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Sample records for normal ocular fundus

  1. Ocular Fundus Photography as an Educational Tool.

    PubMed

    Mackay, Devin D; Garza, Philip S

    2015-10-01

    The proficiency of nonophthalmologists with direct ophthalmoscopy is poor, which has prompted a search for alternative technologies to examine the ocular fundus. Although ocular fundus photography has existed for decades, its use has been traditionally restricted to ophthalmology clinical care settings and textbooks. Recent research has shown a role for nonmydriatic fundus photography in nonophthalmic settings, encouraging more widespread adoption of fundus photography technology. Recent studies have also affirmed the role of fundus photography as an adjunct or alternative to direct ophthalmoscopy in undergraduate medical education. In this review, the authors examine the use of ocular fundus photography as an educational tool and suggest future applications for this important technology. Novel applications of fundus photography as an educational tool have the potential to resurrect the dying art of funduscopy. PMID:26444395

  2. [The application of industrial endoscope to observation of the ocular-fundus in small laboratory animals].

    PubMed

    Kiyosawa, I; Aruga, N; Kawakubo, M; Naito, J; Saito, T R; Takahashi, K W

    1992-01-01

    Observation and recording methods of the ocular-fundus in small laboratory animals were studied using the industrial endoscope and VTR systems, respectively. The ocular-fundus was observed widely, brightly and clearly in the usual animal facility. In addition, the ocular-fundus was recorded easily and it was possible to examine the ocular-fundus recorded by the VTR systems. PMID:1740168

  3. Effect of small head tilt on ocular fundus image: Consideration of proper head positioning for ocular fundus scanning.

    PubMed

    Park, Shin Hae; Kang, Nam Yeo; Kim, Jihyun; Baek, Jiwon; Hong, Seung Woo

    2016-08-01

    Head tilt and resultant ocular cyclotorsion can influence the results of ophthalmologic examinations. Thus, proper head positioning during fundus scanning has been emphasized. However, there is no perfect method to control the head tilt and little is known about the effect of small head tilts. In this study, we investigated the effect of minimal head tilt on the ocular cyclotorsion which we cannot easily detect.Forty-seven participants without ophthalmologic or vestibular abnormalities were recruited as normal subjects. Their faces were positioned at the desired head tilt using a customized adjustable head tilter and facial and fundus photographs of both the left and right eyes were taken in the upright neutral position; as well as at rightward and leftward head tilts of 2°, 4°, and 6°. The actual head tilt was determined using the facial photographs by measuring the slope of a line that intersected the corneal reflexes of both eyes. Rotational changes in the fundus images were recorded and the correlation of these changes with the degree of head tilt was determined.The degree of head tilt was significantly correlated with rotational changes in the fundus images from both the right and left eyes (P < 0.001; right eye: R = 0.897, left eye: R = 0.899). The mean relative compensations for head tilt, mediated by the ocular counterrolling reflex, were 0.376 ± 0.255 in the right eye (range: -0.02 to 1.0), and 0.350 ± 0.263 in the left eye (range: -0.03 to 1.0), and exhibited a significant negative correlation with head tilt (P < 0.05). The mean relative compensation of the right eye did not differ significantly from that of the left eye (P = 0.380), but the value did vary widely among individuals and within individuals.Even very small head tilt was partially and variably compensated for, and caused significant rotation in the fundus image. We concluded that proper head positioning does not guarantee the minimal ocular cyclotorsion change

  4. Effect of small head tilt on ocular fundus image: Consideration of proper head positioning for ocular fundus scanning

    PubMed Central

    Park, Shin Hae; Kang, Nam Yeo; Kim, Jihyun; Baek, Jiwon; Hong, Seung Woo

    2016-01-01

    Abstract Head tilt and resultant ocular cyclotorsion can influence the results of ophthalmologic examinations. Thus, proper head positioning during fundus scanning has been emphasized. However, there is no perfect method to control the head tilt and little is known about the effect of small head tilts. In this study, we investigated the effect of minimal head tilt on the ocular cyclotorsion which we cannot easily detect. Forty-seven participants without ophthalmologic or vestibular abnormalities were recruited as normal subjects. Their faces were positioned at the desired head tilt using a customized adjustable head tilter and facial and fundus photographs of both the left and right eyes were taken in the upright neutral position; as well as at rightward and leftward head tilts of 2°, 4°, and 6°. The actual head tilt was determined using the facial photographs by measuring the slope of a line that intersected the corneal reflexes of both eyes. Rotational changes in the fundus images were recorded and the correlation of these changes with the degree of head tilt was determined. The degree of head tilt was significantly correlated with rotational changes in the fundus images from both the right and left eyes (P < 0.001; right eye: R2 = 0.897, left eye: R2 = 0.899). The mean relative compensations for head tilt, mediated by the ocular counterrolling reflex, were 0.376 ± 0.255 in the right eye (range: −0.02 to 1.0), and 0.350 ± 0.263 in the left eye (range: −0.03 to 1.0), and exhibited a significant negative correlation with head tilt (P < 0.05). The mean relative compensation of the right eye did not differ significantly from that of the left eye (P = 0.380), but the value did vary widely among individuals and within individuals. Even very small head tilt was partially and variably compensated for, and caused significant rotation in the fundus image. We concluded that proper head positioning does not guarantee the minimal ocular

  5. Robust approach to ocular fundus image analysis

    NASA Astrophysics Data System (ADS)

    Tascini, Guido; Passerini, Giorgio; Puliti, Paolo; Zingaretti, Primo

    1993-07-01

    The analysis of morphological and structural modifications of retinal blood vessels plays an important role both to establish the presence of some systemic diseases as hypertension and diabetes and to study their course. The paper describes a robust set of techniques developed to quantitatively evaluate morphometric aspects of the ocular fundus vascular and micro vascular network. They are defined: (1) the concept of 'Local Direction of a vessel' (LD); (2) a special form of edge detection, named Signed Edge Detection (SED), which uses LD to choose the convolution kernel in the edge detection process and is able to distinguish between the left or the right vessel edge; (3) an iterative tracking (IT) method. The developed techniques use intensively both LD and SED in: (a) the automatic detection of number, position and size of blood vessels departing from the optical papilla; (b) the tracking of body and edges of the vessels; (c) the recognition of vessel branches and crossings; (d) the extraction of a set of features as blood vessel length and average diameter, arteries and arterioles tortuosity, crossing position and angle between two vessels. The algorithms, implemented in C language, have an execution time depending on the complexity of the currently processed vascular network.

  6. [Ocular fundus lesions in systemic lupus erythematosus model mice].

    PubMed

    Nakamura, A; Yokoyama, T; Kodera, S; Zhang, D; Hirose, S

    1998-01-01

    To evaluate spontaneous development of the ocular fundus abnormalities associated with collagen disease, we investigated the ocular fundus lesions in systemic lupus erythematosus (SLE) models. (NZW x BXSB) F1 mice were employed as SLE models with antiphospholipid syndrome. The abnormal findings in the ocular fundus were recorded with a fundus camera for small animals (KOWA Co., Ltd.), and the chorioretinal lesions were studied histopathologically. As in the systemic symptoms of SLE, the incidence of ocular fundus abnormalities in these (NZW x BXSB) F1 mice was significantly higher in males than in females, suggesting the influence of the Yaa (Y chromosome-linked autoimmune acceleration) gene. Lesions in the fundus appeared in the form of white spots, which increased in number along with the course of the disease. The lesion developed into retinal detachment in some animals. Dilatation of veins and narrowing of arteries were marked. These lesions were very similar to multifocal posterior pigment epitheliopathy (MPPE) in humans in that white spots appear first and then develop into exudative retinal detachment caused by retinal pigment epithelial disorder. Histopathological findings included 1. structural destruction of the photoreceptor cell layer, 2. degeneration and loss of the retinal pigment epithelium, and 3. narrowing and occlusion of the choriocapillaris associated with thrombus formation, cellular infiltration into the surrounding tissues, and wall thickening of the choroidal arterioles. The study of these SLE mouse may contribute to the elucidation of abnormalities in the fundus associated with collagen diseases, including the relationship between thrombus formation and antiphospholipid syndrome. PMID:9489364

  7. Nonmydriatic ocular fundus photography among headache patients in an emergency department

    PubMed Central

    Thulasi, Praneetha; Fraser, Clare L.; Biousse, Valérie; Wright, David W.; Newman, Nancy J.

    2013-01-01

    Objectives: Determine the frequency of and the predictive factors for abnormal ocular fundus findings among emergency department (ED) headache patients. Methods: Cross-sectional study of prospectively enrolled adult patients presenting to our ED with a chief complaint of headache. Ocular fundus photographs were obtained using a nonmydriatic fundus camera that does not require pupillary dilation. Demographic and neuroimaging information was collected. Photographs were reviewed independently by 2 neuroophthalmologists for findings relevant to acute care. The results were analyzed using univariate statistics and logistic regression modeling. Results: We included 497 patients (median age: 40 years, 73% women), among whom 42 (8.5%, 95% confidence interval: 6%–11%) had ocular fundus abnormalities. Of these 42 patients, 12 had disc edema, 9 had optic nerve pallor, 6 had grade III/IV hypertensive retinopathy, and 15 had isolated retinal hemorrhages. Body mass index ≥35 kg/m2 (odds ratio [OR]: 2.3, p = 0.02), younger age (OR: 0.7 per 10-year increase, p = 0.02), and higher mean arterial blood pressure (OR: 1.3 per 10-mm Hg increase, p = 0.003) were predictive of abnormal retinal photography. Patients with an abnormal fundus had a higher percentage of hospital admission (21% vs 10%, p = 0.04). Among the 34 patients with abnormal ocular fundi who had brain imaging, 14 (41%) had normal imaging. Conclusions: Ocular fundus abnormalities were found in 8.5% of patients with headache presenting to our ED. Predictors of abnormal funduscopic findings included higher body mass index, younger age, and higher blood pressure. Our study confirms the importance of funduscopic examination in patients with headache, particularly in the ED, and reaffirms the utility of nonmydriatic fundus photography in this setting. PMID:23284060

  8. Image analysis of ocular fundus for retinopathy characterization

    SciTech Connect

    Ushizima, Daniela; Cuadros, Jorge

    2010-02-05

    Automated analysis of ocular fundus images is a common procedure in countries as England, including both nonemergency examination and retinal screening of patients with diabetes mellitus. This involves digital image capture and transmission of the images to a digital reading center for evaluation and treatment referral. In collaboration with the Optometry Department, University of California, Berkeley, we have tested computer vision algorithms to segment vessels and lesions in ground-truth data (DRIVE database) and hundreds of images of non-macular centric and nonuniform illumination views of the eye fundus from EyePACS program. Methods under investigation involve mathematical morphology (Figure 1) for image enhancement and pattern matching. Recently, we have focused in more efficient techniques to model the ocular fundus vasculature (Figure 2), using deformable contours. Preliminary results show accurate segmentation of vessels and high level of true-positive microaneurysms.

  9. In vivo diffuse correlation spectroscopy investigation of the ocular fundus

    NASA Astrophysics Data System (ADS)

    Cattini, Stefano; Staurenghi, Giovanni; Gatti, Antonietta; Rovati, Luigi

    2013-05-01

    Diffuse correlation spectroscopy (DCS) measurements in vivo recorded from rabbits' ocular fundus are presented. Despite the complexity of these ocular tissues, we provide a clear and simple demonstration of the DCS abilities to analyze variations in physiological quantities of clinical interest. Indeed, the reported experimental activities demonstrate that DCS can reveal both choroidal-flow and temperature variations and detect nano- and micro-aggregates in ocular fundus circulation. Such abilities can be of great interest both in fundamental research and practical clinical applications. The proposed measuring system can be useful in: (a) monitoring choroidal blood flow variations, (b) determining the end-point for photo-dynamic therapy and transpupillary thermo therapy and, (c) managing the dye injection and determining an end-point for dye-enhanced photothrombosis. Moreover, it could allow both diagnoses when the presence of nano- and micro-aggregates is related to specific diseases and verifying the effects of nanoparticle injection in nanomedicine. Even though the reported results demonstrate the applicability of DCS to investigate ocular fundus, a detailed and accurate investigation of the limits of detection is beyond the scope of this article.

  10. Fundus Autofluorescence Imaging in an Ocular Screening Program

    PubMed Central

    Kolomeyer, A. M.; Nayak, N. V.; Szirth, B. C.; Khouri, A. S.

    2012-01-01

    Purpose. To describe integration of fundus autofluorescence (FAF) imaging into an ocular screening program. Methods. Fifty consecutive screening participants were included in this prospective pilot imaging study. Color and FAF (530/640 nm exciter/barrier filters) images were obtained with a 15.1MP Canon nonmydriatic hybrid camera. A clinician evaluated the images on site to determine need for referral. Visual acuity (VA), intraocular pressure (IOP), and ocular pathology detected by color fundus and FAF imaging modalities were recorded. Results. Mean ± SD age was 47.4 ± 17.3 years. Fifty-two percent were female and 58% African American. Twenty-seven percent had a comprehensive ocular examination within the past year. Mean VA was 20/39 in the right eye and 20/40 in the left eye. Mean IOP was 15 mmHg bilaterally. Positive color and/or FAF findings were identified in nine (18%) individuals with diabetic retinopathy or macular edema (n = 4), focal RPE defects (n = 2), age-related macular degeneration (n = 1), central serous retinopathy (n = 1), and ocular trauma (n = 1). Conclusions. FAF was successfully integrated in our ocular screening program and aided in the identification of ocular pathology. Larger studies examining the utility of this technology in screening programs may be warranted. PMID:23316224

  11. Multispectral imaging of the ocular fundus using LED illumination

    NASA Astrophysics Data System (ADS)

    Everdell, N. L.; Styles, I. B.; Claridge, E.; Hebden, J. C.; Calcagni, A. S.

    2009-07-01

    We present preliminary data from an imaging system based on LED illumination for obtaining sequential multispectral optical images of the human ocular fundus. The system is capable of acquiring images at speeds of up to 20fps and we have demonstrated that the system is fast enough to allow images to be acquired with minimal inter-frame movement. Further improvements have been identified that will improve both imaging speed and image quality. The long-term goal is to use the system in conjunction with novel image analysis algorithms to extract chromophore concentrations from images of the ocular fundus, with a particular emphasis on age-related macular degeneration. The system has also found utility in fluorescence microscopy.

  12. Nonmydriatic Ocular Fundus Photography in the Emergency Department: How It Can Benefit Neurologists.

    PubMed

    Bruce, Beau B

    2015-10-01

    Examination of the ocular fundus is a critical aspect of the neurologic examination. For example, in patients with headache the ocular fundus examination is needed to uncover "red flags" suggestive of secondary etiologies. However, ocular fundus examination is infrequently and poorly performed in clinical practice. Nonmydriatic ocular fundus photography provides an alternative to direct ophthalmoscopy that has been studied as part of the Fundus Photography versus Ophthalmoscopy Trial Outcomes in the Emergency Department (FOTO-ED) Study. Herein, the results of the FOTO-ED study are reviewed with a particular focus on the study's implications for the acute care of patients presenting with headache and focal neurologic deficits. In headache patients, not only optic disc edema and optic disc pallor were observed as would be expected, but also a large number of abnormalities associated with hypertension. Based upon subjects with focal neurologic deficits, the FOTO-ED study suggests that the ocular fundus examination may assist with the triage of patients presenting with suspected transient ischemic attack. Continued advances in the ease and portability of nonmydriatic fundus photography will hopefully help to restore ocular fundus examination as a routinely performed component of all neurologic examinations. PMID:26444394

  13. Pattern Recognition Of Blood Vessel Networks In Ocular Fundus Images

    NASA Astrophysics Data System (ADS)

    Akita, K.; Kuga, H.

    1982-11-01

    We propose a computer method of recognizing blood vessel networks in color ocular fundus images which are used in the mass diagnosis of adult diseases such as hypertension and diabetes. A line detection algorithm is applied to extract the blood vessels, and the skeleton patterns of them are made to analyze and describe their structures. The recognition of line segments of arteries and/or veins in the vessel networks consists of three stages. First, a few segments which satisfy a certain constraint are picked up and discriminated as arteries or veins. This is the initial labeling. Then the remaining unknown ones are labeled by utilizing the physical level knowledge. We propose two schemes for this stage : a deterministic labeling and a probabilistic relaxation labeling. Finally the label of each line segment is checked so as to minimize the total number of labeling contradictions. Some experimental results are also presented.

  14. Non-mydriatic ocular fundus photography and telemedicine: past, present, and future

    PubMed Central

    Bruce, Beau B.; Newman, Nancy J.; Pérez, Mario A.; Biousse, Valérie

    2013-01-01

    Non-mydriatic ocular fundus photography is a promising alternative to direct ophthalmoscopy, particularly when combined with telemedicine. This review discusses these technologies from a longitudinal perspective: past, present, and future. The focus is directed to the role that non-mydriatic fundus photography and telemedicine have played in medical research and patient care, with emphasis on the major advances to date. Also discussed are the challenges to their widespread application and their substantial promise for revitalizing the importance of the ocular fundus examination in patient care, providing improved access to ophthalmic consultative services, and facilitating clinical and epidemiologic research. PMID:24244059

  15. Time course and topographic distribution of ocular fundus pulsation measured by low-coherence tissue interferometry.

    PubMed

    Dragostinoff, Nikolaus; Werkmeister, René M; Klaizer, József; Gröschl, Martin; Schmetterer, Leopold

    2013-12-01

    Low-coherence tissue interferometry is a technique for the depth-resolved measurement of ocular fundus pulsations. Whereas fundus pulsation amplitudes at preselected axial positions can readily be assessed by this method, coupling of the interferometer with a pulse oximeter additionally allows for the reconstruction of the time course of ocular fundus pulsation with respect to the cardiac cycle of the subject. For this purpose, the interferogram resulting from the superposition of waves reflected at the cornea and the ocular fundus is recorded synchronously with the plethysmogram. A new method for evaluating the time course of synthetic interferograms in combination with plethysmograms based on averaging several pulse periods has been developed. This technique allows for the analysis of amplitudes, time courses, and phase differences of fundus pulsations at preselected axial and transversal positions and for creating fundus pulsation movies. Measurements are performed in three healthy emmetropic subjects at angles from 0 deg to 18 deg to the axis of vision. Considerably different time courses, amplitudes, and phases with respect to the cardiac cycle are found at different angles. Data on ocular fundus pulsation obtained with this technique can--among other applications--be used to verify and to improve biomechanical models of the eye. PMID:24091698

  16. Spectral reflectance of the ocular fundus as a diagnostic marker for cerebral malaria

    NASA Astrophysics Data System (ADS)

    Liu, Xun; Rice, David A.; Khoobehi, Bahram

    2012-03-01

    The challenge of correctly identifying malaria infection continues to impede our efforts to control this disease. Recent studies report highly specific retinal changes in severe malaria patients; these retinal changes may represent a very useful diagnostic indicator for this disease. To further explore the ocular manifestations of malaria, we used hyperspectral imaging to study retinal changes caused by Plasmodium berghei ANKA parasitization in a mouse model. We collected the spectral reflectance of the ocular fundus from hyperspectral images of the mouse eye. The blood oxygen sensitive spectral region was normalized for variances in illumination, and used to calculate relative values that correspond to oxygenated hemoglobin levels. Oxygen hemoglobin levels are markedly lower in parasitized mice, indicating that hemoglobin digestion by P. berghei may be detected using spectral reflectance. Furthermore, the ocular reflectance of parasitized mice was abnormally elevated between 660nm and 750nm, suggesting fluorescence in this region. While the source of this fluorescence is not yet clear, its presence correlates strongly with P. Berghei parasitization, and may indicate the presence of hemozoin deposits in the retinal vasculature. The pathology of severe malaria still presents many questions for clinicians and scientists, and our understanding of cerebral malaria has been generally confined to clinical observation and postmortem examination. As the retina represents a portion of the central nervous system that can be easily examined noninvasively, our technique may provide the basis for an automated tool to detect and examine severe malaria via retinal changes.

  17. Diagnostic accuracy and use of non-mydriatic ocular fundus photography by emergency department physicians: Phase II of the FOTO-ED study

    PubMed Central

    Bruce, Beau B.; Thulasi, Praneetha; Fraser, Clare L.; Keadey, Matthew T.; Ward, Antoinette; Heilpern, Katherine L.; Wright, David W.; Newman, Nancy J.; Biousse, Valérie

    2013-01-01

    Objective During the first phase of the FOTO-ED Study, 13% (44/350;95%CI:9–17%) of patients had an ocular fundus finding, such as papilledema, relevant to their emergency department (ED) management found by non-mydriatic ocular fundus photography reviewed by neuro-opthalmologists. All of these findings were missed by ED physicians (EPs), who only examined 14% of enrolled patients by direct ophthalmoscopy. In the present study, we evaluated the sensitivity of non-mydriatic ocular fundus photography, an alternative to direct ophthalmoscopy, for relevant findings when photographs were made available for use by EPs during routine clinical care. Methods 354 patients presenting to our ED with headache, focal neurologic deficit, visual change, or diastolic blood pressure ≥120 mmHg had non-mydriatic fundus photography obtained (Kowa nonmyd-alpha-D). Photographs were placed on the electronic medical record for EPs review. Identification of relevant findings on photographs by EPs was compared to a reference standard of neuro-ophthalmologist review. Results EPs reviewed photographs of 239 patients (68%). 35 patients (10%;95%CI:7–13%) had relevant findings identified by neuro-ophthalmologist review (6 disc edema, 6 grade III/IV hypertensive retinopathy, 7 isolated hemorrhages, 15 optic disc pallor, and 1 retinal vascular occlusion). EPs identified 16/35 relevant findings (sensitivity:46%;95%CI:29–63%), and also identified 289/319 normal findings (specificity:96%; 95%CI:87–94%). EPs reported that photographs were helpful for 125 patients (35%). Conclusions EPs used non-mydriatic fundus photographs more frequently than they perform direct ophthalmoscopy, and their detection of relevant abnormalities improved. Ocular fundus photography often assisted ED care even when normal. Non-mydriatic ocular fundus photography offers a promising alternative to direct ophthalmoscopy. PMID:23433654

  18. Local resolved spectroscopy at the human ocular fundus in vivo: technique and clinical examples

    NASA Astrophysics Data System (ADS)

    Hammer, Martin; Schweitzer, Dietrich; Scibor, Mateusz

    1996-01-01

    Ocular fundus reflectometry is known as a method for the determination of the optical density of pigments at the eye ground. This has been described for diagnostic investigations at single locations. The new technique of imaging spectroscopy enables the recording of one dimensional local distribution of spectra from the fundus which is illuminated confocal to the entrance slit of a spectrograph. A fundus reflectometer consisting of a Zeiss fundus camera, an imaging spectrograph, and an intensified CCD-camera are presented. The local resolved spectra gained by this apparatus are approximated by a mathematical model on the basis of the anatomy of the fundus as a structure of layers with different optical properties. Each spectrum is assumed to be described by a function of the absorption spectra of the pigments found in the retinal and choroidal tissue. Assuming the existence of parameters which are independent from the fundus location we have to approximate the measured local distribution of spectra by a system of coupled non-linear equations. By a least square fit the local distribution of the extinction of melanin, xantophyll and hemoglobin may be obtained as well as the extension of pathologic alterations at the fundus. The benefits of the method for clinical diagnostics are discussed at first measurements from physiological and pathological examples.

  19. Two-photon excited fluorescence microscopy application for ex vivo investigation of ocular fundus samples

    NASA Astrophysics Data System (ADS)

    Peters, Sven; Hammer, Martin; Schweitzer, Dietrich

    2011-07-01

    Two-photon excited fluorescence (TPEF) imaging of ocular tissue has recently become a promising tool in ophthalmology for diagnostic and research purposes. The feasibility and the advantages of TPEF imaging, namely deeper tissue penetration and improved high-resolution imaging of microstructures, have been demonstrated lately using human ocular samples. The autofluorescence properties of endogenous fluorophores in ocular fundus tissue are well known from spectrophotometric analysis. But fluorophores, especially when it comes to fluorescence lifetime, typically display a dependence of their fluorescence properties on local environmental parameters. Hence, a more detailed investigation of ocular fundus autofluorescence ideally in vivo is of utmost interest. The aim of this study is to determine space-resolved the stationary and time-resolved fluorescence properties of endogenous fluorophores in ex vivo porcine ocular fundus samples by means of two-photon excited fluorescence spectrum and lifetime imaging microscopy (FSIM/FLIM). By our first results, we characterized the autofluorescence of individual anatomical structures of porcine retina samples excited at 760 nm. The fluorescence properties of almost all investigated retinal layers are relatively homogenous. But as previously unknown, ganglion cell bodies show a significantly shorter fluorescence lifetime compared to the adjacent mueller cells. Since all retinal layers exhibit bi-exponential autofluorescence decays, we were able to achieve a more precise characterization of fluorescence properties of endogenous fluorophores compared to a present in vivo FLIM approach by confocal scanning laser ophthalmoscope (cSLO).

  20. Ocular Fundus Photography as a Tool to Study Stroke and Dementia.

    PubMed

    Cheung, Carol Y; Chen, Christopher; Wong, Tien Y

    2015-10-01

    Although cerebral small vessel disease has been linked to stroke and dementia, due to limitations of current neuroimaging technology, direct in vivo visualization of changes in the cerebral small vessels (e.g., cerebral arteriolar narrowing, tortuous microvessels, blood-brain barrier damage, capillary microaneurysms) is difficult to achieve. As the retina and the brain share similar embryological origin, anatomical features, and physiologic properties with the cerebral small vessels, the retinal vessels offer a unique and easily accessible "window" to study the correlates and consequences of cerebral small vessel diseases in vivo. The retinal microvasculature can be visualized, quantified and monitored noninvasively using ocular fundus photography. Recent clinic- and population-based studies have demonstrated a close link between retinal vascular changes seen on fundus photography and stroke and dementia, suggesting that ocular fundus photography may provide insights to the contribution of microvascular disease to stroke and dementia. In this review, we summarize current knowledge on retinal vascular changes, such as retinopathy and changes in retinal vascular measures with stroke and dementia as well as subclinical makers of cerebral small vessel disease, and discuss the possible clinical implications of these findings in neurology. Studying pathologic changes of retinal blood vessels may be useful for understanding the etiology of various cerebrovascular conditions; hence, ocular fundus photography can be potentially translated into clinical practice. PMID:26444393

  1. Fundus image change analysis: geometric and radiometric normalization

    NASA Astrophysics Data System (ADS)

    Shin, David S.; Kaiser, Richard S.; Lee, Michael S.; Berger, Jeffrey W.

    1999-06-01

    Image change analysis will potentiate fundus feature quantitation in natural history and intervention studies for major blinding diseases such as age-related macular degeneration and diabetic retinopathy. Geometric and radiometric normalization of fundus images acquired at two points in time are required for accurate change detection, but existing methods are unsatisfactory for change analysis. We have developed and explored algorithms for correction of image misalignment (geometric) and inter- and intra-image brightness variation (radiometric) in order to facilitate highly accurate change detection. Thirty-five millimeter color fundus photographs were digitized at 500 to 1000 dpi. Custom-developed registration algorithms correcting for translation only; translation and rotation; translation, rotation, and scale; and polynomial based image-warping algorithms allowed for exploration of registration accuracy required for change detection. Registration accuracy beyond that offered by rigid body transformation is required for accurate change detection. Radiometric correction required shade-correction and normalization of inter-image statistical parameters. Precise geometric and radiometric normalization allows for highly accurate change detection. To our knowledge, these results are the first demonstration of the combination of geometric and radiometric normalization offering sufficient accuracy to allow for accurate fundus image change detection potentiating longitudinal study of retinal disease.

  2. Clinical research on intravitreal injection of bevacizumab in the treatment of macula lutea and retinal edema of ocular fundus disease.

    PubMed

    Yan, Ying; Wang, Tao; Cao, Jing; Wang, Meng; Li, Fenghua

    2015-07-01

    This paper aimed to explore clinically curative effect of intravitreal injection of bevacizumab in the treatment of macula lutea and retinal edema of ocular fundus disease. The number of 300 patients (390 eyes) with ocular fundus diseases including retinal vein occlusion (RVO), diabetic retinopathy (DR), age-related macular degeneration (ARMD), central serous chorioretinopathy (CSC), choridal new vessel (CNV) received and cured in the hospital from February 2010 to February 2014 were given intravitreal injection of bevacizumab (1.5mg) with once per month and a total of 2-3 times. Results of patients' vision and fluorescence fundus angiography (FFA), optical coherence tomography (OCT) before and after treatment were compared and curative effects were evaluated. Vision of 349 eyes (89.49%) improved obviously with the average of more than 2 lines, patient's intraocular pressure (IOP) was normal and all indexes were clearly better; vision of 26 eyes (6.67%) was stable before the treatment and without any changes after the treatment, the situation of fundus got better without increased IOP; vision of 15 eyes (3.85%) decreased to some extent, and the symptoms eased slightly after symptomatic treatment. In the 1st day after intravitreal injection, best-corrected visual acuity increased to 0.239±0.175, best-corrected visual acuity in 1 m was 0.315±0.182, in 3m continuously climbed to 0.350±0.270, and in 6 m was 0.362±0.282. Compared with vision before injection, t value was t=3.184, t=7.213, t=9.274 and t=9.970 (P=0.002, P=0.000, P=0.000 and P=0.000) respectively, and all P were less than 0.01. Furthermore, the difference was significant if a=0.01, which could confirm that 1m best corrected visual acuity of patients after intravitreal injection improved clearly in combination with before injection and 3m and 6 m visions enhanced constantly after injection. To sum up, intravitreal injection of bevacizumab in treating ocular fundus disease improves patient's vision

  3. Optical contrast enhancement of high-resolution ocular fundus imaging in vivo using polarimetry

    NASA Astrophysics Data System (ADS)

    Yang, Hansheng; Rao, Xuejun; Zhang, Yudong

    2007-11-01

    The adaptive optics (AO) retina imaging was performed with contrast enhancement by characterizing polarization parameters of the living retina. A removable pair of polarization state generating unit near the optical source and analysis unit near the CCD camera was incorporated into the basic 37-channle deformable mirror AO microscopic ophthalmoscope. Double-pass imaging polarimetry of the human eye was carried out, then incomplete Mueller matrix was calculated and analyzed to optimize the retina imaging condition using polarized light, which caused the subretinal structures with different polarization properties to emerge from the scattering light background, so the contrast of the image can be substantially enhanced. This method is demonstrated briefly and its validity was tested in the laboratory. The high-resolution images of ocular fundus are compared with 8-frame-averaging images we obtained prior to this method. The experiment results now show improved visualization of fundus structures to some extent without greatly sacrificing image resolution.

  4. Method for Calculating the Optical Diffuse Reflection Coefficient for the Ocular Fundus

    NASA Astrophysics Data System (ADS)

    Lisenko, S. A.; Kugeiko, M. M.

    2016-07-01

    We have developed a method for calculating the optical diffuse reflection coefficient for the ocular fundus, taking into account multiple scattering of light in its layers (retina, epithelium, choroid) and multiple refl ection of light between layers. The method is based on the formulas for optical "combination" of the layers of the medium, in which the optical parameters of the layers (absorption and scattering coefficients) are replaced by some effective values, different for cases of directional and diffuse illumination of the layer. Coefficients relating the effective optical parameters of the layers and the actual values were established based on the results of a Monte Carlo numerical simulation of radiation transport in the medium. We estimate the uncertainties in retrieval of the structural and morphological parameters for the fundus from its diffuse reflectance spectrum using our method. We show that the simulated spectra correspond to the experimental data and that the estimates of the fundus parameters obtained as a result of solving the inverse problem are reasonable.

  5. Depth-resolved measurement of ocular fundus pulsations by low-coherence tissue interferometry

    NASA Astrophysics Data System (ADS)

    Dragostinoff, Nikolaus; Werkmeister, René M.; Gröschl, Martin; Schmetterer, Leopold

    2009-09-01

    A device that allows for the measurement of ocular fundus pulsations at preselected axial positions of a subject's eye is presented. Unlike previously presented systems, which only allow for observation of the strongest reflecting retinal layer, our system enables the measurement of fundus pulsations at a preselected ocular layer. For this purpose the sample is illuminated by light of low temporal coherence. The layer is then selected by positioning one mirror of a Michelson interferometer according to the depth of the layer. The device contains a length measurement system based on partial coherence interferometry and a line scan charge-coupled device camera for recording and online inspection of the fringe system. In-vivo measurements in healthy humans are performed as proof of principle. The algorithms used for enhancing the recorded images are briefly introduced. The contrast of the observed interference pattern is evaluated for different positions of the measurement mirror and at various distances from the front surface of the cornea. The applications of such a system may be wide, including assessment of eye elongation during myopia development and blood-flow-related changes in intraocular volume.

  6. Evaluation of time-resolved autofluorescence images of the ocular fundus

    NASA Astrophysics Data System (ADS)

    Schweitzer, Dietrich; Hammer, Martin; Schweitzer, Frank; Schenke, Stefan; Gaillard, Elizabeth R.

    2003-10-01

    Changes in the metabolism can be assumed as a first sign of several ocular diseases. If such metabolic alterations are detectable, diseases might be treatable, before morphological alterations are manifest. The redox pairs of co-enzymes fluoresce after excitation and change their fluorescence properties depending on the oxidative state of cellular metabolism. Metabolic by-products and connective tissue exhibit also auto-fluorescence. The detection and discrimination of endogenous fluorophores at the fundus by selected excitation or evaluation of emission spectra is not possible with a high spatial resolution. The lifetime of electrons in the excited stage is also substance specific and is not influenced by the absorption spectra of non-fluorescent substances at the fundus. For that reason, a Laser Scanning Ophthalmoscope was developed for the 2-dimensional measurement of time - resolved auto-fluorescence at the living human eye-ground. In first studies, different changes in auto-fluorescence were found after respiration of oxygen between fundus sites. Between young and older persons as well as patients suffering from age-related macular degeneration different lifetime-ranges were detected from the same anatomical region. For comparison, lifetime measurements were performed on single substances. In a first step of interpretation, the frequency distribution of each lifetime in a region of interest can be compared between in vivo and in vitro measurements. Presenting the results in Tau 1-Tau 2 diagrams, specific clusters can be found in both types of measurement, covering each other partially and allowing interpretation of measurements from the living human eye.

  7. Correlation between ocular perfusion pressure and ocular pulse amplitude in glaucoma, ocular hypertension, and normal eyes

    PubMed Central

    Figueiredo, Bruno P; Cronemberger, Sebastião; Kanadani, Fabio N

    2013-01-01

    Background The purpose of this study was to investigate the correlation between ocular perfusion pressure and ocular pulse amplitude in glaucoma, ocular hypertension, and normal eyes. Methods Ninety eyes from 90 patients were included. Thirty patients had been recently diagnosed with glaucoma and had no previous history of treatment for ocular hypotension, 30 had elevated intraocular pressure (IOP) without evidence of glaucoma, and 30 had normal IOP (<21 mmHg) with no detectable glaucomatous damage. Goldmann applanation tonometry (GAT), dynamic contour tonometry (DCT), blood pressure measurement, pachymetry, Humphrey visual field, and routine ophthalmic examination was performed in each patient. Ocular perfusion pressure was calculated as the difference between mean arterial pressure and IOP. The ocular pulse amplitude was given by DCT. The Pearson correlation coefficient was used to compare the glaucomatous and ocular hypertensive groups, and comparisons with the normal IOP group were done using the Spearman’s rank correlation coefficient. Results Mean IOP by DCT was 22.7 ± 4.3 mmHg in the glaucoma group, 22.3 ± 2.8 mmHg in the ocular hypertension group, and 14.3 ± 1.6 mmHg in the control group. Mean IOP by GAT was 19.0 ± 5.1 mmHg for glaucoma, 22.4 ± 2.1 mmHg for ocular hypertension, and 12.9 ± 2.2 mmHg for controls. Mean ocular pulse amplitude was 3.4 ± 1.2 mmHg in the glaucoma group, 3.5 ± 1.2 mmHg in the ocular hypertension group, and 2.6 ± 0.9 mmHg in the control group. Mean ocular perfusion pressure was 46.3 ± 7.9 mmHg in the glaucoma group, 46.3 ± 7.9 mmHg in the ocular hypertension group, and 50.2 ± 7.0 mmHg in controls. No significant correlation between ocular perfusion pressure and ocular pulse amplitude was found in any of the groups (P = 0.865 and r = −0.032, P = 0.403 and r = −0.156, P = 0.082 and ρ = −0.307 for glaucoma, ocular hypertension, and normal eyes, respectively). Conclusion There is no significant correlation between

  8. Multispectral imaging of the ocular fundus using light emitting diode illumination

    NASA Astrophysics Data System (ADS)

    Everdell, N. L.; Styles, I. B.; Calcagni, A.; Gibson, J.; Hebden, J.; Claridge, E.

