the chlorophyll-less mutant Albino lemma was significantly greater in the light than in the dark. The results indicate that intact caryopses have the ability to translocate {sup 14}C-labeled assimilate derived from external CO{sub 2} to the endosperm/embryo. Carboxylating activity in the transparent layer appears to be confined to phosphoenolpyruvate carboxylase activity but that in the chloroplast-containing cross-cells may be accounted for by both ribulose-1,5-bisphosphate carboxylase-oxygenase and phosphoenolpyruvate carboxylase activity. Depending on a number of assumptions, the amount of CO{sub 2} fixed is sufficient to account for about 2% of the weight of starch found in the mature caryposis.

  3. A detachable mobile and adjustable telemetry system

    PubMed Central

    Parker, Tommy S; Persons, William E; Bradley, Joseph G; Gregg, Margaret; Gonzales, Shinelle K; Helton, Jesse S

    2013-01-01

    Many traditional mobile telemetry systems require permanently mounting a rod through the cabin of a vehicle to serve as the mast for a directional antenna. In this article we present an alternative to this configuration by providing a platform that can be placed atop the vehicle in which the antenna mast can be mounted and controlled from the cabin of the vehicle. Thereby making this design a viable option for researchers who share vehicles with others that may not approve of permanent vehicle modifications such as placing a hole in the roof of the vehicle as required by traditional mobile configurations. We tested the precision and accuracy of detachable mobile and adjustable telemetry system (DMATS) in an urban park with varying terrain, tree stands, overhead wires, and other structures that can contribute to signal deflection. We placed three radiocollars 50 m apart and 1.2 m above the ground then established three testing stations ∼280 m from the location of the radiocollars. The DMATS platform required 12 h for completion and cost $1059 USD. Four technicians were randomly assigned radio collars to triangulate using DMATS and a handheld telemetry system. We used a one-way analysis of variance (ANOVA) with a Scheffe post hoc test to compare error ellipses between azimuths taken using DMATS and the hand held system. Average error ellipses for all testers was 1.96 ± 1.22 ha. No significant differences were found between error ellipses of testers (P = 0.292). Our design, the DMATS, does not require any vehicle modification; thereby, making this a viable option for researchers sharing vehicles with others that may not approve of permanent vehicle alterations. PMID:23919133

  4. [Congenital retinal folds in different clinical cases].

    PubMed

    Munteanu, M

    2005-01-01

    We present 12 clinical cases of congenital retinal folds with different etiologies: posterior primitive vitreous persistency and hyperplasia (7 cases),retinocytoma (1 case). retinopathy of prematurity (1 case), astrocytoma of the retina (1 case), retinal vasculitis (1 case), Goldmann-Favre syndrome (1 case). Etiopathogenic and nosological aspects are discussed; the congenital retinal folds are interpreted as a symptom in a context of a congenital or acquired vitreo-retinal pathology.

  5. [Unusual retinal abnormality: retinal hemorrhages related to scurvy].

    PubMed

    Errera, M-H; Dupas, B; Man, H; Gualino, V; Gaudric, A; Massin, P

    2011-03-01

    A diet restricted to rice and boiled fruit and vegetables leads to vitamin C deficiency. We describe the third case, to our knowledge, of retinal hemorrhages related to scurvy. Reduced bilateral visual acuity in a 50-year-old patient was associated with macrocytic anemia, denutrition, and cutaneous ecchymoses. Oral vitamin C treatment provided subjective clinical improvement and regression of the retinal hemorrhages on fundus examination, with no side effects. Vitamin C plays an important role in collagen stability in vascular and bone walls.

  6. One- and two-photon detachment of O-

    NASA Astrophysics Data System (ADS)

    Génévriez, Matthieu; Urbain, Xavier; Dochain, Arnaud; Cyr, Alain; Dunseath, Kevin M.; Terao-Dunseath, Mariko

    2016-08-01

    Cross sections for one- and two-photon detachment of O-(1 s22 s22 p5P2o) have been determined in a joint experimental and theoretical study. The absolute measurement is based on the animated-crossed-beam technique, which is extended to the case of pulsed lasers, pulsed ion beams, and multiphoton detachment. The ab initio calculations employ R -matrix Floquet theory, with simple descriptions of the initial bound state and the residual oxygen atom which reproduce well the electron affinity and ground-state polarizability. For one-photon detachment, the measured and computed cross sections are in good mutual agreement, departing significantly from previous reference experiments and calculations. The generalized two-photon detachment cross section, measured at the Nd:YAG laser wavelength, is in good agreement with the R -matrix Floquet calculations. Long-standing discrepancies between theory and experiment are thus resolved.

  7. 4. VIEW OF COTTAGE NO. 8, SHOWING ORIGINAL SINGLECAR, DETACHED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF COTTAGE NO. 8, SHOWING ORIGINAL SINGLE-CAR, DETACHED GARAGE, LOOKING NORTH - Nine Mile Hydroelectric Development, Cottage No. 8, State Highway 291 along Spokane River, Nine Mile Falls, Spokane County, WA

  8. Bimatoprost Induced Serous Macular Detachment after Cataract Surgery

    PubMed Central

    Kaliaperumal, Subashini; Deb, Amit Kumar; Babu, K. Ramesh; Srinivasan, Renuka

    2016-01-01

    We report a case of bimatoprost induced serous macular detachment and choroidal folds following uneventful cataract surgery. A 66-year-old male using topical bimatoprost in both eyes for open angle glaucoma underwent uneventful cataract surgery in the right eye. Postoperatively, he was restarted on topical bimatoprost and antibiotic-steroids combination drops. One week after surgery, he presented with conjunctival hyperemia, serous macular detachment, and choroidal folds at the posterior pole. Fundus fluorescein angiography showed perifoveal leaks in early stage with pooling of dye in late stage. Discontinuation of bimatoprost led to resolution of serous detachment and choroidal folds within 3 weeks with significant improvement in visual acuity. Occurrence of serous macular detachment and choroidal folds in this case could be probably related to the proinflammatory property of bimatoprost. Hence, it should be used with caution in the immediate postoperative period after cataract surgery. PMID:27957367

  9. On Favorable Thermal Fields for Detached Bridgman Growth

    NASA Technical Reports Server (NTRS)

    Stelian, Carmen; Volz, Martin P.; Derby, Jeffrey J.

    2009-01-01

    The thermal fields of two Bridgman-like configurations, representative of real systems used in prior experiments for the detached growth of CdTe and Ge crystals, are studied. These detailed heat transfer computations are performed using the CrysMAS code and expand upon our previous analyses [14] that posited a new mechanism involving the thermal field and meniscus position to explain stable conditions for dewetted Bridgman growth. Computational results indicate that heat transfer conditions that led to successful detached growth in both of these systems are in accordance with our prior assertion, namely that the prevention of crystal reattachment to the crucible wall requires the avoidance of any undercooling of the melt meniscus during the growth run. Significantly, relatively simple process modifications that promote favorable thermal conditions for detached growth may overcome detrimental factors associated with meniscus shape and crucible wetting. Thus, these ideas may be important to advance the practice of detached growth for many materials.

  10. Shock detachment process on cones in hypervelocity flows

    NASA Astrophysics Data System (ADS)

    Leyva, Ivett Alejandra

    1999-11-01

    The shock detachment process on cones in hypervelocity flows is one of the most sensitive flows to relaxation effects. The critical angle for shock detachment under frozen conditions can be very different from the critical angle under chemical and thermal equilibrium. The rate of increase of the detachment distance with cone angle is also affected by the relaxation rate. The purpose of this study is to explain the effects of nonequilibrium on the shock detachment distance and its growth rate on cones in hypervelocity flows. The study consists of an experimental and a computational program. The experimental part has been carried out at Caltech's hypervelocity reflected shock tunnel. Six free-stream conditions were chosen, using both N2 and CO2 as test gases. The experimental data obtained are holographic interferograms, surface temperature, and pressure measurements. The code employed for the numerical simulations is a Navier-Stokes solver that can account for thermal and chemical nonequilibrium in axisymmetric flows. The data obtained for the shock detachment distance confirms a previous theoretical model that predicts the detachment distance will grow more slowly for relaxing flows than for frozen or equilibrium flows. This difference is due to the behavior of the sonic line inside the shock layer. Different growth rates result when the detachment distance is controlled by the diameter of the cone (frozen and equilibrium cases) than when it is controlled by the relaxation length (nonequilibrium flows). The behavior of the detachment distance from the frozen to equilibrium limits for a given cone half-angle and free-stream condition has also been studied. It was confirmed that the ratio of the detachment distance to the cone diameter is constant in the two extremes and rapidly switches from one value to the other for cone diameters of about 2 cm to 16 cm. The experimental interferograms are also compared with numerical ones in terms of the detachment distance, the

  11. Choroidal melanoma clinically simulating a retinal angioma.

    PubMed

    Shields, J A; Joffe, L; Guibor, P

    1978-01-01

    An amelanotic fundus lesion in a 35-year-old man was associated with a dilated retinal vessel, thus suggesting the diagnosis of retinal angioma. Fluorescein angiography and B-scan ultrasonography were not diagnostic, but a radioactive phosphorus uptake test suggested the lesion was malignant. The enucleated globe showed a malignant choroidal melanoma drained by a large retinal vein.

  12. Inherited Retinal Degenerative Clinical Trial Network

    DTIC Science & Technology

    2009-10-01

    ending in blindness. In the United States, the total number of individuals affected by retinitis pigmentosa (RP) and other forms of rare inherited...AD_________________ AWARD NUMBER: W81XWH-07-1-0720 TITLE: Inherited Retinal Degenerative...Final 3. DATES COVERED 27 Sep 2007 – 29 Sep 2009 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Inherited Retinal Degenerative Clinical Trial Network

  13. Exploring the retinal connectome

    PubMed Central

    Anderson, James R.; Jones, Bryan W.; Watt, Carl B.; Shaw, Margaret V.; Yang, Jia-Hui; DeMill, David; Lauritzen, James S.; Lin, Yanhua; Rapp, Kevin D.; Mastronarde, David; Koshevoy, Pavel; Grimm, Bradley; Tasdizen, Tolga; Whitaker, Ross

    2011-01-01

    Purpose A connectome is a comprehensive description of synaptic connectivity for a neural domain. Our goal was to produce a connectome data set for the inner plexiform layer of the mammalian retina. This paper describes our first retinal connectome, validates the method, and provides key initial findings. Methods We acquired and assembled a 16.5 terabyte connectome data set RC1 for the rabbit retina at ≈2 nm resolution using automated transmission electron microscope imaging, automated mosaicking, and automated volume registration. RC1 represents a column of tissue 0.25 mm in diameter, spanning the inner nuclear, inner plexiform, and ganglion cell layers. To enhance ultrastructural tracing, we included molecular markers for 4-aminobutyrate (GABA), glutamate, glycine, taurine, glutamine, and the in vivo activity marker, 1-amino-4-guanidobutane. This enabled us to distinguish GABAergic and glycinergic amacrine cells; to identify ON bipolar cells coupled to glycinergic cells; and to discriminate different kinds of bipolar, amacrine, and ganglion cells based on their molecular signatures and activity. The data set was explored and annotated with Viking, our multiuser navigation tool. Annotations were exported to additional applications to render cells, visualize network graphs, and query the database. Results Exploration of RC1 showed that the 2 nm resolution readily recapitulated well known connections and revealed several new features of retinal organization: (1) The well known AII amacrine cell pathway displayed more complexity than previously reported, with no less than 17 distinct signaling modes, including ribbon synapse inputs from OFF bipolar cells, wide-field ON cone bipolar cells and rod bipolar cells, and extensive input from cone-pathway amacrine cells. (2) The axons of most cone bipolar cells formed a distinct signal integration compartment, with ON cone bipolar cell axonal synapses targeting diverse cell types. Both ON and OFF bipolar cells receive

  14. HAMLET binding to α-actinin facilitates tumor cell detachment.

    PubMed

    Trulsson, Maria; Yu, Hao; Gisselsson, Lennart; Chao, Yinxia; Urbano, Alexander; Aits, Sonja; Mossberg, Ann-Kristin; Svanborg, Catharina

    2011-03-08

    Cell adhesion is tightly regulated by specific molecular interactions and detachment from the extracellular matrix modifies proliferation and survival. HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) is a protein-lipid complex with tumoricidal activity that also triggers tumor cell detachment in vitro and in vivo, suggesting that molecular interactions defining detachment are perturbed in cancer cells. To identify such interactions, cell membrane extracts were used in Far-western blots and HAMLET was shown to bind α-actinins; major F-actin cross-linking proteins and focal adhesion constituents. Synthetic peptide mapping revealed that HAMLET binds to the N-terminal actin-binding domain as well as the integrin-binding domain of α-actinin-4. By co-immunoprecipitation of extracts from HAMLET-treated cancer cells, an interaction with α-actinin-1 and -4 was observed. Inhibition of α-actinin-1 and α-actinin-4 expression by siRNA transfection increased detachment, while α-actinin-4-GFP over-expression significantly delayed rounding up and detachment of tumor cells in response to HAMLET. In response to HAMLET, adherent tumor cells rounded up and detached, suggesting a loss of the actin cytoskeletal organization. These changes were accompanied by a reduction in β1 integrin staining and a decrease in FAK and ERK1/2 phosphorylation, consistent with a disruption of integrin-dependent cell adhesion signaling. Detachment per se did not increase cell death during the 22 hour experimental period, regardless of α-actinin-4 and α-actinin-1 expression levels but adherent cells with low α-actinin levels showed increased death in response to HAMLET. The results suggest that the interaction between HAMLET and α-actinins promotes tumor cell detachment. As α-actinins also associate with signaling molecules, cytoplasmic domains of transmembrane receptors and ion channels, additional α-actinin-dependent mechanisms are discussed.

  15. Clinical Trials in Retinal Dystrophies

    PubMed Central

    Grob, Seanna R.; Finn, Avni; Papakostas, Thanos D.; Eliott, Dean

    2016-01-01

    Research development is burgeoning for genetic and cellular therapy for retinal dystrophies. These dystrophies are the focus of many research efforts due to the unique biology and accessibility of the eye, the transformative advances in ocular imaging technology that allows for in vivo monitoring, and the potential benefit people would gain from success in the field – the gift of renewed sight. Progress in the field has revealed the immense complexity of retinal dystrophies and the challenges faced by researchers in the development of this technology. This study reviews the current trials and advancements in genetic and cellular therapy in the treatment of retinal dystrophies and also discusses the current and potential future challenges. PMID:26957839

  16. Rat retinal transcriptome

    PubMed Central

    Kozhevnikova, Oyuna S.; Korbolina, Elena E.; Ershov, Nikita I.; Kolosova, Natalia G.

    2013-01-01

    Pathogenesis of age-related macular degeneration (AMD), the leading cause of vision loss in the elderly, remains poorly understood due to the paucity of animal models that fully replicate the human disease. Recently, we showed that senescence-accelerated OXYS rats develop a retinopathy similar to human AMD. To identify alterations in response to normal aging and progression of AMD-like retinopathy, we compared gene expression profiles of retina from 3- and 18-mo-old OXYS and control Wistar rats by means of high-throughput RNA sequencing (RNA-Seq). We identified 160 and 146 age-regulated genes in Wistar and OXYS retinas, respectively. The majority of them are related to the immune system and extracellular matrix turnover. Only 24 age-regulated genes were common for the two strains, suggestive of different rates and mechanisms of aging. Over 600 genes showed significant differences in expression between the two strains. These genes are involved in disease-associated pathways such as immune response, inflammation, apoptosis, Ca2+ homeostasis and oxidative stress. The altered expression for selected genes was confirmed by qRT-PCR analysis. To our knowledge, this study represents the first analysis of retinal transcriptome from young and old rats with biologic replicates generated by RNA-Seq technology. We can conclude that the development of AMD-like retinopathy in OXYS rats is associated with an imbalance in immune and inflammatory responses. Aging alters the expression profile of numerous genes in the retina, and the genetic background of OXYS rats has a profound impact on the development of AMD-like retinopathy. PMID:23656783

  17. Retinal Optical Coherence Tomography Imaging

    NASA Astrophysics Data System (ADS)

    Drexler, Wolfgang; Fujimoto, James G.

    The eye is essentially transparent, transmitting light with only minimal optical attenuation and scattering providing easy optical access to the anterior segment as well as the retina. For this reason, ophthalmic and especially retinal imaging has been not only the first but also most successful clinical application for optical coherence tomography (OCT). This chapter focuses on the development of OCT technology for retinal imaging. OCT has significantly improved the potential for early diagnosis, understanding of retinal disease pathogenesis, as well as monitoring disease progression and response to therapy. Development of ultrabroad bandwidth light sources and high-speed detection techniques has enabled significant improvements in ophthalmic OCT imaging performance, demonstrating the potential of three-dimensional, ultrahigh-resolution OCT (UHR OCT) to perform noninvasive optical biopsy of the living human retina, i.e., the in vivo visualization of microstructural, intraretinal morphology in situ approaching the resolution of conventional histopathology. Significant improvements in axial resolution and speed not only enable three-dimensional rendering of retinal volumes but also high-definition, two-dimensional tomograms, topographic thickness maps of all major intraretinal layers, as well as volumetric quantification of pathologic intraretinal changes. These advances in OCT technology have also been successfully applied in several animal models of retinal pathologies. The development of light sources emitting at alternative wavelengths, e.g., around #1,060 nm, not only enabled three-dimensional OCT imaging with enhanced choroidal visualization but also improved OCT performance in cataract patients due to reduced scattering losses in this wavelength region. Adaptive optics using deformable mirror technology, with unique high stroke to correct higher-order ocular aberrations, with specially designed optics to compensate chromatic aberration of the human eye, in

  18. Retinal Image Quality During Accommodation

    PubMed Central

    López-Gil, N.; Martin, J.; Liu, T.; Bradley, A.; Díaz-Muñoz, D.; Thibos, L.

    2013-01-01

    Purpose We asked if retinal image quality is maximum during accommodation, or sub-optimal due to accommodative error, when subjects perform an acuity task. Methods Subjects viewed a monochromatic (552nm), high-contrast letter target placed at various viewing distances. Wavefront aberrations of the accommodating eye were measured near the endpoint of an acuity staircase paradigm. Refractive state, defined as the optimum target vergence for maximising retinal image quality, was computed by through-focus wavefront analysis to find the power of the virtual correcting lens that maximizes visual Strehl ratio. Results Despite changes in ocular aberrations and pupil size during binocular viewing, retinal image quality and visual acuity typically remain high for all target vergences. When accommodative errors lead to sub-optimal retinal image quality, acuity and measured image quality both decline. However, the effect of accommodation errors of on visual acuity are mitigated by pupillary constriction associated with accommodation and binocular convergence and also to binocular summation of dissimilar retinal image blur. Under monocular viewing conditions some subjects displayed significant accommodative lag that reduced visual performance, an effect that was exacerbated by pharmacological dilation of the pupil. Conclusions Spurious measurement of accommodative error can be avoided when the image quality metric used to determine refractive state is compatible with the focusing criteria used by the visual system to control accommodation. Real focusing errors of the accommodating eye do not necessarily produce a reliably measurable loss of image quality or clinically significant loss of visual performance, probably because of increased depth-of-focus due to pupil constriction. When retinal image quality is close to maximum achievable (given the eye’s higher-order aberrations), acuity is also near maximum. A combination of accommodative lag, reduced image quality, and reduced

  19. Effects of Nanoscale Surface Roughness on Colloid Detachment

    NASA Astrophysics Data System (ADS)

    Rasmuson, J. A.; Johnson, W. P.

    2015-12-01

    Recent advances in colloid transport science have demonstrated the importance of surface roughness on colloid attachment; however, few studies have investigated the influence of nano-scale roughness on colloid detachment. This study explores the effects of flow perturbations on a variety of mineral surfaces, as well as NaOH treated (i.e. rough, Figure 1a) and untreated (i.e. smooth, Figure 1b) surfaces for colloids of various sizes attached in an impinging jet system under flowing and stagnant conditions. These experiments showed minimal detachment from the roughened surfaces (treated glass) and significant detachment from the smooth surfaces (untreated glass and mica). A correlation between residence time and attachment irreversibility was also revealed, indicating that the particles that spent the longest time attached to the surface developed the strongest adhesion. The representative surface-heterogeneity model developed by Pazmino et al. (2014) was used to conduct detachment simulations under similar geochemical and flow conditions. While simulated results show qualitative agreement with experimental results, they tend to over-predict detachment, highlighting differences among simulated versus real surfaces, which may be related to surface roughness. These results suggest that more sophisticated models that incorporate surface roughness and time-based adhesion are needed to accurately predict colloid detachment in environmental systems.

  20. Defect Density Characterization of Detached-Grown Germanium Crystals

    NASA Technical Reports Server (NTRS)

    Schweizer, M.; Cobb, S. D.; Volz, M. P.; Szoke, J.; Szofran, F. R.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Several (111)-oriented, Ga-doped germanium crystals were grown in pyrolytic boron nitride (pBN) containers by the Bridgman and the detached Bridgman growth techniques. Growth experiments in closed-bottom pBN containers resulted in nearly completely detached-grown crystals, because the gas pressure below the melt can build up to a higher pressure than above the melt. With open-bottom tubes the gas pressure above and below the melt is balanced during the experiment, and thus no additional force supports the detachment. In this case the crystals grew attached to the wall. Etch pit density (EPD) measurements along the axial growth direction indicated a strong improvement of the crystal quality of the detached-grown samples compared to the attached samples. Starting in the seed with an EPD of 6-8 x 10(exp 3)/square cm it decreased in the detached-grown crystals continuously to about 200-500/square cm . No significant radial difference between the EPD on the edge and the middle of the crystal exists. In the attached grown samples the EPD increases up to a value of about 2-4 x 10(exp 4)/square cm (near the edge) and up to 1 x 10(exp 4)/square cm in the middle of the sample. Thus the difference between the detached- and the attached-grown crystals with respect to the EPD is approximately two orders of magnitude.

  1. Improved Crystal Quality By Detached Solidification in Microgravity

    NASA Technical Reports Server (NTRS)

    Regel, Liya L.; Wilcox, William R.; Wang, Yaz-Hen; Wang, Jian-Bin

    2003-01-01

    Many microgravity directional solidification experiments yielded ingots with portions that grew without contacting the ampoule wall, leading to greatly improved crystallographic perfection. Our long term goals have been: (1) To develop a complete understanding of all of the phenomena of detached solidification.; (2) To make it possible to achieve detached solidification reproducibly; (3) To increase crystallographic perfection through detached solidification. We have three major achievements to report here: (1) We obtained a new material balance solution for the Moving Meniscus Model of detached solidification. This solution greatly clarifies the physics as well as the roles of the parameters in the system; (2) We achieved detached solidification of InSb growing on earth in BN-coated ampoules; (3) We performed an extensive series of experiments on freezing water that showed how to form multiple gas bubbles or tubes on the ampoule wall. However, these did not propagate around the wall and lead to fully detached solidification unless the ampoule wall was extremely rough and non-wetted.