    2010-09-01

    We present an imaging system based on light emitting diode (LED) illumination that produces multispectral optical images of the human ocular fundus. It uses a conventional fundus camera equipped with a high power LED light source and a highly sensitive electron-multiplying charge coupled device camera. It is able to take pictures at a series of wavelengths in rapid succession at short exposure times, thereby eliminating the image shift introduced by natural eye movements (saccades). In contrast with snapshot systems the images retain full spatial resolution. The system is not suitable for applications where the full spectral resolution is required as it uses discrete wavebands for illumination. This is not a problem in retinal imaging where the use of selected wavelengths is common. The modular nature of the light source allows new wavelengths to be introduced easily and at low cost. The use of wavelength-specific LEDs as a source is preferable to white light illumination and subsequent filtering of the remitted light as it minimizes the total light exposure of the subject. The system is controlled via a graphical user interface that enables flexible control of intensity, duration, and sequencing of sources in synchrony with the camera. Our initial experiments indicate that the system can acquire multispectral image sequences of the human retina at exposure times of 0.05 s in the range of 500-620 nm with mean signal to noise ratio of 17 dB (min 11, std 4.5), making it suitable for quantitative analysis with application to the diagnosis and screening of eye diseases such as diabetic retinopathy and age-related macular degeneration.

  9. Fundus image fusion in EYEPLAN software: An evaluation of a novel technique for ocular melanoma radiation treatment planning

    SciTech Connect

    Daftari, Inder K.; Mishra, Kavita K.; O'Brien, Joan M.; and others

    2010-10-15

    Purpose: The purpose of this study is to evaluate a novel approach for treatment planning using digital fundus image fusion in EYEPLAN for proton beam radiation therapy (PBRT) planning for ocular melanoma. The authors used a prototype version of EYEPLAN software, which allows for digital registration of high-resolution fundus photographs. The authors examined the improvement in tumor localization by replanning with the addition of fundus photo superimposition in patients with macular area tumors. Methods: The new version of EYEPLAN (v3.05) software allows for the registration of fundus photographs as a background image. This is then used in conjunction with clinical examination, tantalum marker clips, surgeon's mapping, and ultrasound to draw the tumor contour accurately. In order to determine if the fundus image superimposition helps in tumor delineation and treatment planning, the authors identified 79 patients with choroidal melanoma in the macular location that were treated with PBRT. All patients were treated to a dose of 56 GyE in four fractions. The authors reviewed and replanned all 79 macular melanoma cases with superimposition of pretreatment and post-treatment fundus imaging in the new EYEPLAN software. For patients with no local failure, the authors analyzed whether fundus photograph fusion accurately depicted and confirmed tumor volumes as outlined in the original treatment plan. For patients with local failure, the authors determined whether the addition of the fundus photograph might have benefited in terms of more accurate tumor volume delineation. Results: The mean follow-up of patients was 33.6{+-}23 months. Tumor growth was seen in six eyes of the 79 macular lesions. All six patients were marginal failures or tumor miss in the region of dose fall-off, including one patient with both in-field recurrence as well as marginal. Among the six recurrences, three were managed by enucleation and one underwent retreatment with proton therapy. Three

  10. Computerised calculation scheme for ocular magnification with the Zeiss telecentric fundus camera.

    PubMed

    Langenbucher, Achim; Seitz, Berthold; Viestenz, Arne

    2003-09-01

    Littmann (1982) described a method to determine the magnification of the eye in order to relate the size of a retinal feature to its measured image size on a telecentric fundus camera film. This required information only about ametropia and corneal curvature. Several other methods have been reported since then which consider other biometric data to enhance the accuracy of this classical method. The purpose of this study is to describe a numerical calculation scheme to determine the magnification q of the eye in two cardinal meridians using paraxial raytracing. Our calculation scheme is based on ametropia, keratometry, as well as biometric data such as axial length, anterior chamber depth and thickness of the crystalline lens. It is described step-by-step in order (1) to determine the refractive powers of both surfaces of the crystalline lens, which are not directly measurable in vivo, (2) to derive the retinal image conjugate to a circular object using paraxial raytracing, (3) to fit an ellipse to the retinal image, (4) to determine the secondary principal points (Gaussian length) separately for both cardinal meridians and (5) to calculate the ocular magnification q. The power of the crystalline lens is estimated to compensate for the spherocylindrical refraction at the spectacle plane and the corneal refraction with an astigmatic component thus creating a sharp image focused at the retinal plane. The capabilities of this computing scheme are demonstrated with five clinical examples and are related to the respective values of the classical Littmann formula as well as to enhanced methods described by Bennett (1988), Bennett et al. (1994) and Garway-Heath et al. (1998). PMID:12950891

  11. Ocular Blood Flow and Normal Tension Glaucoma

    PubMed Central

    Fan, Ning; Wang, Pei; Tang, Li; Liu, Xuyang

    2015-01-01

    Normal tension glaucoma (NTG) is known as a multifactorial optic neuropathy characterized by progressive retinal ganglion cell death and glaucomatous visual field loss, even though the intraocular pressure (IOP) does not exceed the normal range. The pathophysiology of NTG remains largely undetermined. It is hypothesized that the abnormal ocular blood flow is involved in the pathogenesis of this disease. A number of evidences suggested that the vascular factors played a significant role in the development of NTG. In recent years, the new imaging techniques, fluorescein angiography, color Doppler imaging (CDI), magnetic resonance imaging (MRI), and laser speckle flowgraphy (LSFG), have been used to evaluate the ocular blood flow and blood vessels, and the impaired vascular autoregulation was found in patients with NTG. Previous studies showed that NTG was associated with a variety of systemic diseases, including migraine, Alzheimer's disease, primary vascular dysregulation, and Flammer syndrome. The vascular factors were involved in these diseases. The mechanisms underlying the abnormal ocular blood flow in NTG are still not clear, but the risk factors for glaucomatous optic neuropathy likely included oxidative stress, vasospasm, and endothelial dysfunction. PMID:26558263

  12. Ocular Blood Flow and Normal Tension Glaucoma.

    PubMed

    Fan, Ning; Wang, Pei; Tang, Li; Liu, Xuyang

    2015-01-01

    Normal tension glaucoma (NTG) is known as a multifactorial optic neuropathy characterized by progressive retinal ganglion cell death and glaucomatous visual field loss, even though the intraocular pressure (IOP) does not exceed the normal range. The pathophysiology of NTG remains largely undetermined. It is hypothesized that the abnormal ocular blood flow is involved in the pathogenesis of this disease. A number of evidences suggested that the vascular factors played a significant role in the development of NTG. In recent years, the new imaging techniques, fluorescein angiography, color Doppler imaging (CDI), magnetic resonance imaging (MRI), and laser speckle flowgraphy (LSFG), have been used to evaluate the ocular blood flow and blood vessels, and the impaired vascular autoregulation was found in patients with NTG. Previous studies showed that NTG was associated with a variety of systemic diseases, including migraine, Alzheimer's disease, primary vascular dysregulation, and Flammer syndrome. The vascular factors were involved in these diseases. The mechanisms underlying the abnormal ocular blood flow in NTG are still not clear, but the risk factors for glaucomatous optic neuropathy likely included oxidative stress, vasospasm, and endothelial dysfunction. PMID:26558263

  13. Imaging autofluorescence temporal signatures of the human ocular fundus in vivo

    NASA Astrophysics Data System (ADS)

    Papour, Asael; Taylor, Zachary; Stafsudd, Oscar; Tsui, Irena; Grundfest, Warren

    2015-11-01

    We demonstrate real-time in vivo fundus imaging capabilities of our fluorescence lifetime imaging technology for the first time. This implementation of lifetime imaging uses light emitting diodes to capture full-field images capable of showing direct tissue contrast without executing curve fitting or lifetime calculations. Preliminary results of fundus images are presented, investigating autofluorescence imaging potential of various retina biomarkers for early detection of macular diseases.

  14. Detection of early metabolic alterations in the ocular fundus of diabetic patients by time-resolved autofluorescence of endogenous fluorophores

    NASA Astrophysics Data System (ADS)

    Schweitzer, D.; Klemm, M.; Quick, S.; Deutsch, L.; Jentsch, S.; Hammer, M.; Dawczynski, J.; Kloos, C. H.; Mueller, U. A.

    2011-07-01

    Measurements of time-resolved autofluorescence (FLIM) at the human ocular fundus of diabetic patients permit the detection of early pathologic alterations before signs of diabetic retinopathy are visible. The measurements were performed by the Jena Fluorescence Lifetime Laser Scanner Ophthalmoscope applying time-correlated single photon counting (TCSPC) in two spectral channels (K1: 490-560 nm, K2:560-700ps). The fluorescence was excited by 70 ps pulses (FWHM) at 448 nm. The decay of fluorescence intensity was triple-exponentially approximated. The frequency of amplitudes, lifetimes, and relative contributions was compared in fields of the same size and position in healthy subjects and in diabetic patients. The most sensitive parameter was the lifetime T2 in the short-wavelength channel, which corresponds to the neuronal retina. The changes in lifetime point to a loss of free NADH and an increased contribution of protein-bound NADH in the pre-stage of diabetic retinopathy.

  15. Contour Photography Of The Ocular Fundus: Evaluation Of An Automated Image Processing Algorithm

    NASA Astrophysics Data System (ADS)

    Shapiro, Jerrold M.; Bush, Karen S.

    1986-07-01

    A new technique for making a three dimensional map of the optic nerve head is expected to have a major impact on the way in which glaucoma is diagnosed and treated. The new technique, contour photography, allows the health of the optic nerve head to be objectively evaluated every six months during the patient's routine office visit. In contour photography, a set of parallel lines of light are projected into the patient's eye and the back of the eye is photographed using a standard camera that is available in almost all ophthalmologist's offices. The three dimensional information is encoded in the positions of the photographed lines, and is decoded by treating each stripe as the intersection of a plane of light with the fundus. At present, a trained human observer identifies the edges of the stripes. In order to decrease the data extraction time, several automated edge detection algorithms were examined for their suitability in the analysis of contour photographs, and the best was extensively evaluated using Monte Carlo simulation. The accuracy and reproducibility of the edge position estimate in images with various amounts of film grain noise were measured for many values of the edge detector parameter and of the signal parameter, its modulation, m. When normalized by the amount of film grain noise, the relationship between reproducibility and l/m was found to be linear over the range of parameters likely to be encountered in contour photography. The accuracy was found to be independent of the amount of film grain noise, and linearly related to 1/m. By estimating m for each edge, the accuracy could be treated as a correctable systematic error of the edge detection process. A sample calculation which used parameter values that are likely to be found in contour photography showed that the automated edge detection process would be expected to produce a random variation in the measurement of the depth of the optic nerve head surface whose standard deviation is 0

  16. Improved diagnostics by automated matching and enhancement in fluorescein angiography of the ocular fundus

    NASA Astrophysics Data System (ADS)

    Noordmans, Herke Jan; van den Biesen, Pieter; de Roode, Rowland; Verdaasdonk, Rudolf

    2008-02-01

    An interactive image matching program has been developed to help ophthalmologists in perceiving subtle differences between sequential images obtained during fluorescein angiography. In a pilot experiment, it appeared that the image matching program could effectively correct camera alignment errors. By offering simple tools like image overlay, blinking and image subtraction, differences between angiograms can be greatly enhanced and interpreted. It appeared that newly formed, leaking blood vessels could be detected at an earlier stage of the disease process using these tools. Treatment can be initiated right away, thereby preventing the patient from having additional visual loss. The matching program seems to improve the quality of fundus diagnostics but needs to be validated in future studies.

  17. Normal Ocular Development in Young Rhesus Monkeys (Macaca mulatta)

    PubMed Central

    Qiao-Grider, Ying; Hung, Li-Fang; Kee, Chea-su; Ramamirtham, Ramkumar; Smith, Earl L.

    2007-01-01

    Purpose The purpose of this study was to characterize normal ocular development in infant monkeys and to establish both qualitative and quantitative relationships between human and monkey refractive development. Methods The subjects were 214 normal rhesus monkeys. Cross-sectional data were obtained from 204 monkeys at about 3 weeks of age and longitudinal data were obtained from 10 representative animals beginning at about 3 weeks of age for a period of up to 5 years. Ocular development was characterized via refractive status, corneal power, crystalline lens parameters, and the eye’s axial dimensions, which were determined by retinoscopy, keratometry, phakometry and A-scan ultrasonography, respectively. Results From birth to about 5 years of age, the growth curves for refractive error and most ocular components (excluding lens thickness and equivalent lens index) followed exponential trajectories and were highly coordinated between the two eyes. However, overall ocular growth was not a simple process of increasing the scale of each ocular component in a proportional manner. Instead the rates and relative amounts of change varied within and between ocular structures. Conclusion The configuration and contribution of the major ocular components in infant and adolescent monkey eyes are qualitatively and quantitatively very comparable to those in human eyes and their development proceeds in a similar manner in both species. As a consequence, in both species the adolescent eye is not simply a scaled version of the infant eye. PMID:17416396

  18. [Ophthalmoscopic observations of ocular fundus in colony-born cynomolgus monkeys aged from 0 day to 90 days].

    PubMed

    Suzuki, M T; Narita, H; Tanaka, Y; Cho, F; Fukui, M

    1984-04-01

    Apparently healthy 242 colony-born cynomolgus monkeys (Macaca fascicularis) aged from 0 day to 90 days were examined for the findings of ocular fundus by using ophthalmoscope. One drop of mixed solution of 0.5% tropicamide and 0.5% phenylephrine hydrochloride was instilled into each eye of the monkey. Then, those monkeys were anesthetized with ketamine-HC1 at the dose level of 10mg/kg B. W. Regular and fluorescein photographs were taken with Kowa RC-II ophthalmoscope-camera by using daylight typed color film. Following findings were obtained in each age class: Retinal color was salmon pink with 0 to 3-days-old neonates, salmon pink and blue to green with 7 days to 14-days-old animals and blue to green with 60-days to 90-days-old monkeys. As regards optic disc, 0- to 14-days-old animals were observed to be light orange in color, and the infant aged more than 28-days showed orange color. Retinal arteries and veins were lightly reddish in color with every age class. Macular color was salmon pink in 0-day-old cases, slightly dark in 3-days-old neonates and very dark after 14-days of age. Lightly retinal reflex was noted in 0- and 7-days-old animals. The reflex was observable in 14-days-old animals without any case of exception. Retinal hemorrhages were recorded in 22 (67%) of 36 neonates born in natural condition and 10 (33%) of 30 neonates born by cesarean section. These findings will be useful as the criteria for ophthalmoscopic observations of the cynomolgus monkeys as laboratory use. PMID:6468512

  19. Fundus depolarization imaging with GDx VCC scanning laser polarimeter and depolarization characteristics of normal eyes

    NASA Astrophysics Data System (ADS)

    Zhou, Qienyuan; Leder, Henry A.; Lo, Barrick P.; Reed, Geradus C.; Knighton, Robert W.; Cousins, Scott W.

    2009-02-01

    GDx VCC is a confocal scanning laser polarimeter (SLP) developed to assess the retinal nerve fiber layer (RNFL) of the eye based on measurement of the phase retardation in the backscattered light from the fundus. In addition to the phase retardation measurement, a depolarization measurement is readily available from the same image series. We hypothesize that the depolarized light in the GDx signal consists of backscattering from the retinal pigment epithelium (RPE) and the RPE-Bruch's membrane junction, and further, that subRPE deposits contribute to the depolarized backscattered light in proportion to their thickness. Therefore, a quantitative macular depolarization map will provide information about both spatial distribution and heterogeneity of the RPE structure and deposit thickness. Ultimately we predict that depolarization mapping will significantly increase the positive predictive power to identify early dry AMD eyes. In this paper, depolarization measurements in normal eyes and age related changes are reported. Data collection was performed at the Duke University Eye Center. A commercial GDx VCC system was modified with a central fixation target and, instead of depolarized light intensity images, normalized depolarization images were derived and saved in the database. Macular depolarization was observed to increase with age in normal eyes at a rate of 0.27%/yr.

  20. Normal and abnormal human vestibular ocular function

    NASA Technical Reports Server (NTRS)

    Peterka, R. J.; Black, F. O.

    1986-01-01

    The major motivation of this research is to understand the role the vestibular system plays in sensorimotor interactions which result in spatial disorientation and motion sickness. A second goal was to explore the range of abnormality as it is reflected in quantitative measures of vestibular reflex responses. The results of a study of vestibular reflex measurements in normal subjects and preliminary results in abnormal subjects are presented in this report. Statistical methods were used to define the range of normal responses, and determine age related changes in function.

  1. Characterization of the normal microbiota of the ocular surface.

    PubMed

    Willcox, Mark D P

    2013-12-01

    The ocular surface is continually exposed to the environment and as a consequence to different types of microbes, but whether there is a normal microbiota of the ocular surface remains unresolved. Using traditional microbial culture techniques has shown that <80% of swabs of the conjunctiva yield cultivable microbes. These usually belong to the bacterial types of the coagulase-negative staphylococci, Propionibacterium sp., with low frequency of isolation of bacteria such as Staphylococcus aureus, Micrococcus sp., Gram-negative bacteria or fungi. Even when these are grown, the numbers of colony forming units (cfu) per swab of the conjunctiva is usually much less than 100 cfu. Swabs of the lid more commonly result in microbial growth, of the same species as from the conjunctiva and slightly higher cfu. Contact lenses have also been cultured, and they yield similar microbial types. Microbes can be isolated from the ocular surface almost immediately after birth. The advent of molecular techniques for microbial identification based on 16S rRNA sequencing has opened up the possibility of determining whether there are non-cultivable microbes that can colonise the ocular surface. Additionally, use of these techniques with cross-sectional and longitudinal studies may help to understand whether the ocular surface harbours its own unique microbiota, or whether the microbiota are only transiently present. PMID:23797046

  2. Hyperspectral fundus imager

    NASA Astrophysics Data System (ADS)

    Truitt, Paul W.; Soliz, Peter; Meigs, Andrew D.; Otten, Leonard John, III

    2000-11-01

    A Fourier Transform hyperspectral imager was integrated onto a standard clinical fundus camera, a Zeiss FF3, for the purposes of spectrally characterizing normal anatomical and pathological features in the human ocular fundus. To develop this instrument an existing FDA approved retinal camera was selected to avoid the difficulties of obtaining new FDA approval. Because of this, several unusual design constraints were imposed on the optical configuration. Techniques to calibrate the sensor and to define where the hyperspectral pushbroom stripe was located on the retina were developed, including the manufacturing of an artificial eye with calibration features suitable for a spectral imager. In this implementation the Fourier transform hyperspectral imager can collect over a hundred 86 cm-1 spectrally resolved bands with 12 micro meter/pixel spatial resolution within the 1050 nm to 450 nm band. This equates to 2 nm to 8 nm spectral resolution depending on the wavelength. For retinal observations the band of interest tends to lie between 475 nm and 790 nm. The instrument has been in use over the last year successfully collecting hyperspectral images of the optic disc, retinal vessels, choroidal vessels, retinal backgrounds, and macula diabetic macular edema, and lesions of age-related macular degeneration.

  3. Location of Tessellations in Ocular Fundus and Their Associations with Optic Disc Tilt, Optic Disc Area, and Axial Length in Young Healthy Eyes

    PubMed Central

    Terasaki, Hiroto; Yamashita, Takehiro; Yoshihara, Naoya; Kii, Yuya; Tanaka, Minoru; Nakao, Kumiko; Sakamoto, Taiji

    2016-01-01

    Tessellated fundus is found as common and early-phase characteristic of myopic eyes and their locations are varied among patients. However, the relationship between their locations and morphological parameters of the eyes is still unknown. The purpose is this study is to determine the locations of the tessellations in the ocular fundus of young healthy eyes, and to determine relationships between their locations and morphological parameters of the eyes. This is a prospective observational cross sectional study of 126 eyes of 126 healthy volunteers (mean age 26.0±4.1 years). The eyes were classified into eight groups based on the location of the tessellations; no tessellation, temporal, infra-temporal, inferior, nasal, peripapillary, whole retina, and unclassified tessellations. The degree of optic disc tilt was quantified using a sine curve fitting program on the optical coherence tomographic circle scan images. The correlations between each tessellation location and the axial length, area of the optic disc plus conus (AOC), and optic disc tilt were determined. Forty-four eyes were place in the no tessellation group, 12 eyes in the temporal, 21 eyes in the infra-temporal, 9 eyes in the inferior, 8 eyes in the nasal, 15 eyes in the peripapillary, 11 eyes in the whole, and 6 eyes in the unclassified groups. The differences in the axial lengths between the no tessellation group and the infra-temporal groups were significant. A significant difference was found in the AOC between the no tessellation and the inferior, infra-temporal, and peripapilalry groups. A significant difference was found in the optic disc tilt between the no tessellation and infra-temporal groups (P<0.05). The tessellations are located at specific sites in the fundus of young healthy eyes with the infra-temporal location most frequent. It was correlated with some parameters associated with myopia. PMID:27275584

  4. Location of Tessellations in Ocular Fundus and Their Associations with Optic Disc Tilt, Optic Disc Area, and Axial Length in Young Healthy Eyes.

    PubMed

    Terasaki, Hiroto; Yamashita, Takehiro; Yoshihara, Naoya; Kii, Yuya; Tanaka, Minoru; Nakao, Kumiko; Sakamoto, Taiji

    2016-01-01

    Tessellated fundus is found as common and early-phase characteristic of myopic eyes and their locations are varied among patients. However, the relationship between their locations and morphological parameters of the eyes is still unknown. The purpose is this study is to determine the locations of the tessellations in the ocular fundus of young healthy eyes, and to determine relationships between their locations and morphological parameters of the eyes. This is a prospective observational cross sectional study of 126 eyes of 126 healthy volunteers (mean age 26.0±4.1 years). The eyes were classified into eight groups based on the location of the tessellations; no tessellation, temporal, infra-temporal, inferior, nasal, peripapillary, whole retina, and unclassified tessellations. The degree of optic disc tilt was quantified using a sine curve fitting program on the optical coherence tomographic circle scan images. The correlations between each tessellation location and the axial length, area of the optic disc plus conus (AOC), and optic disc tilt were determined. Forty-four eyes were place in the no tessellation group, 12 eyes in the temporal, 21 eyes in the infra-temporal, 9 eyes in the inferior, 8 eyes in the nasal, 15 eyes in the peripapillary, 11 eyes in the whole, and 6 eyes in the unclassified groups. The differences in the axial lengths between the no tessellation group and the infra-temporal groups were significant. A significant difference was found in the AOC between the no tessellation and the inferior, infra-temporal, and peripapilalry groups. A significant difference was found in the optic disc tilt between the no tessellation and infra-temporal groups (P<0.05). The tessellations are located at specific sites in the fundus of young healthy eyes with the infra-temporal location most frequent. It was correlated with some parameters associated with myopia. PMID:27275584

  5. Inter-ocular contrast normalization in human visual cortex

    PubMed Central

    Moradi, Farshad; Heeger, David J.

    2009-01-01

    The brain combines visual information from the two eyes and forms a coherent percept, even when inputs to the eyes are different. However, it is not clear how inputs from the two eyes are combined in visual cortex. We measured fMRI responses to single gratings presented monocularly, or pairs of gratings presented monocularly or dichoptically with several combinations of contrasts. Gratings had either the same orientation or orthogonal orientations (i.e., plaids). Observers performed a demanding task at fixation to minimize top-down modulation of the stimulus-evoked responses. Dichoptic presentation of compatible gratings (same orientation) evoked greater activity than monocular presentation of a single grating only when contrast was low (<10%). A model that assumes linear summation of activity from each eye failed to explain binocular responses at 10% contrast or higher. However, a model with binocular contrast normalization, such that activity from each eye reduced the gain for the other eye, fitted the results very well. Dichoptic presentation of orthogonal gratings evoked greater activity than monocular presentation of a single grating for all contrasts. However, activity evoked by dichoptic plaids was equal to that evoked by monocular plaids. Introducing an onset asynchrony (stimulating one eye 500 ms before the other, which under attentive vision results in flash suppression) had no impact on the results; the responses to dichoptic and monocular plaids were again equal. We conclude that when attention is diverted, inter-ocular suppression in V1 can be explained by a normalization model in which the mutual suppression between orthogonal orientations does not depend on the eye of origin, nor on the onset times, and cross-orientation suppression is weaker than inter-ocular (same orientation) suppression. PMID:19757952

  6. Regional Image Features Model for Automatic Classification between Normal and Glaucoma in Fundus and Scanning Laser Ophthalmoscopy (SLO) Images.

    PubMed

    Haleem, Muhammad Salman; Han, Liangxiu; Hemert, Jano van; Fleming, Alan; Pasquale, Louis R; Silva, Paolo S; Song, Brian J; Aiello, Lloyd Paul

    2016-06-01

    Glaucoma is one of the leading causes of blindness worldwide. There is no cure for glaucoma but detection at its earliest stage and subsequent treatment can aid patients to prevent blindness. Currently, optic disc and retinal imaging facilitates glaucoma detection but this method requires manual post-imaging modifications that are time-consuming and subjective to image assessment by human observers. Therefore, it is necessary to automate this process. In this work, we have first proposed a novel computer aided approach for automatic glaucoma detection based on Regional Image Features Model (RIFM) which can automatically perform classification between normal and glaucoma images on the basis of regional information. Different from all the existing methods, our approach can extract both geometric (e.g. morphometric properties) and non-geometric based properties (e.g. pixel appearance/intensity values, texture) from images and significantly increase the classification performance. Our proposed approach consists of three new major contributions including automatic localisation of optic disc, automatic segmentation of disc, and classification between normal and glaucoma based on geometric and non-geometric properties of different regions of an image. We have compared our method with existing approaches and tested it on both fundus and Scanning laser ophthalmoscopy (SLO) images. The experimental results show that our proposed approach outperforms the state-of-the-art approaches using either geometric or non-geometric properties. The overall glaucoma classification accuracy for fundus images is 94.4% and accuracy of detection of suspicion of glaucoma in SLO images is 93.9 %. PMID:27086033

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

    PubMed Central

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

    2014-01-01

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

  8. Visual-Ocular Control of Normal and Learning-Disabled Children.

    ERIC Educational Resources Information Center

    Polatajko, H. J.

    1987-01-01

    Differences in visual-ocular function, particularly optokinetic nystagmus (OKN), were compared with 40 learning disabled and 40 normal children (8-12 years-old). No significant differences were found between groups on the variables tested (refixation saccades, smooth ocular pursuit, spontaneous nystagmus, gaze nystagmus, and OKN). (Author/DB)

  9. Intra-ocular pressure normalization technique and equipment

    NASA Technical Reports Server (NTRS)

    Baehr, E. F. (Inventor)

    1979-01-01

    A method and apparatus is described for safely reducing abnormally high intraocular pressure in an eye during a predetermined time interval. This allows maintenance of normal intraocular pressure during glaucoma surgery. A pressure regulator of the spring-biassed diaphragm type is provided with additional bias by a column of liquid. The hypodermic needle can be safely inserted into the anterior chamber of the eye. Liquid is then bled out of the column to reduce the bias on the diaphragm of the pressure regulator and, consequently, the output pressure of the regulator. This lowering pressure of the regulator also occurs in the eye by means of a small second bleed path provided between the pressure regulator and the hypodermic needle.

  10. Intra-ocular pressure normalization technique and equipment

    NASA Technical Reports Server (NTRS)

    Mcgannon, W. J. (Inventor)

    1980-01-01

    A method and apparatus for safely reducing abnormally high intraocular pressure in an eye during a predetermined time interval is presented. This allows maintenance of normal intraocular pressure during glaucoma surgery. According to the invention, a pressure regulator of the spring biased diaphragm type is provided with additional bias by a column of liquid. The height of the column of liquid is selected such that the pressure at a hypodermic needle connected to the output of the pressure regulator is equal to the measured pressure of the eye. The hypodermic needle can then be safely inserted into the anterior chamber of the eye. Liquid is then bled out of the column to reduce the bias on the diaphragm of the pressure regulator and, consequently, the output pressure of the regulator. This lowering pressure of the regulator also occurs in the eye by means of a small second bleed path provided between the pressure regulator and the hypodermic needle. Alternately, a second hypodermic needle may be inserted into the eye to provide a controlled leak off path for excessive pressure and clouded fluid from the anterior chamber.

  11. Evaluation of optic disc size in patients with optic nerve head drusen using fundus photography

    PubMed Central

    Gili, Pablo; Flores-Rodríguez, Patricia; Yangüela, Julio; Orduña-Azcona, Javier; Martín-Ríos, María Dolores

    2012-01-01

    Purpose To evaluate if fundus photography is useful to study the size of the optic disc in patients with optic nerve head drusen (ONHD). Methods Cross-sectional study. Fifty-five patients with ONHD confirmed by B-scan echography and 52 patients’ normal controls were studied. Fundus photography was done in all the cases with a telecentric optical system FF450 IR plus from Zeiss with 20° magnification and Visupac measuring system. We measured total optic disc area, vertical and horizontal diameter. Results Patients with ONHD had smaller optic disc area 2.6 ± 0.55 mm2 (mean ± SD), horizontal diameter (1.68 ± 0.18 mm) and vertical diameter (1.94 ± 0.28 mm) than normal controls (2.93 ± 0.43 mm2, 1.86 ± 0.14 mm and 1.98 ± 0.17 mm, respectively). Significant differences were found in area (p = 0.002) and horizontal diameter (p < 0.001). Conclusions Patients with optic nerve head drusen had smaller optic disc size than normal controls, under digital fundus photography. Fundus photography could be helpful to differentiate optic nerve drusen from other ocular conditions.

  12. Novel fundus camera design

    NASA Astrophysics Data System (ADS)

    Dehoog, Edward A.

    A fundus camera a complex optical system that makes use of the principle of reflex free indirect ophthalmoscopy to image the retina. Despite being in existence as early as 1900's, little has changed in the design of a fundus camera and there is minimal information about the design principles utilized. Parameters and specifications involved in the design of fundus camera are determined and their affect on system performance are discussed. Fundus cameras incorporating different design methods are modeled and a performance evaluation based on design parameters is used to determine the effectiveness of each design strategy. By determining the design principles involved in the fundus camera, new cameras can be designed to include specific imaging modalities such as optical coherence tomography, imaging spectroscopy and imaging polarimetry to gather additional information about properties and structure of the retina. Design principles utilized to incorporate such modalities into fundus camera systems are discussed. Design, implementation and testing of a snapshot polarimeter fundus camera are demonstrated.

  13. Normal ocular parameters and characterization of ophthalmic lesions in a group of captive bald eagles (Haliaeetus leucocephalus).

    PubMed

    Kuhn, Sonia E; Jones, Michael P; Hendrix, Diane V H; Ward, Daniel A; Baine, Katherine H

    2013-06-01

    Sixteen adult captive bald eagles (Haliaeetus leucocephalus) underwent a complete bilateral ocular examination to assess normal ocular parameters and describe ophthalmic lesions. Tear production was measured with the Schirmer tear test 1 and intraocular pressure was measured with applanation tonometry. The menace response was normal bilaterally in 13 of 16 eagles. Two birds had normal menace responses despite having fundic lesions, and 2 birds with an inconsistent or absent menace response did not have appreciable ophthalmic lesions. Mean (SD) tear production was 14 +/- 2 mm/min (range, 8-19 mm/min). Mean intraocular pressure was 21.5 +/- 1.7 mm Hg (range, 15-26 mm Hg). At least 1 ocular lesion was present in 50% of examined eyes. Cataracts, the most common lesion observed, were present in 8 eyes of 5 birds. Three of 4 known geriatric birds were or had been affected with bilateral cataracts. Overall, ocular lesions are common in captive bald eagles, and cataracts appear to be more prevalent in geriatric bald eagles. An obvious positive menace response is present in most visual birds but may be absent in some eagles that are either normal or that do not have appreciable ophthalmic lesions. Applanation tonometry and the Schirmer tear test 1 can be performed easily on adult bald eagles and provide reproducible results. PMID:23971217

  14. Portable dynamic fundus instrument

    NASA Technical Reports Server (NTRS)

    Taylor, Gerald R. (Inventor); Meehan, Richard T. (Inventor); Hunter, Norwood R. (Inventor); Caputo, Michael P. (Inventor); Gibson, C. Robert (Inventor)

    1992-01-01

    A portable diagnostic image analysis instrument is disclosed for retinal funduscopy in which an eye fundus image is optically processed by a lens system to a charge coupled device (CCD) which produces recordable and viewable output data and is simultaneously viewable on an electronic view finder. The fundus image is processed to develop a representation of the vessel or vessels from the output data.

  15. The dynamic sclera: extracellular matrix remodeling in normal ocular growth and myopia development.

    PubMed

    Harper, Angelica R; Summers, Jody A

    2015-04-01

    Myopia is a common ocular condition, characterized by excessive elongation of the ocular globe. The prevalence of myopia continues to increase, particularly among highly educated groups, now exceeding 80% in some groups. In parallel with the increased prevalence of myopia, are increases in associated blinding ocular conditions including glaucoma, retinal detachment and macular degeneration, making myopia a significant global health concern. The elongation of the eye is closely related to the biomechanical properties of the sclera, which in turn are largely dependent on the composition of the scleral extracellular matrix. Therefore an understanding of the cellular and extracellular events involved in the regulation of scleral growth and remodeling during childhood and young adulthood will provide future avenues for the treatment of myopia and its associated ocular complications. PMID:25819458

  16. Precise modelling of the eye for proton therapy of intra-ocular tumours

    NASA Astrophysics Data System (ADS)

    Dobler, Barbara; Bendl, Rolf

    2002-02-01

    A new method is described that allows precise modelling of organs at risk and target volume for radiation therapy of intra-ocular tumours. The aim is to optimize the dose distribution and thus to reduce normal tissue complication probability. A geometrical 3D model based on elliptic shapes was developed that can be used for multimodal model-based segmentation of 3D patient data. The tumour volume cannot be clearly identified in CT and MR data, whereas the tumour outline can be discriminated very precisely in fundus photographs. Therefore, a multimodal 2D fundus diagram was developed, which allows us to correlate and display simultaneously information extracted from the eye model, 3D data and the fundus photograph. Thus, the connection of fundus diagram and 3D data is well-defined and the 3D volume can be calculated directly from the tumour outline drawn onto the fundus photograph and the tumour height measured by ultrasound. The method allows the calculation of a precise 3D eye model of the patient, including the different structures of the eye as well as the tumour volume. The method was developed as part of the new 3D treatment planning system OCTOPUS for proton therapy of ocular tumours within a national research project together with the Hahn-Meitner-Institut Berlin.

  17. Ocular motor responses to abrupt interaural head translation in normal humans

    NASA Technical Reports Server (NTRS)

    Ramat, Stefano; Zee, David S.; Shelhamer, M. J. (Principal Investigator)

    2003-01-01

    We characterized the interaural translational vestibulo-ocular reflex (tVOR) in 6 normal humans to brief (approximately 200 ms), high-acceleration (0.4-1.4g) stimuli, while they fixed targets at 15 or 30 cm. The latency was 19 +/- 5 ms at 15-cm and 20 +/- 12 ms at 30-cm viewing. The gain was quantified using the ratio of actual to ideal behavior. The median position gain (at time of peak head velocity) was 0.38 and 0.37, and the median velocity gain, 0.52 and 0.62, at 15- and 30-cm viewing, respectively. These results suggest the tVOR scales proportionally at these viewing distances. Likewise, at both viewing distances, peak eye velocity scaled linearly with peak head velocity and gain was independent of peak head acceleration. A saccade commonly occurred in the compensatory direction, with a greater latency (165 vs. 145 ms) and lesser amplitude (1.8 vs. 3.2 deg) at 30- than 15-cm viewing. Even with saccades, the overall gain at the end of head movement was still considerably undercompensatory (medians 0.68 and 0.77 at 15- and 30-cm viewing). Monocular viewing was also assessed at 15-cm viewing. In 4 of 6 subjects, gains were the same as during binocular viewing and scaled closely with vergence angle. In sum the low tVOR gain and scaling of the response with viewing distance and head velocity extend previous results to higher acceleration stimuli. tVOR latency (approximately 20 ms) was lower than previously reported. Saccades are an integral part of the tVOR, and also scale with viewing distance.

  18. Improved scanning laser fundus imaging using polarimetry

    NASA Astrophysics Data System (ADS)

    Bueno, Juan M.; Hunter, Jennifer J.; Cookson, Christopher J.; Kisilak, Marsha L.; Campbell, Melanie C. W.

    2007-05-01

    We present a polarimetric technique to improve fundus images that notably simplifies and extends a previous procedure [Opt. Lett.27, 830 (2002)]. A generator of varying polarization states was incorporated into the illumination path of a confocal scanning laser ophthalmoscope. A series of four images, corresponding to independent incoming polarization states, were recorded. From these images, the spatially resolved elements of the top row of the Mueller matrix were computed. From these elements, images with the highest and lowest quality (according to different image quality metrics) were constructed, some of which provided improved visualization of fundus structures of clinical importance (vessels and optic nerve head). The metric values were better for these constructed images than for the initially recorded images and better than averaged images. Entropy is the metric that is most sensitive to differences in the image quality. Improved visualization of features could aid in the detection, localization, and tracking of ocular disease and may be applicable in other biomedical imaging.

  19. The fundus slit lamp.

    PubMed

    Gellrich, Marcus-Matthias

    2015-01-01

    Fundus biomicroscopy with the slit lamp as it is practiced widely nowadays was not established until the 1980-es with the introduction of the Volk lenses +90 and +60D. Thereafter little progress has been made in retinal imaging with the slit lamp. It is the aim of this paper to fully exploit the potential of a video slit lamp for fundus documentation by using easily accessible additions. Suitable still images are easily retrieved from videorecordings of slit lamp examinations. The effects of changements in the slit lamp itself (slit beam and apertures) and its examination equipment (converging lenses from +40 to +90D) on quality and spectrum of fundus images are demonstrated. Imaging software is applied for reconstruction of larger fundus areas in a mosaic pattern (Hugin®) and to perform the flicker test in order to visualize changes in the same fundus area at different points of time (Power Point®). The three lenses +90/+60/+40D are a good choice for imaging the whole spectrum of retinal diseases. Displacement of the oblique slit light can be used to assess changes in the surface profile of the inner retina which occurs e.g. in macular holes or pigment epithelial detachment. The mosaic function in its easiest form (one strip macula adapted to one strip with the optic disc) provides an overview of the posterior pole comparable to a fundus camera's image. A reconstruction of larger fundus areas is feasible for imaging in vitreoretinal surgery or occlusive vessel disease. The flicker test is a fine tool for monitoring progressive glaucoma by changes in the optic disc, and it is also a valuable diagnostic tool in macular disease. Nearly all retinal diseases can be imaged with the slit lamp - irrespective whether they affect the posterior pole, mainly the optic nerve or the macula, the whole retina or only its periphery. Even a basic fundus controlled perimetry is possible. Therefore fundus videography with the slit lamp is a worthwhile approach especially for the

  20. The Cervico-Ocular Reflex of normal human subjects in response to transient and sinusoidal trunk rotations

    NASA Technical Reports Server (NTRS)

    Sawyer, Robert N., Jr.; Thurston, Stephen E.; Becker, Keith R.; Ackley, Charles V.; Seidman, Scott H.; Leigh, R. John

    1994-01-01

    We used the magnetic search coil technique to measure the horizontal cervico-ocular reflex (COR) of 8 subjects in response to transient or sinusoidal (0.1-1.0 Hz) trunk rotations while their heads were firmly immobilized. Although we were able to resolve eye rotations of less than 0.05 deg, the COR was hardly measurable (gain was always less than 0.07). This finding, made with the most precise measurement technique used to date, suggests that the COR makes a negligible contribution to the stability of gaze in normal subjects during natural activities.

  1. [Enhancement and assessment of the fundus image].

    PubMed

    Chen, Mengmeng; Xiong, Xingliang; Li, Guang; Zhang, Tingting

    2014-10-01

    A new enhancement method is proposed based on the characteristics of fundus images in this paper. Firstly, top-hat transform is utilized to weaken the background. Secondly, contrast limited adaptive histogram equalization (CLAHE) is performed to improve the uneven illumination. Finally, two-dimensional matched filters are designed to further enhance the contrast between blood vessels and background. The algorithm was tested in DIARETDB0 databases and showed good applicability for both normal and pathological fundus images. A new no-reference image quality assessment method was used to evaluate the enhancement methods objectively. The results demonstrated that the proposed method could effectively weaken the background, increase contrast, enhance details in the fundus images and improve the image quality greatly. PMID:25764739

  2. The Human Vertical Translation Vestibulo-ocular Reflex (tVOR): Normal and Abnormal Responses

    PubMed Central

    Liao, Ke; Walker, Mark F.; Joshi, Anand; Reschke, Millard; Strupp, Michael; Leigh, R. John

    2010-01-01

    Geometric considerations indicate that the human translational vestibulo-ocular reflex (tVOR) should have substantially different properties than the angular vestibulo-ocular reflex (aVOR). Specifically, tVOR cannot simultaneously stabilize images of distant and near objects on the retina. Most studies make the tacit assumption that tVOR acts to stabilize foveal images even though, in humans, tVOR is reported to compensate for less than 60% of foveal image motion. We have determined that the compensation gain (eye rotational velocity / required eye rotational velocity to maintain foveal target fixation) of tVOR is held steady at ~ 0.6 during viewing of either near or distant targets during vertical (bob) translations in ambient illumination. We postulate that tVOR evolved not to stabilize the image of the target on the fovea, but rather to minimize retinal image motion between objects lying in different depth planes, in order to optimize motion parallax information. Such behavior is optimized when binocular visual cues of both far and distant targets are available in ambient light. Patients with progressive supranuclear palsy or cerebellar ataxia show impaired ability to increase tVOR responses appropriately when they view near targets. In cerebellar patients, impaired ability to adjust tVOR responses to viewing conditions occurs despite intact ability to converge at near. Loss of the ability to adjust tVOR according to viewing conditions appears to represent a distinct disorder of vestibular function. PMID:19645882

  3. Digital infrared fundus reflectance.

    PubMed

    Packer, S; Schneider, K; Lin, H Z; Feldman, M

    1980-06-01

    An infrared sensor was inserted at the film plane of a fundus camera. The signal was visualized on an oscilloscope. In this manner we measured infrared reflectance from the surface of the fundus. The purpose was to characterize choroidal malignant melanomas more reliably than is done with infrared color translation photography. Control lesions were choroidal nevi, metastatic tumors, and disciform macular degenerations. Correlations were made with radioactive phosphorus (32P) uptake, fluorescein angiography, and histopathologic findings. Several cases are presented, one in which this new method of infrared detection was the first diagnostic test to detect the spread of a choroidal melanoma. The simplicity of this technique and its increased accuracy justify the needed further refinements. PMID:7413142

  4. Ocular Hypertension

    MedlinePlus

    ... Español Eye Health / Eye Health A-Z Ocular Hypertension Sections What Is Ocular Hypertension? Ocular Hypertension Causes ... Hypertension Diagnosis Ocular Hypertension Treatment What Is Ocular Hypertension? Written by: Kierstan Boyd Reviewed by: J Kevin ...

  5. Von Hippel-Lindau protein in the RPE is essential for normal ocular growth and vascular development

    PubMed Central

    Lange, Clemens A. K.; Luhmann, Ulrich F. O.; Mowat, Freya M.; Georgiadis, Anastasios; West, Emma L.; Abrahams, Sabu; Sayed, Haroon; Powner, Michael B.; Fruttiger, Marcus; Smith, Alexander J.; Sowden, Jane C.; Maxwell, Patrick H.; Ali, Robin R.; Bainbridge, James W. B.

    2012-01-01

    Molecular oxygen is essential for the development, growth and survival of multicellular organisms. Hypoxic microenvironments and oxygen gradients are generated physiologically during embryogenesis and organogenesis. In the eye, oxygen plays a crucial role in both physiological vascular development and common blinding diseases. The retinal pigment epithelium (RPE) is a monolayer of cells essential for normal ocular development and in the mature retina provides support for overlying photoreceptors and their vascular supply. Hypoxia at the level of the RPE is closely implicated in pathogenesis of age-related macular degeneration. Adaptive tissue responses to hypoxia are orchestrated by sophisticated oxygen sensing mechanisms. In particular, the von Hippel-Lindau tumour suppressor protein (pVhl) controls hypoxia-inducible transcription factor (HIF)-mediated adaptation. However, the role of Vhl/Hif1a in the RPE in the development of the eye and its vasculature is unknown. In this study we explored the function of Vhl and Hif1a in the developing RPE using a tissue-specific conditional-knockout approach. We found that deletion of Vhl in the RPE results in RPE apoptosis, aniridia and microphthalmia. Increased levels of Hif1a, Hif2a, Epo and Vegf are associated with a highly disorganised retinal vasculature, chorioretinal anastomoses and the persistence of embryonic vascular structures into adulthood. Additional inactivation of Hif1a in the RPE rescues the RPE morphology, aniridia, microphthalmia and anterior vasoproliferation, but does not rescue retinal vasoproliferation. These data demonstrate that Vhl-dependent regulation of Hif1a in the RPE is essential for normal RPE and iris development, ocular growth and vascular development in the anterior chamber, whereas Vhl-dependent regulation of other downstream pathways is crucial for normal development and maintenance of the retinal vasculature. PMID:22627278

  6. High-Procession Eye Tracking Using Fundus Images

    NASA Technical Reports Server (NTRS)

    Mulligan, Jeffrey B.

    1996-01-01

    Fundus images provide high optical gain for eye movement tracking, i.e. large image displacements occur as a result of small eye rotations. Subpixel registration techniques can provide resolution better than 1 arc minute using images acquired with a CCD camera. Ocular torsion may also be estimated, with a precision of approximately 0.1 degree. This talk will discuss the software algorithms used to attain this performance.

  7. Comparison of Ocular Monochromatic Higher-order Aberrations in Normal Refractive Surgery Candidates of Arab and South Asian Origin

    PubMed Central

    Prakash, Gaurav; Srivastava, Dhruv; Choudhuri, Sounak; Bacero, Ruthchel

    2016-01-01

    Purpose: To compare the ocular monochromatic higher-order aberration. (HOA) profile in normal refractive surgery candidates of Arab and South Asian origin. Methods: This cross-sectional, observational, comparative study was performed in the cornea department of a specialty hospital. Normal refractive surgery candidates with no ocular morbidity except refractive error were recruited. Refractive surgery candidates underwent a preoperative evaluation, including wavefront aberrometry with the iDesign aberrometer (AMO, Inc., Santa Ana, California, United States). The HOA from right eyes were analyzed for HOA signed, absolute, and polar Zernike coefficients. Results: Two hundred Arab participants (group 1) and 200 participants of South-Asian origin (group 2) comprised the study sample. The age and refractive status were comparable between groups. The mean of the HOA root mean square (RMS) was 0.36 ± 17 μ and 0.38 ± 18 μ for Arab and South-Asian eyes, respectively (P < 0.05, rank sum test [RST]). Of the 22 higher order signed Zernike modes, only Z3−3, Z3−1,31, Z4−4, Z4−2, Z40, Z44, and Z5−5 were significantly different from zero (one sample t-test, P < 0.002, with a Bonferroni correction of 0.05/22). All the signed and absolute Zernike terms were comparable between groups (RST, P > 0.002 [0.05/22]). The polar coefficients for coma, trefoil, spherical aberration, and tetrafoil were comparable between groups (P > 0.05, RST). Combined RMS values of third, fourth, fifth, and sixth order also were comparable between groups (P > 0.05, RST). Conclusions: Preoperative whole eye HOA were similar for refractive surgery candidates of Arab and South-Asian origin. The values were comparable to historical data for Caucasian eyes and were lower than Asian (Chinese) eyes. These findings may aid in refining refractive nomograms for wavefront ablations. PMID:26957850

  8. Fundus Camera Guided Photoacoustic Ophthalmoscopy

    PubMed Central

    Liu, Tan; Li, Hao; Song, Wei; Jiao, Shuliang; Zhang, Hao F.

    2014-01-01

    Purpose To demonstrate the feasibility of fundus camera guided photoacoustic ophthalmoscopy (PAOM) system and its multimodal imaging capabilities. Methods We integrated PAOM and a fundus camera consisting of a white-light illuminator and a high-sensitivity, high-speed CCD. The fundus camera captures both retinal anatomy and PAOM illumination at the same time to provide a real-time feedback when we position the PAOM illuminating light. We applied the integrated system to image rat eyes in vivo and used full-spectrum, visible (VIS), and near infrared (NIR) illuminations in fundus photography. Results Both albino and pigmented rat eyes were imaged in vivo. During alignment, different trajectories of PAOM laser scanning were successfully visualized by the fundus camera, which reduced the PAOM alignment time from several minutes to 30 s. In albino eyes, in addition to retinal vessels, main choroidal vessels were observed using VIS-illumination, which is similar to PAOM images. In pigmented eyes, the radial striations of retinal nerve fiber layer were visualized by fundus photography using full-spectrum illumination; meanwhile, PAOM imaged both retinal vessels and the retinal pigmented epithelium melanin distribution. Conclusions The results demonstrated that PAOM can be well-integrated with fundus camera without affecting its functionality. The fundus camera guidance is faster and easier comparing with our previous work. The integrated system also set the stage for the next-step verification between oximetry methods based on PAOM and fundus photography. PMID:24131226

  9. Fundus autofluorescence and colour fundus imaging compared during telemedicine screening in patients with diabetes.

    PubMed

    Kolomeyer, Anton M; Baumrind, Benjamin R; Szirth, Bernard C; Shahid, Khadija; Khouri, Albert S

    2013-06-01

    We investigated the use of fundus autofluorescence (FAF) imaging in screening the eyes of patients with diabetes. Images were obtained from 50 patients with type 2 diabetes undergoing telemedicine screening with colour fundus imaging. The colour and FAF images were obtained with a 15.1 megapixel non-mydriatic retinal camera. Colour and FAF images were compared for pathology seen in nonproliferative and proliferative diabetic retinopathy (NPDR and PDR, respectively). A qualitative assessment was made of the ease of detecting early retinopathy changes and the extent of existing retinopathy. The mean age of the patients was 47 years, most were male (82%) and most were African American (68%). Their mean visual acuity was 20/45 and their mean intraocular pressure was 14.3 mm Hg. Thirty-eight eyes (76%) did not show any diabetic retinopathy changes on colour or FAF imaging. Seven patients (14%) met the criteria for NPDR and five (10%) for severe NPDR or PDR. The most common findings were microaneurysms, hard exudates and intra-retinal haemorrhages (IRH) (n = 6 for each). IRH, microaneurysms and chorioretinal scars were more easily visible on FAF images. Hard exudates, pre-retinal haemorrhage and fibrosis, macular oedema and Hollenhorst plaque were easier to identify on colour photographs. The value of FAF imaging as a complementary technique to colour fundus imaging in detecting diabetic retinopathy during ocular screening warrants further investigation. PMID:24163061

  10. [Fundus Autofluorescence Imaging].

    PubMed

    Schmitz-Valckenberg, S

    2015-09-01

    Fundus autofluorescence (FAF) imaging allows for non-invasive mapping of changes at the level of the retinal pigment epithelium/photoreceptor complex and of alterations of macular pigment distribution. This imaging method is based on the visualisation of intrinsic fluorophores and may be easily and rapidly used in routine patient care. Main applications include degenerative disorders of the outer retina such as age-related macular degeneration, hereditary and acquired retinal diseases. FAF imaging is particularly helpful for differential diagnosis, detection and extent of involved retinal areas, structural-functional correlations and monitoring of changes over time. Recent developments include - in addition to the original application of short wavelength light for excitation ("blue" FAF imaging) - the use of other wavelength ranges ("green" or "near-infrared" FAF imaging), widefield imaging for visualisation of peripheral retinal areas and quantitative FAF imaging. PMID:26280647

  11. Endothelium Expression of Bcl-2 Is Essential for Normal and Pathological Ocular Vascularization.

    PubMed

    Zaitoun, Ismail S; Johnson, Ryan P; Jamali, Nasim; Almomani, Reem; Wang, Shoujian; Sheibani, Nader; Sorenson, Christine M

    2015-01-01

    Bcl-2 is an anti-apoptotic protein with important roles in vascular homeostasis and angiogenesis. Mice globally lacking Bcl-2 (Bcl-2 -/-) are small in stature and succumb to renal failure shortly after weaning as a result of renal hypoplasia/cystic dysplasia. We have shown that Bcl-2 -/- mice displayed attenuated retinal vascular development and neovascularization. In vitro studies indicated that in addition to modulating apoptosis, Bcl-2 expression also impacts endothelial and epithelial cell adhesion, migration and extracellular matrix production. However, studies delineating the cell autonomous role Bcl-2 expression plays in the endothelium during vascular development, pruning and remodeling, and neovascularization are lacking. Here we generated mice carrying a conditional Bcl-2 allele (Bcl-2Flox/Flox) and VE-cadherin-cre (Bcl-2EC mice). Bcl-2EC mice were of normal stature and lifespan and displayed some but not all of the retinal vascular defects previously observed in global Bcl-2 deficient mice. Bcl-2EC mice had decreased numbers of endothelial cells, decreased retinal arteries and premature primary branching of the retinal vasculature, but unlike the global knockout mice, spreading of the retinal superficial vascular layer proceeded normally. Choroidal neovascularization was attenuated in Bcl-2EC mice, although retinal neovascularization accompanying oxygen-induced ischemic retinopathy was not. Thus, Bcl-2 expression in the endothelium plays a significant role during postnatal retinal vascularization, and pathological choroidal but not retinal neovascularization, suggesting vascular bed specific Bcl-2 function in the endothelium. PMID:26444547

  12. Endothelium Expression of Bcl-2 Is Essential for Normal and Pathological Ocular Vascularization

    PubMed Central

    Zaitoun, Ismail S.; Johnson, Ryan P.; Jamali, Nasim; Almomani, Reem; Wang, Shoujian; Sheibani, Nader; Sorenson, Christine M.

    2015-01-01

    Bcl–2 is an anti-apoptotic protein with important roles in vascular homeostasis and angiogenesis. Mice globally lacking Bcl–2 (Bcl–2 -/-) are small in stature and succumb to renal failure shortly after weaning as a result of renal hypoplasia/cystic dysplasia. We have shown that Bcl–2 -/- mice displayed attenuated retinal vascular development and neovascularization. In vitro studies indicated that in addition to modulating apoptosis, Bcl–2 expression also impacts endothelial and epithelial cell adhesion, migration and extracellular matrix production. However, studies delineating the cell autonomous role Bcl–2 expression plays in the endothelium during vascular development, pruning and remodeling, and neovascularization are lacking. Here we generated mice carrying a conditional Bcl–2 allele (Bcl-2Flox/Flox) and VE-cadherin-cre (Bcl-2EC mice). Bcl-2EC mice were of normal stature and lifespan and displayed some but not all of the retinal vascular defects previously observed in global Bcl–2 deficient mice. Bcl-2EC mice had decreased numbers of endothelial cells, decreased retinal arteries and premature primary branching of the retinal vasculature, but unlike the global knockout mice, spreading of the retinal superficial vascular layer proceeded normally. Choroidal neovascularization was attenuated in Bcl-2EC mice, although retinal neovascularization accompanying oxygen-induced ischemic retinopathy was not. Thus, Bcl–2 expression in the endothelium plays a significant role during postnatal retinal vascularization, and pathological choroidal but not retinal neovascularization, suggesting vascular bed specific Bcl–2 function in the endothelium. PMID:26444547

  13. Discrimination thresholds of normal and anomalous trichromats: Model of senescent changes in ocular media density on the Cambridge Colour Test.

    PubMed

    Shinomori, Keizo; Panorgias, Athanasios; Werner, John S

    2016-03-01

    Age-related changes in chromatic discrimination along dichromatic confusion lines were measured with the Cambridge Colour Test (CCT). One hundred and sixty-two individuals (16 to 88 years old) with normal Rayleigh matches were the major focus of this paper. An additional 32 anomalous trichromats classified by their Rayleigh matches were also tested. All subjects were screened to rule out abnormalities of the anterior and posterior segments. Thresholds on all three chromatic vectors measured with the CCT showed age-related increases. Protan and deutan vector thresholds increased linearly with age while the tritan vector threshold was described with a bilinear model. Analysis and modeling demonstrated that the nominal vectors of the CCT are shifted by senescent changes in ocular media density, and a method for correcting the CCT vectors is demonstrated. A correction for these shifts indicates that classification among individuals of different ages is unaffected. New vector thresholds for elderly observers and for all age groups are suggested based on calculated tolerance limits. PMID:26974943

  14. Subretinal Fibrosis in Stargardt's Disease with Fundus Flavimaculatus and ABCA4 Gene Mutation

    PubMed Central

    Rossi, Settimio; Testa, Francesco; Attanasio, Marcella; Orrico, Ada; de Benedictis, Antonella; Corte, Michele Della; Simonelli, Francesca

    2012-01-01

    Purpose To report on 4 patients affected by Stargardt's disease (STGD) with fundus flavimaculatus (FFM) and ABCA4 gene mutation associated with subretinal fibrosis. Methods Four patients with a diagnosis of STGD were clinically examined. All 4 cases underwent a full ophthalmologic evaluation, including best-corrected visual acuity measured by the Snellen visual chart, biomicroscopic examination, fundus examination, fundus photography, electroretinogram, microperimetry, optical coherence tomography and fundus autofluorescence. All patients were subsequently screened for ABCA4 gene mutations, identified by microarray genotyping and confirmed by conventional DNA sequencing of the relevant exons. Results In all 4 patients, ophthalmologic exam showed areas of subretinal fibrosis in different retinal sectors. In only 1 case, these lesions were correlated to an ocular trauma as confirmed by biomicroscopic examination of the anterior segment that showed a nuclear cataract dislocated to the superior site and vitreous opacities along the lens capsule. The other patients reported a lifestyle characterized by competitive sport activities. The performed instrumental diagnostic investigations confirmed the diagnosis of STGD with FFM in all patients. Moreover, in all 4 affected individuals, mutations in the ABCA4 gene were found. Conclusions Patients with the diagnosis of STGD associated with FFM can show atypical fundus findings. We report on 4 patients affected by STGD with ABCA4 gene mutation associated with subretinal fibrosis. Our findings suggest that this phenomenon can be accelerated by ocular trauma and also by ocular microtrauma caused by sport activities, highlighting that lifestyle can play a role in the onset of these lesions. PMID:23341817

  15. Automatic Microaneurysm Detection and Characterization Through Digital Color Fundus Images

    SciTech Connect

    Martins, Charles; Veras, Rodrigo; Ramalho, Geraldo; Medeiros, Fatima; Ushizima, Daniela

    2008-08-29

    Ocular fundus images can provide information about retinal, ophthalmic, and even systemic diseases such as diabetes. Microaneurysms (MAs) are the earliest sign of Diabetic Retinopathy, a frequently observed complication in both type 1 and type 2 diabetes. Robust detection of MAs in digital color fundus images is critical in the development of automated screening systems for this kind of disease. Automatic grading of these images is being considered by health boards so that the human grading task is reduced. In this paper we describe segmentation and the feature extraction methods for candidate MAs detection.We show that the candidate MAs detected with the methodology have been successfully classified by a MLP neural network (correct classification of 84percent).

  16. Human Visual System-Based Fundus Image Quality Assessment of Portable Fundus Camera Photographs.

    PubMed

    Wang, Shaoze; Jin, Kai; Lu, Haitong; Cheng, Chuming; Ye, Juan; Qian, Dahong

    2016-04-01

    Telemedicine and the medical "big data" era in ophthalmology highlight the use of non-mydriatic ocular fundus photography, which has given rise to indispensable applications of portable fundus cameras. However, in the case of portable fundus photography, non-mydriatic image quality is more vulnerable to distortions, such as uneven illumination, color distortion, blur, and low contrast. Such distortions are called generic quality distortions. This paper proposes an algorithm capable of selecting images of fair generic quality that would be especially useful to assist inexperienced individuals in collecting meaningful and interpretable data with consistency. The algorithm is based on three characteristics of the human visual system--multi-channel sensation, just noticeable blur, and the contrast sensitivity function to detect illumination and color distortion, blur, and low contrast distortion, respectively. A total of 536 retinal images, 280 from proprietary databases and 256 from public databases, were graded independently by one senior and two junior ophthalmologists, such that three partial measures of quality and generic overall quality were classified into two categories. Binary classification was implemented by the support vector machine and the decision tree, and receiver operating characteristic (ROC) curves were obtained and plotted to analyze the performance of the proposed algorithm. The experimental results revealed that the generic overall quality classification achieved a sensitivity of 87.45% at a specificity of 91.66%, with an area under the ROC curve of 0.9452, indicating the value of applying the algorithm, which is based on the human vision system, to assess the image quality of non-mydriatic photography, especially for low-cost ophthalmological telemedicine applications. PMID:26672033

  17. Ocular findings associated with chromosome 22q11.2 duplication.

    PubMed

    Forbes, Brian J; McDonald-McGinn, Donna M; Wootton, Georgia; Dawson, Lindsay; Zackai, Elaine; Binenbaum, Gil

    2016-06-01

    We describe the ocular features of the chromosome 22q11.2 duplication syndrome and provide ophthalmologic examination recommendations for affected patients. The medical records of 19 children with chromosome 22q11.2 duplication who had undergone complete ophthalmological examination, including dilated fundus examination and cycloplegic refraction, were studied retrospectively. Over half of the children with 22q11.2 duplication syndrome were found to have visually significant ocular abnormalities, including 6 with strabismus, 2 with moderately high astigmatism requiring glasses, 1 with unilateral congenital cataract requiring surgery, 1 with optic disk drusen, 1 with bilateral megalocornea with normal eye pressures, 1 with nystagmus that resolved spontaneously, and 1 with delayed visual maturation. Because of the high incidence of conditions that could affect visual development, we recommend that children with 22q11.2 duplication syndrome have a complete ophthalmological examination on diagnosis and regular vision screenings by their primary care physician thereafter. PMID:27108843

  18. Evaluation of ocular findings in patients with vitiligo.

    PubMed

    Karadag, Remzi; Esmer, Oktay; Karadag, Ayse S; Bilgili, Serap Gunes; Cakici, Ozgur; Demircan, Yuhanize Tas; Bayramlar, Huseyin

    2016-03-01

    In this study, we aimed to investigate ocular manifestations in patients with vitiligo. Sixty-one patients with vitiligo were included in the study. From the patients who referred for examination to the dermatology and ophthalmology clinic, 57 patients without any systemic disease were taken as the control group. In both groups, otorefractometry, keratometry, visual acuity test, intraocular pressure measurement, anterior segment, and fundus examinations of the eye with slit lamp, Schirmer test, and perimetry were carried out. The mean age was 24.54 ± 11.90 years and 23.03 ± 8.72 years in the patients and control group, respectively. The mean Schirmer test results were as follows: 16.74 ± 9.11 mm and 17.64 ± 9.41 mm for the right and left eyes of the patients, and 21.96 ± 12.51 mm and 23.42 ± 12.51 mm for the right and left eyes of controls, respectively. Of the patients, 36 eyes showed lenticular findings. However, only 12 eyes of the controls have some lenticular findings. Twenty-nine eyes in the vitiligo group and four in the controls showed some fundus findings. When the two groups were compared with each other, there was a statistically significant difference between them in terms of Schirmer test results, lens, and fundus findings (P < 0.05 for all). However, there was no significant difference in terms of age, gender, visual acuity, refraction, keratometry, intraocular pressure, perimetry, and corneal findings (P > 0.05 for all). Patients with vitiligo may have more lenticular and retinal findings than normal. They can be more prone to dry eye syndrome as well. PMID:26235484

  19. Ocular Blood Flow Autoregulation Mechanisms and Methods

    PubMed Central

    Luo, Xue; Shen, Yu-meng; Jiang, Meng-nan; Lou, Xiang-feng; Shen, Yin

    2015-01-01

    The main function of ocular blood flow is to supply sufficient oxygen and nutrients to the eye. Local blood vessels resistance regulates overall blood distribution to the eye and can vary rapidly over time depending on ocular need. Under normal conditions, the relation between blood flow and perfusion pressure in the eye is autoregulated. Basically, autoregulation is a capacity to maintain a relatively constant level of blood flow in the presence of changes in ocular perfusion pressure and varied metabolic demand. In addition, ocular blood flow dysregulation has been demonstrated as an independent risk factor to many ocular diseases. For instance, ocular perfusion pressure plays key role in the progression of retinopathy such as glaucoma and diabetic retinopathy. In this review, different direct and indirect techniques to measure ocular blood flow and the effect of myogenic and neurogenic mechanisms on ocular blood flow are discussed. Moreover, ocular blood flow regulation in ocular disease will be described. PMID:26576295

  20. Unconventional techniques of fundus imaging: A review.

    PubMed

    Shanmugam, Mahesh P; Mishra, Divyansh Kailash Chandra; Rajesh, R; Madhukumar, R

    2015-07-01

    The methods of fundus examination include direct and indirect ophthalmoscopy and imaging with a fundus camera are an essential part of ophthalmic practice. The usage of unconventional equipment such as a hand-held video camera, smartphone, and a nasal endoscope allows one to image the fundus with advantages and some disadvantages. The advantages of these instruments are the cost-effectiveness, ultra portability and ability to obtain images in a remote setting and share the same electronically. These instruments, however, are unlikely to replace the fundus camera but then would always be an additional arsenal in an ophthalmologist's armamentarium. PMID:26458475

  1. Unconventional techniques of fundus imaging: A review

    PubMed Central

    Shanmugam, Mahesh P; Mishra, Divyansh Kailash Chandra; Rajesh, R; Madhukumar, R

    2015-01-01

    The methods of fundus examination include direct and indirect ophthalmoscopy and imaging with a fundus camera are an essential part of ophthalmic practice. The usage of unconventional equipment such as a hand-held video camera, smartphone, and a nasal endoscope allows one to image the fundus with advantages and some disadvantages. The advantages of these instruments are the cost-effectiveness, ultra portability and ability to obtain images in a remote setting and share the same electronically. These instruments, however, are unlikely to replace the fundus camera but then would always be an additional arsenal in an ophthalmologist's armamentarium. PMID:26458475

  2. Ocular Complications of Chloroquine Therapy

    PubMed Central

    Lloyd, Lois A.; Hiltz, John W.

    1965-01-01

    Ocular complications of long-term chloroquine therapy were observed in 18 of 45 patients so treated. This therapy was used in patients with rheumatoid arthritis, lupus erythematosus, sarcoidosis, discoid lupus and other chronic “collagen disease”. Thirteen patients had reversible corneal opacifications, and seven had irreversible retinal changes, with visual loss and visual field defects. Pathological evidence of chloroquine retinopathy was obtained in one patient. Physicians are therefore warned to use this drug only after careful consideration. If it is used, repeated ocular examinations should include assessment of visual acuity, visual fields on a tangent screen and fundus examination through a dilated pupil. ImagesFig. 4Fig. 7Fig. 8 PMID:14275038

  3. Coaxial fundus camera for opthalmology

    NASA Astrophysics Data System (ADS)

    de Matos, Luciana; Castro, Guilherme; Castro Neto, Jarbas C.

    2015-09-01

    A Fundus Camera for ophthalmology is a high definition device which needs to meet low light illumination of the human retina, high resolution in the retina and reflection free image1. Those constraints make its optical design very sophisticated, but the most difficult to comply with is the reflection free illumination and the final alignment due to the high number of non coaxial optical components in the system. Reflection of the illumination, both in the objective and at the cornea, mask image quality, and a poor alignment make the sophisticated optical design useless. In this work we developed a totally axial optical system for a non-midriatic Fundus Camera. The illumination is performed by a LED ring, coaxial with the optical system and composed of IR of visible LEDs. The illumination ring is projected by the objective lens in the cornea. The Objective, LED illuminator, CCD lens are coaxial making the final alignment easily to perform. The CCD + capture lens module is a CCTV camera with autofocus and Zoom built in, added to a 175 mm focal length doublet corrected for infinity, making the system easily operated and very compact.

  4. The Portable Dynamic Fundus Instrument: Uses in telemedicine and research

    NASA Technical Reports Server (NTRS)

    Hunter, Norwood; Caputo, Michael; Billica, Roger; Taylor, Gerald; Gibson, C. Robert; Manuel, F. Keith; Mader, Thomas; Meehan, Richard

    1994-01-01

    For years ophthalmic photographs have been used to track the progression of many ocular diseases such as macular degeneration and glaucoma as well as the ocular manifestations of diabetes, hypertension, and hypoxia. In 1987 a project was initiated at the Johnson Space Center (JSC) to develop a means of monitoring retinal vascular caliber and intracranial pressure during space flight. To conduct telemedicine during space flight operations, retinal images would require real-time transmissions from space. Film-based images would not be useful during in-flight operations. Video technology is beneficial in flight because the images may be acquired, recorded, and transmitted to the ground for rapid computer digital image processing and analysis. The computer analysis techniques developed for this project detected vessel caliber changes as small as 3 percent. In the field of telemedicine, the Portable Dynamic Fundus Instrument demonstrates the concept and utility of a small, self-contained video funduscope. It was used to record retinal images during the Gulf War and to transmit retinal images from the Space Shuttle Columbia during STS-50. There are plans to utilize this device to provide a mobile ophthalmic screening service in rural Texas. In the fall of 1993 a medical team in Boulder, Colorado, will transmit real-time images of the retina during remote consultation and diagnosis. The research applications of this device include the capability of operating in remote locations or small, confined test areas. There has been interest shown utilizing retinal imaging during high-G centrifuge tests, high-altitude chamber tests, and aircraft flight tests. A new design plan has been developed to incorporate the video instrumentation into face-mounted goggle. This design would eliminate head restraint devices, thus allowing full maneuverability to the subjects. Further development of software programs will broaden the application of the Portable Dynamic Fundus Instrument in

  5. Diabetic Rethinopathy Screening by Bright Lesions Extraction from Fundus Images

    NASA Astrophysics Data System (ADS)

    Hanđsková, Veronika; Pavlovičova, Jarmila; Oravec, Miloš; Blaško, Radoslav

    2013-09-01

    Retinal images are nowadays widely used to diagnose many diseases, for example diabetic retinopathy. In our work, we propose the algorithm for the screening application, which identifies the patients with such severe diabetic complication as diabetic retinopathy is, in early phase. In the application we use the patient's fundus photography without any additional examination by an ophtalmologist. After this screening identification, other examination methods should be considered and the patient's follow-up by a doctor is necessary. Our application is composed of three principal modules including fundus image preprocessing, feature extraction and feature classification. Image preprocessing module has the role of luminance normalization, contrast enhancement and optical disk masking. Feature extraction module includes two stages: bright lesions candidates localization and candidates feature extraction. We selected 16 statistical and structural features. For feature classification, we use multilayer perceptron (MLP) with one hidden layer. We classify images into two classes. Feature classification efficiency is about 93 percent.

  6. Dark-without-pressure fundus lesions.

    PubMed Central

    Nagpal, K C; Goldberg, M F; Asdourian, G; Goldbaum, M; Huamonte, F

    1975-01-01

    Seven black patients had dark brown homogeneous geographical areas of the fundus. Six cases were associated with sickle cell haemoglobinopathies and one was associated with systemic hypertension. These flat lesions were uniform in colour and occurred in the posterior pole or in the midperiphery. They appeared to be transient and often disappeared leaving no residue. The cause is unknown. By analogy with white-without-pressure fundus lesions, we have called these areas dark-without-pressure. Images PMID:1203232

  7. [Ocular syphilis].

    PubMed

    Chiquet, C; Khayi, H; Puech, C; Tonini, M; Pavese, P; Aptel, F; Romanet, J-P

    2014-04-01

    Syphilis is a sexually transmitted disease caused by Treponema pallidum. Previously known as the "great imitator", this disease can have numerous and complex manifestations. The ophthalmologist should suspect the diagnosis in patients with uveitis or optic neuropathy and high-risk sexual behavior and/or another sexually transmitted disease (such as HIV) or those presenting with posterior placoid chorioretinitis or necrotising retinitis. Ocular involvement in acquired syphilis is rare, tending to occur during the secondary and tertiary stages of the disease. Syphilis may affect all the structures of the eye, but uveitis (accounting for 1-5% of the uveitis in a tertiary referral center) is the most common ocular finding. Granulomatous or non-granulomatous iridocyclitis (71%), panuveitis, posterior uveitis (8%) and keratouveitis (8%) are often described. In the secondary stage, the meninges and the central nervous system can be affected, sometimes with no symptoms, which justifies performing lumbar puncture in patients with uveitis and/or optic neuropathy. The diagnosis of ocular syphilis requires screening with a non-treponemal serology and confirmation with a treponemal-specific test. Parenterally administered penicillin G is considered first-line therapy for all stages of ocular syphilis. Systemic corticosteroids are an appropriate adjunct treatment for posterior uveitis, scleritis and optic neuritis if ocular inflammation is severe. Prolonged follow-up is necessary because of the possibility of relapse of the disease. With proper diagnosis and prompt antibiotic treatment, the majority of cases of ocular syphilis can be cured. PMID:24655791

  8. The Characteristics of Peripapillary Retinal Perfusion by Optical Coherence Tomography Angiography in Tessellated Fundus Eyes

    PubMed Central

    Kong, Xiangmei; Zhu, Li; Sun, Xinghuai

    2016-01-01

    Purpose To evaluate the peripapillary and perifoveal retinal perfusions of young healthy eyes with a tessellated fundus using optical coherence tomography (OCT) angiography. Methods Thirty-five Chinese subjects with a tessellated fundus and 35 subjects without a tessellated fundus from a population-based cross-sectional study in Shanghai were included. All participants underwent OCT angiography. The flow index and vessel density were examined in the peripapillary and perifoveal retinal areas, and their relationships with other ocular parameters were analyzed. Results In the peripapillary area, the eyes with a tessellated fundus had a lower retinal nerve fiber layer (RNFL) flow index (0.055 ± 0.009 vs. 0.061 ± 0.007, P = 0.006), RNFL vessel density (61.8 ± 7.3 vs. 65.9 ± 5.2, P = 0.010), retinal flow index (0.086 ± 0.010 vs. 0.092 ± 0.008, P = 0.012), and retinal vessel density (83.7 ± 5.0 vs. 86.4 ± 3.7, P = 0.018) than the control eyes, and the difference remained significant even after adjustments were made for gender and RNFL thickness. No difference was found in the perifoveal area. Multivariable linear regression analysis showed that the retinal flow index and vessel density in the peripapillary area were significantly correlated with the tessellated fundus diagnosis (flow index: β = -0.006, P = 0.005; vessel density: β = -2.597, P = 0.006), gender (flow index: β = 0.005, P = 0.019; vessel density: β = 3.129, P = 0.002) and RNFL thickness (flow index: β = 0.000, P = 0.002; vessel density: β = 0.190, P = 0.002). The RNFL flow index and vessel density were significantly associated with the tessellated fundus diagnosis (flow index: β = -0.005, P = 0.005; vessel density: β = -3.572, P = 0.008) and the thickness of RNFL (flow index: β = 0.001, P < 0.001; vessel density: β = 0.421, P < 0.001). Conclusions Eyes with tessellated fundus with a relative decreased peripapillary retinal perfusion compared with eyes without a tessellated fundus were

  9. Color Doppler Imaging Analysis of Ocular Blood Flow Velocities in Normal Tension Glaucoma Patients: A Meta-Analysis

    PubMed Central

    Xu, Shuo; Huang, Shouyue; Lin, Zhongjing; Liu, Wangmin; Zhong, Yisheng

    2015-01-01

    Background. To evaluate the potential diagnostic value of CDI of retrobulbar hemodynamic changes in NTG patients. Methods. Relevant publications which included PSV, EDV, and RI of OA, CRA, NPCA, and TPCA in NTG patients and normal controls measured by CDI were retrieved from the Cochrane Central Register of Controlled Trials, PubMed, the ISI Web of Knowledge, and EMBASE from 1990 to 2014. Subgroup analyses were made based on IOP-lowering medications uses. Result. In OA, there was significant decrease of PSV with moderate heterogeneity (P < 0.00001, I2 = 49%) and significant decrease of EDV with significant heterogeneity (P = 0.0005, I2 = 87%) in NTG patients. In CRA, similar results of PSV (P < 0.00001, I2 = 42%) and EDV (P < 0.00001, I2 = 80%) were detected. Significant decrease of PSV and EDV with significant heterogeneity was also found in both NPCA (P < 0.0001, I2 = 70%; P < 0.0001, I2 = 76%; resp.) and TPCA (P < 0.00001, I2 = 54%; P < 0.00001, I2 = 65%; resp.). Statistically significant increases of RI were found in CRA (P = 0.0002, I2 = 89%) and TPCA (P = 0.02, I2 = 81%) with significant heterogeneities, though RI in OA (P = 0.25, I2 = 94%) and in NPCA (P = 0.15, I2 = 86%) showed no statistical changes with significant heterogeneities. Conclusions. Ischemic change of retrobulbar hemodynamics is one of the important manifestations of NTG. Hemodynamic parameters measured by CDI might be potential diagnostic tools for NTG. PMID:26634152

  10. Ocular Syphilis among HIV-Infected Individuals

    PubMed Central

    Li, Jonathan Z.; Tucker, Joseph D.; Lobo, Ann-Marie; Marra, Christina M.; Davis, Benjamin T.; Papaliodis, George N.; Felsenstein, Donna; Durand, Marlene L.; Yawetz, Sigal; Robbins, Gregory K.