  2. [Study on preferred retinal locus].

    PubMed

    Dai, Bing-Fa; Hu, Jian-Min; Xu, Duan-Lian

    2012-03-01

    Preferred retinal locus (PRL) is always found in the age-related macular degeneration and other macular damages in patients with low vision, and it is a very important anatomic position in patients with central vision impairment to achieve the rehabilitation. In recent years, the training of preferred retinal locus (PRL) has become a research hotspot of low vision rehabilitation, it can clearly improve functional vision and quality of life. The authors reviewed relevant literatures, and summarized the definition, position, characteristics, training and clinical implications of the PRL.

  3. Retinitis pigmentosa in southern Africa.

    PubMed

    Greenberg, J; Bartmann, L; Ramesar, R; Beighton, P

    1993-11-01

    Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal disorders which are a common cause of genetic blindness. The relative frequencies of the different forms of RP in South Africa, as determined from the register at the DNA banking centre for RP at the Department of Human Genetics, University of Cape Town, are presented and discussed. Of the 125 families analysed, 29 (23%) showed autosomal dominant, 33 (27%) autosomal recessive and 3 (3%) X-linked inheritance. In 10 families the pedigree data were insufficient to allow accurate genetic subtyping and a further 50 patients were sporadic without a family history of RP or other syndromic features which would allow categorization.

  4. Fluid flow in extensional detachments determined from stable isotope analyses: Application to Kettle dome detachment, Washington, USA

    NASA Astrophysics Data System (ADS)

    Quilichini, A.; Teyssier, C.; Mulch, A.; Nachlas, W.

    2009-04-01

    In detachment systems that border metamorphic core complexes fluids convect from the surface to the detachment along faults and fractures in the brittle crust that serve as zones of recharge and discharge. This buoyancy-driven fluid flow is controlled by a high heat flow at the base of the system, beneath the detachment, where heat is advected by crustal thinning and magma intrusions. This hydrothermal convective flow is focused in the detachment for the duration of activity of the detachment and at relatively high temperature (300-500°C), resulting in very significant fluid-rock interaction and isotopic exchange. Studies of detachments in the North American Cordilleran core complexes suggest that meteoric fluids permeate detachment zones, as recorded by the deuterium composition of hydrous phases such as white mica, biotite, and amphibole. Quantifying fluid flux in detachments is a challenge because permeability of ductilely deforming rocks is poorly understood. The approach we are using focuses on oxygen and hydrogen isotopes in quartzite (+ minor mica) sections of detachments, complemented by high-precision chemical analyses of mica to understand their growth history and recrystallization process. The initial fluid isotopic composition is approximated using the deuterium composition of mica at a particular temperature that is given by oxygen isotopes in quartz-mica pairs. The more fluid interact with the quartzite, the larger the expected shift in oxygen isotope value. The Eocene Kettle Dome detachment in the North American Cordillera provides a continuous section of ~200 m thick quartzite mylonite where this methodology is applied. High-resolution sampling (up to 5 m) complements the initial sampling that was performed every 10 m in this section (Mulch et al., 2006, Tectonics, TC4001). Based on mica deuterium values, the fluid that participated in mica crystallization was meteoric in origin (~110 per mil). Interaction of this fluid with the quartz mylonite

  5. ACUTE RETINAL ARTERIAL OCCLUSIVE DISORDERS

    PubMed Central

    Hayreh, Sohan Singh

    2011-01-01

    The initial section deals with basic sciences; among the various topics briefly discussed are the anatomical features of ophthalmic, central retinal and cilioretinal arteries which may play a role in acute retinal arterial ischemic disorders. Crucial information required in the management of central retinal artery occlusion (CRAO) is the length of time the retina can survive following that. An experimental study shows that CRAO for 97 minutes produces no detectable permanent retinal damage but there is a progressive ischemic damage thereafter, and by 4 hours the retina has suffered irreversible damage. In the clinical section, I discuss at length various controversies on acute retinal arterial ischemic disorders. Classification of acute retinal arterial ischemic disorders These are of 4 types: CRAO, branch retinal artery occlusion (BRAO), cotton wools spots and amaurosis fugax. Both CRAO and BRAO further comprise multiple clinical entities. Contrary to the universal belief, pathogenetically, clinically and for management, CRAO is not one clinical entity but 4 distinct clinical entities – non-arteritic CRAO, non-arteritic CRAO with cilioretinal artery sparing, arteritic CRAO associated with giant cell arteritis (GCA) and transient non-arteritic CRAO. Similarly, BRAO comprises permanent BRAO, transient BRAO and cilioretinal artery occlusion (CLRAO), and the latter further consists of 3 distinct clinical entities - non-arteritic CLRAO alone, non-arteritic CLRAO associated with central retinal vein occlusion and arteritic CLRAO associated with GCA. Understanding these classifications is essential to comprehend fully various aspects of these disorders. Central retinal artery occlusion The pathogeneses, clinical features and management of the various types of CRAO are discussed in detail. Contrary to the prevalent belief, spontaneous improvement in both visual acuity and visual fields does occur, mainly during the first 7 days. The incidence of spontaneous visual

  6. Digital tracking and control of retinal images

    NASA Astrophysics Data System (ADS)

    Barrett, Steven F.; Jerath, Maya R.; Rylander, Henry G.; Welch, Ashley J.

    1994-01-01

    Laser-induced retinal lesions are used to treat a variety of eye disorders such as diabetic retinopathy and retinal tears. An instrumentation system has been developed to track a specific lesion coordinate on the retinal surface and provide corrective signals to maintain laser position on the coordinate. High-resolution retinal images are acquired via a CCD camera coupled to a fundus camera and video frame grabber. Optical filtering and histogram modification are used to enhance the retinal vessel network against the lighter retinal background. Six distinct retinal landmarks are tracked on the high contrast image obtained from the frame grabber using 2D blood vessel templates. An overview of the robotic laser system design is followed by implementation and testing of a development system for proof of concept and, finally, specifications for a real-time system are provided.

  7. Detachment folding, fold amplification, and diapirism in thrust wedge experiments

    NASA Astrophysics Data System (ADS)

    Bonini, Marco

    2003-12-01

    The relations between detachment folding, fold amplification, and salt diapirism in contractional settings have been investigated by means of scaled analogue models. The viscosity of the silicone layer simulating salt in nature and the shortening rates were combined in order to reproduce weak (type 1 models) and strong (type 2 models) décollements. Deformation patterns in the roof sequence exhibited two contrasting styles, (1) outward propagation of detachment folding along the décollement (OFP mode) and (2) passive roof duplex (PRD mode). In type 2 models, detachment folding propagated away from the most external thrust in the floor sequence, while in type 1 models, long-lived detachment folds almost invariably localized amplified above a floor thrust tip as a result of strain localization. A silicone wall intruded occasionally into the crestal graben of detachment folds in type 1 and OFP models. Best fitting of transition models data points indicates nonlinear relations with regression curves close to the equilateral hyperbola equation for both OFP-PRD and amplified detachment folds-box folds transitions. A quantitative comparison of model results with nature has been attempted by plotting salt-based fold-and-thrust belts data points on the scaled transition curves obtained from the modeling. Such a comparison relates shear stress products and ratios to the conditions favoring the amplification of detachment folds and the potential emplacement of ductile diapirs in their core. By reducing the roof sequence strength, pore fluid pressure λb is inferred to shift the equilibrium of fold-and-thrust belts toward the field of OFP and diapirism.

  8. Automatic temperature controlled retinal photocoagulation

    NASA Astrophysics Data System (ADS)

    Schlott, Kerstin; Koinzer, Stefan; Ptaszynski, Lars; Bever, Marco; Baade, Alex; Roider, Johann; Birngruber, Reginald; Brinkmann, Ralf

    2012-06-01

    Laser coagulation is a treatment method for many retinal diseases. Due to variations in fundus pigmentation and light scattering inside the eye globe, different lesion strengths are often achieved. The aim of this work is to realize an automatic feedback algorithm to generate desired lesion strengths by controlling the retinal temperature increase with the irradiation time. Optoacoustics afford non-invasive retinal temperature monitoring during laser treatment. A 75 ns/523 nm Q-switched Nd:YLF laser was used to excite the temperature-dependent pressure amplitudes, which were detected at the cornea by an ultrasonic transducer embedded in a contact lens. A 532 nm continuous wave Nd:YAG laser served for photocoagulation. The ED50 temperatures, for which the probability of ophthalmoscopically visible lesions after one hour in vivo in rabbits was 50%, varied from 63°C for 20 ms to 49°C for 400 ms. Arrhenius parameters were extracted as ΔE=273 J mol-1 and A=3.1044 s-1. Control algorithms for mild and strong lesions were developed, which led to average lesion diameters of 162+/-34 μm and 189+/-34 μm, respectively. It could be demonstrated that the sizes of the automatically controlled lesions were widely independent of the treatment laser power and the retinal pigmentation.

  9. Retinitis Pigmentosa and Education Issues

    ERIC Educational Resources Information Center

    Brown, Thomas J.

    2005-01-01

    Retinitis Pigmentosa includes a number of inherited diseases which usually result in blindness. The disease is progressive in nature and begins with the deterioration of cells in the eye responsible for peripheral vision. As the condition worsens there is a gradual loss of peripheral vision and night blindness. Proper educational planning requires…

  10. Automatic temperature controlled retinal photocoagulation.

    PubMed

    Schlott, Kerstin; Koinzer, Stefan; Ptaszynski, Lars; Bever, Marco; Baade, Alex; Roider, Johann; Birngruber, Reginald; Brinkmann, Ralf

    2012-06-01

    Laser coagulation is a treatment method for many retinal diseases. Due to variations in fundus pigmentation and light scattering inside the eye globe, different lesion strengths are often achieved. The aim of this work is to realize an automatic feedback algorithm to generate desired lesion strengths by controlling the retinal temperature increase with the irradiation time. Optoacoustics afford non-invasive retinal temperature monitoring during laser treatment. A 75 ns/523 nm Q-switched Nd:YLF laser was used to excite the temperature-dependent pressure amplitudes, which were detected at the cornea by an ultrasonic transducer embedded in a contact lens. A 532 nm continuous wave Nd:YAG laser served for photocoagulation. The ED50 temperatures, for which the probability of ophthalmoscopically visible lesions after one hour in vivo in rabbits was 50%, varied from 63°C for 20 ms to 49°C for 400 ms. Arrhenius parameters were extracted as ΔE=273 J mol(-1) and A=3 x 10(44) s(-1). Control algorithms for mild and strong lesions were developed, which led to average lesion diameters of 162 ± 34 μm and 189 ± 34 μm, respectively. It could be demonstrated that the sizes of the automatically controlled lesions were widely independent of the treatment laser power and the retinal pigmentation.

  11. Mesospheric electron detachment and LORE recovery times

    NASA Astrophysics Data System (ADS)

    Gordillo-Vazquez, Francisco J.; Haldoupis, Christos; Luque, Alejandro

    2015-04-01

    We present new results concerning the recovery times (> 10 minutes) of LOng Recovery Early VLF events (LORE) in the upper mesosphere connected to electromagnetic pulses (EMP) of large (> 250 kA km) charge moment change (CMC) ± CG (cloud to ground) lightning capable of producing elves or elve-sprite pairs (in the case of +CG parent lightning) [1], [2]. We have modeled two possible scenarios considering first the relaxation of slightly perturbed ambient electron densities (ne0 + Δne) without an impulsive ionization source and another scenario where the ambient electron density is considerably enhanced due to an impulsive ionization source (the lightning EMP). The full non-equilibrium kinetic and 2D EMP modelling of the perturbed mesosphere in the 76 km - 92 km range during LORE occurring conditions indicates that the electron density relaxation time (defined as the time the perturbed electron density, Δne, takes to decay a factor 1/e of the way to the ambient electron density (ne0)) is critically controlled at each altitude by the relative importance of associative detachment (of O- by, respectively, O and CO and of O2- by O) with respect to electron loss mechanisms (mainly 3-body, 2-body attachment and electron-ion recombination at the highest altitudes). We found that the maximum electron density relaxation time (> 15000 s) occur between 80 km and 82 km while it decreases with increasing altitudes to 12000 s (at 85 km) and about 2000 s (at 92 km). However, LORES are presumably due to VLF scattering from electron density enhancements caused by lightning-induced EMPs in the uppermost D region ionosphere (85 - 92 km). Thus the observed VLF signal recoveries (LORE recovery times) should associate with the relaxation of the maximum enhanced electron densities produced by elves between 85 km and 92 km [3]. Finally, our results for the lowest altitudes considered (76 km and 77 km) are in good agreement with the recovery times (between 20 s and 120 s) of the typical

  12. [Noninvasive analysis of retinal microstructure and function: challenges and a promising future].

    PubMed

    Yoshida, Akitoshi

    2013-03-01

    Challenges in the evaluation of the retinal microstructure. To facilitate evaluation of the retinal microstructure we participated in the development of a scanning laser ophthalmoscope (SLO) for 32 years. The 'retro-mode' is the latest developed lateral aperture SLO made in Japan. This instrument enables us to observe the cystoid spaces and retinal microfolds underlying the epiretinal membrane. We investigated the pathogenesis and the mechanism of early development of idiopathic macular holes (MHs) and the vitreomacular interface in idiopathic full-thickness MHs using spectral-domain optical coherence tomography (SD-OCT). We studied the anatomic morphology of stage 1-A impending MHs, characterized by a foveolar yellow spot, using SD-OCT in the fellow eyes of patients diagnosed with a full-thickness MH. SD-OCT showed the reflectivity of the perifoveal posterior vitreous detachment (PVD) with vitreofoveal adhesion in the eyes with a yellow spot; the foveal microstructure had a triangular foveolar detachment of the cone outer segment tip line. The foveolar detachment of the cone outer segment tip line might be responsible for the yellow spot seen in stage 1-A MHs. Using SD-OCT, we also analyzed the vitreomacular interface in idiopathic full-thickness MHs and identified four configurations of the vitreomacular interface in MHs without a complete PVD. The majority, i.e., 92%, of eyes with a MH without a complete PVD are likely due to the anteroposterior vitreofoveal traction exerted by a perifoveal PVD. About 55% of cases with an open roof in the eyes without a complete PVD might be at risk of progression to operculum formation (loss of retinal tissue). 2. Challenges in the evaluation of retinal function SLO microperimetry is used to evaluate the retinal function during observation of the retinal microstructure. We evaluated the retinal sensitivity and the focal visual acuity using our original microperimetry program and clarified the characteristics of the preferred

  13. Miocene detachment faulting predating EPR propagation: Southern Baja California

    NASA Astrophysics Data System (ADS)

    Bot, Anna; Geoffroy, Laurent; Authemayou, Christine; Bellon, Hervé; Graindorge, David; Pik, Raphaël.

    2016-05-01

    At the southern tip of the Baja California peninsula, we characterize the onshore structures and kinematics associated with crustal necking leading up to the Pliocene breakup and early East Pacific Rise seafloor spreading. From a combination of tectonic field investigations, K-Ar and cosmogenic isotope dating and geomorphology, we propose that the Los Cabos block represents the exhumed footwall of a major detachment fault. This north trending detachment fault is marked by a conspicuous low-dipping brittle-ductile shear zone showing a finite displacement with top to the SE ending to the ESE. This major feature is associated with fluid circulations which led to rejuvenation of the deformed Cretaceous magmatic rocks at a maximum of 17.5 Ma. The detachment footwall displays kilometer-scale corrugations controlling the present-day drainage pattern. This major detachment is synchronous with the development of the San José del Cabo Basin where syntectonic sedimentation took place from the middle Miocene to probably the early Pliocene. We propose that this seaward dipping detachment fault accommodates the proximal crustal necking of the Baja California passive margin, which predates the onset of formation of the East Pacific Rise spreading axis in the Cabo-Puerto Vallarta segment. Our data illustrate an apparent anticlockwise rotation of the stretching direction in Baja California Sur from ~17 Ma to the Pliocene.

  14. Retinal vasculature classification using novel multifractal features

    NASA Astrophysics Data System (ADS)

    Ding, Y.; Ward, W. O. C.; Duan, Jinming; Auer, D. P.; Gowland, Penny; Bai, L.

    2015-11-01

    Retinal blood vessels have been implicated in a large number of diseases including diabetic retinopathy and cardiovascular diseases, which cause damages to retinal blood vessels. The availability of retinal vessel imaging provides an excellent opportunity for monitoring and diagnosis of retinal diseases, and automatic analysis of retinal vessels will help with the processes. However, state of the art vascular analysis methods such as counting the number of branches or measuring the curvature and diameter of individual vessels are unsuitable for the microvasculature. There has been published research using fractal analysis to calculate fractal dimensions of retinal blood vessels, but so far there has been no systematic research extracting discriminant features from retinal vessels for classifications. This paper introduces new methods for feature extraction from multifractal spectra of retinal vessels for classification. Two publicly available retinal vascular image databases are used for the experiments, and the proposed methods have produced accuracies of 85.5% and 77% for classification of healthy and diabetic retinal vasculatures. Experiments show that classification with multiple fractal features produces better rates compared with methods using a single fractal dimension value. In addition to this, experiments also show that classification accuracy can be affected by the accuracy of vessel segmentation algorithms.

  15. Paleostress analyses in the uppermost footwalls of the Whipple detachment and the West Salton detachment faults, southern California

    NASA Astrophysics Data System (ADS)

    Luther, A. L.; Axen, G. J.; Selverstone, J.; Michelsen, K. J.

    2010-12-01

    Low-angle normal faults (LANFs) slip while nearly perpendicular to the regional S1, presenting a mechanical paradox that may be explained by rotation of S1 toward the fault as it is approached, weak materials reducing friction and/or high pore-fluid pressure. Well-exposed LANF footwalls provide opportunities for detailed studies of weak faults. Paleostress inversions of fault-slip data coupled with structural and chemical analyses of footwall rocks are in progress on the Whipple detachment fault (WDF; >40 km Miocene slip; evolved from ductile shear zone to brittle fault) and the West Salton detachment fault (WSDF; ~10 km slip during dextral-wrench tectonism coeval with San Andreas Fault slip). Both were folding during detachment slip. Paleostress analyses indicate that both faults slipped mainly in extensional stress fields (sub-vertical S1) and in axial compression (S2 ≈ S3). Over 40% of extensional stress fields yield S1 plunging >70° relative to the detachment, but ~30% yield plunges of 40° to 60° relative to the detachment. Thus, the stress field may have been locally and/or temporarily rotated away from sub-vertical during detachment slip. About 15% of the inversions yield shortening stress fields (S1 ~horizontal) consistent with folding and/or dextral-wrench deformation. Mutually cross-cutting relationships between fracture sets suggest that the stress fields may have alternated through time. “Mini-detachments” (MDs) are small, detachment-parallel faults that are structurally analogous to the main faults. Inversions yield S1 ~45° from the MDs and a larger magnitude of S2 relative to S3. Damage zones subjacent to MD fault cores commonly yield more moderately plunging S1 than do MD fault cores or deeper rocks. Petrological evidence suggests that the MDs formed early in the detachment history (Selverstone et al., GSA Abstract, 2009). If their damage zones also formed early, then S1 may have been shallower early in detachment history and(or) at greater

  16. Characterizing the Outer Divertor Leg Transition to Full Detachment

    NASA Astrophysics Data System (ADS)

    McLean, A. G.; Allen, S. L.; Fenstermacher, M. E.; Lasnier, C. J.; Meyer, W. H.; Porter, G. D.; Soukhanovskii, V. A.; Bray, B. D.; Carlstrom, T. N.; Leonard, A. W.; Liu, C.; Eldon, D.; Groth, M.; Stangeby, P. C.; Tsui, C. K.

    2013-10-01

    Experiments at DIII-D have explored the transition from an attached to fully detached divertor condition in L- and H-mode with an unprecedented level of detail. Improved divertor Thomson scattering capturing Te <= 1 eV, coupled with high resolution spectroscopic studies of molecular and neutral emissions, and Stark broadening of the deuterium Paschen series provide essential data for modeling the transition to detachment. 2D Te and ne profiles of the outer leg reveal movement of the ionization front away from the plate not replicated in modeling. Measured Paschen and molecular emissions suggest the onset of recombination occurs prior to, and to a greater extent than modeled. These data help guide and expose any missing physics in predictions for detached operation in future devices. This work supported in part by the US Department of Energy under DE-AC52-07NA27344 and DE-FC02-04ER54698.

  17. Detachment energies of spheroidal particles from fluid-fluid interfaces

    NASA Astrophysics Data System (ADS)

    Davies, Gary B.; Krüger, Timm; Coveney, Peter V.; Harting, Jens

    2014-10-01

    The energy required to detach a single particle from a fluid-fluid interface is an important parameter for designing certain soft materials, for example, emulsions stabilised by colloidal particles, colloidosomes designed for targeted drug delivery, and bio-sensors composed of magnetic particles adsorbed at interfaces. For a fixed particle volume, prolate and oblate spheroids attach more strongly to interfaces because they have larger particle-interface areas. Calculating the detachment energy of spheroids necessitates the difficult measurement of particle-liquid surface tensions, in contrast with spheres, where the contact angle suffices. We develop a simplified detachment energy model for spheroids which depends only on the particle aspect ratio and the height of the particle centre of mass above the fluid-fluid interface. We use lattice Boltzmann simulations to validate the model and provide quantitative evidence that the approach can be applied to simulate particle-stabilized emulsions, and highlight the experimental implications of this validation.