    2010-01-01

    We describe a human immunodeficiency virus (HIV)–infected individual with ocular manifestations of secondary syphilis. Twelve other cases of HIV-associated ocular syphilis are also presented. Six of 12 individuals had normal cerebrospinal fluid study results, and 3 patients required retreatment within 1.5 years. In patients with HIV infection, clinicians should be vigilant for ocular syphilis despite normal cerebrospinal fluid measures and for syphilis reinfection. PMID:20604717

  11. Multimodal fundus imaging in Best vitelliform macular dystrophy

    PubMed Central

    Ferrara, Daniela C.; Tsang, Stephen; Calucci, Daniela; Jorge, Rodrigo; Freund, K. Bailey

    2010-01-01

    Background Best vitelliform macular dystrophy (BVMD) is a rare autosomal dominant retinal disease of highly variable phenotypic expression. Interpretations of disease mechanisms based on histopathology, electrophysiology, genetic analysis, and retinal imaging are somewhat discordant in fundamental issues such as the location and extension of primary retinal changes. Herein we describe the morphological macular features in patients with BVMD undergoing simultaneous multimodal fundus imaging and compare to those of normal age-matched subjects. Methods Comparative study including seven patients with BVMD (14 eyes) and seven age-matched healthy subjects (14 eyes). All participants were submitted to complete ophthalmological examination, fundus photography, and standardized multimodal fundus imaging protocol including Fourier-domain optical coherence tomography (Fd-OCT) combined with near-infrared reflectance and blue-light fundus autofluorescence (FAF). Results In two eyes in the “subclinical” stage, Fd-OCT revealed thickening of the middle highly reflective layer (HRL) localized between the photoreceptors’ inner/outer segments junction (inner-HRL) and RPE/Bruch’s membrane reflective complex (outer-HRL) throughout the macula. In one eye in the “vitelliform” stage, a homogeneous hyper-reflective material on Fd-OCT was observed between the middle-HRL and outer-HRL; this material presented increased fluorescence on FAF. The outer nuclear layer (ONL) was thinned in the central macula and subretinal fluid was not identified in these earlier disease stages. In patients of “pseudohypopyon” (two eyes), “vitelliruptive” (eight eyes) and “atrophic” (one eye) stages, Fd-OCT revealed a variety of changes in the middle- and inner-HRLs and thinning of ONL. These changes were found to be associated with the level of visual acuity observed. Thickening of the middle-HRL was observed beyond the limits of the clinically evident macular lesion in all eyes

  12. Fundus changes in mesangiocapillary glomerulonephritis type II: vitreous fluorophotometry.

    PubMed Central

    Raines, M F; Duvall-Young, J; Short, C D

    1989-01-01

    We have described a complex abnormality of retinal pigment epithelium, Bruch's membrane, and choriocapillaris in mesangiocapillary glomerulonephritis (MCGN) type II. Patients with MCGN type II were examined by vitreous fluorophotometry which reveals that there is a breakdown of the blood retinal barrier (BRB) in those patients with the typical fundus lesions. The function of this barrier was calculated as a penetration ratio and was statistically greater in these patients when compared with a group of (a) normal persons, (b) patients with drusen, and (c) patients with other forms of glomerulonephritis. Images PMID:2605145

  13. Retinal oxygen saturation evaluation by multi-spectral fundus imaging

    NASA Astrophysics Data System (ADS)

    Khoobehi, Bahram; Ning, Jinfeng; Puissegur, Elise; Bordeaux, Kimberly; Balasubramanian, Madhusudhanan; Beach, James

    2007-03-01

    Purpose: To develop a multi-spectral method to measure oxygen saturation of the retina in the human eye. Methods: Five Cynomolgus monkeys with normal eyes were anesthetized with intramuscular ketamine/xylazine and intravenous pentobarbital. Multi-spectral fundus imaging was performed in five monkeys with a commercial fundus camera equipped with a liquid crystal tuned filter in the illumination light path and a 16-bit digital camera. Recording parameters were controlled with software written specifically for the application. Seven images at successively longer oxygen-sensing wavelengths were recorded within 4 seconds. Individual images for each wavelength were captured in less than 100 msec of flash illumination. Slightly misaligned images of separate wavelengths due to slight eye motion were registered and corrected by translational and rotational image registration prior to analysis. Numerical values of relative oxygen saturation of retinal arteries and veins and the underlying tissue in between the artery/vein pairs were evaluated by an algorithm previously described, but which is now corrected for blood volume from averaged pixels (n > 1000). Color saturation maps were constructed by applying the algorithm at each image pixel using a Matlab script. Results: Both the numerical values of relative oxygen saturation and the saturation maps correspond to the physiological condition, that is, in a normal retina, the artery is more saturated than the tissue and the tissue is more saturated than the vein. With the multi-spectral fundus camera and proper registration of the multi-wavelength images, we were able to determine oxygen saturation in the primate retinal structures on a tolerable time scale which is applicable to human subjects. Conclusions: Seven wavelength multi-spectral imagery can be used to measure oxygen saturation in retinal artery, vein, and tissue (microcirculation). This technique is safe and can be used to monitor oxygen uptake in humans. This work

  14. A comparison of the ocular hypotensive effect of 0.025% bromocriptine and 0.25% timolol eye drops in normal human volunteers.

    PubMed Central

    al-Sereiti, M R; Coakes, R L; O'Sullivan, D P; Turner, P

    1989-01-01

    1. The ocular hypotensive effect of 0.025% bromocriptine and 0.25% timolol eye drops was compared in nine healthy human volunteers, using non-contact tonometry. 2. Considering all post-dosing measurements compared with placebo and including the baseline values as continuous independent variables, using multiple linear regression analysis, both bromocriptine and timolol had a significant ocular hypotensive effect (P less than 0.0001) in the treated eye with a significant but lesser effect in the contralateral eye. 3. In the concentrations used, timolol was more efficacious than bromocriptine in lowering intraocular pressure (P less than 0.025). 4. Using other forms of vehicles for bromocriptine to improve efficacy and studying the ocular hypotensive effect of topical application of other dopamine-2-receptor agonists such as pergolide and lisuride was suggested. PMID:2590602

  15. Use of laser speckle flowgraphy in ocular blood flow research.

    PubMed

    Sugiyama, Tetsuya; Araie, Makoto; Riva, Charles E; Schmetterer, Leopold; Orgul, Selim

    2010-11-01

    Laser speckle flowgraphy (LSFG) allows for the quantitative estimation of blood flow in the optic nerve head, choroid, retina and iris in vivo. It was developed to facilitate the non-contact analysis of ocular blood flow in living eyes, utilizing the laser speckle phenomenon. The technique uses a fundus camera, a diode laser, an image sensor, an infrared charge-coupled device (CCD) camera and a high-resolution digital CCD camera. Normalized blur (NB), an approximate reciprocal of speckle contrast, represents an index of blood velocity, and shows a good correlation with tissue blood flow rates determined with the microsphere method in the retina, choroid or iris, as well as blood flow rates determined with the hydrogen gas clearance method in the optic nerve head. The square blur ratio (SBR), another index for quantitative estimation of blood velocity, is proportional to the square of the NB. The SBR is theoretically a more exact measurement which is proportional to velocity, whereas the NB is an approximation. Normalized blur was calculated in earlier versions of LSFG because of technical limitations; the SBR is used in current versions of the LSFG instrument. As these values are in arbitrary units, they should not be used to make comparisons between different eyes or different sites in an eye. Clinical protocols, calibration, evaluation procedures and possible limitations of the LSFG technique are described and the results of ocular blood flow studies using LSFG are briefly summarized. The LSFG method is suitable for monitoring the time-course of change in the tissue circulation at the same site in the same eye at various intervals, ranging from seconds to months. Unresolved issues concern the effect of pupil size on measurement results, the effects of various stimulations, and how to measure choroidal and retinal blood flow velocity separately without using the blue-component of argon laser. PMID:19725814

  16. Ocular toxoplasmosis in Iran: 40 cases analysis

    PubMed Central

    Tabatabaei, Seidali; Soleimani, Mohammad; Foroutan, Alireza; Ahmadabadi, Mehdinili; Zarei, Reza; Piri, Nilofar; Gordiz, Arzhang

    2011-01-01

    AIM To report ocular symptoms, funduscopic findings and demographic distribution of ocular toxoplasmosis in Iran METHODS In this cross-sectional study, a total of 40 patients with ocular toxoplasmosis (24 female, 16 male) were enrolled. The distribution of symptoms and funduscopic findings were studied. RESULTS The patients' age was in the range of 13-52 with the most common age of 19 years old. Twenty-four patients were female (60.0%). The most common presenting sign was visual loss. There was anterior chamber (AC) inflammation in 23 patients (57.5%). Vitritis was presented in 36 patients (90.0%). In 35 patients (87.5%), the retinal lesion was central. In patients with peripheral lesion, 3 patients (60.0%) had flashing vs 12.5% chance of flashing in all patients. Older patients had larger lesion (P=0.04). CONCLUSION Ocular toxoplasmosis substantially varies among patients with different age, gender, status of immunity, site of lesion and other undetermined factors. One of ocular symptoms, flashing, may necessitate a more precise peripheral fundus examination. PMID:22553642

  17. Human ocular anatomy.

    PubMed

    Kels, Barry D; Grzybowski, Andrzej; Grant-Kels, Jane M

    2015-01-01

    We review the normal anatomy of the human globe, eyelids, and lacrimal system. This contribution explores both the form and function of numerous anatomic features of the human ocular system, which are vital to a comprehensive understanding of the pathophysiology of many oculocutaneous diseases. The review concludes with a reference glossary of selective ophthalmologic terms that are relevant to a thorough understanding of many oculocutaneous disease processes. PMID:25704934

  18. MILES device: ocular hazard evaluation. Interim report, 1 May-30 September 1979

    SciTech Connect

    Zuclich, J.A.; Tredici, T.J.; Mikesell, G.W. Jr.; Gibbons, W.D.; Schmidt, R.E.

    1980-03-01

    This report describes an attempt to find ocular effects in the primate eye as a result of exposure to a MILES (Multiple Integrated Laser Engagement System) laser transmitter for a M16A1 rifle. The MILES device incorporates a pulsed gallium arsenide laser operating in the near infrared. For the exposure parameters reported, no ocular alterations could be detected with either a fundus camera or a direct ophthalmoscope.

  19. 21 CFR 886.1395 - Diagnostic Hruby fundus lens.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Diagnostic Hruby fundus lens. 886.1395 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1395 Diagnostic Hruby fundus lens. (a) Identification. A diagnostic Hruby fundus lens is a device that is a 55 diopter lens intended for use in...

  20. 21 CFR 886.1395 - Diagnostic Hruby fundus lens.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Diagnostic Hruby fundus lens. 886.1395 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1395 Diagnostic Hruby fundus lens. (a) Identification. A diagnostic Hruby fundus lens is a device that is a 55 diopter lens intended for use in...

  1. 21 CFR 886.1395 - Diagnostic Hruby fundus lens.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Diagnostic Hruby fundus lens. 886.1395 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1395 Diagnostic Hruby fundus lens. (a) Identification. A diagnostic Hruby fundus lens is a device that is a 55 diopter lens intended for use in...

  2. 21 CFR 886.1395 - Diagnostic Hruby fundus lens.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Diagnostic Hruby fundus lens. 886.1395 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1395 Diagnostic Hruby fundus lens. (a) Identification. A diagnostic Hruby fundus lens is a device that is a 55 diopter lens intended for use in...

  3. 21 CFR 886.1395 - Diagnostic Hruby fundus lens.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Diagnostic Hruby fundus lens. 886.1395 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1395 Diagnostic Hruby fundus lens. (a) Identification. A diagnostic Hruby fundus lens is a device that is a 55 diopter lens intended for use in...

  4. In Vivo Confocal Microscopy and Anterior Segment Optic Coherence Tomography Findings in Ocular Ochronosis

    PubMed Central

    Demirkilinc Biler, Elif; Guven Yilmaz, Suzan; Palamar, Melis; Hamrah, Pedram

    2015-01-01

    Purpose. To report clinical and in vivo confocal microscopy (IVCM) findings of two patients with ocular ochronosis secondary due to alkaptonuria. Materials and Methods. Complete ophthalmologic examinations, including IVCM (HRT II/Rostock Cornea Module, Heidelberg, Germany), anterior segment optical coherence tomography (AS-OCT) (Topcon 3D spectral-domain OCT 2000, Topcon Medical Systems, Paramus, NJ, USA), corneal topography (Pentacam, OCULUS Optikgeräte GmbH, Wetzlar, Germany), and anterior segment photography, were performed. Results. Biomicroscopic examination showed bilateral darkly pigmented lesions of the nasal and temporal conjunctiva and episclera in both patients. In vivo confocal microscopy of the lesions revealed prominent degenerative changes, including vacuoles and fragmentation of collagen fibers in the affected conjunctival lamina propria and episclera. Hyperreflective pigment granules in different shapes were demonstrated in the substantia propria beneath the basement membrane. AS-OCT of Case 1 demonstrated hyporeflective areas. Fundus examination was within normal limits in both patients, except tilted optic discs with peripapillary atrophy in one of the patients. Corneal topography, thickness, and macular OCT were normal bilaterally in both cases. Conclusion. The degenerative and anatomic changes due to ochronotic pigment deposition in alkaptonuria can be demonstrated in detail with IVCM and AS-OCT. Confocal microscopic analysis in ocular ochronosis may serve as a useful adjunct in diagnosis and monitoring of the disease progression. PMID:26788390

  5. Robust vessel segmentation in fundus images.

    PubMed

    Budai, A; Bock, R; Maier, A; Hornegger, J; Michelson, G

    2013-01-01

    One of the most common modalities to examine the human eye is the eye-fundus photograph. The evaluation of fundus photographs is carried out by medical experts during time-consuming visual inspection. Our aim is to accelerate this process using computer aided diagnosis. As a first step, it is necessary to segment structures in the images for tissue differentiation. As the eye is the only organ, where the vasculature can be imaged in an in vivo and noninterventional way without using expensive scanners, the vessel tree is one of the most interesting and important structures to analyze. The quality and resolution of fundus images are rapidly increasing. Thus, segmentation methods need to be adapted to the new challenges of high resolutions. In this paper, we present a method to reduce calculation time, achieve high accuracy, and increase sensitivity compared to the original Frangi method. This method contains approaches to avoid potential problems like specular reflexes of thick vessels. The proposed method is evaluated using the STARE and DRIVE databases and we propose a new high resolution fundus database to compare it to the state-of-the-art algorithms. The results show an average accuracy above 94% and low computational needs. This outperforms state-of-the-art methods. PMID:24416040

  6. 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. PMID:26139802

  7. 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

  8. Macular pigment optical density: repeatability, intereye correlation, and effect of ocular dominance

    PubMed Central

    Davey, Pinakin Gunvant; Alvarez, Silverio D; Lee, Jessica Y

    2016-01-01

    Purpose To evaluate short-term repeatability, intereye correlation, and effect of ocular dominance on macular pigment optical density (MPOD) measurements obtained using the QuantifEye Heterochromatic Flicker Photometer. Patients and methods A total of 72 study participants were enrolled in this prospective, cross-sectional study. Participants underwent a comprehensive ocular evaluation, including visual acuity, evaluation of ocular dominance, slit lamp examination, intraocular pressure measurement, and optic nerve head and macula analysis using optical coherence tomography and fundus photography. All study participants after initial training underwent MPOD measurement twice in both eyes in a randomized sequence. The repeatability was tested using Altman and Bland plots for first measurements with the second measurements for right eye and left eye and additionally by grouping eyes as a function of ocular dominance. The Pearson correlation coefficient was performed to assess the intereye correlation of MPOD values. Results The mean age of study participants was 35.5 years (range 22–68 years). The mean MPOD measurements for OD (right eye) and OS (left eye) were 0.47 and 0.48, respectively, which followed a normal distribution (Shapiro–Wilk test, P=0.6 and 0.2). The 95% limits of agreement of Altman and Bland plots for the first and second measurements were −0.12 to +0.11 and −0.13 to +0.12 for OD and OS, respectively. The correlation coefficient of mean MPOD measurements of OD and OS was r statistic =0.94 (Pearson correlation coefficient P<0.0001; r2 0.89). The 95% limits of agreement of Altman and Bland plots when evaluated by laterality of eye or by ocular dominance were narrow, with limits of agreement ranging from −0.13 to +0.12. Conclusion The MPOD measurements obtained using the QuantifEye show good short-term repeatability. There is excellent intereye correlation, indicating that the MPOD values of one eye data can predict the fellow eye value with 89

  9. Detection of exudates in fundus imagery using a constant false-alarm rate (CFAR) detector

    NASA Astrophysics Data System (ADS)

    Khanna, Manish; Kapoor, Elina

    2014-05-01

    Diabetic retinopathy is the leading cause of blindness in adults in the United States. The presence of exudates in fundus imagery is the early sign of diabetic retinopathy so detection of these lesions is essential in preventing further ocular damage. In this paper we present a novel technique to automatically detect exudates in fundus imagery that is robust against spatial and temporal variations of background noise. The detection threshold is adjusted dynamically, based on the local noise statics around the pixel under test in order to maintain a pre-determined, constant false alarm rate (CFAR). The CFAR detector is often used to detect bright targets in radar imagery where the background clutter can vary considerably from scene to scene and with angle to the scene. Similarly, the CFAR detector addresses the challenge of detecting exudate lesions in RGB and multispectral fundus imagery where the background clutter often exhibits variations in brightness and texture. These variations present a challenge to common, global thresholding detection algorithms and other methods. Performance of the CFAR algorithm is tested against a publicly available, annotated, diabetic retinopathy database and preliminary testing suggests that performance of the CFAR detector proves to be superior to techniques such as Otsu thresholding.

  10. Ocular onchocerciasis

    PubMed Central

    Thylefors, B.

    1978-01-01

    Well over 20 million people in the world are infected with Onchocerca volvulus and it is probable that 200 000-500 000 people are blind as a result of this infection, which is the most important cause of blindness in certain areas of Africa and Latin America. Treatment of the disease is difficult and often produces serious adverse reactions in the patient. Combined use of diethylcarbamazine citrate and suramin is still the most suitable form of treatment. Screening for the early detection of cases at high risk of ocular manifestations must be organized, and their treatment undertaken, if blindness is to be avoided. Prevention of ocular onchocerciasis is feasible, using vector control methods to reduce transmission, but the procedures are costly and may have to be maintained for many years. Research is needed to improve treatment and to find a chemoprophylactic agent or a preventive vaccine. PMID:307448

  11. The Reflexes of the Fundus Oculi

    PubMed Central

    Ballantyne, A. J.

    1940-01-01

    degeneration of the retina or after the subsidence of severe retinitis or retino-choroiditis. A mirror reflex from the layer of pigmented epithelium or from the external limiting membrane is sometimes recognizable in normal eyes, especially in the brunette fundus. In such, it forms the background to a striking picture of the fine circumfoveal vessels. Pathological reflexes from the level of the pigmented epithelium or of the external limiting membrane are also observed, and these often present a granular, frosted or crystalline appearance. They may indicate a senile change, or result from trauma or from retino-choroidal degeneraion. Somewhat similar reflexes may sometimes be present as small frosted patches anterior to the retinal vessels. Linear sinuous, whether appearing in annular form, as straight needles, as broader single sinuous lines, as the tapering, branched double reflexes of Vogt, or in association with traction or pressure folds, in the retina, are probably always pathological. By the use of selected light of long and short wave lengths, it can be shown that intraretinal or true retinal folds may exist with or without the surface reflexes which indicate a corresponding folding of the internal limiting membrane. On the other hand, superficial linear reflexes of various types may occur without evidence of retinal folding. Annular reflexes usually accompany a rounded elevation of the retina due to tumour, hæmorrhage or exudate, but may indicate the presence of rounded depressions; traction folds occur where there is choroido-retinal scarring, or in association with macular hole or cystic degeneraion at the macula; pressure folds in cases of orbital cyst, abscess or neoplasm; and the other linear reflexes in association with papillo-retinal œdema, for example, in retrobulbar neuritis, in hypertensive neuro-retinitis, in contusio bulbi and in anterior uveitis. Punctate reflexes, other than Gunn's dots, are also pathological. They may occur as one variety of

  12. Rapid Grading of Fundus Photographs for Diabetic Retinopathy Using Crowdsourcing

    PubMed Central

    Villanti, Andrea C; Pearson, Jennifer L; Kirchner, Thomas R; Gupta, Omesh P; Shah, Chirag P

    2014-01-01

    Background Screening for diabetic retinopathy is both effective and cost-effective, but rates of screening compliance remain suboptimal. As screening improves, new methods to deal with screening data may help reduce the human resource needs. Crowdsourcing has been used in many contexts to harness distributed human intelligence for the completion of small tasks including image categorization. Objective Our goal was to develop and validate a novel method for fundus photograph grading. Methods An interface for fundus photo classification was developed for the Amazon Mechanical Turk crowdsourcing platform. We posted 19 expert-graded images for grading by Turkers, with 10 repetitions per photo for an initial proof-of-concept (Phase I). Turkers were paid US $0.10 per image. In Phase II, one prototypical image from each of the four grading categories received 500 unique Turker interpretations. Fifty draws of 1-50 Turkers were then used to estimate the variance in accuracy derived from randomly drawn samples of increasing crowd size to determine the minimum number of Turkers needed to produce valid results. In Phase III, the interface was modified to attempt to improve Turker grading. Results Across 230 grading instances in the normal versus abnormal arm of Phase I, 187 images (81.3%) were correctly classified by Turkers. Average time to grade each image was 25 seconds, including time to review training images. With the addition of grading categories, time to grade each image increased and percentage of images graded correctly decreased. In Phase II, area under the curve (AUC) of the receiver-operator characteristic (ROC) indicated that sensitivity and specificity were maximized after 7 graders for ratings of normal versus abnormal (AUC=0.98) but was significantly reduced (AUC=0.63) when Turkers were asked to specify the level of severity. With improvements to the interface in Phase III, correctly classified images by the mean Turker grade in four-category grading

  13. Comparison of diagnostic capability of macular ganglion cell complex and retinal nerve fiber layer among primary open angle glaucoma, ocular hypertension, and normal population using Fourier-domain optical coherence tomography and determining their functional correlation in Indian population

    PubMed Central

    Barua, Nabanita; Sitaraman, Chitra; Goel, Sonu; Chakraborti, Chandana; Mukherjee, Sonai; Parashar, Hemandra

    2016-01-01

    Context: Analysis of diagnostic ability of macular ganglionic cell complex and retinal nerve fiber layer (RNFL) in glaucoma. Aim: To correlate functional and structural parameters and comparing predictive value of each of the structural parameters using Fourier-domain (FD) optical coherence tomography (OCT) among primary open angle glaucoma (POAG) and ocular hypertension (OHT) versus normal population. Setting and Design: Single centric, cross-sectional study done in 234 eyes. Materials and Methods: Patients were enrolled in three groups: POAG, ocular hypertensive and normal (40 patients in each group). After comprehensive ophthalmological examination, patients underwent standard automated perimetry and FD-OCT scan in optic nerve head and ganglion cell mode. The relationship was assessed by correlating ganglion cell complex (GCC) parameters with mean deviation. Results were compared with RNFL parameters. Statistical Analysis: Data were analyzed with SPSS, analysis of variance, t-test, Pearson's coefficient, and receiver operating curve. Results: All parameters showed strong correlation with visual field (P < 0.001). Inferior GCC had highest area under curve (AUC) for detecting glaucoma (0.827) in POAG from normal population. However, the difference was not statistically significant (P > 0.5) when compared with other parameters. None of the parameters showed significant diagnostic capability to detect OHT from normal population. In diagnosing early glaucoma from OHT and normal population, only inferior GCC had statistically significant AUC value (0.715). Conclusion: In this study, GCC and RNFL parameters showed equal predictive capability in perimetric versus normal group. In early stage, inferior GCC was the best parameter. In OHT population, single day cross-sectional imaging was not valuable. PMID:27221682

  14. Ocular pharmacology.

    PubMed

    Novack, Gary D; Robin, Alan L

    2016-05-01

    Ophthalmic diseases include both those analogous to systemic diseases (eg, inflammation, infection, neuronal degeneration) and not analogous (eg, cataract, myopia). Many anterior segment diseases are treated pharmacologically through eye drops, which have an implied therapeutic index of local therapy. Unlike oral dosage forms administered for systemic diseases, eyedrops require patients not only to adhere to treatment, but to be able to accurately perform-ie, instill drops correctly. Anatomical and physiological barriers make topical delivery to the anterior chamber challenging-in some cases more challenging than absorption through the skin, nasal passages, or gut. Treatment of the posterior segment (eg, vitreous, retina, choroid, and optic nerve) is more challenging due to additional barriers. Recently, intravitreal injections have become a standard of care with biologics for the treatment of macular degeneration and other diseases. Although the eye has esterases, hydroxylases, and transporters, it has relatively little CYP450 enzymes. Because it is challenging to obtain drug concentrations at the target site, ocular clinical pharmacokinetics, and thus pharmacokinetic-pharmacodynamic interactions, are rarely available. Ophthalmic pharmaceuticals require consideration of solubility, physiological pH, and osmolarity, as well as sterility and stability, which in turn requires optimal pharmaceutics. Although applied locally, ocular medications may be absorbed systemically, which results in morbidity and mortality (eg, systemic hypotension, bronchospasm, and bradycardia). PMID:26360129

  15. Ocular dispersion

    NASA Astrophysics Data System (ADS)

    Hammer, Daniel X.; Noojin, Gary D.; Thomas, Robert J.; Stolarski, David J.; Rockwell, Benjamin A.; Welch, Ashley J.

    1999-06-01

    Spectrally resolved white-light interferometry (SRWLI) was used to measure the wavelength dependence of refractive index (i.e., dispersion) for various ocular components. The accuracy of the technique was assessed by measurement of fused silica and water, the refractive indices of which have been measured at several different wavelengths. The dispersion of bovine and rabbit aqueous and vitreous humor was measured from 400 to 1100 nm. Also, the dispersion was measured from 400 to 700 nm for aqueous and vitreous humor extracted from goat and rhesus monkey eyes. For the humors, the dispersion did not deviate significantly from water. In an additional experiment, the dispersion of aqueous and vitreous humor that had aged up to a month was compared to freshly harvested material. No difference was found between the fresh and aged media. An unsuccessful attempt was also made to use the technique for dispersion measurement of bovine cornea and lens. Future refinement may allow measurement of the dispersion of cornea and lens across the entire visible and near-infrared wavelength band. The principles of white- light interferometry including image analysis, measurement accuracy, and limitations of the technique, are discussed. In addition, alternate techniques and previous measurements of ocular dispersion are reviewed.

  16. Fundus imaging with a mobile phone: A review of techniques

    PubMed Central

    Shanmugam, Mahesh P; Mishra, Divyansh KC; Madhukumar, R; Ramanjulu, Rajesh; Reddy, Srinivasulu Y; Rodrigues, Gladys

    2014-01-01

    Fundus imaging with a fundus camera is an essential part of ophthalmic practice. A mobile phone with its in-built camera and flash can be used to obtain fundus images of reasonable quality. The mobile phone can be used as an indirect ophthalmoscope when coupled with a condensing lens. It can be used as a direct ophthalmoscope after minimal modification, wherein the fundus can be viewed without an intervening lens in young patients with dilated pupils. Employing the ubiquitous mobile phone to obtain fundus images has the potential for mass screening, enables ophthalmologists without a fundus camera to document and share findings, is a tool for telemedicine and is rather inexpensive. PMID:25370404

  17. Saccular impact on ocular torsion.

    PubMed

    De Graaf, B; Bos, J E; Groen, E

    1996-01-01

    When someone is tilted laterally, the shear force on the maculae of the utriculus and the sacculus is described by the sine and the cosine of the angle of tilt, respectively. So both the sacculus and the utriculus are stimulated, but in the literature, ocular torsion is normally attributed to utricular function alone (and, thus, seen as a response to y-axis linear acceleration). However, on the base of a series of experiments on a tilt chair, a linear track, human centrifuges, and during parabolic flights, we conclude that the sacculus contributes to ocular torsion as well (there is a response to z-axis linear acceleration). The data suggest that the ratio of the utricular and saccular impact on ocular torsion is 3:1. The utriculus generates conjugate and the sacculus disjunctive torsional eye movements. PMID:8886354

  18. The Ocular Surface Chemical Burns

    PubMed Central

    Baradaran-Rafii, Alireza; Djalilian, Ali R.

    2014-01-01

    Ocular chemical burns are common and serious ocular emergencies that require immediate and intensive evaluation and care. The victims of such incidents are usually young, and therefore loss of vision and disfigurement could dramatically affect their lives. The clinical course can be divided into immediate, acute, early, and late reparative phases. The degree of limbal, corneal, and conjunctival involvement at the time of injury is critically associated with prognosis. The treatment starts with simple but vision saving steps and is continued with complicated surgical procedures later in the course of the disease. The goal of treatment is to restore the normal ocular surface anatomy and function. Limbal stem cell transplantation, amniotic membrane transplantation, and ultimately keratoprosthesis may be indicated depending on the patients' needs. PMID:25105018

  19. Implantation of refractive multifocal intraocular lens with a surface-embedded near section for cataract eyes complicated with a coexisting ocular pathology

    PubMed Central

    Ouchi, M; Kinoshita, S

    2015-01-01

    Purpose To evaluate the postoperative outcomes of cataract eyes complicated with coexisting ocular pathologies that underwent implantation of a refractive multifocal intraocular lens (MIOL) with a surface-embedded near section. Methods LENTIS MPlus (Oculentis GmbH) refractive MIOLs were implanted in 15 eyes with ocular pathologies other than cataract (ie, six high-myopia eyes with an axial length longer than 28 mm, two fundus albipunctatus eyes, two branch retinal-vein occlusion eyes, four glaucoma eyes (one with high myopia), and two keratoconus eyes). Uncorrected or corrected distance and near visual acuity (VA) (UDVA, UNVA, CDVA, and CNVA), contrast sensitivity, and defocus curve were measured at 1 day and 6 months postoperatively, and each patient completed a 6-month postoperative questionnaire regarding vision quality and eyeglass use. Results Thirteen eyes (87%) registered 0 or better in CDVA and 12 eyes (73%) registered better than 0 in CNVA. Contrast sensitivity in the eyes of all patients was comparable to that of normal healthy subjects. No patient required eyeglasses for distance vision, but three patients (20%) required them for near vision. No patient reported poor or very poor vision quality. Conclusion With careful case selection, sectorial refractive MIOL implantation is effective for treating cataract eyes complicated with ocular pathologies. PMID:25744442

  20. Automatic arteriovenous crossing phenomenon detection on retinal fundus images

    NASA Astrophysics Data System (ADS)

    Hatanaka, Yuji; Muramatsu, Chisako; Hara, Takeshi; Fujita, Hiroshi

    2011-03-01

    Arteriolosclerosis is one cause of acquired blindness. Retinal fundus image examination is useful for early detection of arteriolosclerosis. In order to diagnose the presence of arteriolosclerosis, the physicians find the silver-wire arteries, the copper-wire arteries and arteriovenous crossing phenomenon on retinal fundus images. The focus of this study was to develop the automated detection method of the arteriovenous crossing phenomenon on the retinal images. The blood vessel regions were detected by using a double ring filter, and the crossing sections of artery and vein were detected by using a ring filter. The center of that ring was an interest point, and that point was determined as a crossing section when there were over four blood vessel segments on that ring. And two blood vessels gone through on the ring were classified into artery and vein by using the pixel values on red and blue component image. Finally, V2-to-V1 ratio was measured for recognition of abnormalities. V1 was the venous diameter far from the blood vessel crossing section, and V2 was the venous diameter near from the blood vessel crossing section. The crossing section with V2-to-V1 ratio over 0.8 was experimentally determined as abnormality. Twenty four images, including 27 abnormalities and 54 normal crossing sections, were used for preliminary evaluation of the proposed method. The proposed method was detected 73% of crossing sections when the 2.8 sections per image were mis-detected. And, 59% of abnormalities were detected by measurement of V1-to-V2 ratio when the 1.7 sections per image were mis-detected.

  1. Ocular Complications of Leprosy in Yemen

    PubMed Central

    Salem, Raga A. A.

    2012-01-01

    Objectives: This study was conducted to identify the main ocular- and vision-threatening complications of leprosy in Yemen. Methods: This is a cross-sectional observational study which took place from February to July 2010. Leprosy patients attending the Skin and Venereal Diseases Hospital in the City of Light in Taiz, Yemen, who consented to participate in the study, were enrolled. Detailed demographic and medical histories were taken and clinical examination findings were recorded. A detailed eye examination, including visual acuity (VA), slit-lamp, and fundus examinations, was conducted on each patient by a qualified ophthalmologist. Results: A total of 192 patients (180 male, 12 female, with a male to female ratio of 15:1) were included in the study. The majority of the patients (157; 81.8%) were over 40 years. Over two-thirds of the patients (129; 67.2%) had had leprosy for more than 20 years. Ocular complications were found in 97% of cases; 150 (39.1%) of the patients’ eyes had at least one pathology. Eyelid involvement was the most common problem observed in 102 (26.5%) patients. Half of the eyes (192; 50%) had a VA of <6/60. The main cause of blindness among these patients was corneal opacity detected in 69 out of 192 patients (35.9%). Conclusion: Ocular complications are frequent among leprosy patients in Yemen. They are true vision-threatening lesions. It is important to prevent these lesions through early diagnosis and adequate treatment. PMID:23275842

  2. Ocular syphilis: an alarming infectious eye disease

    PubMed Central

    Shen, Jie; Feng, Liguo; Li, Yumin

    2015-01-01

    Background: To describe the clinical manifestations and ancillary examination outcomes of ocular syphilis in Southeast China. Materials and methods: This is a retrospective, nonrandom case study. Demographic information, serum and cerebrospinal fluid (CSF) test results, and findings of fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), and spectral domain optical coherence tomography (SD-OCT) were analyzed. Results: The study examined 21 eyes of 13 patients (average age 50.3 ± 5.9 (range 37-61) years). HIV co-infection was found in one patient. The most common manifestation was chorioretinitis (52.4%). Disc hyperfluorescence (66.7%) and persistent dark spots (91.7%) were the most common findings on FFA and ICGA, respectively. The inner segment/outer segment junction (IS/OS) loss was the most frequent manifestation (86.7%). Among the six patients with confirmed neurosyphilis, the average CSF protein level was 528.8 ± 327.1 mg/L. Visual acuity (VA) was improved in 8 of 13 eyes (61.5%) after treatment. Conclusions: The manifestations of ocular syphilis can mimic any eye disease. Chorioretinitis was the most common finding in this case series. “Leopard spots” was the characteristic manifestation on FFA. IS/OS loss was the most common finding in patients with posterior uveitis on SD-OCT. Lumbar puncture can contribute to the diagnosis of neurosyphilis. Treatment for ocular syphilis was effective in these patients. PMID:26221328

  3. Ocular injuries in survivors of improvised explosive devices (IED) in commuter trains

    PubMed Central

    Mehta, Salil; Agarwal, Vinay; Jiandani, Prakash

    2007-01-01

    Background Ocular injuries are common in survivors of terror incidents that involve the use of explosive materials. These explosives are commonly of a High Explosive type (HE) and may be fashioned into improvised explosive devices (IED) that incorporate additional materials to maximise trauma and injuries. Serial IED explosions have occurred in commuter trains in several cities including London and Madrid but data on ocular injuries is limited. We report the ocular injuries of the survivors of a series of IED explosions in crowded commuter trains. Methods 28 patients (56 eyes, 28 male, ages ranging from 22 to 52 years (mean 35.27 years) were screened in the triage area or the Intensive Care Unit (ICU). Testing included bedside visual acuity testing, torchlight examination of the anterior segment and dilated (or if necessary, undilated) fundus examination. Selected patients underwent B-scan examination, magnetic resonance imaging of the brain, orbits and the optic nerves or visual evoked potential assessment. The injuries, investigations and procedures were entered into the patient's case sheet as well as into a standardised format suggested by the Indian eye injury registry (IER). Results 16 of 28 patients (57.1%) had ocular injuries whereas 12 (42.8%) were found to be normal. Injuries were seen unilaterally in 10 patients and bilaterally in six yielding a total of 22 injured eyes. The common injuries were periorbital haemorrhages (09 eyes, 40%); first or second degree burns to the upper or lower lids (seen in 07 eyes, 31.8 %) and corneal injuries (seen in 08 eyes, 36.3%). Open globe injuries were seen in two eyes of two patients (09%). One patient (4.5%) had a traumatic optic neuropathy. Conclusion Ophthalmologists and traumatologists should be aware of these patterns of ocular injuries. Protocols need to include the screening of large numbers of patients in a short time, diagnostic tests (B scan, visual evoked potential (VEP) etc) and early surgery preferably at

  4. Quantitative Analysis of Fundus-Image Sequences Reveals Phase of Spontaneous Venous Pulsations

    PubMed Central

    Moret, Fabrice; Reiff, Charlotte M.; Lagrèze, Wolf A.; Bach, Michael

    2015-01-01

    Purpose Spontaneous venous pulsation correlates negatively with elevated intracranial pressure and papilledema, and it relates to glaucoma. Yet, its etiology remains unclear. A key element to elucidate its underlying mechanism is the time at which collapse occurs with respect to the heart cycle, but previous reports are contradictory. We assessed this question in healthy subjects using quantitative measurements of both vein diameters and artery lateral displacements; the latter being used as the marker of the ocular systole time. Methods We recorded 5-second fundus sequences with a near-infrared scanning laser ophthalmoscope in 12 young healthy subjects. The image sequences were coregistered, cleaned from microsaccades, and filtered via a principal component analysis to remove nonpulsatile dynamic features. Time courses of arterial lateral displacement and of diameter at sites of spontaneous venous pulsation or proximal to the disk were retrieved from those image sequences and compared. Results Four subjects displayed both arterial and venous pulsatile waveforms. On those, we observed venous diameter waveforms differing markedly among the subjects, ranging from a waveform matching the typical intraocular pressure waveform to a close replica of the arterial waveform. Conclusions The heterogeneity in waveforms and arteriovenous phases suggests that the mechanism governing the venous outflow resistance differs among healthy subjects. Translational relevance Further characterizations are necessary to understand the heterogeneous mechanisms governing the venous outflow resistance as this resistance is altered in glaucoma and is instrumental when monitoring intracranial hypertension based on fundus observations. PMID:26396929

  5. Ocular Outcomes Comparison Between 14- and 70-day Head-down Tilt Bed Rest

    NASA Technical Reports Server (NTRS)

    Cromwell, R.L.; Taibbi, G.; Zanello, S.B.; Yarbough, P.O.; Ploutz-Snyder, R.J.; Vizzen, G.

    2015-01-01

    INTRODUCTION: Ophthalmological changes, including optic disc edema with optic nerve sheath distension, posterior globe flattening with hyperopic shift, choroidal folds and cotton wool spots have been detected in some astronauts involved in long-duration spaceflights. (sup 1) It is hypothesized that elevated intracranial pressure resulting from microgravity-induced cephalad fluid shifts may be responsible for most of these findings. Head-down tilt bed rest (HTDBR) is a ground-based microgravity analog which also produces cephalad fluid shifts. It is conceivable that prolonged HDTBR exposure may induce ocular changes similar to those experienced in microgravity. Therefore, the purpose of the present study was to compare structural and functional ocular outcomes between 14- and 70-day HDTBR in healthy human subjects. It is hypothesized that 70-d HDTBR induced ocular changes of greater magnitude as compared to 14-d HDTBR. METHODS: Two HDTBR studies were conducted at the NASA Flight Analogs Research Unit, located at The University of Texas Medical Branch at Galveston, TX. Identical NASA standard screening procedures and BR conditions (e.g., strict sleep-wake cycle, standardized diet, continuous video monitoring) were implemented in both studies. Participants spent 14 and/or 70 consecutive days in a 6deg HDT position and did not engage in exercise. Subjects received weekly ocular examinations before, during, and after HDTBR. Ocular testing included: distance and near best-corrected visual acuity (BCVA), cycloplegic refraction, intraocular pressure (IOP) measurement, color vision, red dot test, modified Amsler grid test, confrontational visual field, color fundus photography and Spectral-domain OCT scans of the macula and the optic disc. Pre/post HDTBR differences between the two studies will be evaluated for BCVA, spherical equivalent, IOP, retinal nerve fiber layer (RNFL) thickness and macular OCT parameters. RESULTS: 16 (12 males and 4 females) and 6 (5 males and 1

  6. Rare case of optic pathway glioma with extensive intra-ocular involvement in a child with neurofibromatosis type 1.

    PubMed

    Gupta, Vasudha; Sabri, Kourosh; Whelan, Kaitlyn F; Viscardi, Virginia

    2015-01-01

    We present a case of a 3-year-old girl with a positive family history of neurofibromatosis type-1 (NF1) presented with best corrected visual acuity of 20/40 in the right eye and <20/400 in the left eye. External ocular examination revealed left eye proptosis of 3 mm, grade II left relative afferent pupillary defect and full range of ocular motility with no strabismus. Slit lamp examination revealed iris lisch nodules bilaterally. Dilated fundus examination of the right eye was normal. Left eye disclosed a large mass extending from the optic nerve head, with associated subretinal fluid. There was neovascularization at the optic disc as well as a superior retinal hemorrhage. Computed tomography of brain/orbits showed an enlarged left optic nerve with a large mass at the optic nerve head, with no evidence of calcification. In addition, a large left optic pathway glioma (OPG), multiple hamartomas within the brain and a smaller low-grade right OPG was also reported. The remarkable feature of our case is the rare intraocular optic nerve involvement of the OPG. Early and regular ophthalmological assessment of all NF1 suspect/confirmed cases is of paramount importance in order to detect OPG early, resulting in timely intervention and salvage of vision. PMID:25624686

  7. Ultrawide-field fundus photography of the first reported case of gyrate atrophy from Australia

    PubMed Central

    Moloney, Thomas P; O’Hagan, Stephen; Lee, Lawrence

    2014-01-01

    Gyrate atrophy of the choroid and retina is a rare chorioretinal dystrophy inherited in an autosomal recessive pattern. We describe the first documented case of gyrate atrophy from Australia in a 56-year-old woman with a history of previous diagnosis of retinitis pigmentosa and worsening night vision in her right eye over several years. She was myopic and bilaterally pseudophakic, and fundus examination revealed pale optic discs and extensive peripheral chorioretinal atrophy exposing bare sclera bilaterally with only small islands of normal-appearing retina at each posterior pole. Visual field testing showed grossly constricted fields, blood testing showed hyperornithinemia, and further questioning revealed consanguinity between the patient’s parents. We then used the patient’s typical retinal findings of gyrate atrophy to demonstrate the potential use of ultrawide-field fundus photography and angiography in diagnosis and monitoring response in future treatment. PMID:25187693

  8. Automated retinal vessel type classification in color fundus images

    NASA Astrophysics Data System (ADS)

    Yu, H.; Barriga, S.; Agurto, C.; Nemeth, S.; Bauman, W.; Soliz, P.

    2013-02-01

    Automated retinal vessel type classification is an essential first step toward machine-based quantitative measurement of various vessel topological parameters and identifying vessel abnormalities and alternations in cardiovascular disease risk analysis. This paper presents a new and accurate automatic artery and vein classification method developed for arteriolar-to-venular width ratio (AVR) and artery and vein tortuosity measurements in regions of interest (ROI) of 1.5 and 2.5 optic disc diameters from the disc center, respectively. This method includes illumination normalization, automatic optic disc detection and retinal vessel segmentation, feature extraction, and a partial least squares (PLS) classification. Normalized multi-color information, color variation, and multi-scale morphological features are extracted on each vessel segment. We trained the algorithm on a set of 51 color fundus images using manually marked arteries and veins. We tested the proposed method in a previously unseen test data set consisting of 42 images. We obtained an area under the ROC curve (AUC) of 93.7% in the ROI of AVR measurement and 91.5% of AUC in the ROI of tortuosity measurement. The proposed AV classification method has the potential to assist automatic cardiovascular disease early detection and risk analysis.

  9. Ocular lesions in the Earth Day, 1970, histoplasmosis epidemic.

    PubMed

    Davidorf, F H; Anderson, J D

    1975-01-01

    The relationship between systemic histoplasmosis and this particular clinical picutre of a central choroiditis with peripheral atrophic lesions in the fundus was postulated by Woods in 1960 [19]. Since that time there have been many studies attempting to substantiate his hyptthesis [1, 3-5, 7-18]. In a large study performed in Walkersville, Maryland, which is an area endemic for histoplasmosis [14], the prevalence of the characteristic peripheral histoplasmic lesion in the fundus was 27 per 1000 population. The prevalence was 44 per 1000 population with positive histoplasmosis skin tests. In a similar study done in sothern Ohio, the prevalence of peripheral fundus lesions was 1.6 percent of 1417 patients examined [1]. Several generalizations can be made from the information obtained in studying the students involved in the Willis flu, and these can be compared with information from the control students from Bellingham. First, the acute infection at Willis School did not cause significant ocular abnormalities. This finding is supported by the fact that no significant differences occurred in the fundus lesions seen in the control group of students who lived in the same geographic area but were not clinically ill from histoplasmosis. Our evidence shows that the eyegrounds of the individuals living in this area were different from those of the students who lived outside the central Ohio area. How do we account for the similarity of ocular lesions in the affected students and the Delaware control group? Perhaps by the age of 11 or 12, a person living in the histoplasmosis belt will have already been exposed to histoplasmosis, resulting in the characteristic scars that are seen. If, in fact, histoplasmosis is the etiological agent in the patients who are diagnosed as having presumed ocular histoplasmosis, difficulty arises in understanding why those individuals involved in the epidemic did not have more scars than the control group. Perhaps the numbers of patients

  10. Glare-free optical system for fundus visualization

    NASA Astrophysics Data System (ADS)

    Salakhutdinov, Viktor K.; Smetanin, Yuriy G.; Doroshenko, Jasser; Sivachenko, Eugene A.

    2014-05-01

    The paper describes results of development of fundus-camera with non-glare optical scheme. The scheme is based on multiple lenses with a light gathering power (D/F <= 1) substantially less than one. Illumination of fundus can be provided through eye's pupil less than 3 mm. And much attention was directed to method of calculation of the no-glare optical scheme. The key idea is that geometry of optic elements of the system provides that glare in the form of ghost reflection from optical surface of one element focuses on a small-size absorbing screen located on another optical surface. Shows the possibility of implementation and the experimental results. During experiments with B/W camera we got Full HD color image of fundus having the eye's pupil diameter of 1.5 mm and illumination of fundus tissue in accordance with sanitary rules.

  11. A new procedure for fundus photography and fluorescein angiography in small laboratory animal eyes.

    PubMed

    DiLoreto, D; Grover, D A; del Cerro, C; del Cerro, M

    1994-02-01

    Increasing interest in retinal research demands continuous improvement of experimental techniques and interpretation. Thus, the purpose of our research was to devise a new method for funduscopic photography and fluorescein angiography in the normal or diseased retina of the small laboratory animal that would produce results comparable in optical quality and field coverage to those obtained in human clinical practice. To enhance the view of the small eye, a 2.2 Volk Panretinal lens was held in apposition to the lens of a clinical fundus camera, the Topcon TRC 50FT, by means of a custom made metal sleeve. Albino mice, albino rats, and pigmented rats were photographed. Fluorescein angiography was performed on pigmented rats. Fluorescein was administered intravenously via the jugular vein at a dose of 5 mg/kg. Various speeds of film and flash settings were used depending on the light source and the pigmentation of the animal. Attachment of the 2.2 Panretinal lens to the clinical fundus camera allowed for more clearly defined fundus photographs of the small laboratory animal, as well as an enlarged field of observation over conventional techniques. Consequently, angiography fields and stages documented in the small laboratory animal approximated those obtained in human clinical practice. This technique facilitates the visualization of small fundi and it allows for a fuller documentation of experimental retinal models. PMID:8194363

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

    PubMed Central

    Kim, Min Kyung

    2016-01-01

    Purpose We evaluated fundus and fluorescein angiography (FAG) findings and characteristics that can help distinguish nonarteritic anterior ischemic optic neuropathy (NAION) from optic neuritis (ON). Methods Twenty-three NAION patients and 17 ON with disc swelling patients were enrolled in this study. We performed fundus photography and FAG. The disc-swelling pattern, hyperemia grade, presence of splinter hemorrhages, cotton-wool spots, artery/vein ratio and degree of focal telangiectasia were investigated. The FAG findings for each patient were compared with respect to the following features: the pattern of disc leakage in the early phase, arteriovenous (artery/vein) transit time (second), and the presence and pattern of the filling delay. Results Cotton-wool spots, focal telangiectasia, and venous congestion were more common in the affected eyes of NAION patients. Upon FAG, 76.5% of the patients in the ON group exhibited normal choroidal circulation. However, 56.5% of patients in the NAION group demonstrated abnormal filling defects, such as peripapillary, generalized, or watershed zone filling delays. Conclusions Fundus findings, including cotton-wool spots, focal telangiectasia, and venous congestion in the affected eye, may be clues that can be used to diagnose NAION. In addition, choroidal insufficiencies on FAG could be also helpful in differentiating NAION from ON. PMID:27478356

  13. Development of a screening tool for staging of diabetic retinopathy in fundus images

    NASA Astrophysics Data System (ADS)

    Dhara, Ashis Kumar; Mukhopadhyay, Sudipta; Bency, Mayur Joseph; Rangayyan, Rangaraj M.; Bansal, Reema; Gupta, Amod

    2015-03-01

    Diabetic retinopathy is a condition of the eye of diabetic patients where the retina is damaged because of long-term diabetes. The condition deteriorates towards irreversible blindness in extreme cases of diabetic retinopathy. Hence, early detection of diabetic retinopathy is important to prevent blindness. Regular screening of fundus images of diabetic patients could be helpful in preventing blindness caused by diabetic retinopathy. In this paper, we propose techniques for staging of diabetic retinopathy in fundus images using several shape and texture features computed from detected microaneurysms, exudates, and hemorrhages. The classification accuracy is reported in terms of the area (Az) under the receiver operating characteristic curve using 200 fundus images from the MESSIDOR database. The value of Az for classifying normal images versus mild, moderate, and severe nonproliferative diabetic retinopathy (NPDR) is 0:9106. The value of Az for classification of mild NPDR versus moderate and severe NPDR is 0:8372. The Az value for classification of moderate NPDR and severe NPDR is 0:9750.

  14. Atypical Presentation of Ocular Toxoplasmosis: A Case Report of Exudative Retinal Detachment and Choroidal Ischemia

    PubMed Central

    Al-Zahrani, Yahya A.; Al-Dhibi, Hassan A.; Al-Abdullah, Abdulelah A.

    2016-01-01

    A 24-year-old healthy male presented with a chief complaint of blurred vision in the right eye for 1-week. Fundus examination indicated right exudative retinal detachment and choroidal ischemia. The patient responded well to anti-toxoplasmosis medications and steroids. Exudative retinal detachment and choroidal ischemia are atypical presentations of ocular toxoplasmosis. However, both conditions responded well to anti.parasitic therapy with steroid. PMID:26957857

  15. Atypical Presentation of Ocular Toxoplasmosis: A Case Report of Exudative Retinal Detachment and Choroidal Ischemia.

    PubMed

    Al-Zahrani, Yahya A; Al-Dhibi, Hassan A; Al-Abdullah, Abdulelah A

    2016-01-01

    A 24-year-old healthy male presented with a chief complaint of blurred vision in the right eye for 1-week. Fundus examination indicated right exudative retinal detachment and choroidal ischemia. The patient responded well to anti-toxoplasmosis medications and steroids. Exudative retinal detachment and choroidal ischemia are atypical presentations of ocular toxoplasmosis. However, both conditions responded well to anti.parasitic therapy with steroid. PMID:26957857

  16. Adaptive optics fundus camera using a liquid crystal phase modulator

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Tatsuo; Nakazawa, Naoki; Bessho, Kenichiro; Kitaguchi, Yoshiyuki; Maeda, Naoyuki; Fujikado, Takashi; Mihashi, Toshifumi

    2008-05-01

    We have developed an adaptive optics (AO) fundus camera to obtain high resolution retinal images of eyes. We use a liquid crystal phase modulator to compensate the aberrations of the eye for better resolution and better contrast in the images. The liquid crystal phase modulator has a wider dynamic range to compensate aberrations than most mechanical deformable mirrors and its linear phase generation makes it easy to follow eye movements. The wavefront aberration was measured in real time with a sampling rate of 10 Hz and the closed loop system was operated at around 2 Hz. We developed software tools to align consecutively obtained images. From our experiments with three eyes, the aberrations of normal eyes were reduced to less than 0.1 μm (RMS) in less than three seconds by the liquid crystal phase modulator. We confirmed that this method was adequate for measuring eyes with large aberrations including keratoconic eyes. Finally, using the liquid crystal phase modulator, high resolution images of retinas could be obtained.

  17. Automatic detection of red lesions in digital color fundus photographs.

    PubMed

    Niemeijer, Meindert; van Ginneken, Bram; Staal, Joes; Suttorp-Schulten, Maria S A; Abràmoff, Michael D

    2005-05-01

    The robust detection of red lesions in digital color fundus photographs is a critical step in the development of automated screening systems for diabetic retinopathy. In this paper, a novel red lesion detection method is presented based on a hybrid approach, combining prior works by Spencer et al. (1996) and Frame et al. (1998) with two important new contributions. The first contribution is a new red lesion candidate detection system based on pixel classification. Using this technique, vasculature and red lesions are separated from the background of the image. After removal of the connected vasculature the remaining objects are considered possible red lesions. Second, an extensive number of new features are added to those proposed by Spencer-Frame. The detected candidate objects are classified using all features and a k-nearest neighbor classifier. An extensive evaluation was performed on a test set composed of images representative of those normally found in a screening set. When determining whether an image contains red lesions the system achieves a sensitivity of 100% at a specificity of 87%. The method is compared with several different automatic systems and is shown to outperform them all. Performance is close to that of a human expert examining the images for the presence of red lesions. PMID:15889546

  18. Spectral characterization of an ophthalmic fundus camera

    NASA Astrophysics Data System (ADS)

    Miller, Clayton T.; Bassi, Carl J.; Brodsky, Dale; Holmes, Timothy

    2010-02-01

    A fundus camera is an optical system designed to illuminate and image the retina while minimizing stray light and backreflections. Modifying such a device requires characterization of the optical path in order to meet the new design goals and avoid introducing problems. This work describes the characterization of one system, the Topcon TRC-50F, necessary for converting this camera from film photography to spectral imaging with a CCD. This conversion consists of replacing the camera's original xenon flash tube with a monochromatic light source and the film back with a CCD. A critical preliminary step of this modification is determining the spectral throughput of the system, from source to sensor, and ensuring there are sufficient photons at the sensor for imaging. This was done for our system by first measuring the transmission efficiencies of the camera's illumination and imaging optical paths with a spectrophotometer. Combining these results with existing knowledge of the eye's reflectance, a relative sensitivity profile is developed for the system. Image measurements from a volunteer were then made using a few narrowband sources of known power and a calibrated CCD. With these data, a relationship between photoelectrons/pixel collected at the CCD and narrowband illumination source power is developed.

  19. Measurement of retinal blood flow in the rat by combining Doppler Fourier-domain optical coherence tomography with fundus imaging

    NASA Astrophysics Data System (ADS)

    Werkmeister, René M.; Vietauer, Martin; Knopf, Corinna; Fürnsinn, Clemens; Leitgeb, Rainer A.; Reitsamer, Herbert; Gröschl, Martin; Garhöfer, Gerhard; Vilser, Walthard; Schmetterer, Leopold

    2014-10-01

    A wide variety of ocular diseases are associated with abnormalities in ocular circulation. As such, there is considerable interest in techniques for quantifying retinal blood flow, among which Doppler optical coherence tomography (OCT) may be the most promising. We present an approach to measure retinal blood flow in the rat using a new optical system that combines the measurement of blood flow velocities via Doppler Fourier-domain optical coherence tomography and the measurement of vessel diameters using a fundus camera-based technique. Relying on fundus images for extraction of retinal vessel diameters instead of OCT images improves the reliability of the technique. The system was operated with an 841-nm superluminescent diode and a charge-coupled device camera that could be operated at a line rate of 20 kHz. We show that the system is capable of quantifying the response of 100% oxygen breathing on the retinal blood flow. In six rats, we observed a decrease in retinal vessel diameters of 13.2% and a decrease in retinal blood velocity of 42.6%, leading to a decrease in retinal blood flow of 56.7%. Furthermore, in four rats, the response of retinal blood flow during stimulation with diffuse flicker light was assessed. Retinal vessel diameter and blood velocity increased by 3.4% and 28.1%, respectively, leading to a relative increase in blood flow of 36.2%;. The presented technique shows much promise to quantify early changes in retinal blood flow during provocation with various stimuli in rodent models of ocular diseases in rats.

  20. Measurement of retinal blood flow in the rat by combining Doppler Fourier-domain optical coherence tomography with fundus imaging.

    PubMed

    Werkmeister, René M; Vietauer, Martin; Knopf, Corinna; Fürnsinn, Clemens; Leitgeb, Rainer A; Reitsamer, Herbert; Gröschl, Martin; Garhöfer, Gerhard; Vilser, Walthard; Schmetterer, Leopold

    2014-01-01

    A wide variety of ocular diseases are associated with abnormalities in ocular circulation. As such, there is considerable interest in techniques for quantifying retinal blood flow, among which Doppler optical coherence tomography (OCT) may be the most promising. We present an approach to measure retinal blood flow in the rat using a new optical system that combines the measurement of blood flow velocities via Doppler Fourier-domain optical coherence tomography and the measurement of vessel diameters using a fundus camera-based technique. Relying on fundus images for extraction of retinal vessel diameters instead of OCT images improves the reliability of the technique. The system was operated with an 841-nm superluminescent diode and a charge-coupled device camera that could be operated at a line rate of 20 kHz. We show that the system is capable of quantifying the response of 100% oxygen breathing on the retinal blood flow. In six rats, we observed a decrease in retinal vessel diameters of 13.2% and a decrease in retinal blood velocity of 42.6%, leading to a decrease in retinal blood flow of 56.7%. Furthermore, in four rats, the response of retinal blood flow during stimulation with diffuse flicker light was assessed. Retinal vessel diameter and blood velocity increased by 3.4% and 28.1%, respectively, leading to a relative increase in blood flow of 36.2%. The presented technique shows much promise to quantify early changes in retinal blood flow during provocation with various stimuli in rodent models of ocular diseases in rats. PMID:25321400

  1. In situ demonstration of actin in normal and injured ocular tissues using 7-nitrobenz-2-oxa-1,3-diazole phallacidin.

    PubMed

    Gordon, S R; Essner, E; Rothstein, H

    1982-01-01

    The fluorescent derivative of the actin-binding toxin phallacidin, 7-nitrobenz-2-oxa-1,3 diazole phallacidin, has been used to cytologically demonstrate the presence of actin in lens epithelium, corneal endothelium, and retinal pigment epithelium. In these noninjured tissues, no stress fibers are observed and fluorescence is confined mainly to an area at or near the cell membrane, although some diffuse cytoplasmic staining can also be seen. However, following injury to either the lens epithelium or corneal endothelium of rats and frogs, stress fibers are detected, but only in those cells that migrate into the wound area. Cells on the periphery of each tissue do not partake in would repair and thus maintain their normal appearance. After the tissue has regenerated, stress fibers disappear, and those cells involved in the injury response return to their normal morphology. When rabbit corneal endothelium is placed in tissue culture, stress fibers are observed as the cells migrate away from the initial explant. Upon reaching confluency, these cells spread out and each is surrounded by thick actin-containing bands. Furthermore, they exhibit some stress cables within their cytoplasm. This is in contrast to their appearance in vivo where stress fibers are absent and fluorescence is limited to a region near the cell membrane. PMID:6983909

  2. [Mechanism of angiogenesis. Ocular involvement].

    PubMed

    Mocanu, Carmen

    2003-01-01

    Over the past several years, there has been important progress in the field of intrinsec mechanisms of ocular neovascularization. Immunohistological studies succeeded a better systematization of the factors that stimulates and inhibits this process. Their presence in different ocular normal structures, without any angiogenic activity, suggests a physiological balance between VEGF (vascular endothelial growth factor) with stimulatory effect on angiogenesis and PEDF (pigment epithelium derived factor) with inhibitory effect. It has been discussing the possibility of modification of physiological balance between VEGF and PEDF to induce the neovascularization process. The understanding of the physiopathological mechanisms of the substances implicated in inhibition of chorioretinal neovascularization makes to be real the expectations for the development of new treatments. PMID:15083677

  3. Thermography in ocular inflammation

    PubMed Central

    Kawali, Ankush A

    2013-01-01

    Background and Objectives: The purpose of this study was to evaluate ocular inflammatory and non-inflammatory conditions using commercially available thermal camera. Materials and Methods: A non-contact thermographic camera (FLIR P 620) was used to take thermal pictures of seven cases of ocular inflammation, two cases of non-inflammatory ocular pathology, and one healthy subject with mild refractive error only. Ocular inflammatory cases included five cases of scleritis, one case of postoperative anterior uveitis, and a case of meibomian gland dysfunction with keratitis (MGD-keratitis). Non-inflammatory conditions included a case of conjunctival benign reactive lymphoid hyperplasia (BRLH) and a case of central serous chorio-retinopathy. Thermal and non-thermal photographs were taken, and using analyzing software, the ocular surface temperature was calculated. Results: Patient with fresh episode of scleritis revealed high temperature. Eyes with MGD-keratitis depicted lower temperature in clinically more affected eye. Conjunctival BRLH showed a cold lesion on thermography at the site of involvement, in contrast to cases of scleritis with similar clinical presentation. Conclusion: Ocular thermal imaging is an underutilized diagnostic tool which can be used to distinguish inflammatory ocular conditions from non-inflammatory conditions. It can also be utilized in the evaluation of tear film in dry eye syndrome. Its applications should be further explored in uveitis and other ocular disorders. Dedicated “ocular thermographic” camera is today's need of the hour. PMID:24347863

  4. Ocular Outcomes Evaluation in a 14-Day Head-Down Bed Rest Study

    PubMed Central

    Taibbi, Giovanni; Cromwell, Ronita L.; Zanello, Susana B.; Yarbough, Patrice O.; Ploutz-Snyder, Robert J.; Godley, Bernard F.; Vizzeri, Gianmarco

    2014-01-01

    Introduction We evaluated ocular outcomes in a 14-day head-down tilt (HDT) bed rest (BR) study designed to simulate the effects of microgravity on the human body. Methods Healthy subjects were selected using NASA standard screening procedures. Standardized NASA BR conditions were implemented (e.g., strict sleep-wake cycle, standardized diet, 24-hour-a-day BR, continuous video monitoring). Subjects maintained a 6° HDT position for 14 consecutive days. Weekly ophthalmological examinations were performed in the sitting (pre/post-BR) and HDT (in-bed phase) positions. Equivalency tests with optimal-alpha techniques evaluated pre/post-BR differences in best-corrected visual acuity (BCVA), spherical equivalent, intraocular pressure (IOP), Spectral-domain OCT retinal nerve fiber layer thickness (RNFLT), optic disc and macular parameters. Results 16 subjects (12 men and 4 women) were enrolled. Nearly all ocular outcomes were within our predefined clinically relevant thresholds following HDTBR, except near BCVA (pre/post-BR mean difference: −0.06 logMAR), spherical equivalent (−0.30 D), Tonopen XL IOP (+3.03 mmHg) and Spectralis OCT average (+1.14 μm), temporal-inferior (+1.58 μm) and nasal-inferior RNFLT (+3.48 μm). Modified Amsler grid, red dot test, confrontational visual field and color vision were within normal limits throughout. No changes were detected on stereoscopic color fundus photography. Discussion A few functional and structural changes were detected after 14-day HDTBR, notably an improved BCVA possibly due to learning effect and RNFL thickening without signs of optic disc edema. In general, 6° HDTBR determined a small non-progressive IOP elevation, which returned to baseline levels post-BR. Further studies with different BR duration and/or tilt angle are warranted to investigate microgravity-induced ophthalmological changes. PMID:25245897

  5. Effect of dorzolamide and timolol on ocular blood flow in patients with primary open angle glaucoma and ocular hypertension

    PubMed Central

    Fuchsjäger-Mayrl, G; Wally, B; Rainer, G; Buehl, W; Aggermann, T; Kolodjaschna, J; Weigert, G; Polska, E; Eichler, H-G; Vass, C; Schmetterer, L

    2005-01-01

    Background: There is evidence that perfusion abnormalities of the optic nerve head are involved in the pathogenesis of glaucoma. There is therefore considerable interest in the effects of topical antiglaucoma drugs on ocular blood flow. A study was undertaken to compare the ocular haemodynamic effects of dorzolamide and timolol in patients with primary open angle glaucoma (POAG) or ocular hypertension (OHT). Methods: One hundred and forty patients with POAG or OHT were included in a controlled, randomised, double blind study in two parallel groups; 70 were randomised to receive timolol and 70 to receive dorzolamide for a period of 6 months. Subjects whose intraocular pressure (IOP) did not respond to either of the two drugs were switched to the alternative treatment after 2 weeks. Scanning laser Doppler flowmetry was used to measure blood flow in the temporal neuroretinal rim and the cup of the optic nerve head. Pulsatile choroidal blood flow was assessed using laser interferometric measurement of fundus pulsation amplitude. Results: Five patients did not respond to timolol and were changed to the dorzolamide group, and 18 patients changed from dorzolamide treatment to timolol. The effects of both drugs on IOP and ocular perfusion pressure were comparable. Dorzolamide, but not timolol, increased blood flow in the temporal neuroretinal rim (8.5 (1.6)%, p<0.001 versus timolol) and the cup of the optic nerve head (13.5 (2.5)%, p<0.001 versus timolol), and fundus pulsation amplitude (8.9 (1.3)%, p<0.001 versus timolol). Conclusions: This study indicates augmented blood flow in the optic nerve head and choroid after 6 months of treatment with dorzolamide, but not with timolol. It remains to be established whether this effect can help to reduce visual field loss in patients with glaucoma. PMID:16170119

  6. Comparison of the Effects of Dorzolamide/Timolol Fixed Combination versus Latanoprost on Intraocular Pressure and Ocular Perfusion Pressure in Patients with Normal-Tension Glaucoma: A Randomized, Crossover Clinical Trial

    PubMed Central

    Lee, Na Young; Park, Hae-Young Lopilly; Park, Chan Kee

    2016-01-01

    Backgroud To assess the noninferiority of a dorzolamide-timolol fixed combination (DTFC) versus latanoprost in terms of intraocular pressure (IOP) and to compare blood pressure (BP), ocular perfusion pressure (OPP) and diastolic ocular perfusion pressure (DOPP) between the latanoprost and DTFC groups in patients with normal-tension glaucoma (NTG). Methods Prospective, interventional, randomized, single-blinded, crossover design study. Patients with newly diagnosed NTG that had not been treated with a glaucoma medication in the most recent 2 months were recruited. In total, 44 patients with NTG were randomly allocated to one of two groups. Patients in group A were treated with DTFC, lubricant, and latanoprost for 4 weeks each, whereas patients in group B were treated with latanoprost, lubricant, and DTFC for 4 weeks each. Patients were examined on day 1 (without medication), week 4 (under medication), week 8 (without medication), and week 12 (under medication). At weeks 4 and 12, diurnal IOP, systolic and diastolic BP, and OPP were measured at 8:00 AM, 10:00 AM, 12:00 PM, 4:00 PM, and 8:00 PM. Results Baseline demographic characteristics showed no difference in terms of age, sex, central corneal thickness, spherical equivalent, or stage of glaucoma between the groups. The between-group difference was -0.19 ± 0.18 mmHg (mean ± SE, upper bound of one-sided 95% CI, 0.12). Diurnal IOP showed no difference between the groups with an average IOP reduction of 13.1% using latanoprost and 12.3% using DTFC. Diurnal systolic and diastolic BP were lower in the DTFC group than the latanoprost group; however, the difference between the groups was not statistically significant. Diurnal OPP and DOPP also showed no statistically significant difference between the groups. Conclusions IOP lowering efficacy of DTFC was noninferior to that of latanoprost in newly diagnosed NTG patients. There was no difference in BP, OPP, or DOPP between the latanoprost and DTFC groups. This

  7. Postoperative Change in Ocular Torsion in Intermittent Exotropia: Relationship with Postoperative Surgical Outcomes.

    PubMed

    Lee, Ju-Yeun; Hwang, Sungsoon; Oh, Shin Yeop; Park, Kyung-Ah; Oh, Sei Yeul

    2016-01-01

    The aim of this study was to determine whether objective ocular torsion in intermittent exotropia (IXT) changes after recession surgery, and to evaluate the relationship between change in ocular torsion and clinical parameters in IXT. Sixty patients between 3 and 14 years of age underwent lateral rectus (LR) recession for IXT. Digital fundus photographs were obtained from both eyes of each subject and the disc-foveal angle (ocular torsion) was calculated using image software. We compared the preoperative and postoperative amount of ocular torsion, and analyzed the correlation between the difference in ocular torsion (DOC) and clinical parameters including age, duration of strabismus, stereoacuity, amount of preoperative exodeviation, and mean dose response. We categorized the patients according to DOC value: positive DOC value as group 1, and negative DOC value as group 2. A correlation between ocular torsion dominance and fixation preference was also investigated using the Kappa test. The mean ocular torsion was 15.8 ± 4.6 degrees preoperatively and 13.7 ± 5.1 degrees postoperatively. Compared with preoperative values, the mean ocular torsion showed a significant decrease after LR recession (p<0.001), and a greater preoperative ocular torsion was significantly associated with the amount of DOC (r = 0.37, p<0.001). Degree of stereopsis, mean dose-response, and postoperative exodeviation were significantly different between group 1 (positive DOC) and group 2 (negative DOC) (p<0.001, 0.030, and 0.001 respectively). The Kappa test showed that there was a significant correlation between the dominance of ocular torsion and fixation preference (p = 0.020). Therefore, change in ocular torsion after LR recession can be a useful supplementary indicator for evaluating the degree of fusional control and for predicting postoperative surgical response in IXT. PMID:27622574

  8. Fundus image registration for vestibularis research

    NASA Astrophysics Data System (ADS)

    Ithapu, Vamsi K.; Fritsche, Armin; Oppelt, Ariane; Westhofen, Martin; Deserno, Thomas M.

    2010-03-01

    In research on vestibular nerve disorders, fundus images of both left and right eyes are acquired systematically to precisely assess the rotation of the eye ball that is induced by the rotation of entire head. The measurement is still carried out manually. Although various methods have been proposed for medical image registration, robust detection of rotation especially in images with varied quality in terms of illumination, aberrations, blur and noise still is challenging. This paper evaluates registration algorithms operating on different levels of semantics: (i) data-based using Fourier transform and log polar maps; (ii) point-based using scaled image feature transform (SIFT); (iii) edge-based using Canny edge maps; (iv) object-based using matched filters for vessel detection; (v) scene-based detecting papilla and macula automatically and (vi) manually by two independent medical experts. For evaluation, a database of 22 patients is used, where each of left and right eye images is captured in upright head position and in lateral tilt of +/-200. For 66 pairs of images (132 in total), the results are compared with ground truth, and the performance measures are tabulated. Best correctness of 89.3% were obtained using the pixel-based method and allowing 2.5° deviation from the manual measures. However, the evaluation shows that for applications in computer-aided diagnosis involving a large set of images with varied quality, like in vestibularis research, registration methods based on a single level of semantics are not sufficiently robust. A multi-level semantics approach will improve the results since failure occur on different images.