  18. Streetscape showing north sides of five of eight Medical Detachment ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Streetscape showing north sides of five of eight Medical Detachment Barracks on Ramp No. 5. Note that Building No. 9966-B on right has a wooden frame sun porch. This Standard Ward construction is different than most of the other Medical Detachment Barracks, which are all- brick. On the opposite side of this building, the construction is all-brick (Building No. 9966-A, not shown). Buildings No. 9967-B and 9968-B (not shown) also have wooden frame sun porches. Other buildings in photo are, on right, the north B-sides of Buildings Nos. 9965, 9964, 9963 and 9962. On left is Building No. 9971-A on Ramp No. 6. Corridor A is visible in far distance. - Madigan Hospital, Medical Detachment Barracks, Bounded by Wilson & McKinley Avenues & Garfield & Lincoln Streets, Tacoma, Pierce County, WA

  19. Retinitis Pigmentosa and Other Dystrophies.

    PubMed

    Mrejen, Sarah; Audo, Isabelle; Bonnel, Sébastien; Sahel, José-Alain

    2017-01-01

    Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal degenerations characterized by progressive degeneration of rod and cone cells that affects predominantly peripheral visual fields. Macular edema may cause additional central visual acuity decrease. Cystoid macular edema (CME) is one of the few treatable causes of visual loss in RP. The prevalence of CME in RP has been found to be between 10 and 20% on fluorescein angiography-based studies, and as high as 49% on reports based on optical coherence tomography. Macular edema can manifest at any stage of the disease and may be unilateral or bilateral. It can be found in any genetic form, but is more often associated with RP caused by CRB1 mutations. The origin of macular edema in RP patients still remains poorly understood. Some mechanisms have been suggested, including antiretinal antibodies (retinal, carbonic anhydrase, and enolase antibodies), vitreous traction, retinal pigment epithelium dysfunction, and Müller cell edema. There is no gold standard therapeutic strategy. Drug therapy is the primary treatment. Systemic carbonic anhydrase inhibitors, such as oral acetazolamide or topical dorzolamide, are still the mainstays of initial therapy. If CME is refractory to acetazolamide, intravitreal corticosteroid injections may be a therapeutic option. However, antivascular endothelium growth factor injections have limited effect and should be avoided. Vitrectomy has also been evaluated, but its exact role remains to be determined. The benefits of these therapies are variable among patients. The establishment of therapeutic approaches is limited by our poor understanding of the pathophysiology of CME in patients with RP. Autoimmune retinopathies (AIRs) are a group of rare diseases characterized by acute or subacute progressive vision loss and are thought to be mediated by autoantibodies specific to retinal antigens. The AIRs encompass paraneoplastic syndromes, such as cancer-associated retinopathy and

  20. Detached Solidification of Germanium-Silicon Crystals on the ISS

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Mazuruk, K.; Croell, A.

    2016-01-01

    A series of Ge(sub 1-x) Si(sub x) crystal growth experiments are planned to be conducted in the Low Gradient Furnace (LGF) onboard the International Space Station. The primary objective of the research is to determine the influence of containment on the processing-induced defects and impurity incorporation in germanium-silicon alloy crystals. A comparison will be made between crystals grown by the normal and "detached" Bridgman methods and the ground-based float zone technique. Crystals grown without being in contact with a container have superior quality to otherwise similar crystals grown in direct contact with a container, especially with respect to impurity incorporation, formation of dislocations, and residual stress in crystals. "Detached" or "dewetted" Bridgman growth is similar to regular Bridgman growth in that most of the melt is in contact with the crucible wall, but the crystal is separated from the wall by a small gap, typically of the order of 10-100 microns. Long duration reduced gravity is essential to test the proposed theory of detached growth. Detached growth requires the establishment of a meniscus between the crystal and the ampoule wall. The existence of this meniscus depends on the ratio of the strength of gravity to capillary forces. On Earth, this ratio is large and stable detached growth can only be obtained over limited conditions. Crystals grown detached on the ground exhibited superior structural quality as evidenced by measurements of etch pit density, synchrotron white beam X-ray topography and double axis X-ray diffraction.

  1. Numerical Optimization of the Thermal Field in Bridgman Detached Growth

    NASA Technical Reports Server (NTRS)

    Stelian, C.; Volz, M. P.; Derby, J. J.

    2009-01-01

    The global modeling of the thermal field in two vertical Bridgman-like crystal growth configurations, has been performed to get optimal thermal conditions for a successful detached growth of Ge and CdTe crystals. These computations are performed using the CrysMAS code and expand upon our previous analysis [1] that propose a new mechanism involving the thermal field and meniscus position to explain stable conditions for dewetted Bridgman growth. The analysis of the vertical Bridgman configuration with two heaters, used by Palosz et al. for the detached growth of Ge, shows, consistent with their results, that the large wetting angle of germanium on boron nitride surfaces was an important factor to promote a successful detached growth. Our computations predict that by initiating growth much higher into the hot zone of the furnace, the thermal conditions will be favorable for continued detachment even for systems that did not exhibit high contact angles. The computations performed for a vertical gradient freeze configuration with three heaters representative of that used for the detached growth of CdTe, show favorable thermal conditions for dewetting during the entirely growth run described. Improved thermal conditions are also predicted for coated silica crucibles when the solid-liquid interface advances higher into the hot zone during the solidification process. The second set of experiments on CdTe growth described elsewhere has shown the reattachment of the crystal to the crucible after few centimeters of dewetted growth. The thermal modeling of this configuration shows a second solidification front appearing at the top of the sample and approaching the middle line across the third heater. In these conditions, the crystal grows detached from the bottom, but will be attached to the crucible in the upper part because of the solidification without gap in this region. The solidification with two interfaces can be avoided when the top of the sample is positioned below

  2. Rotational auto-detachment of dipole-bound anions

    NASA Astrophysics Data System (ADS)

    Ard, S. G.; Compton, R. N.; Garrett, W. R.

    2016-04-01

    Rotational auto-detachment of acetonitrile, trimethyl-acetonitrile, acetone, and cyclobutanone dipole-bound anions was studied under varying conditions in a Rydberg electron transfer (RET) time-of-flight apparatus. Varying amounts of auto-detachment was observed for anions with similar electron affinity and dipole moment, but different moments of inertia. These results were found to be consistent with predictions based on the calculated rotational spectra for these anions, highlighting the importance of critical binding properties in understanding the stability and lifetime of dipole bound systems.

  3. DUAL ORIGIN OF AEROSOLS IN TITAN'S DETACHED HAZE LAYER

    SciTech Connect

    Cours, T.; Burgalat, J.; Rannou, P.; Rodriguez, S.; Brahic, A.

    2011-11-10

    We have analyzed scattered light profiles from the Cassini Imaging Science Subsystem, taken at the limb and at several large phase angles. We also used results from an occultation observed by Ultraviolet Imaging Spectrograph in the ultraviolet. We found that particles responsible for the scattering in the detached haze have an effective radius around 0.15 {mu}m and the aerosol size distribution follows a power law (exponent about -4.5). We discuss these results along with microphysical constraints and thermal equilibrium of the detached haze, and we conclude that only a strong interaction with atmospheric dynamics can explain such a structure.

  4. Magnetic Detachment and Plume Control in Escaping Magnetized Plasma

    SciTech Connect

    P. F. Schmit and N. J. Fisch

    2008-11-05

    The model of two-fluid, axisymmetric, ambipolar magnetized plasma detachment from thruster guide fields is extended to include plasmas with non-zero injection angular velocity profiles. Certain plasma injection angular velocity profiles are shown to narrow the plasma plume, thereby increasing exhaust efficiency. As an example, we consider a magnetic guide field arising from a simple current ring and demonstrate plasma injection schemes that more than double the fraction of useful exhaust aperture area, more than halve the exhaust plume angle, and enhance magnetized plasma detachment.

  5. Bridgman Growth of Detached GeSi Crystals

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Schweizer, M.; Kaiser, N.; Cobb, S. D.; Vujisic, L.; Motakef, S.; Szofran, F. R.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    The growth of detached crystals by the Bridgman technique, in which the growing crystal is not in contact with the crucible wall, has been observed both on earth and in microgravity conditions. Such detachment has particularly been in evidence in microgravity experiments, where the pressure head of the molten sample is absent. At present, the mechanisms contributing to the detachment are not completely understood and until recently detachment has not been reproducibly obtained. Key parameters which must be considered are the contact angle between the melt and the crucible and the growth angle. Another essential parameter is the pressure difference between the annular gap around the solid below the melt and the volume above the melt. Here we present results of the growth of Ge(0.98)Si(0.02) using adjustments in the applied temperature profile to control the pressure difference between the bottom and top of the melt. The technique is less susceptible to sample contamination than controlling the pressure by connecting the crucible to external gas sources. Using this technique, a pressure difference is created by decreasing the temperature in the volume above the melt while the sample is molten but prior to growth. A maximum pressure difference approximately equal to the pressure head of the molten sample can thus be obtained. Several GeSi crystals were grown in pyrolitic boron nitride crucibles. When a pressure difference was applied, samples were reproducibly grown mostly detached. For comparison, samples were also grown in a configuration in which gas could pass freely between the gap below the melt and the volume above the melt and no pressure difference could be established. These samples were initially attached. Existence of detachment was determined both by measuring the radius of the samples with a profilometer and by observations of the sample surfaces with optical and electron microscopy. The gap thickness between the crucible and detached crystal was on the

  6. Repeat Descemetopexy after Descemet's Membrane Detachment following Phacoemulsification.

    PubMed

    Datar, Sameer; Kelkar, Aditya; Jain, Ashish K; Kelkar, Jai; Kelkar, Shreekant; Gandhi, Poonam; Shah, Rachna; Kedia, Ruchika

    2014-05-01

    Descemet's membrane detachment (DMD) is an uncommon condition with a wide range of possible etiologies. Probably the commonest cause is a localized detachment occurring after cataract extraction surgery. Descemetopexy gives good anatomic attachment rates and visual outcomes and has become the standard treatment for DMD. However, in cases with failed initial descemetopexy, the next step in the management of such cases remains unclear. Before initiating a complex surgical procedure like keratoplasty, which requires good postoperative care and regular follow-ups, repeat descemetopexy with a long-term tamponade using 14% C3F8 gas for recurrent DMD is definitely a worthwhile attempt.

  7. Ultrasonic localization of choroidal detachment associated with flat anterior chamber.

    PubMed

    Portney, G L; Kohl, J W

    1975-01-01

    In postoperative patients with flat anterior chambers and small pupils or dense media, A-scan and B-scan ultrasonography can be useful tools in establishing the proper etiologic diagnosis. By searching for the presence of a choroidal detachment and determining its full location, complete drainage of the suprachoroidal fluid can be accomplished satisfactorily should this form of surgical intervention become necessary. If sufficient evidence of a choroidal detachment is not found, then therapy can be more assuredly directed at relief of pupillary block or reduction of excessive fistulization, other causes of a flat chamber.

  8. Retinal abnormalities in β-thalassemia major

    PubMed Central

    Bhoiwala, Devang L.; Dunaief, Joshua L.

    2015-01-01

    Patients with beta (β)-thalassemia (β-TM: thalassemia major, β-TI: thalassemia intermedia) have a variety of complications that may affect all organs, including the eye. Ocular abnormalities include retinal pigment epithelium degeneration, angioid streaks, venous tortuosity, night blindness, visual field defects, decreased visual acuity, color vision abnormalities, and acute visual loss. Patients with β-TM are transfusion dependent and require iron chelation therapy (ICT) in order to survive. Retinal degeneration may result from either retinal iron accumulation from transfusion-induced iron overload or retinal toxicity induced by ICT. Some who were never treated with ICT exhibited retinopathy, and others receiving ICT had chelator-induced retinopathy. We will focus on retinal abnormalities present in individuals with β-TM viewed in light of new findings on the mechanisms and manifestations of retinal iron toxicity. PMID:26325202

  9. Retinal blood vessels extraction using probabilistic modelling.

    PubMed

    Kaba, Djibril; Wang, Chuang; Li, Yongmin; Salazar-Gonzalez, Ana; Liu, Xiaohui; Serag, Ahmed

    2014-01-01

    The analysis of retinal blood vessels plays an important role in detecting and treating retinal diseases. In this review, we present an automated method to segment blood vessels of fundus retinal image. The proposed method could be used to support a non-intrusive diagnosis in modern ophthalmology for early detection of retinal diseases, treatment evaluation or clinical study. This study combines the bias correction and an adaptive histogram equalisation to enhance the appearance of the blood vessels. Then the blood vessels are extracted using probabilistic modelling that is optimised by the expectation maximisation algorithm. The method is evaluated on fundus retinal images of STARE and DRIVE datasets. The experimental results are compared with some recently published methods of retinal blood vessels segmentation. The experimental results show that our method achieved the best overall performance and it is comparable to the performance of human experts.

  10. Retinal complications after bungee jumping.

    PubMed

    Filipe, J A; Pinto, A M; Rosas, V; Castro-Correia, J

    Bungee jumping is becoming a popular sport in the Western world with some cases of ophthalmic complications being reported in recent literature. The authors reported a case of a 23-year-old healthy female who presented retinal complications following a bungee jumping. Her fundi showed superficial retinal hemorrhages in the right eye and a sub-internal limiting membrane hemorrhage affecting the left eye. A general examination, including a full neurological examination, was normal and laboratorial investigations were all within normal values. More studies are necessary to identify risk factors and the true incidence of related ocular lesions, but until then, we think this sport activity should be desencouraged, especially to those that are not psychological and physically fit.

  11. [Retinal ischemia and nitric oxide].

    PubMed

    Neroev, V V; Arkhipova, M M

    2003-01-01

    Retinal ischemia is the main chain in the pathogenesis of vascular diseases of the eye. It was established that nitric oxide (NO) plays the key role in the development of ischemia. Recent understanding of the NO role, as a universal regulator of the cellular and tissue metabolism, is presented. The authors' and published data were used to design a scheme of pathogenesis of retinal ischemia with regard for the NO role. NO can produce both positive and negative effects depending on a stage of the process, NO concentration and on a number of other factors if they are present. Initial stages of hypoxia/ischemia are accompanied by an activation of all forms of NO-synthases (NOS) caused by the influence of biologically active substances (cytokines, prostaglandins, serotonin, bradykinin, glycolisis suboxide products etc.). The activation of inducible NOS, which synthesize a bigger quantity of NO possessing a direct cytotoxic action and contributing to the production of highly toxic radical of peroxinitrit, is in the focus of attention. The damage of cellular structures due to free-radical processes leads to the development of endothelial, macrophage and thrombocyte malfunctions, which manifest itself through a reduced activity of endothelial NOS and through disruption of NO-dependent processes (vasospasm, an increased aggregation of platelets and a reduced fibrinolytic activity). A sharp reduction of NO synthesis substrate (L-arginine) is observed in patients with retinal ischemia. The aggravation of ischemia causes a decrease of NO synthesis due to an exhaustion of L-arginine and its intensified consumption in the course of free-radical processes. The use of NO-inhibitors and of NO-donors at different stages of retinal ischemia prevents the development of neovascularization and proliferation.

  12. Shock detachment process on cones in hypervelocity flows

    NASA Astrophysics Data System (ADS)

    Leyva, Ivett A.

    1999-11-01

    The shock detachment process on cones in hypervelocity flows is one of the most sensitive flows to relaxation effects. The critical angle for shock detachment under frozen conditions can be very different from the critical angle under chemical and thermal equilibrium. The rate of increase of the detachment distance with cone angle is also affected by the relaxation rate. The purpose of this study is to explain the effects of nonequilibrium on the shock detachment distance and its growth rate on cones in hypervelocity flows. The study consists of an experimental and a computational program. The experimental part has been carried out at Caltech's hypervelocity reflected shock tunnel (T5). Six different free-stream conditions have been chosen, four using N2 as the test gas and two using CO2. About 170 shots were performed on 24 cones. The cones range in diameter from 2 cm to 16 cm with half-angles varying from 55° to 75°. The experimental data obtained are holographic interferograms of every shot, and surface temperature and pressure measurements for the bigger cones. Extensive numerical simulations were made for the N2 flows and some were also made for the CO2 flows. The code employed is a Navier-Stokes solver that can account for thermal and chemical nonequilibrium in axisymmetric flows. The experimental and computational data obtained for the shock detachment distance confirms a previous theoretical model that predicts the detachment distance will grow more slowly for relaxing flows than for frozen or equilibrium flows. This difference is explained in terms of the behavior of the sonic line inside the shock layer. Different growth rates result when the detachment distance is controlled by the diameter of the cone (frozen and equilibrium cases) than when it is controlled by the extent of the relaxation zone inside the shock layer (nonequilibrium flows). The experimental data are also complemented with computational data to observe the behavior of the detachment

  13. Microelectronic Array for Stimulation of Retinal Tissue

    DTIC Science & Technology

    2005-01-01

    from diseases such as retinitis pigmentosa and age-related macular degeneration are the leading causes of blindness in the developing world...53featured research 2005 NRL Review Microelectronic Array for Stimulation of Retinal Tissue D. Scribner,1 L. Johnson,4 P. Skeath,4 R. Klein,4...GOALS The development of a high-resolution retinal prosthesis device at the Naval Research Laboratory (NRL) was first discussed in the late 1990s

  14. Inherited Retinal Degenerative Clinical Trial Network. Addendum

    DTIC Science & Technology

    2013-10-01

    visual impairment usually ending in blindness. In the United States, the total number of individuals affected by retinitis pigmentosa (RP) and other...linica l trial in the NEER network for autosomal dominant retinitis pigmentosa , and the ProgSTAR studies for Stargardt disease) . As new interventions b... retinitis pigmentosa continues at six sites- the CTEC site at University of Utah and five additional recruitment sites- the Retina Foundation of the

  15. Retinal pathways influence temporal niche

    PubMed Central

    Doyle, Susan E.; Yoshikawa, Tomoko; Hillson, Holly; Menaker, Michael

    2008-01-01

    In mammals, light input from the retina entrains central circadian oscillators located in the suprachiasmatic nuclei (SCN). The phase of circadian activity rhythms with respect to the external light:dark cycle is reversed in diurnal and nocturnal species, although the phase of SCN rhythms relative to the light cycle remains unchanged. Neural mechanisms downstream from the SCN are therefore believed to determine diurnality or nocturnality. Here, we report a switch from nocturnal to diurnal entrainment of circadian activity rhythms in double-knockout mice lacking the inner-retinal photopigment melanopsin (OPN4) and RPE65, a key protein used in retinal chromophore recycling. These mice retained only a small amount of rod function. The change in entrainment phase of Rpe65−/−;Opn4−/− mice was accompanied by a reversal of the rhythm of clock gene expression in the SCN and a reversal in acute masking effects of both light and darkness on activity, suggesting that the nocturnal to diurnal switch is due to a change in the neural response to light upstream from the SCN. A switch from nocturnal to diurnal activity rhythms was also found in wild-type mice transferred from standard intensity light:dark cycles to light:dark cycles in which the intensity of the light phase was reduced to scotopic levels. These results reveal a novel mechanism by which changes in retinal input can mediate acute temporal-niche switching. PMID:18695249

  16. Mitochondrial dysfunction underlying outer retinal diseases.

    PubMed

    Lefevere, Evy; Toft-Kehler, Anne Katrine; Vohra, Rupali; Kolko, Miriam; Moons, Lieve; Van Hove, Inge

    2017-03-29

    Dysfunction of photoreceptors, retinal pigment epithelium (RPE) or both contribute to the initiation and progression of several outer retinal disorders. Disrupted Müller glia function might additionally subsidize to these diseases. Mitochondrial malfunctioning is importantly associated with outer retina pathologies, which can be classified as primary and secondary mitochondrial disorders. This review highlights the importance of oxidative stress and mitochondrial DNA damage, underlying outer retinal disorders. Indeed, the metabolically active photoreceptors/RPE are highly prone to these hallmarks of mitochondrial dysfunction, indicating that mitochondria represent a weak link in the antioxidant defenses of outer retinal cells.

  17. Matrix metalloproteinases: a role in the contraction of vitreo-retinal scar tissue.

    PubMed

    Sheridan, C M; Occleston, N L; Hiscott, P; Kon, C H; Khaw, P T; Grierson, I

    2001-10-01

    The most common cause of failure of retinal reattachment surgery is formation of fibrocellular contractile membranes on both surfaces of the neuroretina. This intraocular fibrosis, known as proliferative vitreoretinopathy, results in a blinding tractional retinal detachment because of the contractile nature of the membrane. Contractility is a cell-mediated event that is thought to be dependent on locomotion and adhesion to the extracellular matrix. Interactions between cells and the extracellular matrix can be influenced by matrix metalloproteinases (MMPs) and we investigated the role of MMPs in two in vitro models (two- and three-dimensional) of human retinal pigment epithelial (RPE) cell-mediated contraction. MMP activity was detected using enzyme-linked immunosorbent assays and zymography techniques that revealed MMP-1, -2, -3, and -9 positivity during the collagen matrix contraction assays. RPE-populated collagen matrix contraction (three-dimensional) was inhibited using a cocktail of anti-MMP antibodies and with Galardin (a broad-spectrum MMP inhibitor). Galardin inhibition was dose-dependent, reversible, and dependent on cell number. MMP inhibitors had no effect on contraction when RPEs were seeded on two-dimensional collagen matrices or on cellular adhesion to collagen type I. Our results suggest that MMP activity may be required for three-dimensional but not two-dimensional RPE-collagen matrix contraction.

  18. Characterizing the transition from high recycling to partial detachment

    NASA Astrophysics Data System (ADS)

    McLean, A. G.; Allen, S. L.; Fenstermacher, M.; Lasnier, C.; Meyer, W. H.; Porter, G.; Soukhanovskii, V.; Bray, B. D.; Carlstrom, T. N.; Leonard, A. W.; Liu, C.; Eldon, D.; Groth, M.; Stangeby, P. C.; Tsui, C.

    2014-10-01

    Experiments at DIII-D have explored the transition from the high recycling to the partially detached divertor condition in L- and H-mode with an unprecedented level of detail. Improved divertor and core Thomson scattering diagnostics were coupled with high resolution spectroscopic studies of molecular and neutral emissions. 2-D Te and ne profiles of the outer leg reveal the earliest indications of formation of the detachment front at the target plate, reducing local Te at the outer strike point from 8-10 eV to 2-3 eV with a marginal (< 10 %) increase in upstream. These data help guide and expose any missing physics in simulations of detachment onset using state-of-the-art boundary codes, and in predictions for operation with a partial detached divertor in future devices. This work supported in part by the US Department of Energy under DE-AC52-07NA27344 and DE-FC02-04ER54698.

  19. Engineering Design Guidance for Detached Breakwaters as Shoreline Stabilization Structure

    DTIC Science & Technology

    1993-12-01

    Lakeview Park shoreline. Combinations of wave height, period, direction, and still-water levels were studied to determine test conditions that produced a...77 Structural Design Objectives ........................... 77 Design Wave and Water Level Selection .................... 77...Chesapeake Bay at Bay Ridge, Maryland ................... 9 Figure 8. Aerial view of Lakeview Park , Lorain, Ohio ......... 13 Figure 9. Detached

  20. Detachment faults:Evidence for a low-angle origin

    NASA Astrophysics Data System (ADS)

    Scott, Robert J.; Lister, Gordon S.

    1992-09-01

    The origin of low-angle normal faults or detachment faults mantling metamorphic core complexes in the southwestern United States remains controversial. If σ1 is vertical during extension, the formation of, or even slip along, such low-angle normal faults is mechanically implausible. No records exist of earthquakes on low-angle normal faults in areas currently undergoing continental extension, except from an area of actively forming core complexes in the Solomon Sea, Papua New Guinea. In light of such geophysical and mechanical arguments, W. R. Buck and B. Wernicke and G. J. Axen proposed models in which detachment faults originate as high-angle normal faults, but rotate to low angles and become inactive as extension proceeds. These models are inconsistent with critical field relations in several core complexes. The Rawhide fault, an areally extensive detachment fault in western Arizona, propagated at close to its present subhorizontal orientation late in the Tertiary extension of the region. Neither the Wernicke and Axen nor Buck models predict such behavior; in fact, both models preclude the operation of low-angle normal faults. We must seek alternative explanations or modify existing models to explain the evidence that detachment faults form and operate with gentle dips.

  1. Detachment faults: Evidence for a low-angle origin

    SciTech Connect

    Scott, R.J.; Lister, G.S. )

    1992-09-01

    The origin of low-angle normal faults or detachment faults mantling metamorphic core complexes in the southwestern United States remains controversial. If [sigma][sub 1] is vertical during extension, the formation of, or even slip along, such low-angle normal faults is mechanically implausible. No records exist of earthquakes on low-angle normal faults in areas currently undergoing continental extension, except from an area of actively forming core complexes in the Solomon Sea, Papua New Guinea. In light of such geophysical and mechanical arguments, W.R. Buck and B. Wernicke and G.J. Axen proposed models in which detachment faults originate as high-angle normal faults, but rotate to low angles and become inactive as extension proceeds. These models are inconsistent with critical field relations in several core complexes. The Rawhide fault, an areally extensive detachment fault in western Arizona, propagated at close to its present subhorizontal orientation late in the Tertiary extension of the region. Neither the Wernicke and Axen nor Buck models predict such behavior; in fact, both models preclude the operation of low-angle normal faults. The authors recommend that alternative explanations or modifications of existing models are needed to explain the evidence that detachment faults form and operate with gentle dips.

  2. Turbulent Simulations of Divertor Detachment Based On BOUT + + Framework

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Xu, Xueqiao; Xia, Tianyang; Ye, Minyou

    2015-11-01

    China Fusion Engineering Testing Reactor is under conceptual design, acting as a bridge between ITER and DEMO. The detached divertor operation offers great promise for a reduction of heat flux onto divertor target plates for acceptable erosion. Therefore, a density scan is performed via an increase of D2 gas puffing rates in the range of 0 . 0 ~ 5 . 0 ×1023s-1 by using the B2-Eirene/SOLPS 5.0 code package to study the heat flux control and impurity screening property. As the density increases, it shows a gradually change of the divertor operation status, from low-recycling regime to high-recycling regime and finally to detachment. Significant radiation loss inside the confined plasma in the divertor region during detachment leads to strong parallel density and temperature gradients. Based on the SOLPS simulations, BOUT + + simulations will be presented to investigate the stability and turbulent transport under divertor plasma detachment, particularly the strong parallel gradient driven instabilities and enhanced plasma turbulence to spread heat flux over larger surface areas. The correlation between outer mid-plane and divertor turbulence and the related transport will be analyzed. Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-675075.

  3. Cohesive detachment of an elastic pillar from a dissimilar substrate

    NASA Astrophysics Data System (ADS)

    Fleck, N. A.; Khaderi, S. N.; McMeeking, R. M.; Arzt, E.

    The adhesion of micron-scale surfaces due to intermolecular interactions is a subject of intense interest spanning electronics, biomechanics and the application of soft materials to engineering devices. The degree of adhesion is sensitive to the diameter of micro-pillars in addition to the degree of elastic mismatch between pillar and substrate. Adhesion-strength-controlled detachment of an elastic circular cylinder from a dissimilar substrate is predicted using a Dugdale-type of analysis, with a cohesive zone of uniform tensile strength emanating from the interface corner. Detachment initiates when the opening of the cohesive zone attains a critical value, giving way to crack formation. When the cohesive zone size at crack initiation is small compared to the pillar diameter, the initiation of detachment can be expressed in terms of a critical value Hc of the corner stress intensity. The estimated pull-off force is somewhat sensitive to the choice of stick/slip boundary condition used on the cohesive zone, especially when the substrate material is much stiffer than the pillar material. The analysis can be used to predict the sensitivity of detachment force to the size of pillar and to the degree of elastic mismatch between pillar and substrate.

  4. Existence and Stability of Menisci in Detached Bridgman Growth

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Mazuruk, K.

    2011-01-01

    Detached growth, also referred to as dewetted growth, is a Bridgman crystal growth process in which the melt is in contact with the crucible wall but the crystal is not. A meniscus bridges the gap between the top of the crystal and the crucible wall. The Young-Laplace capillary equation was used to calculate the crystal radii of detached states as a function of the pressure differential across the meniscus. The detached states depend on the contact angle of the melt with the crucible wall, the growth angle of the melt with respect to the solidifying crystal, and the Bond number. A static stability analysis was performed on the calculated detached states. The stability criterion was the sign of the second variation of the potential energy upon admissible meniscus shape perturbations. The conditions considered corresponded to the growth of Ge and InSb, in both terrestrial and microgravity conditions. Stability was found to depend significantly on whether the interior surface was considered to be microscopically rough or smooth, corresponding to pinned or unpinned states. It was also found that all meniscus shapes which are single-valued functions of the radius are statically stable in a microgravity environment.

  5. Liquid Droplet Detachment and Entrainment in Microscale Flows

    NASA Astrophysics Data System (ADS)

    Hidrovo, Carlos

    2005-11-01

    In this talk we will present a first order study of liquid water detachment and entrainment into air flows in hydrophobic microchannels. Silicon based microstructures consisting of 23 mm long U-shaped channels of different geometry were used for this purpose. The structures are treated with a Molecular Vapor Deposition (MVD) process that renders them hydrophobic. Liquid water is injected through a side slot located 2/3 of the way downstream from the air channel inlet. The water entering the air channel beads up into slugs or droplets that grow in size at this injection location until they fill and flood the channel or are carried away by the air flow. The slugs/droplets dimensions at detachment are correlated against superficial gas velocity and proper dimensionless parameters are postulated and examined to compare hydrodynamic forces against surface tension. It is found that slug/droplet detachment is dominated by two main forces: pressure gradient drag, arising from confinement of a viscous flow in the channel, and inertial drag, arising from the stagnation of the air due to obstruction by the slugs/droplets. A detachment regime map is postulated based on the relative importance of these forces under different flow conditions.

  6. Commitment and Detachment in English and Bulgarian Academic Writing.

    ERIC Educational Resources Information Center

    Vassileva, Irena

    2001-01-01

    Examines similarities and differences in the degree of commitment and detachment in English, Bulgarian, and Bulgarian English research articles in linguistics. Analysis shows considerable difference in the overall distribution of hedges and boosters throughout the introductions, discussions, and conclusions of the articles, which may lead to…

  7. Rear Detachments: Capturing and Resourcing How the Army Fights

    DTIC Science & Technology

    2012-03-22

    operations/ plans officer), is the Rear Detachment Commander. Captain Basil H. Liddell-Hart was correct in noting that “even the bonds of patriotism...January, 2010; Kyle Moore and Erica Koelder, “Family Readiness in the ARFORGEN Cycle,” Engineer, May/August 2010. 8 Godwin, The Mission, Organization

  8. Experimental Characterization of Plasma Detachment from Magnetic Nozzles

    NASA Astrophysics Data System (ADS)

    Olsen, Christopher Scott

    Magnetic nozzles, like Laval nozzles, are observed in several natural systems and have application in areas such as electric propulsion and plasma processing. Plasma flowing through these nozzles is inherently tied to the field lines and must separate for momentum redirection or particle transport to occur. Plasma detachment and associated mechanisms from a magnetic nozzle are investigated. Experimental results are presented from the plume of the VASIMRRTM VX-200 device flowing along an axisymmetric magnetic nozzle and operated at two ion energies to explore momentum dependent detachment. The argon plume expanded into a 150m3 vacuum chamber where the background pressure was low enough that charge-exchange mean-free-paths were longer than experiment scale lengths. This magnetic nozzle system is demonstrated to hydrodynamically scale up to astrophysical plasmas, particularly the solar chromosphere, implying general relevance to many systems. Plasma parameters were mapped over a large spatial range using measurements from multiple plasma diagnostics. The data show that the plume does not follow the magnetic field lines. A mapped integration of the ion flux shows the plume may be divided into three regions where 1) the plume briefly follows the magnetic flux, 2) diverges quadratically before 3) expanding with linear trajectories. Transitioning from region 1→2, the ion flux departs from the magnetic flux suggesting ion detachment. An instability forms in region 2 driving an oscillating electric field that causes ions to expand before enhancing electron cross-field transport through anomalous resistivity. Transitioning from region 2→3 the electric field dissipates, the trajectories linearize, and the plume effectively detaches. A delineation of sub-to-super Alfvenic flow aligns well with the inflection points of the linearization without a change in magnetic topology. The detachment process is best described as a two part process: First, ions detach by a breakdown of

  9. Bacterial detachment from salivary conditioning films by dentifrice supernates.

    PubMed

    van der Mei, Henny C; White, Donald J; Cox, Ed R; Geertsema-Doornbusch, Gesinda I; Busscher, Henk J

    2002-01-01

    This study compared the detachment by supernates of nine different dentifrices of four oral bacterial strains adhering to a salivary pellicle in a parallel plate flow chamber. Ultra-thin bovine enamel slabs were coated for 1.5 h with human whole saliva. Following buffer rinsing, a bacterial suspension of Streptococcus oralis, Streptococcus sanguis, Streptococcus mutans or Actinomyces naeslundii was perfused through the flow chamber at a shear rate of 30 s-1 for four hours, and the number of adhering bacteria n4h was enumerated by image analysis after buffer rinsing at the same shear rate. Then, a 25 wt%-dentifrice/water supernate was perfused through the flow chamber for four minutes, followed by eight minutes of buffer rinsing and another enumeration of the number of bacteria that had remained adhering nad. Finally, an air-bubble was passed through the flow chamber to mimic the occasionally high detachment forces occurring in the oral cavity, and the adhering bacteria nab were counted again. On average, S. sanguis was the easiest to detach (73% averaged over all dentifrice supernates), while A. naeslundii was the most difficult (22% on average). The combined detachment of bacteria by dentifrice supernates and air-bubble ranged from a low of 16% to a high of 80%. Dentifrices containing pyrophosphate and polymeric polyphosphate (hexametaphosphate) surface active ingredients appeared to produce the most consistent and strongest desorption effects on plaque bacteria. Factors apparently important to bacterial detachment from pellicle-covered tooth surfaces by dentifrice formulations include the nature of adhesion of bacterial strains and chemical composition of the dentifrice formulations, including pH, surfactant system and the effect of added ingredients (dispersants, metal ions, peroxides, baking soda).

  10. Retinal fundus imaging in mouse models of retinal diseases.

    PubMed

    Alex, Anne F; Heiduschka, Peter; Eter, Nicole

    2013-01-01

    The development of in vivo retinal fundus imaging in mice has opened a new research horizon, not only in ophthalmic research. The ability to monitor the dynamics of vascular and cellular changes in pathological conditions, such as neovascularization or degeneration, longitudinally without the need to sacrifice the mouse, permits longer observation periods in the same animal. With the application of the high-resolution confocal scanning laser ophthalmoscopy in experimental mouse models, access to a large spectrum of imaging modalities in vivo is provided.

  11. Critical taper analysis reveals lithological control of variations in detachment strength: An analysis of the Alpine basal detachment (Swiss Alps)

    NASA Astrophysics Data System (ADS)

    von Hagke, C.; Oncken, O.; Evseev, S.

    2014-01-01

    Although evidence for weak detachments underlying foreland thrust belts exists, very little is known about the lateral variations in effective strength, as well as the geological nature of such variations. Using critical taper analysis, we show that a detailed and systematic measurement of surface slope of the Central European Alps reveals variations in strength parameter F along the detachment, based on the argument that the Alps are close to the critical state. We show that the basal detachment is very weak near the deformation front but strengthens toward the hinterland. Very low F (effective coefficient of friction plus normalized cohesion) values of <0.1 and even 0.05 occur within evaporites and within shales in Triassic (west) or Upper Cretaceous/Lower Tertiary sequences (east) used by the Alpine sole detachment. These very low values in shales--comparably low values are reported from other orogens--are caused partly by slightly elevated pore pressures (λ > 0.54) but may also require additional mechanisms of dynamic weakening.

  12. The bacterial toxin CNF1 as a tool to induce retinal degeneration reminiscent of retinitis pigmentosa

    PubMed Central

    Guadagni, Viviana; Cerri, Chiara; Piano, Ilaria; Novelli, Elena; Gargini, Claudia; Fiorentini, Carla; Caleo, Matteo; Strettoi, Enrica

    2016-01-01

    Retinitis pigmentosa (RP) comprises a group of inherited pathologies characterized by progressive photoreceptor degeneration. In rodent models of RP, expression of defective genes and retinal degeneration usually manifest during the first weeks of postnatal life, making it difficult to distinguish consequences of primary genetic defects from abnormalities in retinal development. Moreover, mouse eyes are small and not always adequate to test pharmacological and surgical treatments. An inducible paradigm of retinal degeneration potentially extensible to large animals is therefore desirable. Starting from the serendipitous observation that intraocular injections of a Rho GTPase activator, the bacterial toxin Cytotoxic Necrotizing Factor 1 (CNF1), lead to retinal degeneration, we implemented an inducible model recapitulating most of the key features of Retinitis Pigmentosa. The model also unmasks an intrinsic vulnerability of photoreceptors to the mechanism of CNF1 action, indicating still unexplored molecular pathways potentially leading to the death of these cells in inherited forms of retinal degeneration. PMID:27775019

  13. Detection and quantification of microtubule detachment from centrosomes and spindle poles.

    PubMed

    Ganguly, Anutosh; Yang, Hailing; Cabral, Fernando

    2013-01-01

    Microtubule detachment from microtubule organizing centers is an important cellular process required for normal cell proliferation. When cells enter mitosis, microtubule turnover increases along with a concurrent increase in microtubule detachment. MCAK, a kinesin-related protein whose abundance is highest during the early stages of mitosis, has been shown to regulate microtubule detachment. Abnormal increases or decreases in the frequency of detachment interfere with spindle function and inhibit cell division. It has been shown that drugs able to promote microtubule assembly (e.g., paclitaxel, epothilones) prevent cell division by suppressing microtubule detachment from centrosomes. Conversely, cytotoxic concentrations of microtubule destabilizing drugs (e.g., vinblastine, nocodazole), tubulin mutations that cause paclitaxel resistance, and specific β-tubulin isotypes increase the frequency of microtubule detachment. In this chapter, we describe a method to calculate the frequency of microtubule detachment by transfecting cells with EGFP-MAP4 and directly observing detachment by live cell imaging.

  14. Screening for anthracnose disease resistance in strawberry using a detached leaf assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inoculation of detached strawberry leaves with Colletotrichum species may provide a rapid, non-destructive method of identifying anthracnose resistant germplasm. The reliability and validity of assessing disease severity is critical to disease management decisions. We inoculated detached strawberr...

  15. Detachment of solids and nitrifiers in integrated, fixed-film activated sludge systems.

    PubMed

    Maas, Carol L A; Parker, Wayne J; Legge, Raymond L

    2008-12-01

    Despite the importance of detachment to biofilm processes, detachment phenomena are not well understood. In this study, researchers investigated biofilm detachment from free-floating biofilm carriers that were established in an integrated, fixed-film activated sludge (IFAS) installation in Mississauga, Ontario. A method for assessing detachment from biofilm carrier systems was devised, evaluated, and refined during this study. In the absence of substrate, superficial air velocity significantly affected the 24-hour detachment rates of total suspended solids from the carriers. Short-term growth conditions did not appear to significantly affect the rate of detachment of solids and nitrifiers. The measured solids-detachment rates were found to be described by a second order function of biofilm attached growth total solids with a detachment coefficient of 0.006 +/- 0.0008 (g/m x d)(-1).

  16. Anatomy of the retinal nerve fiber layer.

    PubMed

    Radius, R L; de Bruin, J

    1981-11-01

    Anatomy of the retinal nerve fiber layer in rabbit eyes is studied by light microscopy, transmission electron microscopy, and scanning electron microscopy. It is demonstrated that retinal striations noted ophthalmoscopically in these eyes represent individual fiber bundles, Axon bundles are compartmentalized within tissue tunnels comprised of elongated processes of glial cell origin.

  17. Fundus autofluorescence applications in retinal imaging

    PubMed Central

    Gabai, Andrea; Veritti, Daniele; Lanzetta, Paolo

    2015-01-01

    Fundus autofluorescence (FAF) is a relatively new imaging technique that can be used to study retinal diseases. It provides information on retinal metabolism and health. Several different pathologies can be detected. Peculiar AF alterations can help the clinician to monitor disease progression and to better understand its pathogenesis. In the present article, we review FAF principles and clinical applications. PMID:26139802

  18. Fundus autofluorescence applications in retinal imaging.

    PubMed

    Gabai, Andrea; Veritti, Daniele; Lanzetta, Paolo

    2015-05-01

    Fundus autofluorescence (FAF) is a relatively new imaging technique that can be used to study retinal diseases. It provides information on retinal metabolism and health. Several different pathologies can be detected. Peculiar AF alterations can help the clinician to monitor disease progression and to better understand its pathogenesis. In the present article, we review FAF principles and clinical applications.

  19. Bestrophin 1 and retinal disease.

    PubMed

    Johnson, Adiv A; Guziewicz, Karina E; Lee, C Justin; Kalathur, Ravi C; Pulido, Jose S; Marmorstein, Lihua Y; Marmorstein, Alan D

    2017-01-30

    Mutations in the gene BEST1 are causally associated with as many as five clinically distinct retinal degenerative diseases, which are collectively referred to as the "bestrophinopathies". These five associated diseases are: Best vitelliform macular dystrophy, autosomal recessive bestrophinopathy, adult-onset vitelliform macular dystrophy, autosomal dominant vitreoretinochoroidopathy, and retinitis pigmentosa. The most common of these is Best vitelliform macular dystrophy. Bestrophin 1 (Best1), the protein encoded by the gene BEST1, has been the subject of a great deal of research since it was first identified nearly two decades ago. Today we know that Best1 functions as both a pentameric anion channel and a regulator of intracellular Ca(2+) signaling. Best1 is an integral membrane protein which, within the eye, is uniquely expressed in the retinal pigment epithelium where it predominantly localizes to the basolateral plasma membrane. Within the brain, Best1 expression has been documented in both glial cells and astrocytes where it functions in both tonic GABA release and glutamate transport. The crystal structure of Best1 has revealed critical information about how Best1 functions as an ion channel and how Ca(2+) regulates that function. Studies using animal models have led to critical insights into the physiological roles of Best1 and advances in stem cell technology have allowed for the development of patient-derived, "disease in a dish" models. In this article we review our knowledge of Best1 and discuss prospects for near-term clinical trials to test therapies for the bestrophinopathies, a currently incurable and untreatable set of diseases.

  20. Neural reprogramming in retinal degenerations

    PubMed Central

    Marc, Robert E.; Jones, Bryan W.; Anderson, James R.; Kinard, Krista; Marshak, David W.; Wilson, John H.; Wensel, Theodore; Lucas, Robert J.

    2008-01-01

    Purpose Early visual defects in degenerative diseases such as retinitis pigmentosa (RP) may arise from phased remodeling of the neural retina. We sought to explore the functional expression of ionotropic (iGluR) and group III, type 6 metabotropic (mGluR6) glutamate receptors in late-stage photoreceptor degenerations. Methods Excitation mapping with organic cations and computational molecular phenotyping were used to determine whether retinal neurons displayed functional glutamate receptor signaling in rodent models of retinal degenerations and a sample of human RP. Results After photoreceptor loss in rodent models of RP, bipolar cells lose mGluR6 and iGluR glutamate-activated currents, while amacrine and ganglion cells retain iGluR-mediated responsivity. Paradoxically, amacrine and ganglion cells show spontaneous iGluR signals in vivo even though bipolar cells lack glutamate-coupled depolarization mechanisms. Cone survival can rescue iGluR expression by OFF bipolar cells. In a case of human RP with cone sparing, iGluR signaling appeared intact, but the numbers of bipolar cells expressing functional iGluRs was double that of normal retina. Conclusions RP triggers permanent loss of bipolar cell glutamate receptor expression, though spontaneous iGluR-mediated signaling by amacrine and ganglion cells implies that such truncated bipolar cells still release glutamate in response to some non-glutamatergic depolarization. Focal cone-sparing can preserve iGluR display by nearby bipolar cells, which may facilitate late-RP photoreceptor transplant attempts. An instance of human RP provides evidence that rod bipolar cell dendrite switching likely triggers new gene expression patterns and may impair cone pathway function. PMID:17591910

  1. [Experimental studies of using polyester-coated materials of Polish production in surgical treatment of retinal detachment].

    PubMed

    Kmera-Muszyńska, M; Kecik, T; Pratnicki, A; Zajkowska, G; Wael, I

    1991-01-01

    The authors evaluated the tolerance of the rabbit eye to a new generation of polyester bands coated by polymethane polyester or by silicone. Investigations consisted on the application of episcleral implants made from polyester coated bands and--for comparison--of already well known polyester non-coated bands The eyes were removed on the 4th, 10th, 30th, 60th and 90th day after operation, macroscopically evaluated and fixed in formaline. The specimen were prepared from the spot of the applied implant together with a margin of surrounding tissues. Clinical observations, macroscopic evaluations as well as histopathological examinations showed a good tolerance of the silicone coated bands; it was discovered instead that the polyurethane coated bands are causing a more pronounced inflammatory reaction in the early postoperative period.

  2. [Viral retinitis following intravitreal triamcinolone injection].

    PubMed

    Zghal, I; Malek, I; Amel, C; Soumaya, O; Bouguila, H; Nacef, L

    2013-09-01

    Necrotizing viral retinitis is associated with infection by the Herpes family of viruses, especially herpes simplex virus (HSV), varicella zoster virus (VZV) and occasionally cytomegalovirus (CMV). When the diagnosis is suspected clinically, antiviral therapy must be instituted immediately. We report the case of a patient presenting with necrotizing viral retinitis 3 months following intravitreal injection of triamcinolone acetonide for diabetic macular edema. Fluorescein angiography demonstrated a superior temporal occlusive vasculitis. A diagnostic anterior chamber paracentesis was performed to obtain deoxyribo-nucleic acid (DNA) for a polymerase chain reaction (PCR) test for viral retinitis. PCR was positive for CMV. The patient was placed on intravenous ganciclovir. CMV retinitis is exceedingly rare in immunocompetent patients; however, it remains the most common cause of posterior uveitis in immunocompromised patients. The incidence of this entity remains unknown. Local immunosuppression, the dose and the frequency of injections may explain the occurrence of this severe retinitis.