  9. Iterative Vessel Segmentation of Fundus Images.

    PubMed

    Roychowdhury, Sohini; Koozekanani, Dara D; Parhi, Keshab K

    2015-07-01

    This paper presents a novel unsupervised iterative blood vessel segmentation algorithm using fundus images. First, a vessel enhanced image is generated by tophat reconstruction of the negative green plane image. An initial estimate of the segmented vasculature is extracted by global thresholding the vessel enhanced image. Next, new vessel pixels are identified iteratively by adaptive thresholding of the residual image generated by masking out the existing segmented vessel estimate from the vessel enhanced image. The new vessel pixels are, then, region grown into the existing vessel, thereby resulting in an iterative enhancement of the segmented vessel structure. As the iterations progress, the number of false edge pixels identified as new vessel pixels increases compared to the number of actual vessel pixels. A key contribution of this paper is a novel stopping criterion that terminates the iterative process leading to higher vessel segmentation accuracy. This iterative algorithm is robust to the rate of new vessel pixel addition since it achieves 93.2-95.35% vessel segmentation accuracy with 0.9577-0.9638 area under ROC curve (AUC) on abnormal retinal images from the STARE dataset. The proposed algorithm is computationally efficient and consistent in vessel segmentation performance for retinal images with variations due to pathology, uneven illumination, pigmentation, and fields of view since it achieves a vessel segmentation accuracy of about 95% in an average time of 2.45, 3.95, and 8 s on images from three public datasets DRIVE, STARE, and CHASE_DB1, respectively. Additionally, the proposed algorithm has more than 90% segmentation accuracy for segmenting peripapillary blood vessels in the images from the DRIVE and CHASE_DB1 datasets. PMID:25700436

  10. Automated lesion detectors in retinal fundus images.

    PubMed

    Figueiredo, I N; Kumar, S; Oliveira, C M; Ramos, J D; Engquist, B

    2015-11-01

    Diabetic retinopathy (DR) is a sight-threatening condition occurring in persons with diabetes, which causes progressive damage to the retina. The early detection and diagnosis of DR is vital for saving the vision of diabetic persons. The early signs of DR which appear on the surface of the retina are the dark lesions such as microaneurysms (MAs) and hemorrhages (HEMs), and bright lesions (BLs) such as exudates. In this paper, we propose a novel automated system for the detection and diagnosis of these retinal lesions by processing retinal fundus images. We devise appropriate binary classifiers for these three different types of lesions. Some novel contextual/numerical features are derived, for each lesion type, depending on its inherent properties. This is performed by analysing several wavelet bands (resulting from the isotropic undecimated wavelet transform decomposition of the retinal image green channel) and by using an appropriate combination of Hessian multiscale analysis, variational segmentation and cartoon+texture decomposition. The proposed methodology has been validated on several medical datasets, with a total of 45,770 images, using standard performance measures such as sensitivity and specificity. The individual performance, per frame, of the MA detector is 93% sensitivity and 89% specificity, of the HEM detector is 86% sensitivity and 90% specificity, and of the BL detector is 90% sensitivity and 97% specificity. Regarding the collective performance of these binary detectors, as an automated screening system for DR (meaning that a patient is considered to have DR if it is a positive patient for at least one of the detectors) it achieves an average 95-100% of sensitivity and 70% of specificity at a per patient basis. Furthermore, evaluation conducted on publicly available datasets, for comparison with other existing techniques, shows the promising potential of the proposed detectors. PMID:26378502

  11. Effect of trabeculectomy on ocular blood flow

    PubMed Central

    Berisha, F; Schmetterer, K; Vass, C; Dallinger, S; Rainer, G; Findl, O; Kiss, B; Schmetterer, L

    2005-01-01

    Background/aim: Current evidence suggests that vascular insufficiencies in the optic nerve head play an important part in the pathogenesis of glaucomatous optic neuropathy. Trabeculectomy is the most common operative procedure for the treatment of medically uncontrolled glaucoma. This study was conducted to investigate whether trabeculectomy may improve ocular haemodynamics. Methods: 30 patients with primary open angle glaucoma about to undergo trabeculectomy were included in the study. Patients were evaluated before surgery and at 2 and 10 weeks after trabeculectomy. Optic nerve head blood flow (OnhBF) was assessed with scanning laser Doppler flowmetry. Fundus pulsation amplitude (FPA) measurements were obtained with laser interferometry. Results: Because of the decrease in intraocular pressure there was a significant increase in ocular perfusion pressure (OPP) following trabeculectomy (18.5% (SD 12.0%) and 19.0% (17.1%) at 2 and 10 weeks postoperatively; p <0.001). A significant increase in OnhBF was observed after trabeculectomy (11.6% (16.4%) and 16.2% (20.2%) for each postoperative visit, respectively; p <0.001). FPA was also significantly higher compared with baseline values (17.2% (17.3%) and 17.4% (16.3%), respectively; p <0.001). A significant association between the increase in OPP and the increase in OnhBF and FPA was observed 10 weeks after surgery (r = 0.47; p = 0.009, and r = 0.50; p = 0.005, respectively). Conclusion: The results of this study suggest that trabeculectomy improves ocular blood flow in patients with chronic open angle glaucoma. PMID:15665350

  12. Role of Protease-Inhibitors in Ocular Diseases.

    PubMed

    Pescosolido, Nicola; Barbato, Andrea; Pascarella, Antonia; Giannotti, Rossella; Genzano, Martina; Nebbioso, Marcella

    2014-01-01

    It has been demonstrated that the balance between proteases and protease-inhibitors system plays a key role in maintaining cellular and tissue homeostasis. Indeed, its alteration has been involved in many ocular and systemic diseases. In particular, research has focused on keratoconus, corneal wounds and ulcers, keratitis, endophthalmitis, age-related macular degeneration, Sorsby fundus dystrophy, loss of nerve cells and photoreceptors during optic neuritis both in vivo and in vitro models. Protease-inhibitors have been extensively studied, rather than proteases, because they may represent a therapeutic approach for some ocular diseases. The protease-inhibitors mainly involved in the onset of the above-mentioned ocular pathologies are: α2-macroglobulin, α1-proteinase inhibitor (α1-PI), metalloproteinase inhibitor (TIMP), maspin, SERPINA3K, SERPINB13, secretory leukocyte protease inhibitor (SLPI), and calpeptin. This review is focused on the several characteristics of dysregulation of this system and, particularly, on a possible role of proteases and protease-inhibitors in molecular remodeling that may lead to some ocular diseases. Recently, researchers have even hypothesized a possible therapeutic effect of the protease-inhibitors in the treatment of injured eye in animal models. PMID:25493637

  13. Pediatric ocular phthiriasis infestation.

    PubMed

    Kairys, D J; Webster, H J; Terry, J E

    1988-02-01

    Although pubic lice infestation of ocular regions is relatively uncommon, the optometrist needs to be aware of the diagnosis and treatment of louse-infested patients. A case report of ocular phthiriasis is presented along with a discussion of its etiology, clinical diagnosis and management. PMID:3361053

  14. Plasticity of the human otolith-ocular reflex

    NASA Technical Reports Server (NTRS)

    Wall, C. 3rd; Smith, T. R.; Furman, J. M.

    1992-01-01

    The eye movement response to earth vertical axis rotation in the dark, a semicircular canal stimulus, can be altered by prior exposure to combined visual-vestibular stimuli. Such plasticity of the vestibulo-ocular reflex has not been described for earth horizontal axis rotation, a dynamic otolith stimulus. Twenty normal human subjects underwent one of two types of adaptation paradigms designed either to attenuate or enhance the gain of the semicircular canal-ocular reflex prior to undergoing otolith-ocular reflex testing with horizontal axis rotation. The adaptation paradigm paired a 0.2 Hz sinusoidal rotation about a vertical axis with a 0.2 Hz optokinetic stripe pattern that was deliberately mismatched in peak velocity. Pre- and post-adaptation horizontal axis rotations were at 60 degrees/s in the dark and produced a modulation in the slow component velocity of nystagmus having a frequency of 0.17 Hz due to putative stimulation of the otolith organs. Results showed that the magnitude of this modulation component response was altered in a manner similar to the alteration in semicircular canal-ocular responses. These results suggest that physiologic alteration of the vestibulo-ocular reflex using deliberately mismatched visual and semicircular canal stimuli induces changes in both canal-ocular and otolith-ocular responses. We postulate, therefore, that central nervous system pathways responsible for controlling the gains of canal-ocular and otolith-ocular reflexes are shared.

  15. The Retinal Disease Screening Study: Prospective Comparison of Nonmydriatic Fundus Photography and Optical Coherence Tomography for Detection of Retinal Irregularities

    PubMed Central

    Ouyang, Yanling; Heussen, Florian M.; Keane, Pearse A.; Sadda, SriniVas R.; Walsh, Alexander C.

    2013-01-01

    Purpose. To compare the sensitivity of volume scanning with optical coherence tomography (OCT) to nonmydriatic color fundus photography (FP) for the detection of retinal irregularities in asymptomatic populations. Methods. Asymptomatic subjects without known ocular disease were recruited over a 6-month period. For each eye, two undilated 45° fundus images and four undilated volume OCT image sets covering the macula and optic nerve were obtained. Color images were evaluated for irregularities both inside and outside the area covered by OCT. OCT image sets were evaluated for internal limiting membrane irregularities, abnormal retinal thickness, hyper/hyporeflective features, and photoreceptor/retinal pigment epithelium (RPE) irregularities. Detection sensitivities were compared and false-negative cases were analyzed. Results. A total of 284 eyes (144 subjects) were included, with a mean age of 38.1 years (range 18–77). Among 253 eyes (135 subjects) with gradable images from both FP and OCTs, the detection sensitivities for OCT were higher (96.2% infield and 85.7% in full field) than for FP (19.9% infield and 43.8% in full field) for all irregularities evaluated in the study (including epiretinal irregularities, abnormal retinal thickness, intraretinal hyperreflective/hyporeflective features, and photoreceptor/RPE irregularities). Overall, the presence of definite irregularities on either fundus imaging or OCT by eye in this asymptomatic population was 42.6% (121/284), with 39.4% (112/284) of eyes having RPE irregularities such as drusen. Conclusions. For detection of a variety of retinal irregularities evaluated in the current study, volume OCT scanning was more sensitive than nonmydriatic retinal photography in our asymptomatic individuals. OCT detected clinically relevant disease features, such as subretinal fluid, that were missed by FP, and had a lower ungradable image rate. It is likely that OCT will be added to photography screening in the near future for

  16. Ocular manifestation of Ichthyosis

    PubMed Central

    Al-Amry, Mohammad A.

    2015-01-01

    Purpose Ichthyosis is a rare dermato-ocular disease. This study evaluates the presenting ocular signs, symptoms, complications and prognosis of ichthyosis in a case series from Saudi Arabia. Methods A retrospective chart review was performed for 11 patients with ichthyosis who presented to King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia, over the last 20 years. Results The most common presenting ocular diagnosis was ectropion of both the lids. Two patients developed corneal perforation with poor prognosis. Most of the patients underwent skin grafting to repair eyelid ectropion. The visual prognosis was excellent because timely surgical interventions were performed. Hence the rate of corneal complications such as perforation was low. Conclusion The most ocular presentation of ichthyosis is ectropion of both the upper and lower lids. Despite good visual prognosis, there were some devastating corneal complications such as perforation with unpredictable outcomes. PMID:26949357

  17. Determining degree of optic nerve edema from color fundus photography

    NASA Astrophysics Data System (ADS)

    Agne, Jason; Wang, Jui-Kai; Kardon, Randy H.; Garvin, Mona K.

    2015-03-01

    Swelling of the optic nerve head (ONH) is subjectively assessed by clinicians using the Frisén scale. It is believed that a direct measurement of the ONH volume would serve as a better representation of the swelling. However, a direct measurement requires optic nerve imaging with spectral domain optical coherence tomography (SD-OCT) and 3D segmentation of the resulting images, which is not always available during clinical evaluation. Furthermore, telemedical imaging of the eye at remote locations is more feasible with non-mydriatic fundus cameras which are less costly than OCT imagers. Therefore, there is a critical need to develop a more quantitative analysis of optic nerve swelling on a continuous scale, similar to SD-OCT. Here, we select features from more commonly available 2D fundus images and use them to predict ONH volume. Twenty-six features were extracted from each of 48 color fundus images. The features include attributes of the blood vessels, optic nerve head, and peripapillary retina areas. These features were used in a regression analysis to predict ONH volume, as computed by a segmentation of the SD-OCT image. The results of the regression analysis yielded a mean square error of 2.43 mm3 and a correlation coefficient between computed and predicted volumes of R = 0:771, which suggests that ONH volume may be predicted from fundus features alone.

  18. Textureless Macula Swelling Detection with Multiple Retinal Fundus Images

    SciTech Connect

    Giancardo, Luca; Meriaudeau, Fabrice; Karnowski, Thomas Paul; Tobin Jr, Kenneth William; Grisan, Enrico; Favaro, Paolo; Ruggeri, Alfredo; Chaum, Edward

    2010-01-01

    Retinal fundus images acquired with non-mydriatic digital fundus cameras are a versatile tool for the diagnosis of various retinal diseases. Because of the ease of use of newer camera models and their relatively low cost, these cameras can be employed by operators with limited training for telemedicine or Point-of-Care applications. We propose a novel technique that uses uncalibrated multiple-view fundus images to analyse the swelling of the macula. This innovation enables the detection and quantitative measurement of swollen areas by remote ophthalmologists. This capability is not available with a single image and prone to error with stereo fundus cameras. We also present automatic algorithms to measure features from the reconstructed image which are useful in Point-of-Care automated diagnosis of early macular edema, e.g., before the appearance of exudation. The technique presented is divided into three parts: first, a preprocessing technique simultaneously enhances the dark microstructures of the macula and equalises the image; second, all available views are registered using non-morphological sparse features; finally, a dense pyramidal optical flow is calculated for all the images and statistically combined to build a naiveheight- map of the macula. Results are presented on three sets of synthetic images and two sets of real world images. These preliminary tests show the ability to infer a minimum swelling of 300 microns and to correlate the reconstruction with the swollen location.

  19. Non-mydriatic, wide field, fundus video camera

    NASA Astrophysics Data System (ADS)

    Hoeher, Bernhard; Voigtmann, Peter; Michelson, Georg; Schmauss, Bernhard

    2014-02-01

    We describe a method we call "stripe field imaging" that is capable of capturing wide field color fundus videos and images of the human eye at pupil sizes of 2mm. This means that it can be used with a non-dilated pupil even with bright ambient light. We realized a mobile demonstrator to prove the method and we could acquire color fundus videos of subjects successfully. We designed the demonstrator as a low-cost device consisting of mass market components to show that there is no major additional technical outlay to realize the improvements we propose. The technical core idea of our method is breaking the rotational symmetry in the optical design that is given in many conventional fundus cameras. By this measure we could extend the possible field of view (FOV) at a pupil size of 2mm from a circular field with 20° in diameter to a square field with 68° by 18° in size. We acquired a fundus video while the subject was slightly touching and releasing the lid. The resulting video showed changes at vessels in the region of the papilla and a change of the paleness of the papilla.

  20. Automated diagnosis of Age-related Macular Degeneration using greyscale features from digital fundus images.

    PubMed

    Mookiah, Muthu Rama Krishnan; Acharya, U Rajendra; Koh, Joel E W; Chandran, Vinod; Chua, Chua Kuang; Tan, Jen Hong; Lim, Choo Min; Ng, E Y K; Noronha, Kevin; Tong, Louis; Laude, Augustinus

    2014-10-01

    Age-related Macular Degeneration (AMD) is one of the major causes of vision loss and blindness in ageing population. Currently, there is no cure for AMD, however early detection and subsequent treatment may prevent the severe vision loss or slow the progression of the disease. AMD can be classified into two types: dry and wet AMDs. The people with macular degeneration are mostly affected by dry AMD. Early symptoms of AMD are formation of drusen and yellow pigmentation. These lesions are identified by manual inspection of fundus images by the ophthalmologists. It is a time consuming, tiresome process, and hence an automated diagnosis of AMD screening tool can aid clinicians in their diagnosis significantly. This study proposes an automated dry AMD detection system using various entropies (Shannon, Kapur, Renyi and Yager), Higher Order Spectra (HOS) bispectra features, Fractional Dimension (FD), and Gabor wavelet features extracted from greyscale fundus images. The features are ranked using t-test, Kullback-Lieber Divergence (KLD), Chernoff Bound and Bhattacharyya Distance (CBBD), Receiver Operating Characteristics (ROC) curve-based and Wilcoxon ranking methods in order to select optimum features and classified into normal and AMD classes using Naive Bayes (NB), k-Nearest Neighbour (k-NN), Probabilistic Neural Network (PNN), Decision Tree (DT) and Support Vector Machine (SVM) classifiers. The performance of the proposed system is evaluated using private (Kasturba Medical Hospital, Manipal, India), Automated Retinal Image Analysis (ARIA) and STructured Analysis of the Retina (STARE) datasets. The proposed system yielded the highest average classification accuracies of 90.19%, 95.07% and 95% with 42, 54 and 38 optimal ranked features using SVM classifier for private, ARIA and STARE datasets respectively. This automated AMD detection system can be used for mass fundus image screening and aid clinicians by making better use of their expertise on selected images that

  1. Quantitative Fundus Autofluorescence and Optical Coherence Tomography in Best Vitelliform Macular Dystrophy

    PubMed Central

    Duncker, Tobias; Greenberg, Jonathan P.; Ramachandran, Rithambara; Hood, Donald C.; Smith, R. Theodore; Hirose, Tatsuo; Woods, Russell L.; Tsang, Stephen H.; Delori, François C.; Sparrow, Janet R.

    2014-01-01

    Purpose. Quantitative fundus autofluorescence (qAF), spectral domain optical coherence tomography (SD-OCT) segmentation, and multimodal imaging were performed to elucidate the pathogenesis of Best vitelliform macular dystrophy (BVMD) and to identify abnormalities in lesion versus nonlesion fundus areas. Methods. Sixteen patients with a clinical diagnosis of BVMD were studied. Autofluorescence images (30°, 488-nm excitation) were acquired with a confocal scanning laser ophthalmoscope equipped with an internal fluorescent reference to account for variable laser power and detector sensitivity. The grey levels (GLs) of each image were calibrated to the reference, zero GL, magnification, and normative optical media density, to yield qAF. Horizontal SD-OCT scans were obtained and retinal layers manually segmented. Additionally, color and near-infrared reflectance (NIR-R) images were registered to AF images. All patients were screened for mutations in BEST1. In three additional BVMD patients, in vivo spectrofluorometric measurements were obtained within the vitelliform lesion. Results. Mean nonlesion qAF was within normal limits for age. Maximum qAF within the lesion was markedly increased compared with controls. By SD-OCT segmentation, outer segment equivalent thickness was increased and outer nuclear layer thickness decreased in the lesion. Changes were also present in a transition zone beyond the lesion border. In subclinical patients, no abnormalities in retinal layer thickness were identified. Fluorescence spectra recorded from the vitelliform lesion were consistent with those of retinal pigment epithelial cell lipofuscin. Conclusions. Based on qAF, mutations in BEST1 do not cause increased lipofuscin levels in nonlesion fundus areas. PMID:24526438

  2. Referral system for hard exudates in eye fundus.

    PubMed

    Naqvi, Syed Ali Gohar; Zafar, Muhammad Faisal; Haq, Ihsan ul

    2015-09-01

    Hard exudates are one of the most common anomalies/artifacts found in the eye fundus of patients suffering from diabetic retinopathy. These exudates are the major cause of loss of sight or blindness in people having diabetic retinopathy. Diagnosis of hard exudates requires considerable time and effort of an ophthalmologist. The ophthalmologists have become overloaded, so that there is a need for an automated diagnostic/referral system. In this paper a referral system for the hard exudates in the eye-fundus images has been presented. The proposed referral system works by combining different techniques like Scale Invariant Feature Transform (SIFT), K-means Clustering, Visual Dictionaries and Support Vector Machine (SVM). The system was also tested with Back Propagation Neural Network as a classifier. To test the performance of the system four fundus image databases were used. One publicly available image database was used to compare the performance of the system to the existing systems. To test the general performance of the system when the images are taken under different conditions and come from different sources, three other fundus image databases were mixed. The evaluation of the system was also performed on different sizes of the visual dictionaries. When using only one fundus image database the area under the curve (AUC) of maximum 0.9702 (97.02%) was achieved with accuracy of 95.02%. In case of mixed image databases an AUC of 0.9349 (93.49%) was recorded having accuracy of 87.23%. The results were compared to the existing systems and were found better/comparable. PMID:26231313

  3. Quantitative Fundus Autofluorescence in Best Vitelliform Macular Dystrophy: RPE Lipofuscin is not Increased in Non-Lesion Areas of Retina.

    PubMed

    Sparrow, Janet R; Duncker, Tobias; Woods, Russell; Delori, François C

    2016-01-01

    Since the lipofuscin of retinal pigment epithelial (RPE) cells has been implicated in the pathogenesis of Best vitelliform macular dystrophy, we quantified fundus autofluorescence (quantitative fundus autofluorescence, qAF) as an indirect measure of RPE lipofuscin levels. Mean non-lesion qAF was found to be within normal limits for age. By spectral domain optical coherence tomography (SD-OCT) vitelliform lesions presented as fluid-filled subretinal detachments containing reflective material. We discuss photoreceptor outer segment debris as the source of the intense fluorescence of these lesions and loss of anion channel functioning as an explanation for the bullous photoreceptor-RPE detachment. Unexplained is the propensity of the disease for central retina. PMID:26427423

  4. Don’t Forget What You Can’t See: A Case of Ocular Syphilis

    PubMed Central

    Lee, Monica I.; Lee, Annie W.C.; Sumsion, Sean M.; Gorchynski, Julie A.

    2016-01-01

    This case describes an emergency department (ED) presentation of ocular syphilis in a human immunodeficiency virus (HIV) infected patient. This is an unusual presentation of syphilis and one that emergency physicians should be aware of. The prevalence of syphilis has reached epidemic proportions since 2001 with occurrences primarily among men who have sex with men (MSM). This is a case of a 24-year-old male who presented to our ED with bilateral painless vision loss. The patient’s history and ED workup were notable for MSM, positive rapid plasmin reagin (RPR) and HIV tests and fundus exam consistent with ocular syphilis, specifically uveitis. Ocular manifestations of syphilis can present at any stage of syphilis. The 2010 Centers for Disease Control and Prevention guidelines now recommend that ocular syphilis be treated as neurosyphilis regardless of the lumbar puncture results. There is a paucity of emergency medicine literature on ocular syphilis. For emergency physicians it is important to be aware of iritis, uveitis, or chorioretinitis as ocular manifestations of neurosyphilis especially in this high-risk population and to obtain RPR and HIV tests in the ED to facilitate early diagnosis, and treatment and to prevent irreversible vision loss. PMID:27429702

  5. Don't Forget What You Can't See: A Case of Ocular Syphilis.

    PubMed

    Lee, Monica I; Lee, Annie W C; Sumsion, Sean M; Gorchynski, Julie A

    2016-07-01

    This case describes an emergency department (ED) presentation of ocular syphilis in a human immunodeficiency virus (HIV) infected patient. This is an unusual presentation of syphilis and one that emergency physicians should be aware of. The prevalence of syphilis has reached epidemic proportions since 2001 with occurrences primarily among men who have sex with men (MSM). This is a case of a 24-year-old male who presented to our ED with bilateral painless vision loss. The patient's history and ED workup were notable for MSM, positive rapid plasmin reagin (RPR) and HIV tests and fundus exam consistent with ocular syphilis, specifically uveitis. Ocular manifestations of syphilis can present at any stage of syphilis. The 2010 Centers for Disease Control and Prevention guidelines now recommend that ocular syphilis be treated as neurosyphilis regardless of the lumbar puncture results. There is a paucity of emergency medicine literature on ocular syphilis. For emergency physicians it is important to be aware of iritis, uveitis, or chorioretinitis as ocular manifestations of neurosyphilis especially in this high-risk population and to obtain RPR and HIV tests in the ED to facilitate early diagnosis, and treatment and to prevent irreversible vision loss. PMID:27429702

  6. Ocular Surface Disease in Breast Cancer Patients Using Aromatase Inhibitors.

    PubMed

    Chatziralli, Irini; Sergentanis, Theodoros; Zagouri, Flora; Chrysikos, Dimosthenis; Ladas, Ioannis; Zografos, George C; Moschos, Marilita

    2016-09-01

    Aromatase inhibitors (AIs) are widely used as adjuvant hormonal therapy in postmenopausal women with hormone receptor-positive breast cancer. The purpose of this study was to investigate the potential impact of AIs on the anterior segment of the eye and especially the ocular surface. Participants in our study were 41 hormone receptor-positive early stage breast cancer patients (80 eyes), treated with AIs, while 80 eyes of 40 age- and gender-matched healthy controls, not previously used AIs for any purpose, were also evaluated. All participants underwent a complete ophthalmological examination, including best corrected visual acuity (BCVA) assessment, slit-lamp biomicroscopy, and dilated fundus examination. Ocular surface disease-related symptoms and signs were also recorded. The most common symptom was found to be blurred vision, while other symptoms included foreign body sensation, tearing, redness, and photophobia. Slit-lamp examination revealed blepharitis and meibomian gland dysfunction in 75% and 42.5% of patients, respectively. Superficial punctate keratitis and conjunctival injection were also present. Our results demonstrated a high prevalence of ocular surface disease-related symptoms and signs in patients receiving AIs compared to healthy controls. This study may raise a flag regarding the use of AIs. However, further and larger prospective longitudinal studies are needed to examine the possible effect of AIs alone or in combination with chemotherapy in the eyes of breast cancer patients. PMID:27296769

  7. Organogenesis of mild ocular coloboma in FLS mice: failure of basement membrane disintegration at optic fissure margins.

    PubMed

    Tsuji, Naho; Kita, Katsutoshi; Ozaki, Kiyokazu; Narama, Isao; Matsuura, Tetsuro

    2012-01-01

    Fatty Liver Shionogi (FLS) mice have been shown to develop a hereditary disorder characterized by localized retinochoroidal defects of the ventral fundus very similar to human typical ocular coloboma without microphthalmia. The objective of this study was to determine when and how the failure of the optic fissure closure occurs, and to clarify the disturbed mechanism of basement membrane disintegration during embryonal stage in FLS mice. Fetuses at day 11.5-15.5 of gestation were obtained from dams of FLS and BALB/c strain of mice. Coronal serial sections through the eye were examined by light and electron microscopy. The sections were followed by observation of the basement membrane using reaction with periodic acid-Schiff (PAS) reagent and immunohistochemical staining with anti-Laminin and anti-Type IV collagen antibodies. Both optic fissure margins closely approached each other up to GD 11.5 in all FLS and BALB/c embryos. The inner and outer layers of the optic cup did not normally fuse at midlenticular levels of the optic fissure in almost 70% of FLS fetuses by GD 15.5, whereas both margins were completely fused in all BALB/c fetuses of the same gestational day. In the FLS fetuses at GD 12.5, rolling on one side of fissure margins and consequent asymmetry were observed at the ventral optic fissure. The basement membrane persisted after the close contact of both sides of the fissure margins during GD 11.5 and 15.5. Ultrastructurally, the basal lamina was not disintegrated and mesenchymal cells intervened between the two neuroepithelial layers, resulting in complete separation of both fissure margins at GD 13.0. It is highly probable that the disturbed basement membrane disintegration right before optic fissure closure causes mild ocular coloboma without microphthalmia in FLS mice. PMID:22182670

  8. Fundus Autofluorescence and Optical Coherence Tomography of Congenital Grouped Albinotic Spots

    PubMed Central

    Kim, David Y.; Hwang, John C.; Moore, Anthony T.; Bird, Alan C.; Tsang, Stephen H.

    2010-01-01

    Purpose To describe fundus autofluorescence (FAF) and optical coherence tomography (OCT) in a series of patients with congenital grouped albinotic spots (CGAS). Methods Three eyes of three patients with CGAS were evaluated with FAF and OCT imaging to evaluate the nature of the albinotic spots. Results In all three eyes with CGAS, FAF imaging revealed autofluorescent spots corresponding to the albinotic spots seen on stereo biomicroscopy. One eye also had additional spots detected on FAF imaging that were not visible on stereo biomicroscopy or color fundus photographs. FAF imaging of the spots demonstrated decreased general autofluorescence as well as decreased peripheral autofluorescence surrounding central areas of retained or increased autofluorescence. OCT revealed a disruption in signal from the hyper-reflective layer corresponding to the photoreceptor inner and outer segment junction as well as increased signal backscattering from the choroid in the area of the spots. Fluorescein angiography (FA) demonstrated early and stable hyperfluorescence of the spots without leakage. Conclusion In this case series, FAF demonstrated decreased autofluorescence of the spots consistent with focal RPE atrophy or abnormal material blocking normal autofluorescence as well as areas of increased autofluorescence suggesting RPE dysfunction. OCT and FA findings suggest photoreceptor and RPE layer abnormalities. FAF and OCT are useful noninvasive diagnostic adjuncts that can aid in the diagnosis of GCAS, help determine extent of disease, and contribute to our understanding of its pathophysiology. PMID:20539258

  9. Blood Vessel Segmentation of Fundus Images by Major Vessel Extraction and Subimage Classification.

    PubMed

    Roychowdhury, Sohini; Koozekanani, Dara D; Parhi, Keshab K

    2015-05-01

    This paper presents a novel three-stage blood vessel segmentation algorithm using fundus photographs. In the first stage, the green plane of a fundus image is preprocessed to extract a binary image after high-pass filtering, and another binary image from the morphologically reconstructed enhanced image for the vessel regions. Next, the regions common to both the binary images are extracted as the major vessels. In the second stage, all remaining pixels in the two binary images are classified using a Gaussian mixture model (GMM) classifier using a set of eight features that are extracted based on pixel neighborhood and first and second-order gradient images. In the third postprocessing stage, the major portions of the blood vessels are combined with the classified vessel pixels. The proposed algorithm is less dependent on training data, requires less segmentation time and achieves consistent vessel segmentation accuracy on normal images as well as images with pathology when compared to existing supervised segmentation methods. The proposed algorithm achieves a vessel segmentation accuracy of 95.2%, 95.15%, and 95.3% in an average of 3.1, 6.7, and 11.7 s on three public datasets DRIVE, STARE, and CHASE_DB1, respectively. PMID:25014980

  10. Pediatric genetic ocular tumors

    PubMed Central

    Rouhani, Behnaz; Ramasubramanian, Aparna

    2014-01-01

    Pediatric genetic ocular tumors include malignancies like retinoblastoma and phakomatosis like neurofibromatosis, tuberous sclerosis, von Hippel-Lindau syndrome, and nevoid basal cell carcinoma syndrome. It is important to screen for ocular tumors both for visual prognosis and also for systemic implications. The phakomatosis comprise of multitude of benign tumors that are aysmptomatic but their detection can aid in the diagnosis of the syndrome. Retinoblastoma is the most common malignant intraocular tumor in childhood and with current treatment modalities, the survival is more than 95%. It is transmitted as an autosomal dominant fashion and hence the offsprings of all patients with the germline retinoblastoma need to be screened from birth. This review discusses the various pediatric genetic ocular tumors discussing the clinical manifestation, diagnosis and treatment.

  11. Glycobiology of ocular angiogenesis.

    PubMed

    Markowska, Anna I; Cao, Zhiyi; Panjwani, Noorjahan

    2014-12-01

    Ocular neovascularization can affect almost all the tissues of the eye: the cornea, the iris, the retina, and the choroid. Pathological neovascularization is the underlying cause of vision loss in common ocular conditions such as diabetic retinopathy, retinopathy of prematurity and age-related macular neovascularization. Glycosylation is the most common covalent posttranslational modification of proteins in mammalian cells. A growing body of evidence demonstrates that glycosylation influences the process of angiogenesis and impacts activation, proliferation, and migration of endothelial cells as well as the interaction of angiogenic endothelial cells with other cell types necessary to form blood vessels. Recent studies have provided evidence that members of the galectin class of β-galactoside-binding proteins modulate angiogenesis by novel carbohydrate-based recognition systems involving interactions between glycans of angiogenic cell surface receptors and galectins. This review discusses the significance of glycosylation and the role of galectins in the pathogenesis of ocular neovascularization. PMID:25108228

  12. Raman Spectroscopy of Ocular Tissue

    NASA Astrophysics Data System (ADS)

    Ermakov, Igor V.; Sharifzadeh, Mohsen; Gellermann, Warner

    The optically transparent nature of the human eye has motivated numerous Raman studies aimed at the non-invasive optical probing of ocular tissue components critical to healthy vision. Investigations include the qualitative and quantitative detection of tissue-specific molecular constituents, compositional changes occurring with development of ocular pathology, and the detection and tracking of ocular drugs and nutritional supplements. Motivated by a better understanding of the molecular mechanisms leading to cataract formation in the aging human lens, a great deal of work has centered on the Raman detection of proteins and water content in the lens. Several protein groups and the hydroxyl response are readily detectable. Changes of protein compositions can be studied in excised noncataractous tissue versus aged tissue preparations as well as in tissue samples with artificially induced cataracts. Most of these studies are carried out in vitro using suitable animal models and conventional Raman techniques. Tissue water content plays an important role in optimum light transmission of the outermost transparent ocular structure, the cornea. Using confocal Raman spectroscopy techniques, it has been possible to non-invasively measure the water to protein ratio as a measure of hydration status and to track drug-induced changes of the hydration levels in the rabbit cornea at various depths. The aqueous humor, normally supplying nutrients to cornea and lens, has an advantageous anterior location for Raman studies. Increasing efforts are pursued to non-invasively detect the presence of glucose and therapeutic concentrations of antibiotic drugs in this medium. In retinal tissue, Raman spectroscopy proves to be an important tool for research into the causes of macular degeneration, the leading cause of irreversible vision disorders and blindness in the elderly. It has been possible to detect the spectral features of advanced glycation and advanced lipooxydation end products in

  13. Ocular toxicity of fludarabine

    PubMed Central

    Ding, Xiaoyan; Herzlich, Alexandra A; Bishop, Rachel; Tuo, Jingsheng; Chan, Chi-Chao

    2008-01-01

    The purine analogs, fludarabine and cladribine represent an important class of chemotherapy agents used to treat a broad spectrum of lymphoid malignancies. Their toxicity profiles include dose-limiting myelosuppression, immunosuppression, opportunistic infection and severe neurotoxicity. This review summarizes the neurotoxicity of high- and standard-dose fludarabine, focusing on the clinical and pathological manifestations in the eye. The mechanisms of ocular toxicity are probably multifactorial. With increasing clinical use, an awareness of the neurological and ocular vulnerability, particularly to fludarabine, is important owing to the potential for life- and sight-threatening consequences. PMID:18461151

  14. Absolute blood velocity measured with a modified fundus camera

    NASA Astrophysics Data System (ADS)

    Duncan, Donald D.; Lemaillet, Paul; Ibrahim, Mohamed; Nguyen, Quan Dong; Hiller, Matthias; Ramella-Roman, Jessica

    2010-09-01

    We present a new method for the quantitative estimation of blood flow velocity, based on the use of the Radon transform. The specific application is for measurement of blood flow velocity in the retina. Our modified fundus camera uses illumination from a green LED and captures imagery with a high-speed CCD camera. The basic theory is presented, and typical results are shown for an in vitro flow model using blood in a capillary tube. Subsequently, representative results are shown for representative fundus imagery. This approach provides absolute velocity and flow direction along the vessel centerline or any lateral displacement therefrom. We also provide an error analysis allowing estimation of confidence intervals for the estimated velocity.

  15. [Optical coherence tomography and fundus autofluorescence in Best macular dystrophy].

    PubMed

    Chebil, A; Charfi, H; Largueche, L; El Matri, L

    2016-06-01

    Best vitelliform macular dystrophy is the second most frequent hereditary maculopathy, with bilateral involvement and juvenile onset. It is clinically characterized by bilateral deposits of lipofuscin-like autofluorescent material in the subretinal space, with a typical phenotypic manifestation taking the form of a vitelliform macular lesion evolving gradually into more advanced stages. The purpose of our study was to describe fundus autofluorescence patterns and OCT findings in three patients (6 eyes) with several stages of Best vitelliform macular dystrophy. Optical coherence tomography (OCT) has become the first imaging technique to order when confronted with a hereditary maculopathy suggesting Best disease. Fundus autofluorescence combined with OCT allow for better diagnosis and management, which are necessary for any genetic analysis. PMID:27206620

  16. Validation of tablet-based evaluation of color fundus images

    PubMed Central

    Christopher, Mark; Moga, Daniela C.; Russell, Stephen R.; Folk, James C.; Scheetz, Todd; Abràmoff, Michael D.