  3. The cell stress machinery and retinal degeneration.

    PubMed

    Athanasiou, Dimitra; Aguilà, Monica; Bevilacqua, Dalila; Novoselov, Sergey S; Parfitt, David A; Cheetham, Michael E

    2013-06-27

    Retinal degenerations are a group of clinically and genetically heterogeneous disorders characterised by progressive loss of vision due to neurodegeneration. The retina is a highly specialised tissue with a unique architecture and maintaining homeostasis in all the different retinal cell types is crucial for healthy vision. The retina can be exposed to a variety of environmental insults and stress, including light-induced damage, oxidative stress and inherited mutations that can lead to protein misfolding. Within retinal cells there are different mechanisms to cope with disturbances in proteostasis, such as the heat shock response, the unfolded protein response and autophagy. In this review, we discuss the multiple responses of the retina to different types of stress involved in retinal degenerations, such as retinitis pigmentosa, age-related macular degeneration and glaucoma. Understanding the mechanisms that maintain and re-establish proteostasis in the retina is important for developing new therapeutic approaches to fight blindness.

  4. Oximetry of retinal capillaries by multicomponent analysis.

    PubMed

    Furukawa, Hiromitsu; Arimoto, Hidenobu; Shirai, Tomohiro; Ooto, Sotaro; Hangai, Masanori; Yoshimura, Nagahisa

    2012-08-01

    Retinal oximetry of capillaries was performed for early detection of retinal vascular abnormalities, which are caused predominantly by complications of systemic circulatory diseases. As the conventional method for determining absorbance is not applicable to capillaries, multicomponent analysis was used to estimate the absorbance spectra of the retinal blood vessels. In this analysis, the capillary spectrum was classified as intermediate between those of the retinal arteries and veins, enabling relative estimation of oxygen saturation in the capillaries. This method could be useful for early recognition of disturbances in the peripheral circulation. Furthermore, a spectroscopic ophthalmoscope system based on the proposed method was developed to examine the human retina. A clinical trial of this system demonstrated that oximetry of the retinal capillaries may be an improvement over the present diagnosis for patients of malignant hypertension.

  5. Detached macroalgae: Its importance to inshore sandy beach fauna

    NASA Astrophysics Data System (ADS)

    Orr, Kyla K.; Wilding, Thomas A.; Horstmeyer, Lena; Weigl, Simon; Heymans, Johanna J.

    2014-10-01

    Kelp forests shed a large proportion of their biomass through storm-mediated defoliation, senescence of kelp blades, and constant erosion of particulate organic matter from the kelp fronds. Much of this detached macroalgae drifts in the water column and is deposited on intertidal zones of beaches. Detached macroalgae may provide inshore sandy beach fauna with refuge and food subsidies in an exposed and bare environment, with limited in situ primary production. We evaluated the relationship between detached macroalgae and the density of inshore fauna, where 'inshore' was the body of water extending from low water seawards for approximately 50 m. Inshore fauna were sampled using a push-net (1 mm mesh) on 11 beaches, and using a beam-trawl (4 mm mesh) on a subset of 8 beaches. On each beach, the density of detached macroalgae in the water column was quantified, together with a suite of physico-chemical beach characteristics. Push-net samples principally comprised omnivorous and detritivorous crustaceans such as gammarid amphipods, mysids and valviferan isopods, which have limited swimming abilities and reside inshore year-round. Beam-trawl fauna were mainly carnivorous decapods and fish, which undergo seasonal inshore-offshore migrations to utilize sandy beaches as nursery habitats. Linear models predicted increases of 11% (95% CI: 3.5-19%) and 2.4% (95% CI: 0.7-4.2%) in the density of push-net and beam-trawl fauna, respectively, with a 1 ℓ.100 m-3 increase in detached macroalgae. This suggests that detached macroalgae is more important in the provision of food and shelter to small, weak-swimming detritivores/omnivores than to larger and more mobile predators. The densities of large predators were mostly explained by physical beach characteristics, which overshadowed the role of macroalgae. Maximum abundances of decapods and fish were found on wide, flat beaches with low wave heights. Large accumulations of macroalgae may inhibit the foraging efficiencies of

  6. The outcomes and prognostic factors of vitrectomy in chronic diabetic traction macular detachment

    PubMed Central

    Abunajma, Muneera A; Al-Dhibi, Hassan; Abboud, Emad B; Al Zahrani, Yahya; Alharthi, Essam; Alkharashi, Abdullah; Ghazi, Nicola G

    2016-01-01

    Purpose To investigate the outcomes of pars plana vitrectomy (PPV) for chronic diabetic traction macular detachment (CTMD). Methods Ninety-six eyes that underwent PPV for CTMD of at least 6 months duration were retrospectively analyzed. Retinal reattachment rate, final vision, and prognostic factors for poor visual outcome were the main outcome measures. Results All eyes had long-standing TMD (median 12, range: 6–70 months). The median postoperative follow-up was 15 (range: 3–65) months. Eighty-seven eyes (90.6%) had their retina and macula reattached after one PPV. At final examination, 84 eyes (87.5%) had stable vision or at least one line improvement, and three had no light perception. Seventeen (17.7%) and 41 (43%) eyes had preoperative visual acuity of ≥20/200 and ≥5/200 as compared to 40 (41.6%; P=0.0005) and 64 (66.7%; P=0.0014) eyes at final follow-up, respectively. Age >50 years (Odds ratio [OR] =5.84, 95% confidence interval [CI] =1.53–22.19, P=0.01), preoperative vision <20/400 (OR =7.012, 95% CI =1.82–26.93, P=0.005), and ischemic macula (OR =14.13, 95% CI =3.61–55.33, P<0.001) were significantly associated with final vision <20/400. Conclusion PPV for CTMD may be beneficial particularly in patients who are relatively younger and have good baseline vision and no macular ischemia. PMID:27616879

  7. Intellectual property rights and detached human body parts.

    PubMed

    Pila, Justine

    2014-01-01

    This paper responds to an invitation by the editors to consider whether the intellectual property (IP) regime suggests an appropriate model for protecting interests in detached human body parts. It begins by outlining the extent of existing IP protection for body parts in Europe, and the relevant strengths and weaknesses of the patent system in that regard. It then considers two further species of IP right of less obvious relevance. The first are the statutory rights of ownership conferred by domestic UK law in respect of employee inventions, and the second are the economic and moral rights recognised by European and international law in respect of authorial works. In the argument made, both of these species of IP right may suggest more appropriate models of sui generis protection for detached human body parts than patent rights because of their capacity better to accommodate the relevant public and private interests in respect of the same.

  8. Abrupt tectonics and rapid slab detachment with grain damage.

    PubMed

    Bercovici, David; Schubert, Gerald; Ricard, Yanick

    2015-02-03

    A simple model for necking and detachment of subducting slabs is developed to include the coupling between grain-sensitive rheology and grain-size evolution with damage. Necking is triggered by thickened buoyant crust entrained into a subduction zone, in which case grain damage accelerates necking and allows for relatively rapid slab detachment, i.e., within 1 My, depending on the size of the crustal plug. Thick continental crustal plugs can cause rapid necking while smaller plugs characteristic of ocean plateaux cause slower necking; oceanic lithosphere with normal or slightly thickened crust subducts without necking. The model potentially explains how large plateaux or continental crust drawn into subduction zones can cause slab loss and rapid changes in plate motion and/or induce abrupt continental rebound.

  9. Acute lymphoblastic leukemia presenting with bilateral serous macular detachment.

    PubMed

    Vieira, Luisa; Silva, Nuno Aguiar; Medeiros, Marco Dutra; Flores, Rita; Maduro, Vitor

    2015-01-01

    Acute lymphoblastic leukemia is a malignant hematopoietic neoplasia, which is rare in adults. Although ocular fundus alterations may be commonly observed in the course of the disease, such alterations are rarely the presenting signs of the disease. Here we describe the case of a patient with painless and progressive loss of visual acuity (right eye, 2/10; left eye, 3/10) developing over two weeks, accompanied by fever and cervical lymphadenopathy. Fundus examination showed bilateral macular serous detachment, which was confirmed by optical coherence tomography. Fluorescein angiography revealed hyperfluorescent pinpoints in the posterior poles. The limits of the macular detachment were revealed in the late phase of the angiogram. The results of blood count analysis triggered a thorough, systematic patient examination. The diagnosis of acute lymphoblastic leukemia B (CD10+) was established, and intensive systemic chemotherapy was immediately initiated. One year after the diagnosis, the patient remains in complete remission without any ophthalmologic alterations.

  10. Shape Evolution of Detached Bridgman Crystals Grown in Microgravity

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Mazuruk, K.

    2015-01-01

    Detached (or dewetted) Bridgman crystal growth defines that process in which a gap exists between a growing crystal and the crucible wall. In microgravity, the parameters that influence the existence of a stable gap are the growth angle of the solidifying crystal, the contact angle between the melt and the crucible wall, and the pressure difference across the meniscus. During actual crystal growth, the initial crystal radius will not have the precise value required for stable detached growth. Beginning with a crystal diameter that differs from stable conditions, numerical calculations are used to analyze the transient crystal growth process. Depending on the initial conditions and growth parameters, the crystal shape will either evolve towards attachment at the crucible wall, towards a stable gap width, or inwards towards eventual collapse of the meniscus. Dynamic growth stability is observed only when the sum of the growth and contact angles exceeds 180 degrees.

  11. Modeling of detachment experiments at DIII-D

    DOE PAGES

    Canik, John M.; Briesemeister, Alexis R.; Lasnier, C. J.; ...

    2014-11-26

    Edge fluid–plasma/kinetic–neutral modeling of well-diagnosed DIII-D experiments is performed in order to document in detail how well certain aspects of experimental measurements are reproduced within the model as the transition to detachment is approached. Results indicate, that at high densities near detachment onset, the poloidal temperature profile produced in the simulations agrees well with that measured in experiment. However, matching the heat flux in the model requires a significant increase in the radiated power compared to what is predicted using standard chemical sputtering rates. Lastly, these results suggest that the model is adequate to predict the divertor temperature, provided thatmore » the discrepancy in radiated power level can be resolved.« less

  12. Modeling of detachment experiments at DIII-D

    SciTech Connect

    Canik, John M.; Briesemeister, Alexis R.; Lasnier, C. J.; Leonard, A. W.; Lore, J. D.; McLean, A. G.; Watkins, J. G.

    2014-11-26

    Edge fluid–plasma/kinetic–neutral modeling of well-diagnosed DIII-D experiments is performed in order to document in detail how well certain aspects of experimental measurements are reproduced within the model as the transition to detachment is approached. Results indicate, that at high densities near detachment onset, the poloidal temperature profile produced in the simulations agrees well with that measured in experiment. However, matching the heat flux in the model requires a significant increase in the radiated power compared to what is predicted using standard chemical sputtering rates. Lastly, these results suggest that the model is adequate to predict the divertor temperature, provided that the discrepancy in radiated power level can be resolved.

  13. Abrupt tectonics and rapid slab detachment with grain damage

    PubMed Central

    Bercovici, David; Schubert, Gerald; Ricard, Yanick

    2015-01-01

    A simple model for necking and detachment of subducting slabs is developed to include the coupling between grain-sensitive rheology and grain-size evolution with damage. Necking is triggered by thickened buoyant crust entrained into a subduction zone, in which case grain damage accelerates necking and allows for relatively rapid slab detachment, i.e., within 1 My, depending on the size of the crustal plug. Thick continental crustal plugs can cause rapid necking while smaller plugs characteristic of ocean plateaux cause slower necking; oceanic lithosphere with normal or slightly thickened crust subducts without necking. The model potentially explains how large plateaux or continental crust drawn into subduction zones can cause slab loss and rapid changes in plate motion and/or induce abrupt continental rebound. PMID:25605890

  14. Evaluation of metal trace detachment from dosing pumps using PIXE

    NASA Astrophysics Data System (ADS)

    Lozano, Omar; Mejia, Jorge; Laloy, Julie; Alpan, Lütfiye; Toussaint, Olivier; Dogné, Jean-Michel; Lucas, Stéphane

    2014-07-01

    Metal trace detachment evaluation is essential for instruments destined for pharmaceutical applications, such as pumps. Particle-Induced X-ray Emission (PIXE) was used to determine and quantify metal traces originated from stainless steel and ceramic dosing pumps. Metal traces were quantified from either distilled water samples or cellulose filters in two tests: a short-term test of 16 h mimicking a daily cycle of a dosing pump for industrial applications, and a long-term test of 9 days evaluating the pump wearing. The main result is that ceramic dosing pumps present lower metal detachment than stainless steel counterparts. Traces of Si and Al were found originating from pieces around the pumps (pipes and joints).

  15. Detached Solidification of InSb on Earth

    NASA Technical Reports Server (NTRS)

    Wang, Jianbin; Regel, Liya L.; Wilcox, William R.

    2003-01-01

    Detached solidification of lightly gallium-doped indium antimonide was achieved in the laboratory only when the ampoule was coated with hexagonal boron nitride and when the material appeared to be oxide-free. A furnace was constructed with the temperature increasing with height in order to minimize bouyancy-driven convection, so as to maximize transport of segregated dissolved gases into the gap between the growing solid and the ampoule wall. There appeared to be no difference in results with freezing rates of 5 mmh and 10 mm/h. Best results were obtained when the ampoule was backfilled with 20 kPa of Ar-10%H2 prior to sealing. The detached portions were depressed by several pm from adjacent attached regions, were rough, and sometimes had microfacets and steps.

  16. Reflexivity and detachment: a discursive approach to women's depression.

    PubMed

    Crowe, Marie

    2002-06-01

    Reflexivity and detachment: a discursive approach to women's depression This paper explores a discursive approach to understanding women's depression by presenting the results of research into women's narratives of their experiences. The discursive approach taken acknowledges women's immersion in cultural practices that determine the subject positions available to them and places a value on attributes of reflexivity and detachment that are not usually associated with their performance. The social and cultural context of the individual's experience is significant because if the focus is simply on the individual this supposes that the problem lies solely with the individual. An understanding of cultural expectations and their relation to mental distress is important to mental health nursing practice. The psychotherapeutic relationship that is fundamental to mental health nursing practice requires an understanding of the meaning of individual's responses in their cultural context in order to provide facilitative and meaningful care for the women that they nurse.

  17. Rapid Orbital Decay in Detached Binaries: Evidence for Circumbinary Disks

    NASA Astrophysics Data System (ADS)

    Chen, Wen-Cong; Podsiadlowski, Philipp

    2017-03-01

    Some short-period, detached binary systems have recently been reported as experiencing very rapid orbital decay, much faster than is expected from the angular-momentum loss caused by gravitational radiation alone. As these systems contain fully convective stars, magnetic braking is not believed to be operative, making the large orbital-period derivative puzzling. Here, we explore whether a resonant interaction between the binary and a surrounding circumbinary (CB) disk could account for the observed orbital decay. Our calculations indicate that the observed orbital-period derivatives in seven detached binaries can be produced by the resonant interaction between the binary and a CB disk if the latter has a mass in the range of {10}-4{--}{10}-2 {M}ȯ , which is of the same order as the inferred disk mass (∼ 2.4× {10}-4 {M}ȯ ) in the post-common-envelope binary NN Ser.

  18. Modeling detachment physics in the NSTX snowflake divertor

    NASA Astrophysics Data System (ADS)

    Meier, E. T.; Soukhanovskii, V. A.; Bell, R. E.; Diallo, A.; Kaita, R.; LeBlanc, B. P.; McLean, A. G.; Podestà, M.; Rognlien, T. D.; Scotti, F.

    2015-08-01

    The snowflake divertor is a proposed technique for coping with the tokamak power exhaust problem in next-step experiments and eventually reactors, where extreme power fluxes to material surfaces represent a leading technological and physics challenge. In lithium-conditioned National Spherical Torus Experiment (NSTX) discharges, application of the snowflake divertor typically induced partial outer divertor detachment and severalfold heat flux reduction. UEDGE is used to analyze and compare conventional and snowflake divertor configurations in NSTX. Matching experimental upstream profiles and divertor measurements in the snowflake requires target recycling of 0.97 vs. 0.91 in the conventional case, implying partial saturation of the lithium-based pumping mechanism. Density scans are performed to analyze the mechanisms that facilitate detachment in the snowflake, revealing that increased divertor volume provides most of the parallel heat flux reduction. Also, neutral gas power loss is magnified by the increased wetted area in the snowflake, and plays a key role in generating volumetric recombination.

  19. Fixation strategies for retinal immunohistochemistry.

    PubMed

    Stradleigh, Tyler W; Ishida, Andrew T

    2015-09-01

    Immunohistochemical and ex vivo anatomical studies have provided many glimpses of the variety, distribution, and signaling components of vertebrate retinal neurons. The beauty of numerous images published to date, and the qualitative and quantitative information they provide, indicate that these approaches are fundamentally useful. However, obtaining these images entailed tissue handling and exposure to chemical solutions that differ from normal extracellular fluid in composition, temperature, and osmolarity. Because the differences are large enough to alter intercellular and intracellular signaling in neurons, and because retinae are susceptible to crush, shear, and fray, it is natural to wonder if immunohistochemical and anatomical methods disturb or damage the cells they are designed to examine. Tissue fixation is typically incorporated to guard against this damage and is therefore critically important to the quality and significance of the harvested data. Here, we describe mechanisms of fixation; advantages and disadvantages of using formaldehyde and glutaraldehyde as fixatives during immunohistochemistry; and modifications of widely used protocols that have recently been found to improve cell shape preservation and immunostaining patterns, especially in proximal retinal neurons.

  20. Measurement of retinal blood velocity

    NASA Astrophysics Data System (ADS)

    Winchester, Leonard W., Jr.; Chou, Nee-Yin

    2006-02-01

    A fundus camera was modified to illuminate the retina of a rabbit model with low power laser light in order to obtain laser speckle images. A fast-exposure charge-coupled device (CCD) camera was used to capture laser speckle images of the retina. Image acquisition was synchronized with the arterial pulses of the rabbit to ensure that all images are obtained at the same point in the cardiac cycle. The rabbits were sedated and a speculum was inserted to prevent the eyelid from closing. Both albino (New Zealand; pigmented (Dutch belted) rabbits were used in the study. The rabbit retina is almost avascular. The measurements are obtained for choroidal tissue as well as retinal tissue. Because the retina is in a region of high metabolism, blood velocity is strongly affected by blood oxygen saturation. Measurements of blood velocity obtained over a wide range of O II saturations (58%-100%) showed that blood velocity increases with decreasing O II saturation. For most experiments, the left eye of the rabbit was used for laser measurements whereas the right eye served as a control. No observable difference between pre- and post-experimented eye was noted. Histological examinations of retinal tissue subjected to repeated laser measurements showed no indication of tissue damage.

  1. Fixation Strategies For Retinal Immunohistochemistry

    PubMed Central

    Stradleigh, Tyler W.; Ishida, Andrew T.

    2015-01-01

    Immunohistochemical and ex vivo anatomical studies have provided many glimpses of the variety, distribution, and signaling components of vertebrate retinal neurons. The beauty of numerous images published to date, and the qualitative and quantitative information they provide, indicate that these approaches are fundamentally useful. However, obtaining these images entailed tissue handling and exposure to chemical solutions that differ from normal extracellular fluid in composition, temperature, and osmolarity. Because the differences are large enough to alter intercellular and intracellular signaling in neurons, and because retinae are susceptible to crush, shear, and fray, it is natural to wonder if immunohistochemical and anatomical methods disturb or damage the cells they are designed to examine. Tissue fixation is typically incorporated to guard against this damage and is therefore critically important to the quality and significance of the harvested data. Here, we describe mechanisms of fixation; advantages and disadvantages of using formaldehyde and glutaraldehyde as fixatives during immunohistochemistry; and modifications of widely used protocols that have recently been found to improve cell shape preservation and immunostaining patterns, especially in proximal retinal neurons. PMID:25892361

  2. Antimicrobials Influence Bond Stiffness and Detachment of Oral Bacteria.

    PubMed

    Song, L; Hou, J; van der Mei, H C; Veeregowda, D H; Busscher, H J; Sjollema, J

    2016-07-01

    Oral biofilm can never be fully removed by oral hygiene measures. Biofilm left behind after brushing is often left behind on the same sites and exposed multiple times to antimicrobials from toothpastes and mouthrinses, after which removal becomes increasingly difficult. On the basis of this observation, we hypothesize that oral bacteria adhering to salivary conditioning films become more difficult to remove after adsorption of antimicrobials due to stiffening of their adhesive bond. To verify this hypothesis, bacteria adhering to bare and saliva-coated glass were exposed to 3 different mouthrinses, containing chlorhexidine-digluconate, cetylpyridinium-chloride, or amine-fluoride, after which bacterial vibration spectroscopy was carried out or a liquid-air interface was passed over the adhering bacteria to stimulate their detachment. Brownian motion-induced nanoscopic vibration amplitudes of 4 oral streptococcal strains, reflecting their bond stiffness, decreased after exposure to mouthrinses. Concurrently, the percentage detachment of adhering bacteria upon the passage of a liquid-air interface decreased after exposure to mouthrinses. A buffer control left both vibration amplitudes and detachment percentages unaffected. Exposure to either of the selected mouthrinses yielded more positively charged bacteria by particulate microelectrophoresis, suggesting antimicrobial adsorption to bacterial cell surface components. To rule out that exposure of adhering bacteria to the mouthrinses stimulated polysaccharide production with an impact on their detachment, Fourier transform infrared spectroscopy was carried out on bacteria adhering to an internal reflection element, prior to and after exposure to the mouthrinses. Infrared absorption band areas indicated no significant change in amount of polysaccharides after exposure of adhering bacteria to mouthrinses, but wave number shifts demonstrated stiffening of polysaccharides in the bond, as a result of antimicrobial

  3. A Promising Adjuvant to Detachable Coils for Cavernous Packing: Onyx

    PubMed Central

    Lv, X.; Jiang, C.; Li, Y.; Wu, Z.

    2009-01-01

    Summary Transvenous embolization of cavernous dural arteriovenous fistulae (CDAVFs) with Onyx has recently been reported. This study was undertaken to assess the value of Onyx in transvenous treatment of CDAVFs. We retrospectively reviewed 18 patients who underwent transvenous embolization for CDAVFs of Barrow Type D with detachable coils and Onyx at our institution over five years. Patients were divided into two groups: group A, patients who had been treated with detachable coils; group B, patients who had been treated with a combination of detachable coils and Onyx. The approach routes, angiographic results, complications and clinical outcome were assessed for both groups. Eighteen patients with CDAVFs of Barrow Type D were treated: nine women and nine men; mean age was 41.9 years. Eleven patients treated by 19 procedures of transvenous coiling belonged to group A. Seven patients treated by eight procedures of transvenous Onyx injection belonged to group B. The periprocedural complication rate associated with coiling for both groups was 18.2% vs 16.7% with Onyx. The duration of the procedure in both groups was 6.77±2.49 hours vs 3.75±1.63 hours with coiling vs Onyx, and the cost of Onyx was cheaper than coils. An excellent outcome was achieved in both groups: 90.9% vs 100% (group A vs group B). Our results associated with both modalities of CDAVFs treatment with clinical outcome show that transvenous embolization with Onyx is a safe alternative to detachable coils in the treatment of CDAVFs. However, more cases need to be evaluated. PMID:20465891

  4. The Mobile Obstacle Detachment of the Soviet Ground Forces.

    DTIC Science & Technology

    1980-06-01

    reproduced in whole or in part without permission of the Commander, US Army% Russian Institute, APO ,lew York 09053. This 6ocument has been cleared for...artificial obstacles is an integral part of modern ground force tactical operations. Obstacles of all types are used by forces for a wide variety of...overlooked or relegated to a posi- tion of relatively low importance. 3 Although the mobile obstacle detachment com- prises only a very small part of

  5. The Missing Magnetic WDs in Detached Close Binaries

    NASA Astrophysics Data System (ADS)

    Tovmassian, G.; Gonzalez-Buitrago, D.; Zharikov, S.

    2017-03-01

    A substantial fraction of isolated white dwarfs (WDs) are strongly magnetic. An even higher number of magnetic WDs are reported in cataclysmic variables (CVs). However, we have been struggling to find them in detached, close binaries. Recently, we identified a pair of such systems with K star companions. We suggest that we could not recognize them because they replicate CV behavior by fueling accretion onto the WD through the coupled magnetic fields of the WD and chromospherically active K star.

  6. Detachable connection for a nuclear reactor fuel assembly

    DOEpatents

    Christiansen, David W.; Karnesky, Richard A.

    1986-01-01

    A locking connection for releasably attaching a handling socket to the duct tube of a fuel assembly for a nuclear reactor. The connection comprises a load pad housing mechanically attached to the duct tube and a handling socket threadably secured within the housing. A retaining ring is interposed between the housing and the handling socket and is formed with a projection and depression engageable within a cavity and groove of the housing and handling socket, respectively, to form a detachable interlocked connection assembly.

  7. Detachable connection for a nuclear reactor fuel assembly

    DOEpatents

    Christiansen, D.W.; Karnesky, R.A.

    1983-08-29

    A locking connection for releasably attaching a handling socket to the duct tube of a fuel assembly for a nuclear reactor. The connection comprises a load pad housing mechanically attached to the duct tube and a handling socket threadably secured within the housing. A retaining ring is interposed between the housing and the handling socket and is formed with a projection and depression engagable within a cavity and groove of the housing and handling socket, respectively, to form a detachable interlocked connection assembly.

  8. Thermomechanical analysis of strain localization in a ductile detachment zone

    NASA Astrophysics Data System (ADS)

    Mulch, A.; Teyssier, C.; Cosca, M. A.; Vennemann, T. W.

    2006-12-01

    At the latitude of the Thor-Odin dome (British Columbia) the Columbia River Detachment defines the eastern margin of the Shuswap metamorphic core complex and localizes in a 1 km thick muscovite-bearing quartzite mylonite. We present a combined 40Ar/39Ar, (micro)structural, and oxygen isotope study of the deformation history in the detachment and evaluate the spatial and temporal relationships between microstructure formation and localization of strain. High-precision 40Ar/39Ar geochronology from different levels in the mylonite delineates a pattern of increasingly younger (49.0 to 47.9 Ma) deformation ages in deeper levels of the mylonitic footwall. The correlation of 40Ar/39Ar ages with decreasing deformation temperatures (˜550°-400°C) in the top 200 m of the mylonite indicates that deformation migrated downward from the contact with the hanging wall. Strain localization was diachronous in progressively deeper levels of the footwall and was likely controlled by fluid-assisted strain hardening due to advective heat removal and contemporaneous reaction weakening due to dissolution-reprecipitation of white mica. The observed constant high-stress microstructures across the entire detachment indicate that flow stress was buffered by the interplay of strain rate and temperature, where high strain rates at elevated temperature produced the same microstructure as lower strain rates under decreasing temperature conditions. The combined data suggest that the complex interplay among temporally nonuniform rates of footwall exhumation, heat advection, and embrittlement by meteoric fluids strongly determines the thermomechanical behavior of extensional detachments.

  9. Collisional Detachment of Anions using Fourier Transform Mass Spectrometry

    DTIC Science & Technology

    1992-12-01

    results from the crossing of covalent and ionic potential energy surfaces. In accordance with the Landau - Zener [143] relation, the crossing is adiabatic...Charge transfer and associative detachment (Reactions (d) and (f)) are precluded for the rare gas targets. Landau and Zener [1431 have shown the...Illinois: Wolfram Research, Inc, 1990. 143. Zener , Clarence. "Non-Adiabatic Crossing of Energy Levels," Proceedings of the Royal Society of London, A137:696

  10. Detached cataclysmic variables are crossing the orbital period gap

    NASA Astrophysics Data System (ADS)

    Zorotovic, M.; Schreiber, M. R.; Parsons, S. G.; Gänsicke, B. T.; Hardy, A.; Agurto-Gangas, C.; Nebot Gómez-Morán, A.; Rebassa-Mansergas, A.; Schwope, A. D.

    2016-04-01

    A central hypothesis in the theory of cataclysmic variable (CV) evolution is the need to explain the observed lack of accreting systems in the ≃2-3 h orbital period range, known as the period gap. The standard model, disrupted magnetic braking (DMB), reproduces the gap by postulating that CVs transform into inconspicuous detached white dwarf (WD) plus main sequence systems, which no longer resemble CVs. However, observational evidence for this standard model is currently indirect and thus this scenario has attracted some criticism throughout the last decades. Here, we perform a simple but exceptionally strong test of the existence of detached CVs (dCVs). If the theory is correct, dCVs should produce a peak in the orbital period distribution of detached close binaries consisting of a WD and an M4-M6 secondary star. We measured six new periods which brings the sample of such binaries with known periods below 10 h to 52 systems. An increase of systems in the ≃2-3 h orbital period range is observed. Comparing this result with binary population models, we find that the observed peak cannot be reproduced by post-common envelope binaries (PCEBs) alone and that the existence of dCVs is needed to reproduce the observations. Also, the WD mass distribution in the gap shows evidence of two populations in this period range, i.e. PCEBs and more massive dCVs, which is not observed at longer periods. We therefore conclude that CVs are indeed crossing the gap as detached systems, which provides strong support for the DMB theory.

  11. Neural remodeling in retinal degeneration.

    PubMed

    Marc, Robert E; Jones, Bryan W; Watt, Carl B; Strettoi, Enrica

    2003-09-01

    Mammalian retinal degenerations initiated by gene defects in rods, cones or the retinal pigmented epithelium (RPE) often trigger loss of the sensory retina, effectively leaving the neural retina deafferented. The neural retina responds to this challenge by remodeling, first by subtle changes in neuronal structure and later by large-scale reorganization. Retinal degenerations in the mammalian retina generally progress through three phases. Phase 1 initiates with expression of a primary insult, followed by phase 2 photoreceptor death that ablates the sensory retina via initial photoreceptor stress, phenotype deconstruction, irreversible stress and cell death, including bystander effects or loss of trophic support. The loss of cones heralds phase 3: a protracted period of global remodeling of the remnant neural retina. Remodeling resembles the responses of many CNS assemblies to deafferentation or trauma, and includes neuronal cell death, neuronal and glial migration, elaboration of new neurites and synapses, rewiring of retinal circuits, glial hypertrophy and the evolution of a fibrotic glial seal that isolates the remnant neural retina from the surviving RPE and choroid. In early phase 2, stressed photoreceptors sprout anomalous neurites that often reach the inner plexiform and ganglion cell layers. As death of rods and cones progresses, bipolar and horizontal cells are deafferented and retract most of their dendrites. Horizontal cells develop anomalous axonal processes and dendritic stalks that enter the inner plexiform layer. Dendrite truncation in rod bipolar cells is accompanied by revision of their macromolecular phenotype, including the loss of functioning mGluR6 transduction. After ablation of the sensory retina, Müller cells increase intermediate filament synthesis, forming a dense fibrotic layer in the remnant subretinal space. This layer invests the remnant retina and seals it from access via the choroidal route. Evidence of bipolar cell death begins in

  12. Modeling of extinguishing ELMs in detached divertor plasmas

    NASA Astrophysics Data System (ADS)

    Pigarov, A.; Krasheninnikov, S.; Hollmann, E.; Rognlien, T.

    2015-11-01

    Detached plasmas, the primary operational regime for divertors in next-step fusion devices, should be compatible with both good H-mode confinement and relatively small ELMs providing tolerable heat power loads on divertor targets. Here, dynamics of boundary plasma, impurities and material walls over a sequence of many type-I ELM events under detached divertor plasma conditions is studied with UEGDE-MB-W, the newest version of 2D edge plasma transport code, which incorporates Macro-Blob (MB) approach to simulate non-diffusive filamentary transport and various ``Wall'' (W) models for time-dependent hydrogen wall inventory and recycling. We present the results of multi-parametric analysis on the impact of the size and frequency of ELMs on the divertor plasma parameters where we vary the MB characteristics under different pedestals and divertor configurations. We discuss the conditions, under which small but frequent type-I ELMs (typical for high-power H-mode discharges on current tokamaks with hard deuterium gas puff) are not ``burning through'' the formed detached divertor plasma. In this case, the inner and outer divertors are filled by sub-eV, recombining, highly-impure plasma. Variations of impurity plasma content, radiation pattern, and deuterium wall inventory over the ELM cycle are analyzed. UEDGE-MB-W modeling results are compared to available experimental data.

  13. Physics of Coanda jet detachment at high-pressure ratio

    NASA Astrophysics Data System (ADS)

    Cornelius, Kenneth C.; Lucius, Gerald A.

    1994-05-01

    Experimental measurements of surface pressure for an underexpanded two-dimensional supersonic Coanda flow with static conditions exterior to the jet flow was obtained for a fixed slot height to a radius ratio of 0.04. The data demonstrate that an oblique shock forms near the jet exit plane which vectors the jet flow from the curved surface at a pressure ratio of 7.6. The jet detachment occurs at a pressure ratio which is a function of the ratio of slot height to cylinder radius. An increase in the pressure ratio to 11.5 before jet detachment has been demonstrated by the translation of the upper wall providing for a converging-diverging geometry. The physics of the Coanda expansion and the jet detachment are qualitatively described using an optical schlieren system. A compressible inviscid model was derived analytically to demonstrate the variation in Mach number and surface pressure as a function of the geometric parameters with increasing pressure ratio.

  14. Farnesol induces cell detachment from established S. epidermidis biofilms.

    PubMed

    Cerca, Nuno; Gomes, Fernanda; Bento, Joana C; França, Angela; Rolo, Joana; Miragaia, Maria; Teixeira, Pilar; Oliveira, Rosário

    2013-05-01

    Antibiotic resistance is a serious problem in Staphylococcus epidermidis infections as many clinical isolates of this organism are resistant to up to eight different antibiotics. The increased resistance to conventional antibiotic therapy has lead to the search for new antimicrobial therapeutic agents. Farnesol, an essential oil found in many plants, has been shown to be active against S. epidermidis. Using a type control strain we recently described that although farnesol was not efficient at killing biofilm bacteria, a strong reduction on biofilm biomass was detected, and we hypothesize that farnesol could, somehow, induce biofilm detachment. In this report, to test our hypothesis we used 36 representative clinical strains of S. epidermidis from different geographic locations and characterized them in terms of genetic variability by multilocus sequence typing and staphylococcal chromosome cassette mec. Strains were tested for biofilm formation, and the presence of ica, bhp and aap genes was determined. Stronger biofilms had always the presence of ica operon but often co-harbored bhp and aap genes. Farnesol was then used in biofilm-forming strains, and biofilm detachment was detected in half of the strains tested. Furthermore, we also showed that farnesol inability to kill biofilm bacteria was not the result of the biofilm structure but was related to high cell density. Our results demonstrate, for the first time, that the biomass reduction previously found by us, and many other groups, is the result not of cell killing but instead is the result of biofilm detachment.

  15. Compatibility of Detached Divertor Operation with Robust Edge Pedestal Performance

    NASA Astrophysics Data System (ADS)

    Leonard, A. W.; Osborne, T. H.; Snyder, P. B.; Makowski, M. A.; McLean, A. G.

    2014-10-01

    The compatibility of radiative detached divertor operation with the maintenance of a robust H-mode pedestal is examined in DIII-D. A density scan with deuterium injection into H-mode spanned a range of divertor conditions from fully attached, ~30 eV at the target, with little divertor radiation to a fully detached with Te < 5 eV throughout the divertor up to the X-point. Over this scan of pedestal density from n /nGW = 30% to 60% the pedestal Te was reduced from 800 eV to 350 eV, representing a ~20% reduction in pedestal pressure with a similar reduction in normalized energy confinement. The reduction in pedestal pressure at high density was found to be consistent with a reduced pedestal ELM MHD stability limit at high collisionality. The scaling of the pedestal top pressure with density was also consistent with the EPED model, which assumes an additional constraint on the local pressure gradient. The MHD stability limit at the highest collisionality depends on details of the ELM instability growth rate normalization. This result is encouraging for future burning plasmas where a low collisionality pedestal is expected to be maintained even for high density detached divertor operation. Work supported by the US DOE under DE-FC02-04ER54698 and DE-AC52-07NA27344.

  16. On the W7-X divertor performance under detached conditions

    NASA Astrophysics Data System (ADS)

    Feng, Y.; Beidler, C. D.; Geiger, J.; Helander, P.; Hölbe, H.; Maassberg, H.; Turkin, Y.; Reiter, D.; W7-X Team

    2016-12-01

    We present a theoretical/numerical predictive analysis of the performance of the W7-X island divertor under conditions of detachment characterized by intensive radiation. The analysis is based on EMC3-Eirene simulations and the earlier W7-AS experimental and numerical experience. Carbon is employed as a representative radiator. The associated drawbacks, i.e. core contamination and recycling degradation (reduced recycling flux), are evaluated by determining the carbon density at the last closed flux surface (LCFS) and the neutral pressure in the divertor chamber. Optimum conditions are explored in both configuration and plasma parameter space. This study aims to identify the key geometric/magnetic and plasma parameters that affect the performance of detached plasmas in W7-X. Emphasis is placed on what occurs when the islands are enlarged far beyond the maximum size available in W7-AS and whether an island size limit for optimal detachment operation exists, and why. Further issues addressed are the power removal ability of the W7-X edge islands, potentially limiting factors, compatibility between particle and power exhaust, and particle refueling capability of the recycling neutrals.

  17. Electron attachment and detachment: C6F6

    NASA Astrophysics Data System (ADS)

    Miller, Thomas M.; van Doren, Jane M.; Viggiano, A. A.

    2004-04-01

    Electron attachment to C6F6 is especially interesting because of the large change in symmetry between the neutral (D6h) and anion (C2v). We have made measurements of rate constants for electron attachment to C6F6 and thermal electron detachment from the parent anion, C6F6-, over the temperature range 297-400 K, in 133 Pa of He gas. A flowing-afterglow Langmuir probe (FALP) apparatus was used for this work. At 298 K, the electron attachment rate constant is ka=8.6+/-3.0×10-8 cm3 s-1, and the detachment rate constant kd is approximately 35 s-1. As the temperature increases kd increases rapidly, to about 3000 s-1 at 400 K. The attachment/detachment equilibrium implies that the electron affinity of C6F6 is 0.53+/-0.05 eV. Density functional calculations were carried out in order to obtain thermal quantities needed to convert the equilibrium constant ka/kd into EA(C6F6). G3(MP2) calculations yielded an electron affinity of 0.454 eV. The fluoride affinity of C6F6 was calculated to be 1.26 eV at 298 K using this same method. We expect the G3(MP2) results to be good within 0.1 eV.

  18. Detachment, compartmentalization, and schizophrenia: linking dissociation and psychosis by subtype.

    PubMed

    Vogel, Matthias; Braungardt, Tanja; Grabe, Hans Jörgen; Schneider, Wolfgang; Klauer, Thomas

    2013-01-01

    To explain the phenomenological overlap between dissociation and schizophrenia, a dissociative subtype of schizophrenia has been proposed as a possibility. Dissociation is often believed to be organized on a continuum, although 2 qualitatively different phenomena can be distinguished in theory, research, and clinical practice: (a) states of separation from self or environment (detachment dissociation) and (b) inaccessibility of normally accessible mental contents (compartmentalization dissociation). This study used the Positive and Negative Syndrome Scale (PANSS) and the Association for Methodology and Documentation in Psychiatry module for the interview assessment of dissociation to investigate the relationships between PANSS subscales, detachment dissociation, and compartmentalization dissociation in a sample of 72 patients with schizophrenia. A confirmatory factor analysis sustained the bipartite model, yielding factors that grouped dissociative items around amnesia and depersonalization/derealization. The latter factor also contained identity disturbances and was therefore not entirely consistent with the theoretical formulations of detachment dissociation. It is important to note that the structure of those factors may be influenced by the symptoms of schizophrenia to which they were specifically linked: The factor containing depersonalization/derealization was connected to the positive symptoms subscale of the PANSS, whereas the factor containing amnesia was associated with the negative subscale. Hence, a dichotomy of dissociation is confirmed inasmuch as its subtypes are as distinguishable as PANSS subscales. This has implications on theoretical and clinical levels.

  19. The active transport of fluorescein by the retinal vessels and the retina

    PubMed Central

    Cunha-Vaz, J. G.; Maurice, D. M.

    1967-01-01

    1. The movement of fluorescein across the retinal surface of the rabbit's eye was estimated by measuring the concentration gradient of the dye in the vitreous body. These measurements were made in vivo by means of a slit-lamp fluorophotometer, or were taken from frozen sections of enucleated eyes. 2. In the normal eye, fluorescein does not pass from the blood to the vitreous body across any part of the retina. When injected into the vitreous body it passes rapidly out across the entire retinal surface, even against a very large concentration gradient. 3. A variety of metabolic and competitive inhibitors, effective in blocking organic anion transport in the kidney and liver, tend to abolish this unidirectional movement of fluorescein across the retina. 4. The region occupied by the retinal vessels is more sensitive to inhibition than other areas of the retina. Occlusion of the vessels by diathermy prevents the exchange of fluorescein in this region. 5. It appears, then, that there is an active transport of organic anions out of the vitreous body, both by the retinal capillaries and by the retina itself. The latter system is probably located in the pigment epithelium and seems to be carried forward to the rear surface of the iris. 6. Since the walls of the retinal vessels of the rabbit are freely in contact with the vitreous body, the active transport must take place across the capillary endothelial cells themselves. These vessels have structural and permeability characteristics found only in the central nervous system and it is to be presumed that the anion transport system is shared by the capillaries of the brain. 7. The function of the transport in the retina may be to protect the nervous tissue from toxic materials by preventing their entry from the blood or by removing products of metabolism conjugated as organic anions. Alternatively, the mechanism may be concerned in maintaining the normal adhesion of the retina to the choroid, since retinal detachment was

  20. GUIDELINES FOR INTERPRETING RETINAL PHOTOGRAPHS AND CODING FINDINGS IN THE SUBMACULAR SURGERY TRIALS (SST)

    PubMed Central

    2005-01-01

    Purpose To describe the guidelines followed by the Submacular Surgery Trials (SST) Research Group in the interpretation of color fundus photographs and fluorescein angiograms of subfoveal choroidal neovascular lesions evaluated in the SST and to assist ophthalmologists in applying the results of the SST. Methods Stereoscopic color fundus photographs and fluorescein angiograms of the study eye and nonstudy eye of 1,015 patients with subfoveal choroidal neovascular lesions secondary to age-related macular degeneration, ocular histoplasmosis syndrome, or idiopathic choroidal neovascularization (CNV) were obtained and graded by certified SST fundus photograph readers at the baseline examination in three randomized clinical trials comparing surgery with observation. Adherence to the inclusion and exclusion criteria and ocular features that might affect visual outcome were documented. Stereoscopic color fundus photography and fluorescein angiography were repeated 1 month after randomization for patients assigned to surgery to provide documentation that surgery was performed and to assess compliance with the surgery protocol. Photographs and fluorescein angiograms of both the study eye and the fellow eye in all patients then were obtained 3 months, 6 months, and 12 months after randomization and then annually up to 48 months. The κ statistic was used to evaluate interobserver reliability of photograph gradings. Results Lesion components at baseline included classic CNV, occult CNV, and features contiguous to CNV, including blood, fibrous tissue, hypofluorescence not corresponding to blood, serous detachment of the retinal pigment epithelium, and prior areas of laser photocoagulation. At follow-up, fluorescein leakage from CNV was assessed peripheral to or within the area of the retinal pigment epithelium abnormality after surgery. The lesion at follow-up could include any of the features identified at baseline as well as retinal pigment epithelium abnormalities, such as

  1. Automated retinal image analysis over the internet.

    PubMed

    Tsai, Chia-Ling; Madore, Benjamin; Leotta, Matthew J; Sofka, Michal; Yang, Gehua; Majerovics, Anna; Tanenbaum, Howard L; Stewart, Charles V; Roysam, Badrinath

    2008-07-01

    Retinal clinicians and researchers make extensive use of images, and the current emphasis is on digital imaging of the retinal fundus. The goal of this paper is to introduce a system, known as retinal image vessel extraction and registration system, which provides the community of retinal clinicians, researchers, and study directors an integrated suite of advanced digital retinal image analysis tools over the Internet. The capabilities include vasculature tracing and morphometry, joint (simultaneous) montaging of multiple retinal fields, cross-modality registration (color/red-free fundus photographs and fluorescein angiograms), and generation of flicker animations for visualization of changes from longitudinal image sequences. Each capability has been carefully validated in our previous research work. The integrated Internet-based system can enable significant advances in retina-related clinical diagnosis, visualization of the complete fundus at full resolution from multiple low-angle views, analysis of longitudinal changes, research on the retinal vasculature, and objective, quantitative computer-assisted scoring of clinical trials imagery. It could pave the way for future screening services from optometry facilities.