    2012-01-01

    Purpose To compare diabetic retinopathy (DR) referral recommendations made by viewing fundus images using a tablet computer to recommendations made using a standard desktop display. Methods A tablet computer (iPad) and a desktop PC with a high-definition color display were compared. For each platform, two retinal specialists independently rated 1200 color fundus images from patients at risk for DR using an annotation program, Truthseeker. The specialists determined whether each image had referable DR, and also how urgently each patient should be referred for medical examination. Graders viewed and rated the randomly presented images independently and were masked to their ratings on the alternative platform. Tablet- and desktop display-based referral ratings were compared using cross-platform, intra-observer kappa as the primary outcome measure. Additionally, inter-observer kappa, sensitivity, specificity, and area under ROC (AUC) were determined. Results A high level of cross-platform, intra-observer agreement was found for the DR referral ratings between the platforms (κ=0.778), and for the two graders, (κ=0.812). Inter-observer agreement was similar for the two platforms (κ=0.544 and κ=0.625 for tablet and desktop, respectively). The tablet-based ratings achieved a sensitivity of 0.848, a specificity of 0.987, and an AUC of 0.950 compared to desktop display-based ratings. Conclusions In this pilot study, tablet-based rating of color fundus images for subjects at risk for DR was consistent with desktop display-based rating. These results indicate that tablet computers can be reliably used for clinical evaluation of fundus images for DR. PMID:22495326

  17. New perspectives in ocular surface disorders. An integrated approach for diagnosis and management.

    PubMed

    Sangwan, V S; Tseng, S C

    2001-09-01

    The cornea, conjuctiva and the limbus comprise the tissues at the ocular surface. All of them are covered by stratified, squamous, non-keratinizing epithelium and a stable tear film. The ocular surface health is ensured by intimate relationship between ocular surface epithelia and the preocular team film. There are two types of ocular surface failure. The first one is characterized by squamous metaplasia and loss of goblet cells and mucin expression. This is consistent with unstable tear film which is the hallmark of various dry-eye disorders. The second type of ocular surface failure is characterized by the replacement of the normal corneal epithelium in a process called limbal stem cell deficiency. It is essential to establish accurate diagnosis for appropriate management of complex ocular surface disorders. There has been considerable advancement in the understanding of the pathophysiology of ocular surface disease. Management has improved with introduction of the limbal stem cell concept and use of amniotic membrane transplantation. PMID:15887723

  18. Compact Laser Doppler Flowmeter (LDF) Fundus Camera for the Assessment of Retinal Blood Perfusion in Small Animals

    PubMed Central

    Chiquet, Christophe; Godin-Ribuot, Diane; Amoos, Serge; Loeuillet, Corinne; Bernabei, Mario; Geiser, Martial

    2015-01-01

    Purpose Noninvasive techniques for ocular blood perfusion assessment are of crucial importance for exploring microvascular alterations related to systemic and ocular diseases. However, few techniques adapted to rodents are available and most are invasive or not specifically focused on the optic nerve head (ONH), choroid or retinal circulation. Here we present the results obtained with a new rodent-adapted compact fundus camera based on laser Doppler flowmetry (LDF). Methods A confocal miniature flowmeter was fixed to a specially designed 3D rotating mechanical arm and adjusted on a rodent stereotaxic table in order to accurately point the laser beam at the retinal region of interest. The linearity of the LDF measurements was assessed using a rotating Teflon wheel and a flow of microspheres in a glass capillary. In vivo reproducibility was assessed in Wistar rats with repeated measurements (inter-session and inter-day) of retinal arteries and ONH blood velocity in six and ten rats, respectively. These parameters were also recorded during an acute intraocular pressure increase to 150 mmHg and after heart arrest (n = 5 rats). Results The perfusion measurements showed perfect linearity between LDF velocity and Teflon wheel or microsphere speed. Intraclass correlation coefficients for retinal arteries and ONH velocity (0.82 and 0.86, respectively) indicated strong inter-session repeatability and stability. Inter-day reproducibility was good (0.79 and 0.7, respectively). Upon ocular blood flow cessation, the retinal artery velocity signal substantially decreased, whereas the ONH signal did not significantly vary, suggesting that it could mostly be attributed to tissue light scattering. Conclusion We have demonstrated that, while not adapted for ONH blood perfusion assessment, this device allows pertinent, stable and repeatable measurements of retinal blood perfusion in rats. PMID:26226150

  19. Homocysteine in ocular diseases.

    PubMed

    Ajith, Thekkuttuparambil Ananthanarayanan; Ranimenon

    2015-10-23

    Homocysteine (Hcy) is a derived sulfur-containing and non-proteinogenic amino acid. The metabolism of Hcy occurs either through the remethylation to methionine or transsulfuration to cysteine. Studies have identified hyperhomocysteinemia (HHcy) as one of the possible risk factors for a multitude of diseases including vascular, neurodegenerative and ocular diseases. Association of HHcy with eye diseases such as retinopathy, pseudoexfoliative glaucoma maculopathy, cataract, optic atrophy and retinal vessel atherosclerosis is established. The molecular mechanism underlying these ocular diseases has been reported as impaired vascular endothelial function, apoptosis of retinal ganglion cells, extracellular matrix alterations, decreased lysyl oxidase activity and oxidative stress. The formed homocysteine-thiolactone in HHcy has stronger cytotoxicity and pro-inflammatory properties which can induce lens opacification and optic nerve damage. The metabolism of Hcy requires enzymes with vitamins such as folic acid, vitamins B12 and B6. Despite the mixed conclusion of various studies regarding the level of these vitamins in elder people, studies recommended the treatment with folate and B12 to reduce Hcy levels in subjects with or without any defect in the enzymes involved in its metabolism. The levels of Hcy, folate, B6 as well as B12 should be measured early in patients with visual impairment that would aid to screen patients for life-threatening disorders related with HHcy. Elder patients may supplement with these vitamins in order to attenuate the ocular damages. This article discusses the association of Hcy in ocular diseases and the possible mechanism in the pathogenesis. PMID:26343924

  20. [Ocular Manifestations in Sarcoidosis].

    PubMed

    Walscheid, K; Tappeiner, C; Heiligenhaus, A

    2016-05-01

    Sarcoidosis is an inflammatory multi-organ disease of unknown pathogenesis, characterised by non-necrotising granulomata. Sarcoidosis predominantly manifests in the lung, but any other organ may be affected. Ocular involvement is present in about 25 to 50 % of patients. The most common ocular manifestation is uveitis, especially of the anterior eye segment. If ocular sarcoidosis is suspected, interdisciplinary assessment of the patient is mandatory, including laboratory tests, chest X-ray, assessment by a specialist in internal medicine and, ideally, histological evidence of granuloma formation in a tissue specimen. Other (infectious) causes of granulomatous inflammation need to be excluded, especially tuberculosis or syphilis. For the ophthalmological assessment, detection of granulomatous lesions is of particular importance, especially by visualising chorioretinal granuloma by fluorescein and indocyanin green angiography. Cystoid macular oedema and glaucoma are the most frequent complications limiting visual acuity. Corticosteroids, which can be administered either locally or systemically, are the mainstay of therapy. Depending on the clinical course and the development of ocular complications, systemic steroid-sparing immunosuppressive medication may be indicated. PMID:27187879

  1. Instrument Measures Ocular Counterrolling

    NASA Technical Reports Server (NTRS)

    Levitan, Barry M.; Reschke, Millard F.; Spector, Lawrence N.

    1991-01-01

    Compact, battery-powered, noninvasive unit replaces several pieces of equipment and operator. Instrument that looks like pair of goggles with small extension box measures ocular counterrotation. Called "otolith tilt-translation reinterpretation" (OTTR) goggles, used in studies of space motion sickness. Also adapted to use on Earth and determine extent of impairment in patients who have impaired otolith functions.

  2. Ocular Screening System

    NASA Technical Reports Server (NTRS)

    1985-01-01

    An ocular screening system designed for safe, convenient screening of large groups was developed at Marshall Space Flight Center, leading to the formation of Medical Sciences Corporation. The system identifies visual defects accurately and inexpensively, and includes a photorefractor telephoto lens and an electronic flash. Medical Sciences Corporation is using the device to test at schools, industrial plants, etc.

  3. Ocular Surface Membrane-Associated Mucins.

    PubMed

    Ablamowicz, Anna F; Nichols, Jason J

    2016-07-01

    Ocular surface epithelial cells produce and secrete mucins that form a hydrophilic barrier for protection and lubrication of the eye. This barrier, the glycocalyx, is formed by high molecular weight heavily glycosylated membrane-associated mucins (MAMs) that include MUC1, MUC4, and MUC16. These mucins extend into the tear film from the anterior surfaces of the conjunctiva and cornea, and, through interactions with galectin-3, prevent penetrance of pathogens into the eye. Due primarily to the glycosylation of the mucins, the glycocalyx also creates less friction during blinking and enables the tear film to maintain wetting of the eye. The secretory mucins include soluble MUC7 and gel-forming MUC5AC. These mucins, particularly MUC5AC, assist with removal of debris from the tear film and contribute to the hydrophilicity of the tear film. While new methodologies and cell culture models have expanded our understanding of mucin structure and function on the ocular surface, there is still a paucity of studies characterizing the glycosylation of MAMs on a normal ocular surface and a diseased ocular surface. Although studies have shown alterations in mucin production and expression in dry eye diseases, the relationship between changes in mucins and functional consequences is unclear. This review focuses on comparing what is known about MAMs in wet-surfaced epithelia of the body to what has been studied on the eye. PMID:27154035

  4. Disseminated mite infection with ocular involvement in a juvenile bald eagle (Haliaeetus leucocephalus).

    PubMed

    Bueno-Padilla, Irene; Klauss, Gia; Gardiner, Chris H; Wuenschmann, Arno

    2012-07-01

    A bald eagle (Haliaeetus leucocephalus) was found unable to fly and was admitted to The Raptor Center (TRC). Major clinical signs were thin body condition and a cardiac arrhythmia. Ten days after admission to TRC, ophthalmic examination revealed multiple, distinct serpiginous lesions of chorioretinal atrophy in the ocular fundus of the right eye (OD). The bird was euthanized because of clinical deterioration and poor prognosis. Mites of an undetermined species were found histologically in the retina, episcleral tissues, lungs, and liver at the postmortem examination. Disseminated mite infection should be considered in the differential diagnosis of serpiginous chorioretinal lesions in bald eagles (H. leucocephalus). PMID:22151197

  5. Quantitative Fundus Autofluorescence and Optical Coherence Tomography in ABCA4 Carriers

    PubMed Central

    Duncker, Tobias; Stein, Gregory E.; Lee, Winston; Tsang, Stephen H.; Zernant, Jana; Bearelly, Srilaxmi; Hood, Donald C.; Greenstein, Vivienne C.; Delori, François C.; Allikmets, Rando; Sparrow, Janet R.

    2015-01-01

    Purpose To assess whether carriers of ABCA4 mutations have increased RPE lipofuscin levels based on quantitative fundus autofluorescence (qAF) and whether spectral-domain optical coherence tomography (SD-OCT) reveals structural abnormalities in this cohort. Methods Seventy-five individuals who are heterozygous for ABCA4 mutations (mean age, 47.3 years; range, 9–82 years) were recruited as family members of affected patients from 46 unrelated families. For comparison, 57 affected family members with biallelic ABCA4 mutations (mean age, 23.4 years; range, 6–67 years) and two noncarrier siblings were also enrolled. Autofluorescence images (30°, 488-nm excitation) were acquired with a confocal scanning laser ophthalmoscope equipped with an internal fluorescent reference. The gray levels (GLs) of each image were calibrated to the reference, zero GL, magnification, and normative optical media density to yield qAF. Horizontal SD-OCT scans through the fovea were obtained and the thicknesses of the outer retinal layers were measured. Results In 60 of 65 carriers of ABCA4 mutations (age range, 9–60), qAF levels were within normal limits (95% confidence level) observed for healthy noncarrier subjects, while qAF levels of affected family members were significantly increased. Perifoveal fleck-like abnormalities were observed in fundus AF images in four carriers, and corresponding changes were detected in the outer retinal layers in SD-OCT scans. Thicknesses of the outer retinal layers were within the normal range. Conclusions With few exceptions, individuals heterozygous for ABCA4 mutations and between the ages of 9 and 60 years do not present with elevated qAF. In a small number of carriers, perifoveal fleck-like changes were visible. PMID:26551331

  6. Visible light optical coherence tomography for microvascular oximetry in ocular circulation (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Chen, Siyu; Yi, Ji; Zhang, Hao F.

    2016-03-01

    Visible light optical coherence tomography (vis-OCT) is intrinsically capable of optical determination of blood oxygen saturation (sO2). Thanks to its 3D sectioning ability, confounding factors that plaque multi-wavelength fundus photography can be avoided. We further supplemented it with motion-enhanced angiography (vis-OCTA), which allowed us to resolve retinal micro vessels without losing spectral information. As a result, spectroscopic vis-OCTA can extract microvascular sO2 which are generally inaccessible. Here we extend the theoretical formulation of vis-OCTA oximetry to include optical attenuation, scattering and motion contrast. The model allows robust estimation of sO2, while also promising reduction of illuminating power to 1/3 of current value of ~1 mW. To demonstrate the capability of our approach, we performed oxygen challenge while taking vis-OCTA measurements on rat ocular circulation in vivo. We supplied the experiment animal with the following gas mixture: normal air, 5% CO2 air, pure O2 and 10% O2 air. For each inhalation gas, the OCTA measurements were compared with peripheral capillary sO2 (spO2) provided by a pulse oximeter. The retinal artery sO2 measurements corresponded well with spO2 reading as expected (R2 = 0.87). We found that both retinal and choroidal circulation sO2 moderately increased when we supplied 5% CO2 air. 100% O2 inhalation significantly increased both artery and vein oxygenation. On the contrary, 10% O2 air could deplete the oxygen reservoir in the circulation and lead to low sO2 readings.

  7. Ocular blood flow levels and visual prognosis in a patient with nonischemic type central retinal vein occlusion

    PubMed Central

    Maeda, Kimihito; Ishikawa, Futoshi; Ohguro, Hiroshi

    2009-01-01

    We look at the case of a 39-year-old female patient suffering from a sudden decrease in her left visual acuity (0.08). Her macular edema was examined using optical coherence tomography, and her optic disc blood flow was examined with laser speckle flowgraphy (LSFG). Additionally, the degree of seriousness of the central vein occlusion was evaluated through fluorescein angiography (FA). Ocular fundus findings revealed central vein occlusion associated with macular edema, and FA determined her disease type as a nonischemic-central vein occlusion. Daily doses of 100 mg of aspirin were administered orally to the patient. Upon administration, her ocular blood flow almost immediately increased. In this study, we demonstrate the potential of LSFG as a means to investigate ocular blood flow. PMID:19750123

  8. Ocular blood flow levels and visual prognosis in a patient with nonischemic type central retinal vein occlusion.

    PubMed

    Maeda, Kimihito; Ishikawa, Futoshi; Ohguro, Hiroshi

    2009-01-01

    We look at the case of a 39-year-old female patient suffering from a sudden decrease in her left visual acuity (0.08). Her macular edema was examined using optical coherence tomography, and her optic disc blood flow was examined with laser speckle flowgraphy (LSFG). Additionally, the degree of seriousness of the central vein occlusion was evaluated through fluorescein angiography (FA). Ocular fundus findings revealed central vein occlusion associated with macular edema, and FA determined her disease type as a nonischemic-central vein occlusion. Daily doses of 100 mg of aspirin were administered orally to the patient. Upon administration, her ocular blood flow almost immediately increased. In this study, we demonstrate the potential of LSFG as a means to investigate ocular blood flow. PMID:19750123

  9. Diagnostic Accuracy of Ultrasound B scan using 10 MHz linear probe in ocular trauma;results from a high burden country

    PubMed Central

    Shazlee, Muhammad Kashif; Ali, Muhammad; SaadAhmed, Muhammad; Hussain, Ammad; Hameed, Kamran; Lutfi, Irfan Amjad; Khan, Muhammad Tahir

    2016-01-01

    Objective: To study the diagnostic accuracy of Ultrasound B scan using 10 MHz linear probe in ocular trauma. Methods: A total of 61 patients with 63 ocular injuries were assessed during July 2013 to January 2014. All patients were referred to the department of Radiology from Emergency Room since adequate clinical assessment of the fundus was impossible because of the presence of opaque ocular media. Based on radiological diagnosis, the patients were provided treatment (surgical or medical). Clinical diagnosis was confirmed during surgical procedures or clinical follow-up. Results: A total of 63 ocular injuries were examined in 61 patients. The overall sensitivity was 91.5%, Specificity was 98.87%, Positive predictive value was 87.62 and Negative predictive value was 99%. Conclusion: Ultrasound B-scan is a sensitive, non invasive and rapid way of assessing intraocular damage caused by blunt or penetrating eye injuries. PMID:27182245

  10. Cataract screening by minimally trained remote observer with non-mydriatic digital fundus camera

    NASA Astrophysics Data System (ADS)

    Choi, Ann; Hjelmstad, David; Taibl, Jessica N.; Sayegh, Samir I.

    2013-03-01

    We propose a method that allows an inexperienced observer, through the examination of the digital fundus image of a retina on a computer screen, to simply determine the presence of a cataract and the necessity to refer the patient for further evaluation. To do so, fundus photos obtained with a non-mydriatic camera were presented to an inexperienced observer that was briefly instructed on fundus imaging, nature of cataracts and their probable effect on the image of the retina and the use of a computer program presenting fundus image pairs. Preliminary results of pair testing indicate the method is very effective.

  11. Ocular colobomata, cardiac defect, and other anomalies: a study of seven cases including two sibs.

    PubMed Central

    Ho, C K; Kaufman, R L; Podos, S M

    1975-01-01

    An association of ocular colobomata and congenital heart disease was observed in seven patients. Two of these were maternal half sisters whose mother also had ocular colobomata. All the patients had normal karyotypes. There was a high incidence of other associated abnormalities involving the central nervous, skeletal, and urogenital systems. Discovery of an ocular coloboma should alert the clinician to search for other abnormalities. PMID:1177280

  12. Ocular delivery of macromolecules

    PubMed Central

    Kim, Yoo-Chun; Chiang, Bryce; Wu, Xianggen; Prausnitz, Mark R.

    2014-01-01

    Biopharmaceuticals are making increasing impact on medicine, including treatment of indications in the eye. Macromolecular drugs are typically given by physician-administered invasive delivery methods, because non--invasive ocular delivery methods, such as eye drops, and systemic delivery, have low bioavailability and/or poor ocular targeting. There is a need to improve delivery of biopharmaceuticals to enable less-invasive delivery routes, less-frequent dosing through controlled-release drug delivery and improved drug targeting within the eye to increase efficacy and reduce side effects. This review discusses the barriers to drug delivery via various ophthalmic routes of administration in the context of macromolecule delivery and discusses efforts to develop controlled-release systems for delivery of biopharmaceuticals to the eye. The growing number of macromolecular therapies in the eye needs improved drug delivery methods that increase drug efficacy, safety and patient compliance. PMID:24998941

  13. Validating and Troubleshooting Ocular In Vitro Toxicology Tests

    PubMed Central

    Barile, Frank A.

    2010-01-01

    In vitro organotypic models for testing ocular irritants have warranted sufficient interest as methods to replace in vivo ocular testing. The in vitro organotypic models claim to maintain short-term normal physiological and biochemical function of the mammalian cornea in an isolated system. In these test methods, damage by the test substance is assessed by quantitative measurements of changes in corneal opacity and permeability using opacitometry and spectrophotometry, respectively. Both measurements are used quantitatively for irritancy classification for prediction of the in vivo ocular irritation potential of a test substance. Examples of organotypic models that incorporate these criteria include: the bovine corneal opacity and permeability (BCOP) assay, the isolated chicken eye (ICE) test method and the isolated rabbit eye (IRE) assay. A fourth method, the hen's egg test-chorioallantoic membrane (HET-CAM) assay, differs in the evaluation criteria but is also normally included among this class of in vitro protocols. Each of these protocols is discussed in detail as representative candidate in vitro methods for assessing ocular irritation and corrosion. The methodologies, protocol details, applications, and their validation status are discussed. A brief historical perspective of the development of original in vitro ocular testing models is also mentioned. More importantly, improvement and troubleshooting the current techniques, in order to present the models as stand-alone in vitro tools for ocular toxicity assessment, is emphasized. PMID:20096797

  14. Validating and troubleshooting ocular in vitro toxicology tests.

    PubMed

    Barile, Frank A

    2010-01-01

    In vitro organotypic models for testing ocular irritants have warranted sufficient interest as methods to replace in vivo ocular testing. The in vitro organotypic models claim to maintain short-term normal physiological and biochemical functions of the mammalian cornea in an isolated system. In these test methods, damage by the test substance is assessed by quantitative measurements of changes in corneal opacity and permeability using opacitometry and spectrophotometry, respectively. Both measurements are used quantitatively for irritancy classification for prediction of the in vivo ocular irritation potential of a test substance. Examples of organotypic models that incorporate these criteria include: the bovine corneal opacity and permeability (BCOP) assay, the isolated chicken eye (ICE) test method and the isolated rabbit eye (IRE) assay. A fourth method, the hen's egg test-chorioallantoic membrane (HET-CAM) assay, differs in the evaluation criteria but is also normally included among this class of in vitro protocols. Each of these protocols is discussed in detail as representative candidate in vitro methods for assessing ocular irritation and corrosion. The methodologies, protocol details, applications, and their validation status are discussed. A brief historical perspective of the development of original in vitro ocular testing models is also mentioned. More importantly, improving and troubleshooting the current techniques, in order to present the models as stand-alone in vitro tools for ocular toxicity assessment, is emphasized. PMID:20096797

  15. Ocular sparganosis from Assam

    PubMed Central

    Nath, Reema; Gogoi, Rajendra Nath

    2015-01-01

    Sparganosis is caused by plerocercoid larvae of the Pseudophyllidea tapeworms of the genus Spirometra. Though prevalent in East Asian and south east Asian countries like China, Japan, Korea, Taiwan, Vietnam, Thailand; yet very few cases are reported from India. We report a case of migrating sub-conjunctival ocular sparganosis mimicking scleritis which later on developed into orbital cellulitis from Dibrugarh, Assam, North-eastern part of India. This case is reported for its rarity. PMID:25709957

  16. An ocular motility conundrum.

    PubMed

    McElnea, Elizabeth Margaret; Stephenson, Kirk; Lanigan, Bernie; Flitcroft, Ian

    2014-01-01

    Two siblings, an 11-year-old boy and a 7-year-old girl presented with bilateral symmetrical ptosis and limited eye movements. Having already been reviewed on a number of occasions by a variety of specialists in multiple hospital settings a diagnosis of their ocular motility disorder had remained elusive. We describe their cases, outline the differential diagnosis and review the investigations performed which were influential in finally making a diagnosis. PMID:25349186

  17. Ocular Proton Therapy Centers

    NASA Astrophysics Data System (ADS)

    Kacperek, Andrzej

    This chapter describes a review of proton therapy (PT) centers and the techniques used for the treatment of ocular lesions. The role of ion beam therapy (IBT) for eye treatments, principally choroidal melanomas, has become well established among the competing treatment modalities. More national centers now offer PT for these lesions, but not necessarily in a hospital environment. Significant improvements in eye treatment planning, patient positioning, and QA dosimetry have been realized, to the benefit of treatment efficiency and accuracy of dose delivery.

  18. 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. PMID:23150359

  19. Non-invasive measurement of choroidal volume change and ocular rigidity through automated segmentation of high-speed OCT imaging

    PubMed Central

    Beaton, L.; Mazzaferri, J.; Lalonde, F.; Hidalgo-Aguirre, M.; Descovich, D.; Lesk, M. R.; Costantino, S.

    2015-01-01

    We have developed a novel optical approach to determine pulsatile ocular volume changes using automated segmentation of the choroid, which, together with Dynamic Contour Tonometry (DCT) measurements of intraocular pressure (IOP), allows estimation of the ocular rigidity (OR) coefficient. Spectral Domain Optical Coherence Tomography (OCT) videos were acquired with Enhanced Depth Imaging (EDI) at 7Hz during ~50 seconds at the fundus. A novel segmentation algorithm based on graph search with an edge-probability weighting scheme was developed to measure choroidal thickness (CT) at each frame. Global ocular volume fluctuations were derived from frame-to-frame CT variations using an approximate eye model. Immediately after imaging, IOP and ocular pulse amplitude (OPA) were measured using DCT. OR was calculated from these peak pressure and volume changes. Our automated segmentation algorithm provides the first non-invasive method for determining ocular volume change due to pulsatile choroidal filling, and the estimation of the OR constant. Future applications of this method offer an important avenue to understanding the biomechanical basis of ocular pathophysiology. PMID:26137373

  20. Residual deformations in ocular tissues

    PubMed Central

    Wang, Ruoya; Raykin, Julia; Gleason, Rudolph L.; Ethier, C. Ross

    2015-01-01

    Residual deformations strongly influence the local biomechanical environment in a number of connective tissues. The sclera is known to be biomechanically important in healthy and diseased eyes, such as in glaucoma. Here, we study the residual deformations of the sclera, as well as the adjacent choroid and retina. Using freshly harvested porcine eyes, we developed two approaches of quantifying residual deformations in the spherically shaped tissues of interest. The first consisted of punching discs from the posterior wall of the eye and quantifying the changes in the area and eccentricity of these samples. The second consisted of cutting a ring from the equatorial sclera and making stress-relieving cuts in it. Measurements of curvature were made before and after the stress-relieving cuts. Using the first approach, we observed a 42% areal contraction of the choroid, but only modest contractions of the sclera and retina. The observed contractions were asymmetric. In the second approach, we observed an opening of the scleral rings (approx. 10% decrease in curvature). We conclude that residual bending deformations are present in the sclera, which we speculate may be due to radially heterogeneous growth and remodelling of the tissue during normal development. Further, residual areal deformations present in the choroid may be due to the network of elastic fibres in this tissue and residual deformations in the constituent vascular bed. Future studies of ocular biomechanics should attempt to include effects of these residual deformations into mechanical models in order to gain a better understanding of the biomechanics of the ocular wall. PMID:25740853

  1. Ocular Toxicity Testing of Lunar Dust

    NASA Technical Reports Server (NTRS)

    Meyers, Valerie E.

    2010-01-01

    This slide presentation reviews the use of ocular testing to determine the toxicity of lunar dust. The OECD recommendations are reviewed. With these recommendations in mind the test methodology was to use EpiOcular, tissues derived from normal human epidermal keratinocytes, the cells of which have been differentiated on cell culture inserts to form a multi-layered structure, which closely parallels the corneal epithelium and to dose the tissue with 100 mg dust from various sources. The in-vitro study provides evidence that lunar dust is not severely corrosive or irritating, however, in vitro tests have limitations, and in vivo tests provides a more complete scenario, and information, it is recommended that in vivo tests be performed.

  2. Ridge-based retinal image registration algorithm involving OCT fundus images

    NASA Astrophysics Data System (ADS)

    Li, Ying; Gregori, Giovanni; Knighton, Robert W.; Lujan, Brandon J.; Rosenfeld, Philip J.; Lam, Byron L.

    2011-03-01

    This paper proposes an algorithm for retinal image registration involving OCT fundus images (OFIs). The first application of the algorithm is to register OFIs with color fundus photographs; such registration between multimodal retinal images can help correlate features across imaging modalities, which is important for both clinical and research purposes. The second application is to perform the montage of several OFIs, which allows us to construct 3D OCT images over a large field of view out of separate OCT datasets. We use blood vessel ridges as registration features. The brute force search and an Iterative Closest Point (ICP) algorithm are employed for image pair registration. Global alignment to minimize the distance between matching pixel pairs is used to obtain the montage of OFIs. Quality of OFIs is the big limitation factor of the registration algorithm. In the first experiment, the effect of manual OFI enhancement on registration was evaluated for the affine model on 11 image pairs from diseased eyes. The average root mean square error (RMSE) decreases from 58 μm to 40 μm. This indicates that the registration algorithm is robust to manual enhancement. In the second experiment for the montage of OFIs, the algorithm was tested on 6 sets from healthy eyes and 6 sets from diseased eyes, each set having 8 partially overlapping SD-OCT images. Visual evaluation showed that the montage performance was acceptable for normal cases, and not good for abnormal cases due to low visibility of blood vessels. The average RMSE for a typical montage case from a healthy eye is 2.3 pixels (69 μm).

  3. Automated detection of optic disk in retinal fundus images using intuitionistic fuzzy histon segmentation.

    PubMed

    Mookiah, Muthu Rama Krishnan; Acharya, U Rajendra; Chua, Chua Kuang; Min, Lim Choo; Ng, E Y K; Mushrif, Milind M; Laude, Augustinus

    2013-01-01

    The human eye is one of the most sophisticated organs, with perfectly interrelated retina, pupil, iris cornea, lens, and optic nerve. Automatic retinal image analysis is emerging as an important screening tool for early detection of eye diseases. Uncontrolled diabetic retinopathy (DR) and glaucoma may lead to blindness. The identification of retinal anatomical regions is a prerequisite for the computer-aided diagnosis of several retinal diseases. The manual examination of optic disk (OD) is a standard procedure used for detecting different stages of DR and glaucoma. In this article, a novel automated, reliable, and efficient OD localization and segmentation method using digital fundus images is proposed. General-purpose edge detection algorithms often fail to segment the OD due to fuzzy boundaries, inconsistent image contrast, or missing edge features. This article proposes a novel and probably the first method using the Attanassov intuitionistic fuzzy histon (A-IFSH)-based segmentation to detect OD in retinal fundus images. OD pixel intensity and column-wise neighborhood operation are employed to locate and isolate the OD. The method has been evaluated on 100 images comprising 30 normal, 39 glaucomatous, and 31 DR images. Our proposed method has yielded precision of 0.93, recall of 0.91, F-score of 0.92, and mean segmentation accuracy of 93.4%. We have also compared the performance of our proposed method with the Otsu and gradient vector flow (GVF) snake methods. Overall, our result shows the superiority of proposed fuzzy segmentation technique over other two segmentation methods. PMID:23516954

  4. Angiogram, fundus, and oxygen saturation optic nerve head image fusion

    NASA Astrophysics Data System (ADS)

    Cao, Hua; Khoobehi, Bahram

    2009-02-01

    A novel multi-modality optic nerve head image fusion approach has been successfully designed. The new approach has been applied on three ophthalmologic modalities: angiogram, fundus, and oxygen saturation retinal optic nerve head images. It has achieved an excellent result by giving the visualization of fundus or oxygen saturation images with a complete angiogram overlay. During this study, two contributions have been made in terms of novelty, efficiency, and accuracy. The first contribution is the automated control point detection algorithm for multi-sensor images. The new method employs retina vasculature and bifurcation features by identifying the initial good-guess of control points using the Adaptive Exploratory Algorithm. The second contribution is the heuristic optimization fusion algorithm. In order to maximize the objective function (Mutual-Pixel-Count), the iteration algorithm adjusts the initial guess of the control points at the sub-pixel level. A refinement of the parameter set is obtained at the end of each loop, and finally an optimal fused image is generated at the end of the iteration. It is the first time that Mutual-Pixel-Count concept has been introduced into biomedical image fusion area. By locking the images in one place, the fused image allows ophthalmologists to match the same eye over time and get a sense of disease progress and pinpoint surgical tools. The new algorithm can be easily expanded to human or animals' 3D eye, brain, or body image registration and fusion.

  5. Glaucoma detection based on local binary patterns in fundus photographs

    NASA Astrophysics Data System (ADS)

    Alsheh Ali, Maya; Hurtut, Thomas; Faucon, Timothée.; Cheriet, Farida

    2014-03-01

    Glaucoma, a group of diseases that lead to optic neuropathy, is one of the most common reasons for blindness worldwide. Glaucoma rarely causes symptoms until the later stages of the disease. Early detection of glaucoma is very important to prevent visual loss since optic nerve damages cannot be reversed. To detect glaucoma, purely data-driven techniques have advantages, especially when the disease characteristics are complex and when precise image-based measurements are difficult to obtain. In this paper, we present our preliminary study for glaucoma detection using an automatic method based on local texture features extracted from fundus photographs. It implements the completed modeling of Local Binary Patterns to capture representative texture features from the whole image. A local region is represented by three operators: its central pixel (LBPC) and its local differences as two complementary components, the sign (which is the classical LBP) and the magnitude (LBPM). An image texture is finally described by both the distribution of LBP and the joint-distribution of LBPM and LBPC. Our images are then classified using a nearest-neighbor method with a leave-one-out validation strategy. On a sample set of 41 fundus images (13 glaucomatous, 28 non-glaucomatous), our method achieves 95:1% success rate with a specificity of 92:3% and a sensitivity of 96:4%. This study proposes a reproducible glaucoma detection process that could be used in a low-priced medical screening, thus avoiding the inter-experts variability issue.

  6. Simple, Inexpensive Technique for High-Quality Smartphone Fundus Photography in Human and Animal Eyes

    PubMed Central

    Haddock, Luis J.; Kim, David Y.

    2013-01-01

    Purpose. We describe in detail a relatively simple technique of fundus photography in human and rabbit eyes using a smartphone, an inexpensive app for the smartphone, and instruments that are readily available in an ophthalmic practice. Methods. Fundus images were captured with a smartphone and a 20D lens with or without a Koeppe lens. By using the coaxial light source of the phone, this system works as an indirect ophthalmoscope that creates a digital image of the fundus. The application whose software allows for independent control of focus, exposure, and light intensity during video filming was used. With this app, we recorded high-definition videos of the fundus and subsequently extracted high-quality, still images from the video clip. Results. The described technique of smartphone fundus photography was able to capture excellent high-quality fundus images in both children under anesthesia and in awake adults. Excellent images were acquired with the 20D lens alone in the clinic, and the addition of the Koeppe lens in the operating room resulted in the best quality images. Successful photodocumentation of rabbit fundus was achieved in control and experimental eyes. Conclusion. The currently described system was able to take consistently high-quality fundus photographs in patients and in animals using readily available instruments that are portable with simple power sources. It is relatively simple to master, is relatively inexpensive, and can take advantage of the expanding mobile-telephone networks for telemedicine. PMID:24171108

  7. Comparison of Color Fundus Photography, Infrared Fundus Photography, and Optical Coherence Tomography in Detecting Retinal Hamartoma in Patients with Tuberous Sclerosis Complex

    PubMed Central

    Bai, Da-Yong; Wang, Xu; Zhao, Jun-Yang; Li, Li; Gao, Jun; Wang, Ning-Li

    2016-01-01

    Background: A sensitive method is required to detect retinal hamartomas in patients with tuberous sclerosis complex (TSC). The aim of the present study was to compare the color fundus photography, infrared imaging (IFG), and optical coherence tomography (OCT) in the detection rate of retinal hamartoma in patients with TSC. Methods: This study included 11 patients (22 eyes) with TSC, who underwent color fundus photography, IFG, and spectral-domain OCT to detect retinal hamartomas. TSC1 and TSC2 mutations were tested in eight patients. Results: The mean age of the 11 patients was 8.0 ± 2.1 years. The mean spherical equivalent was −0.55 ± 1.42 D by autorefraction with cycloplegia. In 11 patients (22 eyes), OCT, infrared fundus photography, and color fundus photography revealed 26, 18, and 9 hamartomas, respectively. The predominant hamartoma was type I (55.6%). All the hamartomas that detected by color fundus photography or IFG can be detected by OCT. Conclusion: Among the methods of color fundus photography, IFG, and OCT, the OCT has higher detection rate for retinal hamartoma in TSC patients; therefore, OCT might be promising for the clinical diagnosis of TSC. PMID:27174333

  8. Realization of the ergonomics design and automatic control of the fundus cameras

    NASA Astrophysics Data System (ADS)

    Zeng, Chi-liang; Xiao, Ze-xin; Deng, Shi-chao; Yu, Xin-ye

    2012-12-01

    The principles of ergonomics design in fundus cameras should be extending the agreeableness by automatic control. Firstly, a 3D positional numerical control system is designed for positioning the eye pupils of the patients who are doing fundus examinations. This system consists of a electronically controlled chin bracket for moving up and down, a lateral movement of binocular with the detector and the automatic refocusing of the edges of the eye pupils. Secondly, an auto-focusing device for the object plane of patient's fundus is designed, which collects the patient's fundus images automatically whether their eyes is ametropic or not. Finally, a moving visual target is developed for expanding the fields of the fundus images.

  9. Bilateral macular infarction as an ocular manifestation of systemic lupus erythematosus (SLE)

    PubMed Central

    Hu, Chih-Ling; Peng, Kai-Ling

    2014-01-01

    We report a rare case of bilateral macular infarction as an ocular presenting sign of systemic lupus erythematosus (SLE). A 29-year-old woman presented to our ophthalmologic clinic with a 1-week history of progressive visual loss in her left eye after she had visited a rheumatologic clinic where SLE was diagnosed. At examination, best-corrected visual acuity (BCVA) of the right eye was 6/6, and for the left was counting fingers. Fundus examination revealed perivascular hard exudates along some branches of vessels in both eyes. After pulse therapy, her BCVA in the right eye declined to 6/30 and in the left improved to 3/60. She was administered sub-Tenon’s injections of triamcinolone acetonide 50 mg/week in both eyes for 3 weeks. Her BCVA improved to 3/6 in her right eye and remained at 3/60 in her left eye. Macular infarction is an uncommon but most severe complication of SLE. Early and regular exam of the fundus in patients with SLE is necessary to avoid progression of severe ocular complications. PMID:25246764

  10. Reduction of ocular counter-rolling by adaptation to space

    NASA Technical Reports Server (NTRS)

    Dai, Mingjia; Mcgarvie, Leigh; Kozlovskaya, Inessa; Sirota, Mischa; Raphan, Theodore; Cohen, Bernard

    1993-01-01

    We studied the three-dimensional vestibulo-ocular reflex (VOR) of rhesus monkeys before and after the COSMOS Biosatellite 2229 Mission of 1992-1993. This included tests of ocular counter-rolling (OCR), the gain of the vestibulo-ocular reflex (VOR), and spatial orientation of velocity storage. A four-axis vestibular and oculomotor stimulator was transported to the Institute of Biomedical Problems in Moscow for the pre- and postflight ground-based testing. Twelve normal juvenile male rhesus monkey were implanted surgically with eye coils and tested 60-90 days before spaceflight. Two monkey (7906 and 6151), selected from the twelve as flight animals, flew from 12/29/92 to 1/10/93. Upon recovery, they were tested for 11 days postflight along with three control animals. Compensatory ocular torsion was produced in two ways: (1) Lateral head tilts evoked OCR through otolith-ocular reflexes. OCR was also measured dynamically during off-vertical axis rotation (OVAR). (2) Rotation about a naso-occipital axis that was either vertical of horizontal elicited torsional nystagmus through semicircular canal-ocular reflexes (roll VOR). OCR from the otoliths was substantially reduced (70 percent) for 11 days after reentry on both modes of testing. The gain of the roll VOR was also decreased, but less than OCR. These data demonstrate that there was a long-lasting depression of torsional or roll eye movements after adaptation to microgravity in these monkeys, especially those movements produced by the otolith organs.