  2. Lipoprotein(a), homocysteine, and retinal arteriosclerosis

    PubMed Central

    Javadzadeh, Alireza; Argani, Hassan; Nezami, Nariman; Rashtchizadeh, Nadereh; Rafeey, Mandana; Rohbaninoubar, Mohammad; Rahimi-Ardabili, Babak

    2008-01-01

    Purpose Elevated levels of lipoprotein(a) [Lp(a)] and homocysteine (Hcy) have been implicated as risk factors for vascular diseases. The study was performed to explore the possible relationship between retinal arteriosclerosis and serum Lp(a) and Hcy levels. Methods Study subjects consisted of 80 nonsmoking male patients with retinal arteriosclerosis and 54 healthy nonsmoker males as controls. Retinal arteriosclerosis was graded according to the Scheie classification. Serum levels of lipids, lipoproteins, Lp(a), and Hcy were measured by standard methods. Results The serum level of Hcy was higher in patients (24.2±8.1 μmol/l) than controls (10.5±4.1 μmol/l); p<0.01. Serum levels of Lp(a) in patients (47.9±33.1 mg/dl) was also higher than controls (11.7±7.6 mg/dl); p<0.01. There was a significant direct linear correlation between the degree of retinal arteriosclerosis and Lp(a) level (r=0.61, p<0.01), the degree of retinal arteriosclerosis and Hcy level (r=0.72, p<0.01), and also between Lp(a) and Hcy levels (r=0.67, p<0.01). Conclusions The association between retinal arteriosclerosis and serum Lp(a) and Hcy levels suggests that Lp(a) as well as Hcy could play a role in the development of retinal arteriosclerosis. PMID:18806883

  3. Aging Changes in Retinal Microglia and their Relevance to Age-related Retinal Disease.

    PubMed

    Ma, Wenxin; Wong, Wai T

    2016-01-01

    Age-related retinal diseases, such as age-related macular degeneration (AMD) and glaucoma, contain features of chronic retinal inflammation that may promote disease progression. However, the relationship between aging and neuroinflammation is unclear. Microglia are long-lived, resident immune cells of the retina, and mediate local neuroinflammatory reactions. We hypothesize that aging changes in microglia may be causally linked to neuroinflammatory changes underlying age-dependent retinal diseases. Here, we review the evidence for (1) how the retinal microglial phenotype changes with aging, (2) the factors that drive microglial aging in the retina, and (3) aging-related changes in microglial gene expression. We examine how these aspects of microglial aging changes may relate to pathogenic mechanisms of immune dysregulation driving the progression of age-related retinal disease. These relationships can highlight microglial aging as a novel target for the prevention and treatment of retinal disease.

  4. Happy, healthy, and productive: the role of detachment from work during nonwork time.

    PubMed

    Fritz, Charlotte; Yankelevich, Maya; Zarubin, Anna; Barger, Patricia

    2010-09-01

    Mentally distancing oneself from work during nonwork time can help restore resources lost because of work demands. In this study, we examined possible outcomes of such psychological detachment from work, specifically well-being and job performance. Although employees may need to mentally detach from work to restore their well-being, high levels of detachment may require a longer time to get back into "working mode," which may be negatively associated with job performance. Our results indicate that higher levels of self-reported detachment were associated with higher levels of significant other-reported life satisfaction as well as lower levels of emotional exhaustion. In addition, we found curvilinear relationships between psychological detachment and coworker reported job performance (task performance and proactive behavior). Thus, although high psychological detachment may enhance employee well-being, it seems that medium levels of detachment are most beneficial for job performance.

  5. Retinoids for treatment of retinal diseases.

    PubMed

    Palczewski, Krzysztof

    2010-06-01

    Knowledge about retinal photoreceptor signal transduction and the visual cycle required for normal eyesight has increased exponentially over the past decade. Substantial progress in human genetics has facilitated the identification of candidate genes and complex networks underlying inherited retinal diseases. Natural mutations in animal models that mimic human diseases have been characterized and advanced genetic manipulation can now be used to generate small mammalian models of human retinal diseases. Pharmacological repair of defective visual processes in animal models not only validates their involvement in vision, but also provides great promise for the development of improved therapies for millions who are progressing towards blindness or are almost completely robbed of their eyesight.

  6. Retinoids for Treatment of Retinal Diseases

    PubMed Central

    Palczewski, Krzysztof

    2010-01-01

    Knowledge about retinal photoreceptor signal transduction and the visual cycle required for normal eyesight has expanded exponentially over the past decade. Substantial progress in human genetics has allowed identification of candidate genes and complex networks underlying inherited retinal diseases. Natural mutations in animal models that mimic human diseases have been characterized and advanced genetic manipulation now permits generation of small mammalian models of human retinal diseases. Pharmacological repair of defective visual processes in animal models not only validates their involvement in vision but also provides great promise for developing improved therapies for the millions that are progressing towards blindness or are almost completely robbed of eyesight. PMID:20435355

  7. Outer retinal abnormalities associated with inner retinal pathology in nonglaucomatous and glaucomatous optic neuropathies

    PubMed Central

    Werner, J S; Keltner, J L; Zawadzki, R J; Choi, S S

    2011-01-01

    Inner and outer retinal morphology were quantified in vivo for 6 nonglaucomatous and 10 glaucomatous optic neuropathy patients. Custom, ultrahigh-resolution imaging modalities were used to evaluate segmented retinal layer thickness in 3D volumes (Fourier-domain optical coherence tomography), cone photoreceptor density (adaptive optics fundus camera), and the length of inner and outer segments of cone photoreceptors (adaptive optics–optical coherence tomography). Quantitative comparisons were made with age-matched controls, or by comparing affected and nonaffected retinal areas defined by changes in visual fields. The integrity of outer retinal layers on optical coherence tomography B-scans and density of cone photoreceptors were correlated with visual field sensitivity at corresponding retinal locations following reductions in inner retinal thickness. The photoreceptor outer segments were shorter and exhibited greater variability in retinal areas associated with visual field losses compared with normal or less affected areas of the same patient's visual field. These results demonstrate that nonglaucomatous and glaucomatous optic neuropathies are associated with outer retinal changes following long-term inner retinal pathology. PMID:21293495

  8. Laminins and retinal vascular development.

    PubMed

    Edwards, Malia M; Lefebvre, Olivier

    2013-01-01

    The mechanisms controlling vascular development, both normal and pathological, are not yet fully understood. Many diseases, including cancer and diabetic retinopathy, involve abnormal blood vessel formation. Therefore, increasing knowledge of these mechanisms may help develop novel therapeutic targets. The identification of novel proteins or cells involved in this process would be particularly useful. The retina is an ideal model for studying vascular development because it is easy to access, particularly in rodents where this process occurs post-natally. Recent studies have suggested potential roles for laminin chains in vascular development of the retina. This review will provide an overview of these studies, demonstrating the importance of further research into the involvement of laminins in retinal blood vessel formation.

  9. Nanoparticles for Retinal Gene Therapy

    PubMed Central

    Conley, Shannon M.; Naash, Muna I.

    2010-01-01

    Ocular gene therapy is becoming a well-established field. Viral gene therapies for the treatment of Leber’s congentinal amaurosis (LCA) are in clinical trials, and many other gene therapy approaches are being rapidly developed for application to diverse ophthalmic pathologies. Of late, development of non-viral gene therapies has been an area of intense focus and one technology, polymer-compacted DNA nanoparticles, is especially promising. However, development of pharmaceutically and clinically viable therapeutics depends not only on having an effective and safe vector but also on a practical treatment strategy. Inherited retinal pathologies are caused by mutations in over 220 genes, some of which contain over 200 individual disease-causing mutations, which are individually very rare. This review will focus on both the progress and future of nanoparticles and also on what will be required to make them relevant ocular pharmaceutics. PMID:20452457

  10. Retinectomy vs vitrectomy combined with scleral buckling in repair of posterior segment open-globe injuries with retinal incarceration.

    PubMed

    Wei, Y; Zhou, R; Xu, K; Wang, J; Zu, Z

    2016-05-01

    PurposeTo evaluate the anatomic and functional outcome of pars plana vitrectomy (PPV) combined with scleral buckling (SB) vs retinectomy in treating posterior segment open-globe injuries with retinal incarceration.MethodsPatients (38 eyes) with posterior segment open-globe injuries and retinal incarceration were identified, and they underwent either PPV combined with SB (PPV+SB, n=19) or retinectomy (n=19). The two groups were matched in the following categories: the severity of injury (including wound length), the location of the incarceration site and the presence of retinal detachment. Anatomic reattachment of the retina and best-corrected visual acuity (BCVA) were measured at the time of 12 months after operation.ResultsAt 12 months after operation, the PPV+SB group demonstrated a better anatomic retinal attachment rate (84.2% vs 68.4%, P=0.252) and BCVA (73.7% vs 47.4%, P=0.247) compared with the retinectomy group, however, the differences failed to reach statistical significance. Compared with the PPV+SB group, the rectinectomy group had significantly higher rates of hemorrhage (47.4% vs 15.8%, P=0.036), inflammation (42.1% vs 10.5%, P=0.027), and a lower intraocular pressure (IOP, 9.8±3.1 vs 13.6±4.1 mmHg, P=0.002) after silicone oil (SO) removal.ConclusionsFor patients with posterior segment open-globe injuries and retinal incarceration, PPV and SB treatments resulted in a better anatomic and functional outcome and less post-operation complications compared with the retinectomy.

  11. Integration of retinal image sequences

    NASA Astrophysics Data System (ADS)

    Ballerini, Lucia

    1998-10-01

    In this paper a method for noise reduction in ocular fundus image sequences is described. The eye is the only part of the human body where the capillary network can be observed along with the arterial and venous circulation using a non invasive technique. The study of the retinal vessels is very important both for the study of the local pathology (retinal disease) and for the large amount of information it offers on systematic haemodynamics, such as hypertension, arteriosclerosis, and diabetes. In this paper a method for image integration of ocular fundus image sequences is described. The procedure can be divided in two step: registration and fusion. First we describe an automatic alignment algorithm for registration of ocular fundus images. In order to enhance vessel structures, we used a spatially oriented bank of filters designed to match the properties of the objects of interest. To evaluate interframe misalignment we adopted a fast cross-correlation algorithm. The performances of the alignment method have been estimated by simulating shifts between image pairs and by using a cross-validation approach. Then we propose a temporal integration technique of image sequences so as to compute enhanced pictures of the overall capillary network. Image registration is combined with image enhancement by fusing subsequent frames of a same region. To evaluate the attainable results, the signal-to-noise ratio was estimated before and after integration. Experimental results on synthetic images of vessel-like structures with different kind of Gaussian additive noise as well as on real fundus images are reported.

  12. Interfacial photochemistry of retinal proteins

    NASA Astrophysics Data System (ADS)

    Hong, Felix T.

    1999-09-01

    Retinal proteins are membrane-bound protein pigments that contain vitamin A aldehyde (retinal) as the chromophore. They include the visual pigment rhodopsin and four additional ones in the plasma membrane of Halobacterium salinarium (formerly Halobacterium halobium). These proteins maintain a fixed and asymmetric orientation in the membranes, and respond to a light stimulus by generating vectorial charge movement, which can be detected as an electric potential across the membrane or an electric current through the membrane. These phenomena are collectively called the photoelectric effects, which defy a rigorous quantitative treatment by means of either conventional (solution phase) photochemistry or conventional electrophysiology. As an alternative to the mainstream approach, we utilize the analytic tools of electrochemical surface science and electrophysiology to analyze two molecular models of light-induced charge separation and recombination. Being tutorial in nature, this article demands no prior knowledge about the subject. A parsimonious equivalent circuit model is developed. Data obtained from reconstituted bacteriorhodopsin membranes are used to validate the theoretical model and the analytical approach. Data generated and used by critics to refute our approach is shown to actually support it. The present analysis is sufficiently general to be applicable to other pigment-containing membranes, such as the visual photoreceptor membrane and the chlorophyll-based photosynthetic membranes. It provides a coherent description of a wide range of light-induced phenomena associated with various pigment-containing membranes. In contrast, the mainstream approach has been plagued with self-contradictions and paradoxes. Last, but not least, the alternative bioelectrochemical approach also exhibits a predictive power that has hitherto been generally lacking. Comparison of the photoelectric effects is made with regard to bacteriorhodopsin, rhodopsin, and the chlorophyll

  13. Photodiode circuits for retinal prostheses.

    PubMed

    Loudin, J D; Cogan, S F; Mathieson, K; Sher, A; Palanker, D V

    2011-10-01

    Photodiode circuits show promise for the development of high-resolution retinal prostheses. While several of these systems have been constructed and some even implanted in humans, existing descriptions of the complex optoelectronic interaction between light, photodiode, and the electrode/electrolyte load are limited. This study examines this interaction in depth with theoretical calculations and experimental measurements. Actively biased photoconductive and passive photovoltaic circuits are investigated, with the photovoltaic circuits consisting of one or more diodes connected in series, and the photoconductive circuits consisting of a single diode in series with a pulsed bias voltage. Circuit behavior and charge injection levels were markedly different for platinum and sputtered iridium-oxide film (SIROF) electrodes. Photovoltaic circuits were able to deliver 0.038 mC/cm(2) (0.75 nC/phase) per photodiode with 50- μm platinum electrodes, and 0.54-mC/cm(2) (11 nC/phase) per photodiode with 50-μ m SIROF electrodes driven with 0.5-ms pulses of light at 25 Hz. The same pulses applied to photoconductive circuits with the same electrodes were able to deliver charge injections as high as 0.38 and 7.6 mC/cm(2) (7.5 and 150 nC/phase), respectively. We demonstrate photovoltaic stimulation of rabbit retina in-vitro, with 0.5-ms pulses of 905-nm light using peak irradiance of 1 mW/mm(2). Based on the experimental data, we derive electrochemical and optical safety limits for pixel density and charge injection in various circuits. While photoconductive circuits offer smaller pixels, photovoltaic systems do not require an external bias voltage. Both classes of circuits show promise for the development of high-resolution optoelectronic retinal prostheses.

  14. Retinal fractals and acute lacunar stroke.

    PubMed

    Cheung, Ning; Liew, Gerald; Lindley, Richard I; Liu, Erica Y; Wang, Jie Jin; Hand, Peter; Baker, Michelle; Mitchell, Paul; Wong, Tien Y

    2010-07-01

    This study aimed to determine whether retinal fractal dimension, a quantitative measure of microvascular branching complexity and density, is associated with lacunar stroke. A total of 392 patients presenting with acute ischemic stroke had retinal fractal dimension measured from digital photographs, and lacunar infarct ascertained from brain imaging. After adjusting for age, gender, and vascular risk factors, higher retinal fractal dimension (highest vs lowest quartile and per standard deviation increase) was independently and positively associated with lacunar stroke (odds ratio [OR], 4.27; 95% confidence interval [CI], 1.49-12.17 and OR, 1.85; 95% CI, 1.20-2.84, respectively). Increased retinal microvascular complexity and density is associated with lacunar stroke.

  15. Photoreceptor waveguides and effective retinal image quality

    NASA Astrophysics Data System (ADS)

    Vohnsen, Brian

    2007-03-01

    Individual photoreceptor waveguiding suggests that the entire retina can be considered as a composite fiber-optic element relating a retinal image to a corresponding waveguided image. In such a scheme, a visual sensation is produced only when the latter interacts with the pigments of the outer photoreceptor segments. Here the possible consequences of photoreceptor waveguiding on vision are studied with important implications for the pupil-apodization method commonly used to incorporate directional effects of the retina. In the absence of aberrations, it is found that the two approaches give identical predictions for an effective retinal image only when the pupil apodization is chosen twice as narrow as suggested by the traditional Stiles-Crawford effect. In addition, phase variations in the retinal field due to ocular aberrations can delicately alter a waveguided image, and this may provide plausible justification for an improved visual sensation as compared with what should be expected on the grounds of a retinal image only.

  16. Regulatory and Economic Considerations of Retinal Drugs.

    PubMed

    Shah, Ankoor R; Williams, George A

    2016-01-01

    The advent of anti-VEGF therapy for neovascular age-related macular degeneration and macular edema secondary to retinal vein occlusion and diabetes mellitus has prevented blindness in tens of thousands of people. However, the costs of these drugs are without precedent in ophthalmic drug therapeutics. An analysis of the financial implications of retinal drugs and the impact of the Food and Drug Administration on treatment of retinal disease must include not only an evaluation of the direct costs of the drugs and the costs associated with their administration, but also the cost savings which accrue from their clinical benefit. This chapter will discuss the financial and regulatory issues associated with retinal drugs.

  17. Screening Diabetic Retinopathy Through Color Retinal Images

    NASA Astrophysics Data System (ADS)

    Li, Qin; Jin, Xue-Min; Gao, Quan-Xue; You, Jane; Bhattacharya, Prabir

    Diabetic Retinopathy (DR) is a common complication of diabetes that damages the eye's retina. Recognition DR as early as possible is very important to protect patients' vision. We propose a method for screening DR and distin-guishing Prolifetive Diabetic Retinopathy (PDR) from Non-Prolifetive Retino-pathy (NPDR) automatatically through color retinal images. This method evaluates the severity of DR by analyzing the appearnce of bright lesions and retinal vessel patterns. The bright lesions are extracted through morphlogical re-consturction. After that, the retinal vessels are automatically extracted using multiscale matched filters. Then the vessel patterns are analyzed by extracting the vessel net density. The experimental results domonstrate that it is a effective solution to screen DR and distinguish PDR from NPDR by only using color retinal images.

  18. [Retinal vein occlusion in a young patient].

    PubMed

    Zemba, Mihail; Ochinciuc, Uliana; Sarbu, Laura; Avram, Corina; Camburu, Raluca; Stamate, Alina

    2013-01-01

    We present a case report of a 27 years old pacient with central retinal vein occlussion and macular edema. The pacient has a significant reduction of the macular aedema with complete recovery of vision after the treatment.

  19. Digital Tracking and Control of Retinal Images

    DTIC Science & Technology

    1993-05-01

    Diseases .............. 18 2.2.1 Diabetic Retinopathy ....... ...................... 18 2.2.2 Macular Degeneration ............................ 20 2.2.3...retinal diseases includ- ing diabetic retinopathy, macular degeneration , and retinal breaks and tears. During treatment for these diseases an argon...photocoagulated [211. 2.2.2 Macular Degeneration Macular degeneration is also called senile macular degeneration because it is most common in the elderly

  20. Retinal vascular caliber and risk of dementia

    PubMed Central

    de Jong, F.J.; Schrijvers, E.M.C.; Ikram, M.K.; Koudstaal, P.J.; de Jong, P.T.V.M.; Hofman, A.; Vingerling, J.R.

    2011-01-01

    Background: Retinal vessels provide a unique opportunity to study both systemic and cerebrovascular disease. Smaller retinal arteriolar calibers are strongly related to hypertension, whereas larger retinal venular calibers are more related to inflammation, cerebral hypoperfusion, and cerebrovascular disease. Whether retinal vessel calibers are related to dementia remains unclear. Methods: We investigated whether retinal arteriolar and venular calibers are associated with risk of dementia, and its subtypes Alzheimer disease (AD) and vascular dementia, in the prospective population-based Rotterdam Study. Digitized retinal images were available in 5,553 participants aged 55 years or over and dementia-free at baseline (1990–1993). Participants were re-examined in 1993–1994, 1997–1999, and 2002–2004 and were continuously monitored for development of dementia. Results: During a mean follow-up of 11.6 years, 655 participants developed dementia. AD was diagnosed in 519 and vascular dementia in 73 participants. Larger venular calibers were associated with an increased risk of dementia, in particular vascular dementia (age- and sex-adjusted hazard ratio per SD increase: 1.31; 95% confidence interval 1.06–1.64), but not AD. The association remained significant after adjustment for stroke and cardiovascular risk factors. Smaller arteriolar calibers were also associated with an increased risk of vascular dementia, yet only when adjusted for venular calibers. Conclusions: Retinal venular widening is associated with an increased risk of vascular dementia. Our findings are in line with previous observations in stroke and cerebral small-vessel disease and suggest that the association between larger retinal venular calibers and dementia may reflect cerebral hypoperfusion and subsequent ischemia. PMID:21288987

  1. Notch Signaling Functions in Retinal Pericyte Survival

    PubMed Central

    Arboleda-Velasquez, Joseph F.; Primo, Vincent; Graham, Mark; James, Alexandra; Manent, Jan; D'Amore, Patricia A.

    2014-01-01

    Purpose. Pericytes, the vascular cells that constitute the outer layer of capillaries, have been shown to have a crucial role in vascular development and stability. Loss of pericytes precedes endothelial cell dysfunction and vascular degeneration in small-vessel diseases, including diabetic retinopathy. Despite their clinical relevance, the cellular pathways controlling survival of retinal pericytes remain largely uncharacterized. Therefore, we investigated the role of Notch signaling, a master regulator of cell fate decisions, in retinal pericyte survival. Methods. A coculture system of ligand-dependent Notch signaling was developed using primary cultured retinal pericytes and a mesenchymal cell line derived from an inducible mouse model expressing the Delta-like 1 Notch ligand. This model was used to examine the effect of Notch activity on pericyte survival using quantitative PCR (qPCR) and a light-induced cell death assay. The effect of Notch gain- and loss-of-function was analyzed in monocultures of retinal pericytes using antibody arrays to interrogate the expression of apoptosis-related proteins. Results. Primary cultured retinal pericytes differentially expressed key molecules of the Notch pathway and displayed strong expression of canonical Notch/RBPJK (recombination signal-binding protein 1 for J-kappa) downstream targets. A gene expression screen using gain- and loss-of-function approaches identified genes relevant to cell survival as downstream targets of Notch activity in retinal pericytes. Ligand-mediated Notch activity protected retinal pericytes from light-induced cell death. Conclusions. Our results have identified signature genes downstream of Notch activity in retinal pericytes and suggest that tight regulation of Notch signaling is crucial for pericyte survival. PMID:25015359

  2. Programming Retinal Stem Cells into Cone Photoreceptors

    DTIC Science & Technology

    2015-12-01

    to program human stem cells directly into cones. Using RNA -seq, we identified several genes that are upregulated in advance of the earliest...reverse vision loss. 15. SUBJECT TERMS Cone photoreceptor, retina, retinal stem cell, Otx2, Onecut1, Blimp1, RNA -seq., transcription factors, and...1 Keywords: 1. Cone photoreceptor 2. Retina 3. Retinal stem cell 4. Otx2 5. Onecut1 6. Blimp1 7. RNA -seq. 8. Transcription factors 9

  3. Transillumination enhances photographs of retinal hemorrhages.

    PubMed

    Nolte, K B

    1997-09-01

    Light stand photography with direct illumination of the retina is a common method of demonstrating retinal hemorrhages. The lack of contrast between dark hemorrhages and surrounding dark retina, and the difficulty of photographing into the concavity of an eye limit this technique. Transillumination of a bivalved globe with a bright external light source such as a colonoscope or microscope light yields high contrast superior photographs. This technique is useful to document retinal hemorrhages, and provides quality photographs for courtroom demonstrations.

  4. Retinal vessel oximetry: toward absolute calibration

    NASA Astrophysics Data System (ADS)

    Smith, Matthew H.; Denninghoff, Kurt R.; Lompado, Arthur; Hillman, Lloyd W.

    2000-06-01

    Accurately measuring the oxygen saturation of blood within retinal arteries and veins has proven to be a deceptively difficult task. Despite the excellent optical accessibility of the vessels and a wide range of reported instrumentation, we are unaware of any measurement technique that has proven to be calibrated across wide ranges of vessel diameter and fundus pigmentation. We present an overview of our retinal oximetry technique, present the results of an in vitro calibration experiment, and present preliminary human data.

  5. Stem cell-based therapeutic applications in retinal degenerative diseases

    PubMed Central

    Huang, Yiming; Enzmann, Volker; Ildstad, Suzanne T.

    2012-01-01

    Retinal degenerative diseases that target photoreceptors or the adjacent retinal pigment epithelium (RPE) affect millions of people worldwide. Retinal degeneration (RD) is found in many different forms of retinal diseases including retinitis pigmentosa (RP), age-related macular degeneration (AMD), diabetic retinopathy, cataracts, and glaucoma. Effective treatment for retinal degeneration has been widely investigated. Gene-replacement therapy has been shown to improve visual function in inherited retinal disease. However, this treatment was less effective with advanced disease. Stem cell-based therapy is being pursued as a potential alternative approach in the treatment of retinal degenerative diseases. In this review, we will focus on stem cell-based therapies in the pipeline and summarize progress in treatment of retinal degenerative disease. PMID:20859770

  6. Photoreceptor Cells Influence Retinal Vascular Degeneration in Mouse Models of Retinal Degeneration and Diabetes

    PubMed Central

    Liu, Haitao; Tang, Jie; Du, Yunpeng; Saadane, Aicha; Tonade, Deoye; Samuels, Ivy; Veenstra, Alex; Palczewski, Krzysztof; Kern, Timothy S.

    2016-01-01

    Purpose Loss of photoreceptor cells is associated with retinal vascular degeneration in retinitis pigmentosa, whereas the presence of photoreceptor cells is implicated in vascular degeneration in diabetic retinopathy. To investigate how both the absence and presence of photoreceptors could damage the retinal vasculature, we compared two mouse models of photoreceptor degeneration (opsin−/− and RhoP23H/P23H ) and control C57Bl/5J mice, each with and without diabetes. Methods Retinal thickness, superoxide, expression of inflammatory proteins, ERG and optokinetic responses, leukocyte cytotoxicity, and capillary degeneration were evaluated at 1 to 10 months of age using published methods. Results Retinal photoreceptor cells degenerated completely in the opsin mutants by 2 to 4 months of age, and visual function subsided correspondingly. Retinal capillary degeneration was substantial while photoreceptors were still present, but slowed after the photoreceptors degenerated. Diabetes did not further exacerbate capillary degeneration in these models of photoreceptor degeneration, but did cause capillary degeneration in wild-type animals. Photoreceptor cells, however, did not degenerate in wild-type diabetic mice, presumably because the stress responses in these cells were less than in the opsin mutants. Retinal superoxide and leukocyte damage to retinal endothelium contributed to the degeneration of retinal capillaries in diabetes, and leukocyte-mediated damage was increased in both opsin mutants during photoreceptor cell degeneration. Conclusions Photoreceptor cells affect the integrity of the retinal microvasculature. Deterioration of retinal capillaries in opsin mutants was appreciable while photoreceptor cells were present and stressed, but was less after photoreceptors degenerated. This finding proves relevant to diabetes, where persistent stress in photoreceptors likewise contributes to capillary degeneration. PMID:27548901

  7. The role of partners and children for employees' psychological detachment from work and well-being.

    PubMed

    Hahn, Verena C; Dormann, Christian

    2013-01-01

    This study examined the role of partners and children for employees' psychological detachment from work during off-job time. Building on boundary theory, we hypothesized that not only employees' own work-home segmentation preference but also their partners' work-home segmentation preference is associated with employees' psychological detachment. In addition, partners' psychological detachment should influence employees' psychological detachment. We hypothesized that the presence of children in the household moderates partners' influence on employees' psychological detachment. Further, we expected both employees' and their partners' psychological detachment to contribute to employees' well-being. Participants were 114 dual-earner couples who responded to Web-based questionnaires. The hypotheses were tested with multilevel analyses, using the actor-partner interdependence model. Results confirmed our hypotheses. Employees' and their partners' work-home segmentation preferences were associated with employees' psychological detachment. The presence of children moderated the relation between partners' work-home segmentation preference and employees' psychological detachment. The relation was weaker when there were children in the household. Moreover, employees' and their partners' psychological detachment were positively associated. Again, the relation was weaker when there were children in the household. Finally, both employees' and their partners' psychological detachment contributed to employees' well-being.

  8. Slab detachment under the Eastern Alps seen by seismic anisotropy

    PubMed Central

    Qorbani, Ehsan; Bianchi, Irene; Bokelmann, Götz

    2015-01-01

    We analyze seismic anisotropy for the Eastern Alpine region by inspecting shear-wave splitting from SKS and SKKS phases. The Eastern Alpine region is characterized by a breakdown of the clear mountain-chain-parallel fast orientation pattern that has been previously documented for the Western Alps and for the western part of the Eastern Alps. The main interest of this paper is a more detailed analysis of the anisotropic character of the Eastern Alps, and the transition to the Carpathian–Pannonian region. SK(K)S splitting measurements reveal a rather remarkable lateral change in the anisotropy pattern from the west to the east of the Eastern Alps with a transition area at about 12°E. We also model the backazimuthal variation of the measurements by a vertical change of anisotropy. We find that the eastern part of the study area is characterized by the presence of two layers of anisotropy, where the deeper layer has characteristics similar to those of the Central Alps, in particular SW–NE fast orientations of anisotropic axes. We attribute the deeper layer to a detached slab from the European plate. Comparison with tomographic studies of the area indicates that the detached slab might possibly connect with the lithosphere that is still in place to the west of our study area, and may also connect with the slab graveyard to the East, at the depth of the upper mantle transition zone. On the other hand, the upper layer has NW–SE fast orientations coinciding with a low-velocity layer which is found above a more-or-less eastward dipping high-velocity body. The anisotropy of the upper layer shows large-scale NW–SE fast orientation, which is consistent with the presence of asthenospheric flow above the detached slab foundering into the deeper mantle. PMID:25843968

  9. Staphylococcal Adhesion, Detachment and Transmission on Nanopillared Si Surfaces.

    PubMed

    Hizal, Ferdi; Choi, Chang-Hwan; Busscher, Henk J; van der Mei, Henny C

    2016-11-09

    Nanostructured surfaces are extensively considered with respect to their potential impact on bacterial adhesion from aqueous suspensions or air, but in real-life bacteria are often transmitted between surfaces. Mechanistically, transmission involves detachment of adhering bacteria from a donor and adhesion to a receiver surface, controlled by the relative values of the adhesion forces exerted by both surfaces. We here relate staphylococcal adhesion, detachment and transmission to, from, and between smooth and nanopillared-Si surfaces with staphylococcal adhesion forces. Nanopillared-Si surfaces were prepared with pillar-to-pillar distances of 200, 400, and 800 nm. On smooth surfaces, staphylococcal adhesion forces, measured using bacterial-probe Atomic-Force-Microscopy, amounted to 4.4-6.8 and 1.8-2.1 nN (depending on the AFM-loading force) for extracellular-polymeric-substances (EPS) producing and non-EPS producing strains, respectively. Accordingly the EPS producing strain adhered in higher numbers than the non-EPS producing strain. Fractional adhesion forces on nanopillared-Si surfaces relative to the smooth surface ranged from 0.30 to 0.95, depending on AFM-loading force, strain and pillar-to-pillar distance. However, for each strain, the number of adhering bacteria remained similar on all nanopillared surfaces. Detachment of adhering staphylococci decreased significantly with increasing adhesion forces, while staphylococcal transmission to a receiver surface also decreased with increasing adhesion force exerted by the donor. In addition, the strain with ability to produce EPS was killed in high percentages and induced to produce EPS during transmission on nanopillared-Si surfaces, presumably by high local cell-wall stresses. This must be accounted for in applications of nanostructured surfaces: whereas killing may be favorable, EPS production may reduce antimicrobial efficacy.

  10. Slab detachment under the Eastern Alps seen by seismic anisotropy

    NASA Astrophysics Data System (ADS)

    Qorbani, Ehsan; Bianchi, Irene; Bokelmann, Götz

    2015-01-01

    We analyze seismic anisotropy for the Eastern Alpine region by inspecting shear-wave splitting from SKS and SKKS phases. The Eastern Alpine region is characterized by a breakdown of the clear mountain-chain-parallel fast orientation pattern that has been previously documented for the Western Alps and for the western part of the Eastern Alps. The main interest of this paper is a more detailed analysis of the anisotropic character of the Eastern Alps, and the transition to the Carpathian-Pannonian region. SK(K)S splitting measurements reveal a rather remarkable lateral change in the anisotropy pattern from the west to the east of the Eastern Alps with a transition area at about 12°E. We also model the backazimuthal variation of the measurements by a vertical change of anisotropy. We find that the eastern part of the study area is characterized by the presence of two layers of anisotropy, where the deeper layer has characteristics similar to those of the Central Alps, in particular SW-NE fast orientations of anisotropic axes. We attribute the deeper layer to a detached slab from the European plate. Comparison with tomographic studies of the area indicates that the detached slab might possibly connect with the lithosphere that is still in place to the west of our study area, and may also connect with the slab graveyard to the East, at the depth of the upper mantle transition zone. On the other hand, the upper layer has NW-SE fast orientations coinciding with a low-velocity layer which is found above a more-or-less eastward dipping high-velocity body. The anisotropy of the upper layer shows large-scale NW-SE fast orientation, which is consistent with the presence of asthenospheric flow above the detached slab foundering into the deeper mantle.

  11. Slab Detachment Under the Eastern Alps Seen By Seismic Anisotropy

    NASA Astrophysics Data System (ADS)

    Qorbani, E.; Bianchi, I.; Bokelmann, G.

    2014-12-01

    We analyze seismic anisotropy for the Eastern Alpine region by inspecting shear-wave splitting from SKS and SKKS phases. The Eastern Alpine region is characterized by a breakdown of the clear mountain-chain-parallel fast orientation pattern that has been previously documented for the Western Alps and for the western part of the Eastern Alps. The main interest of this paper is a more detailed analysis of the anisotropic character of the Eastern Alps, and the transition to the Carpathian-Pannonian region. SK(K)S splitting measurements reveal a rather remarkable lateral change in the anisotropy pattern from the west to the east of the Eastern Alps with a transition area at about 12°E. We also model the backazimuthal variation of the measurements by a vertical change of anisotropy. We find that the eastern part of the study area is characterized by the presence of two layers of anisotropy, where the deeper layer has characteristics similar to those of the Central Alps, in particular SW-NE fast orientations of anisotropic axes. We attribute the deeper layer to a detached slab from the European plate. Comparison with tomographic studies of the area indicates that the detached slab might possibly connect with the lithosphere that is still in place to the west of our study area, and may also connect with the slab graveyard to the East, at the depth of the upper mantle transition zone. On the other hand, the upper layer has NW-SE fast orientations coinciding with a low-velocity layer which is found above a more-or-less eastward dipping high-velocity body. The anisotropy of the upper layer shows large-scale NW-SE fast orientation, which is consistent with the presence of asthenospheric flow above the detached slab foundering into the deeper mantle.

  12. Slab detachment under the Eastern Alps seen by seismic anisotropy

    NASA Astrophysics Data System (ADS)

    Qorbani, Ehsan; Bianchi, Irene; Bokelmann, Götz

    2015-04-01

    We analyze seismic anisotropy for the Eastern Alpine region by inspecting shear-wave splitting from SKS and SKKS phases. The Eastern Alpine region is characterized by a breakdown of the clear mountain-chain-parallel fast orientation pattern that has been previously documented for the Western Alps and for the western part of the Eastern Alps. The main interest of this paper is a more detailed analysis of the anisotropic character of the Eastern Alps, and the transition to the Carpathian-Pannonian region. SK(K)S splitting measurements reveal a rather remarkable lateral change in the anisotropy pattern from the west to the east of the Eastern Alps with a transition area at about 12°E. We also model the backazimuthal variation of the measurements by a vertical change of anisotropy. We find that the eastern part of the study area is characterized by the presence of two layers of anisotropy, where the deeper layer has characteristics similar to those of the Central Alps, in particular SW-NE fast orientations of anisotropic axes. We attribute the deeper layer to a detached slab from the European plate. Comparison with tomographic studies of the area indicates that the detached slab might possibly connect with the lithosphere that is still in place to the west of our study area, and may also connect with the slab graveyard to the East, at the depth of the upper mantle transition zone. On the other hand, the upper layer has NW-SE fast orientations coinciding with a low-velocity layer which is found above a more-or-less eastward dipping high-velocity body. The anisotropy of the upper layer shows large-scale NW-SE fast orientation, which is consistent with the presence of asthenospheric flow above the detached slab foundering into the deeper mantle.

  13. Choroidal detachment in perforated corneal ulcers: frequency and management

    PubMed Central

    Singh, R; Umapathy, T; Abedin, A; Eatamadi, H; Maharajan, S; Dua, H S

    2006-01-01

    Aims To determine the frequency of choroidal detachment (CD) in eyes with non‐traumatic corneal ulcer perforation and, also, to assess the efficacy and safety of cyanoacrylate glue in sealing corneal perforations. Methods 18 eyes of 17 patients were studied. Inclusion criterion was any patient with a non‐traumatic perforated corneal ulcer. All patients had a thorough history taken and complete ophthalmic examination including B‐scan ultrasonography. Patient demographics, presence of CD, and efficacy of corneal gluing were assessed. Results Eight of the 18 eyes (44%) were documented to have a CD. Among perforations of >2 mm2, six eyes (75%) were documented to have CD compared with two eyes (20%) with perforations of ⩽2 mm2 (p = 0.054). No correlation could be determined between perforation duration and incidence of CD. Of the 15 eyes that underwent gluing, there were 13 successes (87%) and two failures (13%). Within the successes four patients (27%) required re‐gluing because of infection (one patient) or progression of melt and glue loosening (three patients). Failure was the result of severe progression of melting (one patient) and a very large perforation (one patient). Conclusion Choroidal detachment following corneal ulcer perforation is common and is more likely in larger corneal perforations. Preoperative B‐scan should be considered in cases of large corneal perforations requiring therapeutic keratoplasty to document choroidal detachment, which if large may require drainage. Cyanoacrylate glue is an effective and safe method for sealing small corneal perforations. A vigil must be maintained for infection while the glue and bandage contact lens are in situ. PMID:16723362

  14. Slab detachment under the Eastern Alps seen by seismic anisotropy.

    PubMed

    Qorbani, Ehsan; Bianchi, Irene; Bokelmann, Götz

    2015-01-01

    We analyze seismic anisotropy for the Eastern Alpine region by inspecting shear-wave splitting from SKS and SKKS phases. The Eastern Alpine region is characterized by a breakdown of the clear mountain-chain-parallel fast orientation pattern that has been previously documented for the Western Alps and for the western part of the Eastern Alps. The main interest of this paper is a more detailed analysis of the anisotropic character of the Eastern Alps, and the transition to the Carpathian-Pannonian region. SK(K)S splitting measurements reveal a rather remarkable lateral change in the anisotropy pattern from the west to the east of the Eastern Alps with a transition area at about 12°E. We also model the backazimuthal variation of the measurements by a vertical change of anisotropy. We find that the eastern part of the study area is characterized by the presence of two layers of anisotropy, where the deeper layer has characteristics similar to those of the Central Alps, in particular SW-NE fast orientations of anisotropic axes. We attribute the deeper layer to a detached slab from the European plate. Comparison with tomographic studies of the area indicates that the detached slab might possibly connect with the lithosphere that is still in place to the west of our study area, and may also connect with the slab graveyard to the East, at the depth of the upper mantle transition zone. On the other hand, the upper layer has NW-SE fast orientations coinciding with a low-velocity layer which is found above a more-or-less eastward dipping high-velocity body. The anisotropy of the upper layer shows large-scale NW-SE fast orientation, which is consistent with the presence of asthenospheric flow above the detached slab foundering into the deeper mantle.

  15. Retinal imaging using adaptive optics technology☆

    PubMed Central

    Kozak, Igor

    2014-01-01

    Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effect of wave front distortions. Retinal imaging using AO aims to compensate for higher order aberrations originating from the cornea and the lens by using deformable mirror. The main application of AO retinal imaging has been to assess photoreceptor cell density, spacing, and mosaic regularity in normal and diseased eyes. Apart from photoreceptors, the retinal pigment epithelium, retinal nerve fiber layer, retinal vessel wall and lamina cribrosa can also be visualized with AO technology. Recent interest in AO technology in eye research has resulted in growing number of reports and publications utilizing this technology in both animals and humans. With the availability of first commercially available instruments we are making transformation of AO technology from a research tool to diagnostic instrument. The current challenges include imaging eyes with less than perfect optical media, formation of normative databases for acquired images such as cone mosaics, and the cost of the technology. The opportunities for AO will include more detailed diagnosis with description of some new findings in retinal diseases and glaucoma as well as expansion of AO into clinical trials which has already started. PMID:24843304

  16. Retinal remodeling triggered by photoreceptor degenerations.

    PubMed

    Jones, Bryan W; Watt, Carl B; Frederick, Jeanne M; Baehr, Wolfgang; Chen, Ching-Kang; Levine, Edward M; Milam, Ann H; Lavail, Matthew M; Marc, Robert E

    2003-09-08

    Many photoreceptor degenerations initially affect rods, secondarily leading to cone death. It has long been assumed that the surviving neural retina is largely resistant to this sensory deafferentation. New evidence from fast retinal degenerations reveals that subtle plasticities in neuronal form and connectivity emerge early in disease. By screening mature natural, transgenic, and knockout retinal degeneration models with computational molecular phenotyping, we have found an extended late phase of negative remodeling that radically changes retinal structure. Three major transformations emerge: 1) Müller cell hypertrophy and elaboration of a distal glial seal between retina and the choroid/retinal pigmented epithelium; 2) apparent neuronal migration along glial surfaces to ectopic sites; and 3) rewiring through evolution of complex neurite fascicles, new synaptic foci in the remnant inner nuclear layer, and new connections throughout the retina. Although some neurons die, survivors express molecular signatures characteristic of normal bipolar, amacrine, and ganglion cells. Remodeling in human and rodent retinas is independent of the initial molecular targets of retinal degenerations, including defects in the retinal pigmented epithelium, rhodopsin, or downstream phototransduction elements. Although remodeling may constrain therapeutic intervals for molecular, cellular, or bionic rescue, it suggests that the neural retina may be more plastic than previously believed.

  17. Retinal iron homeostasis in health and disease

    PubMed Central

    Song, Delu; Dunaief, Joshua L.

    2013-01-01

    Iron is essential for life, but excess iron can be toxic. As a potent free radical creator, iron generates hydroxyl radicals leading to significant oxidative stress. Since iron is not excreted from the body, it accumulates with age in tissues, including the retina, predisposing to age-related oxidative insult. Both hereditary and acquired retinal diseases are associated with increased iron levels. For example, retinal degenerations have been found in hereditary iron overload disorders, like aceruloplasminemia, Friedreich's ataxia, and pantothenate kinase-associated neurodegeneration. Similarly, mice with targeted mutation of the iron exporter ceruloplasmin and its homolog hephaestin showed age-related retinal iron accumulation and retinal degeneration with features resembling human age-related macular degeneration (AMD). Post mortem AMD eyes have increased levels of iron in retina compared to age-matched healthy donors. Iron accumulation in AMD is likely to result, in part, from inflammation, hypoxia, and oxidative stress, all of which can cause iron dysregulation. Fortunately, it has been demonstrated by in vitro and in vivo studies that iron in the retinal pigment epithelium (RPE) and retina is chelatable. Iron chelation protects photoreceptors and retinal pigment epithelial cells (RPE) in a variety of mouse models. This has therapeutic potential for diminishing iron-induced oxidative damage to prevent or treat AMD. PMID:23825457

  18. Retinal synaptic regeneration via microfluidic guiding channels

    PubMed Central

    Su, Ping-Jung; Liu, Zongbin; Zhang, Kai; Han, Xin; Saito, Yuki; Xia, Xiaojun; Yokoi, Kenji; Shen, Haifa; Qin, Lidong

    2015-01-01

    In vitro culture of dissociated retinal neurons is an important model for investigating retinal synaptic regeneration (RSR) and exploring potentials in artificial retina. Here, retinal precursor cells were cultured in a microfluidic chip with multiple arrays of microchannels in order to reconstruct the retinal neuronal synapse. The cultured retinal cells were physically connected through microchannels. Activation of electric signal transduction by the cells through the microchannels was demonstrated by administration of glycinergic factors. In addition, an image-based analytical method was used to quantify the synaptic connections and to assess the kinetics of synaptic regeneration. The rate of RSR decreased significantly below 100 μM of inhibitor glycine and then approached to a relatively constant level at higher concentrations. Furthermore, RSR was enhanced by chemical stimulation with potassium chloride. Collectively, the microfluidic synaptic regeneration chip provides a novel tool for high-throughput investigation of RSR at the cellular level and may be useful in quality control of retinal precursor cell transplantation. PMID:26314276

  19. Retinal imaging using adaptive optics technology.

    PubMed

    Kozak, Igor

    2014-04-01

    Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effect of wave front distortions. Retinal imaging using AO aims to compensate for higher order aberrations originating from the cornea and the lens by using deformable mirror. The main application of AO retinal imaging has been to assess photoreceptor cell density, spacing, and mosaic regularity in normal and diseased eyes. Apart from photoreceptors, the retinal pigment epithelium, retinal nerve fiber layer, retinal vessel wall and lamina cribrosa can also be visualized with AO technology. Recent interest in AO technology in eye research has resulted in growing number of reports and publications utilizing this technology in both animals and humans. With the availability of first commercially available instruments we are making transformation of AO technology from a research tool to diagnostic instrument. The current challenges include imaging eyes with less than perfect optical media, formation of normative databases for acquired images such as cone mosaics, and the cost of the technology. The opportunities for AO will include more detailed diagnosis with description of some new findings in retinal diseases and glaucoma as well as expansion of AO into clinical trials which has already started.

  20. [Gene therapy for inherited retinal dystrophies].

    PubMed

    Côco, Monique; Han, Sang Won; Sallum, Juliana Maria Ferraz

    2009-01-01

    The inherited retinal dystrophies comprise a large number of disorders characterized by a slow and progressive retinal degeneration. They are the result of mutations in genes that express in either the photoreceptor cells or the retinal pigment epithelium. The mode of inheritance can be autosomal dominant, autosomal recessive, X linked recessive, digenic or mitochondrial DNA inherited. At the moment, there is no treatment for these conditions and the patients can expect a progressive loss of vision. Accurate genetic counseling and support for rehabilitation are indicated. Research into the molecular and genetic basis of disease is continually expanding and improving the prospects for rational treatments. In this way, gene therapy, defined as the introduction of exogenous genetic material into human cells for therapeutic purposes, may ultimately offer the greatest treatment for the inherited retinal dystrophies. The eye is an attractive target for gene therapy because of its accessibility, immune privilege and translucent media. A number of retinal diseases affecting the eye have known gene defects. Besides, there is a well characterized animal model for many of these conditions. Proposals for clinical trials of gene therapy for inherited retinal degenerations owing to defects in the gene RPE65, have recently received ethical approval and the obtained preliminary results brought large prospects in the improvement on patient's quality of life.