  11. Ocular drug delivery.

    PubMed

    Gaudana, Ripal; Ananthula, Hari Krishna; Parenky, Ashwin; Mitra, Ashim K

    2010-09-01

    Ocular drug delivery has been a major challenge to pharmacologists and drug delivery scientists due to its unique anatomy and physiology. Static barriers (different layers of cornea, sclera, and retina including blood aqueous and blood-retinal barriers), dynamic barriers (choroidal and conjunctival blood flow, lymphatic clearance, and tear dilution), and efflux pumps in conjunction pose a significant challenge for delivery of a drug alone or in a dosage form, especially to the posterior segment. Identification of influx transporters on various ocular tissues and designing a transporter-targeted delivery of a parent drug has gathered momentum in recent years. Parallelly, colloidal dosage forms such as nanoparticles, nanomicelles, liposomes, and microemulsions have been widely explored to overcome various static and dynamic barriers. Novel drug delivery strategies such as bioadhesive gels and fibrin sealant-based approaches were developed to sustain drug levels at the target site. Designing noninvasive sustained drug delivery systems and exploring the feasibility of topical application to deliver drugs to the posterior segment may drastically improve drug delivery in the years to come. Current developments in the field of ophthalmic drug delivery promise a significant improvement in overcoming the challenges posed by various anterior and posterior segment diseases. PMID:20437123

  12. Infranuclear ocular motor disorders.

    PubMed

    Lueck, Christian J

    2011-01-01

    This chapter covers the very large number of possible disorders that can affect the three ocular motor nerves, the neuromuscular junction, or the extraocular muscles. Conditions affecting the nerves are discussed under two major headings: those in which the site of damage can be anatomically localized (e.g., fascicular lesions and lesions occurring in the subarachnoid space, the cavernous sinus, the superior orbital fissure, or the orbit) and those in which the site of the lesion is either nonspecific or variable (e.g., vascular lesions, tumors, "ophthalmoplegic migraine," and congenital disorders). Specific comments on the diagnosis and management of disorders of each of the three nerves follow. Ocular motor synkineses (including Duane's retraction syndrome and aberrant regeneration) and disorders resulting in paroxysms of excess activity (e.g., neuromyotonia) are then covered, followed by myasthenia gravis and other disorders that affect the neuromuscular junction. A final section discusses disorders of the extraocular muscles themselves, including thyroid disease, orbital myositis, mitochondrial disease, and the muscular dystrophies. PMID:21601071

  13. Nonhuman Primate Ocular Biometry

    PubMed Central

    Augusteyn, Robert C.; Maceo Heilman, Bianca; Ho, Arthur; Parel, Jean-Marie

    2016-01-01

    Purpose To examine ocular growth in nonhuman primates (NHPs) from measurements on ex vivo eyes. Methods We obtained NHP eyes from animals that had been killed as part of other studies or because of health-related issues. Digital calipers were used to measure the horizontal, vertical, and anteroposterior globe diameters as well as corneal horizontal and vertical diameters of excised globes from 98 hamadryas baboons, 551 cynomolgus monkeys, and 112 rhesus monkeys, at ages ranging from 23 to 360 months. Isolated lens sagittal thickness and equatorial diameter were measured by shadowphotogrammetry. Wet and fixed dry weights were obtained for lenses. Results Nonhuman primate globe growth continues throughout life, slowing toward an asymptotic maximum. The final globe size scales with negative allometry to adult body size. Corneal growth ceases at around 20 months. Lens diameter increases but thickness decreases with increasing age. Nonhuman primate lens wet and dry weight accumulation is monophasic, continuing throughout life toward asymptotic maxima. The dry/wet weight ratio reaches a maximum of 0.33. Conclusions Nonhuman primate ocular globe and lens growth differ in several respects from those in humans. Although age-related losses of lens power and accommodative amplitude are similar, lens growth and properties are different indicating care should be taken in extrapolating NHP observations to the study of human accommodation. PMID:26780314

  14. Ocular tuberculosis: current perspectives

    PubMed Central

    Shakarchi, Faiz I

    2015-01-01

    The World Health Organization currently estimates that nearly two billion people, or one-third of the world’s population, are infected by tuberculosis, and that roughly 10% of the infected people are symptomatic. Tuberculosis affects the lungs in 80% of patients, while in the remaining 20% the disease may affect other organs, including the eye. Uveitis can be seen concurrently with tuberculosis, but a direct association is difficult to prove. Ocular tuberculosis is usually not associated with clinical evidence of pulmonary tuberculosis, as up to 60% of extrapulmonary tuberculosis patients may not have pulmonary disease. The diagnosis of tuberculous uveitis is often problematic and in nearly all reported cases, the diagnosis was only presumptive. Tuberculous uveitis is a great mimicker of various uveitis entities and it can be considered in the differential diagnosis of any type of intraocular inflammation. It is still unknown if ocular manifestations result from a direct mycobacterium infection or hypersensitivity reaction and this is reflected on the management of tuberculous uveitis. Prevalence of tuberculosis as an etiology of uveitis may reach up to 10% in endemic areas. Tuberculous uveitis is a vision-threatening disease that inevitably leads to blindness if not properly diagnosed and treated. The aim of this review is to illustrate the various clinical features and management of presumed tuberculous uveitis. The current review focuses on the diagnostic criteria, significance of tuberculin skin test, and use of systemic corticosteroids in the management of tuberculous uveitis as recommended in recent publications. PMID:26648690

  15. Findings of perinatal ocular examination performed on 3573, healthy full-term newborns

    PubMed Central

    Li, Li-Hong; Li, Na; Zhao, Jun-Yang; Fei, Ping; Zhang, Guo-ming; Mao, Jian-bo; Rychwalski, Paul J

    2013-01-01

    Objective To document the findings of a newborn eye examination programme for detecting ocular pathology in the healthy full-term newborn. Methods This is a cross-sectional study of the majority of newborns born in the Kunming Maternal and Child Healthcare Hospital, China, between May 2010 and June 2011. Infants underwent ocular examination within 42 days after birth using a flashlight, retinoscope, hand-held slit lamp microscope and wide-angle digital retinal image acquisition system. The retinal fundus examination utilised the RetCam wide-field digital imaging system (Clarity Medical Systems, Pleasanton, California, USA). The external eye, pupillary light reflex, red reflex, opacity of refractive media, anterior chamber and posterior segments were also examined. Results A total of 3573 healthy full-term newborns were enrolled and examined in the programme. There was detection of 871 abnormal cases (24.4%). The majority of abnormal exams were 769 (21.52%) retinal haemorrhages. Of these, there were 215 cases of significant retinal haemorrhage, possible sight threatening or amblyogenic, representing 6.02% of the total. In addition, 67 cases (1.88%) involved macular haemorrhage. The other 107 cases (2.99%) with abnormal ocular findings included subconjunctival haemorrhage, congenital microphthalmos, congenital corneal leukoma, posterior synechia, persistent pupillary membrane, congenital cataract, enlarged C/D ratio, retinal hamartoma versus retinoblastoma, optic nerve defects, macular pigment disorder and non-specific peripheral retinopathy. Conclusion Ocular examination of healthy newborns leads to the detection of a significant number of ocular pathologies. The most commonly discovered ocular abnormality during examination of the newborns in this study is retinal haemorrhage. The long-term impact of these findings is unknown. Although presumed by some to benign, neonatal retinal haemorrhages due to birth trauma could be involved in altering visual development

  16. Statistical Characterization and Segmentation of Drusen in Fundus Images

    SciTech Connect

    Santos-Villalobos, Hector J; Karnowski, Thomas Paul; Aykac, Deniz; Giancardo, Luca; Li, Yaquin; Nichols, Trent L; Tobin Jr, Kenneth William; Chaum, Edward

    2011-01-01

    Age related Macular Degeneration (AMD) is a disease of the retina associated with aging. AMD progression in patients is characterized by drusen, pigmentation changes, and geographic atrophy, which can be seen using fundus imagery. The level of AMD is characterized by standard scaling methods, which can be somewhat subjective in practice. In this work we propose a statistical image processing approach to segment drusen with the ultimate goal of characterizing the AMD progression in a data set of longitudinal images. The method characterizes retinal structures with a statistical model of the colors in the retina image. When comparing the segmentation results of the method between longitudinal images with known AMD progression and those without, the method detects progression in our longitudinal data set with an area under the receiver operating characteristics curve of 0.99.

  17. Abnormalities of fundus autofluorescence in pigmented paravenous chorioretinal atrophy.

    PubMed

    Hashimoto, Yuki; Kase, Satoru; Saito, Wataru; Ishida, Susumu

    2012-01-01

    The aim of this study is to investigate fundus autofluorescence (FAF) as well as fluorescein angiography (FA), indocyanine green angiography (IA), and optical coherence tomography (OCT) in a patient with pigmented paravenous chorioretinal atrophy (PPCRA). A funduscopic examination revealed chorioretinal atrophy along the paravenous area in both eyes. A marked bone spicule pigment clumping together with the atrophy was noted left eye. FA and IA showed a window defect and hypofluorescence, respectively, which exclusively corresponds to the atrophic area along the retinal vein area and the optic disc both eyes. FAF revealed geographic hypofluorescence along the paravenous and supranasal retinal areas. Hyperfluorescence was noted, which comparatively surrounded the hypofluorescence in the peripheral paravenous distribution. Hypofluorescence detected by FAF corresponded to the areas of retinal thinning and atrophy detected by OCT and FA. FAF is a useful examination in PPCRA, which can noninvasively demonstrate the distribution of deficit and dysfunction of retinal pigment epithelium. PMID:23264840

  18. Validating retinal fundus image analysis algorithms: issues and a proposal.

    PubMed

    Trucco, Emanuele; Ruggeri, Alfredo; Karnowski, Thomas; Giancardo, Luca; Chaum, Edward; Hubschman, Jean Pierre; Al-Diri, Bashir; Cheung, Carol Y; Wong, Damon; Abràmoff, Michael; Lim, Gilbert; Kumar, Dinesh; Burlina, Philippe; Bressler, Neil M; Jelinek, Herbert F; Meriaudeau, Fabrice; Quellec, Gwénolé; Macgillivray, Tom; Dhillon, Bal

    2013-05-01

    This paper concerns the validation of automatic retinal image analysis (ARIA) algorithms. For reasons of space and consistency, we concentrate on the validation of algorithms processing color fundus camera images, currently the largest section of the ARIA literature. We sketch the context (imaging instruments and target tasks) of ARIA validation, summarizing the main image analysis and validation techniques. We then present a list of recommendations focusing on the creation of large repositories of test data created by international consortia, easily accessible via moderated Web sites, including multicenter annotations by multiple experts, specific to clinical tasks, and capable of running submitted software automatically on the data stored, with clear and widely agreed-on performance criteria, to provide a fair comparison. PMID:23794433

  19. Next generation high resolution adaptive optics fundus imager

    NASA Astrophysics Data System (ADS)

    Fournier, P.; Erry, G. R. G.; Otten, L. J.; Larichev, A.; Irochnikov, N.

    2005-12-01

    The spatial resolution of retinal images is limited by the presence of static and time-varying aberrations present within the eye. An updated High Resolution Adaptive Optics Fundus Imager (HRAOFI) has been built based on the development from the first prototype unit. This entirely new unit was designed and fabricated to increase opto-mechanical integration and ease-of-use through a new user interface. Improved camera systems for the Shack-Hartmann sensor and for the scene image were implemented to enhance the image quality and the frequency of the Adaptive Optics (AO) control loop. An optimized illumination system that uses specific wavelength bands was applied to increase the specificity of the images. Sample images of clinical trials of retinas, taken with and without the system, are shown. Data on the performance of this system will be presented, demonstrating the ability to calculate near diffraction-limited images.

  20. Multiwavelength adaptive optical fundus camera and continuous retinal imaging

    NASA Astrophysics Data System (ADS)

    Yang, Han-sheng; Li, Min; Dai, Yun; Zhang, Yu-dong

    2009-08-01

    We have constructed a new version of retinal imaging system with chromatic aberration concerned and the correlated optical design presented in this article is based on the adaptive optics fundus camera modality. In our system, three typical wavelengths of 550nm, 650nm and 480nm were selected. Longitude chromatic aberration (LCA) was traded off to a minimum using ZEMAX program. The whole setup was actually evaluated on human subjects and retinal imaging was performed at continuous frame rates up to 20 Hz. Raw videos at parafovea locations were collected, and cone mosaics as well as retinal vasculature were clearly observed in one single clip. In addition, comparisons under different illumination conditions were also made to confirm our design. Image contrast and the Strehl ratio were effectively increased after dynamic correction of high order aberrations. This system is expected to bring new applications in functional imaging of human retina.

  1. Validating Retinal Fundus Image Analysis Algorithms: Issues and a Proposal

    PubMed Central

    Trucco, Emanuele; Ruggeri, Alfredo; Karnowski, Thomas; Giancardo, Luca; Chaum, Edward; Hubschman, Jean Pierre; al-Diri, Bashir; Cheung, Carol Y.; Wong, Damon; Abràmoff, Michael; Lim, Gilbert; Kumar, Dinesh; Burlina, Philippe; Bressler, Neil M.; Jelinek, Herbert F.; Meriaudeau, Fabrice; Quellec, Gwénolé; MacGillivray, Tom; Dhillon, Bal

    2013-01-01

    This paper concerns the validation of automatic retinal image analysis (ARIA) algorithms. For reasons of space and consistency, we concentrate on the validation of algorithms processing color fundus camera images, currently the largest section of the ARIA literature. We sketch the context (imaging instruments and target tasks) of ARIA validation, summarizing the main image analysis and validation techniques. We then present a list of recommendations focusing on the creation of large repositories of test data created by international consortia, easily accessible via moderated Web sites, including multicenter annotations by multiple experts, specific to clinical tasks, and capable of running submitted software automatically on the data stored, with clear and widely agreed-on performance criteria, to provide a fair comparison. PMID:23794433

  2. Relations between contractile responses and. beta. -adrenoceptors in gastric fundus of diabetic rats

    SciTech Connect

    Sakai, Yasushi; Inazu, Masato; Aihara, Kazuo; Inoue, Kazuaki; Homma, Ikuo )

    1991-01-01

    Contractile responses to norepinephrine (NE), and the population of {beta}-adrenoceptors, were determined in gastric fundus smooth muscle from rats with diabetes induced by streptozotocin(STZ), and age-matched controls. Relaxation and/or contraction of fundus strips of controls and diabetics were induced by 10{sup {minus}5}M NE. Responses to NE were mainly relaxation in gastric fundus isolated from controls, and contraction in fundus isolated from diabetics. Contraction was blocked by 10{sup {minus}8}M prazosin and relaxation was blocked by 10{sup {minus}6}M propranolol. Relaxation by isoproterenol of contraction induced by 10{sup {minus}6}M acetylcholine was significantly less in fundus from diabetics than in that from controls. The number of {beta}-adrenoceptors, measured with ({sup 125}I)iodocyanopindorol as a ligand, was significantly less in gastic fundus membrane isolated from diabetics than in that from controls, but affinity was no different. The level of plasma catecholamine was higher in diabetics than in controls. Results suggest that depression of gastric fundus relaxation and increase of contraction by NE in diabetics could be due to fewer {beta}-adrenoceptor binding sites caused by down-regulation by higher catecholamine level in diabetic rats.

  3. Health Insurance Portability and Accountability Act-Compliant Ocular Telehealth Network for the Remote Diagnosis and Management of Diabetic Retinopathy

    SciTech Connect

    Li, Yaquin; Karnowski, Thomas Paul; Tobin Jr, Kenneth William; Giancardo, Luca; Garg, Seema; Fox, Karen; Chaum, Edward

    2011-01-01

    In this article, we present the design and implementation of a regional ocular telehealth network for remote assessment and management of diabetic retinopathy (DR), including the design requirements, network topology, protocol design, system work flow, graphics user interfaces, and performance evaluation. The Telemedical Retinal Image Analysis and Diagnosis Network is a computer-aided, image analysis telehealth paradigm for the diagnosis of DR and other retinal diseases using fundus images acquired from primary care end users delivering care to underserved patient populations in the mid-South and southeastern United States.

  4. Ocular Screening System

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Used to detect eye problems in children through analysis of retinal reflexes, the system incorporates image processing techniques. VISISCREEN's photorefractor is basically a 35 millimeter camera with a telephoto lens and an electronic flash. By making a color photograph, the system can test the human eye for refractive error and obstruction in the cornea or lens. Ocular alignment problems are detected by imaging both eyes simultaneously. Electronic flash sends light into the eyes and the light is reflected from the retina back to the camera lens. Photorefractor analyzes the retinal reflexes generated by the subject's response to the flash and produces an image of the subject's eyes in which the pupils are variously colored. The nature of a defect, where such exists, is identifiable by atrained observer's visual examination.

  5. Corticosteroids for ocular toxoplasmosis

    PubMed Central

    Jasper, Smitha; Vedula, Satyanarayana S; John, Sheeja S; Horo, Saban; Sepah, Yasir J; Nguyen, Quan Dong

    2014-01-01

    Background Ocular infestation with Toxoplasma gondii, a parasite, may result in inflammation in the retina, choroid, and uvea and consequently lead to complications such as glaucoma, cataract, and posterior synechiae. Objectives The objective of this systematic review was to assess the effects of adjunctive use of corticosteroids for ocular toxoplasmosis. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 9), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE, (January 1950 to October 2012), EMBASE (January 1980 to October 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to October 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). We searched the reference lists of included studies for any additional studies not identified by the electronic searches. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 11 October 2012. Selection criteria We planned to include randomized and quasi-randomized controlled trials. Eligible trials would have enrolled participants of any age who were immunocompetent and were diagnosed with active ocular toxoplasmosis. Included trials would have compared anti-parasitic therapy plus corticosteroids versus anti-parasitic therapy alone, or different doses or times of initiation of corticosteroids. Data collection and analysis Two authors independently screened titles and abstracts retrieved from the electronic searches. We retrieved full-text articles of studies categorized as ‘unsure’ or ‘include’ after review of the abstracts. Two authors independently reviewed each full-text article. Discrepancies were

  6. Photorefractor ocular screening system

    NASA Technical Reports Server (NTRS)

    Richardson, John R. (Inventor); Kerr, Joseph H. (Inventor)

    1987-01-01

    A method and apparatus for detecting human eye defects, particularly detection of refractive error is presented. Eye reflex is recorded on color film when the eyes are exposed to a flash of light. The photographs are compared with predetermined standards to detect eye defects. The base structure of the ocular screening system is a folding interconnect structure, comprising hinged sections. Attached to one end of the structure is a head positioning station which comprises vertical support, a head positioning bracket having one end attached to the top of the support, and two head positioning lamps to verify precise head positioning. At the opposite end of the interconnect structure is a camera station with camera, electronic flash unit, and blinking fixation lamp, for photographing the eyes of persons being evaluated.

  7. OCT angiography in the management of choroidal neovascular membrane secondary to Sorsby fundus dystrophy.

    PubMed

    Mohla, Aditi; Khan, Kamron; Kasilian, Melissa; Michaelides, Michel

    2016-01-01

    We describe the management of a woman aged 52 years with molecularly confirmed Sorsby fundus dystrophy, who presented with acute visual deterioration in her right eye. Fundus examination identified a right macular lesion suggestive of a choroidal neovascular membrane (CNVM). Optical coherence tomography angiography (OCTA) confirmed the presence of a CNVM. She was treated with 2 monthly intravitreal injections of bevacizumab, associated with OCTA evidence of regression of the CNVM and improvement in her visual acuity. OCTA is a novel, non-invasive method of imaging the retinal vasculature. Images are acquired rapidly, with no associated side effects, offering advantages over the current gold standard technique-fundus fluorescein angiography. PMID:27587748

  8. Ocular complications of diabetes mellitus

    PubMed Central

    Sayin, Nihat; Kara, Necip; Pekel, Gökhan

    2015-01-01

    Diabetes mellitus (DM) is a important health problem that induces ernestful complications and it causes significant morbidity owing to specific microvascular complications such as, retinopathy, nephropathy and neuropathy, and macrovascular complications such as, ischaemic heart disease, and peripheral vasculopathy. It can affect children, young people and adults and is becoming more common. Ocular complications associated with DM are progressive and rapidly becoming the world’s most significant cause of morbidity and are preventable with early detection and timely treatment. This review provides an overview of five main ocular complications associated with DM, diabetic retinopathy and papillopathy, cataract, glaucoma, and ocular surface diseases. PMID:25685281

  9. Ocular myasthenia gravis: A review

    PubMed Central

    Nair, Akshay Gopinathan; Patil-Chhablani, Preeti; Venkatramani, Devendra V; Gandhi, Rashmin Anilkumar

    2014-01-01

    Myasthenia gravis (MG) is a disease that affects the neuro-muscular junction resulting in classical symptoms of variable muscle weakness and fatigability. It is called the great masquerader owing to its varied clinical presentations. Very often, a patient of MG may present to the ophthalmologist given that a large proportion of patients with systemic myasthenia have ocular involvement either at presentation or during the later course of the disease. The treatment of ocular MG involves both the neurologist and ophthalmologist. Thus, the aim of this review was to highlight the current diagnosis, investigations, and treatment of ocular MG. PMID:25449931

  10. Ocular neuromyotonia after radiation therapy

    SciTech Connect

    Lessell, S.; Lessell, I.M.; Rizzo, J.F. III

    1986-12-15

    Ocular neuromyotonia is a paroxysmal monocular deviation that results from spasm of eye muscles secondary to spontaneous discharges from third, fourth, or sixth nerve axons. We observed this rare disorder in four patients who had been treated with radiation for tumors in the region of the sella turcica and cavernous sinus. Based on these cases and four others identified in the literature it would appear that radiation predisposes to a cranial neuropathy in which ocular neuromyotonia may be the major manifestation. Radiation appears to be the most common cause of ocular neuromyotonia.

  11. Ocular complications of diabetes mellitus.

    PubMed

    Sayin, Nihat; Kara, Necip; Pekel, Gökhan

    2015-02-15

    Diabetes mellitus (DM) is a important health problem that induces ernestful complications and it causes significant morbidity owing to specific microvascular complications such as, retinopathy, nephropathy and neuropathy, and macrovascular complications such as, ischaemic heart disease, and peripheral vasculopathy. It can affect children, young people and adults and is becoming more common. Ocular complications associated with DM are progressive and rapidly becoming the world's most significant cause of morbidity and are preventable with early detection and timely treatment. This review provides an overview of five main ocular complications associated with DM, diabetic retinopathy and papillopathy, cataract, glaucoma, and ocular surface diseases. PMID:25685281

  12. Control of ocular inflammation.

    PubMed

    Wilkie, D A

    1990-05-01

    Although both topical and systemic anti-inflammatory agents have a place in veterinary ophthalmology, they play only a small role in overall patient management. They must be used appropriately to prevent ocular damage and loss of vision from inflammation and are not a replacement for a complete ophthalmic examination and specific treatment directed at the etiology of the problem. If used indiscriminately, they can result in local or systemic side effects or toxicities, many of which are worse than the initial problem for which they were selected. Just as topical corticosteroids are contraindicated with infectious keratitis, so are systemic corticosteroids contraindicated in patients with ocular inflammation resulting from a systemic infectious process. Anti-inflammatories must be used at the appropriate dosage and frequency. Use of corticosteroids that have low intraocular penetration for intraocular disease or corticosteroids with low potency is a waste of time and money. The most expensive medication is one that does not work. Avoid combination therapies when only a single medication is required. These do not save time or money and have the potential to result in the development of drug-related diseases. Diseases for which anti-inflammatory therapy has little or no indication include corneal scars, corneal edema, corneal pigmentation, corneal dystrophy, cataracts without inflammation, glaucoma, and retinal atrophy and degeneration. Last, remember that all commercially available ophthalmic medications are specifically formulated for use in the eye. Their pH, concentration, osmolality, and melting temperature all are designed to facilitate penetration. The use of dermal and otic preparations to treat ophthalmic problems is contraindicated. PMID:2194354

  13. Hypercapnia-induced cerebral and ocular vasodilation is not altered by glibenclamide in humans.

    PubMed

    Bayerle-Eder, M; Wolzt, M; Polska, E; Langenberger, H; Pleiner, J; Teherani, D; Rainer, G; Polak, K; Eichler, H G; Schmetterer, L

    2000-06-01

    Carbon dioxide is an important regulator of vascular tone. Glibenclamide, an inhibitor of ATP-sensitive potassium channel (K(ATP)) activation, significantly blunts vasodilation in response to hypercapnic acidosis in animals. We investigated whether glibenclamide also alters the cerebral and ocular vasodilator response to hypercapnia in humans. Ten healthy male subjects were studied in a controlled, randomized, double-blind two-way crossover study under normoxic and hypercapnic conditions. Glibenclamide (5 mg po) or insulin (0.3 mU. kg(-1). min(-1) iv) were administered with glucose to achieve comparable plasma insulin levels. In control experiments, five healthy volunteers received glibenclamide (5 mg) or nicorandil (40 mg) or glibenclamide and nicorandil in a randomized, three-way crossover study. Mean blood flow velocity and resistive index in the middle cerebral artery (MCA) and in the ophthalmic artery (OA) were measured with Doppler sonography. Pulsatile choroidal blood flow was assessed with laser interferometric measurement of fundus pulsation. Forearm blood flow was measured with venous occlusion plethysmography. Hypercapnia increased ocular fundus pulsation amplitude by +18.2-22.3% (P < 0. 001) and mean flow velocity in the MCA by +27.4-33.3% (P < 0.001), but not in the OA (2.1-6.5%, P = 0.2). Forearm blood flow increased by 78.2% vs. baseline (P = 0.041) after nicorandil administration. Glibenclamide did not alter hypercapnia-induced changes in cerebral or ocular hemodynamics and did not affect systemic hemodynamics or forearm blood flow but significantly increased glucose utilization and blunted the nicorandil-induced vasodilation in the forearm. This suggests that hypercapnia-induced changes in the vascular beds under study are not mediated by activation of K(ATP) channels in humans. PMID:10848537

  14. Validity of retinal oxygen saturation analysis: Hyperspectral imaging in visible wavelength with fundus camera and liquid crystal wavelength tunable filter

    NASA Astrophysics Data System (ADS)

    Hirohara, Yoko; Okawa, Yoshitaka; Mihashi, Toshifumi; Yamaguchi, Tatsuo; Nakazawa, Naoki; Tsuruga, Yasuko; Aoki, Hiroyuki; Maeda, Naoyuki; Uchida, Ichiro; Fujikado, Takashi

    2007-05-01

    The purpose of this paper was to investigate the feasibility of a newly developed hyperspectral fundus imaging camera with a liquid crystal tunable filter. The intensities of different wavelengths of light transmitted through an artery, vein, and the area surrounding these vessels and reflected out were measured, and the differential spectral absorptions were analyzed. Measurements were made from 16 normal eyes and from two artificial capillaries. The ratios of absorption (ROA) of arteries to veins from 500 to 580 nm (range 1) and from 600 to 720 nm (range 2) were calculated. For all eyes, the ROArange1 was larger than ROArange2. The ROA obtained from the artificial capillary filled with blood saturated with oxygen or nitrogen was similar to that of simulated data of oxy- and deoxyhemoglobin extinction rate. Most ROAs of human eyes were lower than those of the simulated data and the artificial capillaries. Oxygen saturation analysis by hyperspectral fundus imaging of retinal vessels were qualitatively in agreement with the in vitro analysis or simulated values. However, further improvements are necessary to evaluate the oxygen saturation quantitatively in the retinal blood vessels.

  15. Diurnal Curve of the Ocular Perfusion Pressure

    PubMed Central

    Moreira, TCA; Bezerra, BSP; Vianello, MP; Corradi, J; Dorairaj, SK; Prata, TS

    2016-01-01

    ABSTRACT Purpose: To describe the diurnal variation of the ocular perfusion pressure (OPP) in normal, suspects and glaucoma patients. Materials and methods: Seventy-nine subjects were enrolled in a prospective study. The diurnal curve of intraocular pressure (IOP) was performed and blood pressure measurements were obtained. Each participant was grouped into one of the following based upon the clinical evaluation of the optic disk, IOP and standard achromatic perimetry (SAP): 18 eyes were classified as normal (normal SAP, normal optic disk evaluation and IOP < 21 mm Hg in two different measurements), 30 eyes as glaucoma suspect (GS) (normal SAP and mean deviation (MD), C/D ration > 0.5 or asymmetry > 0.2 and/or ocular hypertension), 31 eyes as early glaucoma (MD < -6 dB, glaucomatous optic neuropathy and SAP and MDs on SAP. Standard achromatic perimetry was performed with the Octopus 3.1.1 Dynamic 24-2 program. Intraocular pressure and blood pressure measurements were taken at 6 am, 9 am, 12, 3 and 6 pm. The patients stayed in the seated position for 5 minutes prior to blood pressure measurements. Results: The mean IOP values in all groups did not follow any regular pattern. The peak IOP was found to be greater in suspect [18.70 ± 3.31 (mm Hg ± SD)] and glaucoma (18.77 ± 4.30 mm Hg) patients as compared to normal subjects (16.11 ± 2.27 mm Hg). In studying the diurnal variation of the OPP, we found lower values at 3 pm in normals (34.21 ± 2.07 mm Hg), at 9 am in suspects (54.35 ± 3.32 mm Hg) and at 12 pm in glaucoma patients (34.84 ± 1.44 mm Hg). Conclusion: Each group has a specific OPP variation during the day with the most homogeneous group being the suspect one. It is important to keep studying the IOP and OPP variation for increased comprehension of the pathophysiology of glaucomatous optic neuropathy. How to cite this article: Kanadani FN, Moreira TCA, Bezerra BSP, Vianello MP, Corradi J, Dorairaj SK, Prata TS. Diurnal Curve of the Ocular Perfusion

  16. Polarization microscopy for characterizing fiber orientation of ocular tissues.

    PubMed

    Jan, Ning-Jiun; Grimm, Jonathan L; Tran, Huong; Lathrop, Kira L; Wollstein, Gadi; Bilonick, Richard A; Ishikawa, Hiroshi; Kagemann, Larry; Schuman, Joel S; Sigal, Ian A

    2015-12-01

    Characterizing the collagen fiber orientation and organization in the eye is necessary for a complete understanding of ocular biomechanics. In this study, we assess the performance of polarized light microscopy to determine collagen fiber orientation of ocular tissues. Our results demonstrate that the method provides objective, accurate, repeatable and robust data on fiber orientation with µm-scale resolution over a broad, cm-scale, field of view, unaffected by formalin fixation, without requiring tissue dehydration, labeling or staining. Together, this shows that polarized light microscopy is a powerful method for studying collagen architecture in the eye, with applications ranging from normal physiology and aging, to pathology and transplantation. PMID:26713188

  17. Polarization microscopy for characterizing fiber orientation of ocular tissues

    PubMed Central

    Jan, Ning-Jiun; Grimm, Jonathan L.; Tran, Huong; Lathrop, Kira L.; Wollstein, Gadi; Bilonick, Richard A.; Ishikawa, Hiroshi; Kagemann, Larry; Schuman, Joel S.; Sigal, Ian A.

    2015-01-01

    Characterizing the collagen fiber orientation and organization in the eye is necessary for a complete understanding of ocular biomechanics. In this study, we assess the performance of polarized light microscopy to determine collagen fiber orientation of ocular tissues. Our results demonstrate that the method provides objective, accurate, repeatable and robust data on fiber orientation with µm-scale resolution over a broad, cm-scale, field of view, unaffected by formalin fixation, without requiring tissue dehydration, labeling or staining. Together, this shows that polarized light microscopy is a powerful method for studying collagen architecture in the eye, with applications ranging from normal physiology and aging, to pathology and transplantation. PMID:26713188

  18. Ocular Tropism of Respiratory Viruses

    PubMed Central

    Rota, Paul A.; Tumpey, Terrence M.

    2013-01-01

    SUMMARY Respiratory viruses (including adenovirus, influenza virus, respiratory syncytial virus, coronavirus, and rhinovirus) cause a broad spectrum of disease in humans, ranging from mild influenza-like symptoms to acute respiratory failure. While species D adenoviruses and subtype H7 influenza viruses are known to possess an ocular tropism, documented human ocular disease has been reported following infection with all principal respiratory viruses. In this review, we describe the anatomical proximity and cellular receptor distribution between ocular and respiratory tissues. All major respiratory viruses and their association with human ocular disease are discussed. Research utilizing in vitro and in vivo models to study the ability of respiratory viruses to use the eye as a portal of entry as well as a primary site of virus replication is highlighted. Identification of shared receptor-binding preferences, host responses, and laboratory modeling protocols among these viruses provides a needed bridge between clinical and laboratory studies of virus tropism. PMID:23471620

  19. Ocular abnormalities in multi-transfused beta-thalassemia patients

    PubMed Central

    Jafari, Reza; Heydarian, Samira; Karami, Hosein; Shektaei, Mohammad Momeni; Dailami, Kiumars Noruzpour; Amiri, Ahmad Ahmadzadeh; Rezaee, Majid Reza Sheikh; Far, Asad Allah Farrokh

    2015-01-01

    Aims: The aim of this study was to assess ocular changes in thalassemia patients who have received multiple transfusions and chelate binding therapy in order to avoid iron accumulation. Settings and Design: A cross-sectional study. Subjects and Methods: A total of 54 thalassemia major patients were selected as case group, and 54 age- and sex-matched healthy subjects were regarded as a control group. Ocular examination included visual acuity, refraction testing, slit lamp examination, funduscopy, tonometry, perimetry, tear break-up time test, and color vision testing were performed for all the participants. We computed the frequency and duration of blood transfusion, the mean serum ferritin level, pretransfusion hemoglobin concentration, and type, duration, and daily dose of chelation therapy for thalassemia patients based on their records. Statistical Analysis Used: All data analysis was performed using SPSS, version 19. Results: All the thalassemic patients were asymptomatic, but abnormal ocular findings (dry eye (33.3%), cataract (10.2%), retinal pigment epithelium degeneration (16.7%), color vision deficiency (3.7%), and visual field defects (33.7%)) were seen in 68.5% of thalassemic group. The prevalence of ocular abnormalities in normal group was 19.4%, which was significantly lower than that in thalassemia patients (P = 0.000). No significant correlation was found between ocular abnormalities and mean serum ferritin level (P = 0.627) and mean hemoglobin concentration (P = 0.143). Correlation of number of blood transfusion with the presence of ocular abnormalities was found to be statistically significant (P = 0.005). Conclusions: As life expectancy for beta-thalassemia patients extends, regular ophthalmological evaluation to detect early changes in their ocular system is recommended. PMID:26632126

  20. Automatic generation of a retinal sensitivity map using infra-red fundus television images.

    PubMed

    Kawai, H; Tamura, S

    1989-01-01

    We have already developed an eye movement analyzing system using an infra-red television fundus camera. Although the quality of the fundus TV images is not good, the system can measure eye movement with an accuracy order of 0.1 degree. We try to apply this system to compensating for eye movements in producing a retinal sensitivity map. A target with variable brightness is presented to various positions on the retina of a subject through a CRT assembled in the infra-red TV fundus camera. The subject is supposed to respond if he can perceive the target. The TV image of the eye fundus, together with the overlaid target and response sign, is recorded on a U-matic (3/4 in) VTR. The image of the video tape is then analyzed by a computer. We have obtained retinal sensitivity maps which show good agreement with the results obtained using the Goldmann perimeter. PMID:2486764

  1. Advances in Image Processing Techniques for Drusens Detection and Quantification in Fundus Images

    NASA Astrophysics Data System (ADS)

    Mora, André; Vieira, Pedro; Fonseca, José

    Age-Related Macular Degeneration (ARMD) is considered the leading cause of irreversible blindness in developed countries. One of its risk factors is the presence of drusens, which are retina abnormalities appearing as yellowish spots in fundus images.

  2. Instrument for measuring the misalignments of ocular surfaces

    NASA Astrophysics Data System (ADS)

    Tabernero, Juan; Benito, Antonio; Nourrit, Vincent; Artal, Pablo

    2006-10-01

    A compact and robust instrument for measuring the alignment of ocular surfaces has been designed and used in living eyes. It is based on recording Purkinje images (reflections of light at the ocular surfaces) at nine different angular fixations. A complete analysis on the causes of misalignments of Purkinje images and its relations with those physical variables to be measured (global eye tilt, lens decentration and lens tilt) is presented. A research prototype based on these ideas was built and tested in normal and pseudophakic eyes (after cataract surgery). The new analysis techniques, together with the semicircular extended source and multiple fixation tests that we used, are significant improvements towards a robust approach to measuring the misalignments of the ocular surfaces in vivo. This instrument will be of use in both basic studies of the eye’s optics and clinical ophthalmology.

  3. A novel image recuperation approach for diagnosing and ranking retinopathy disease level using diabetic fundus image.

    PubMed

    Krishnamoorthy, Somasundaram; Alli, P

    2015-01-01

    Retinal fundus images are widely used in diagnosing and providing treatment for several eye diseases. Prior works using retinal fundus images detected the presence of exudation with the aid of publicly available dataset using extensive segmentation process. Though it was proved to be computationally efficient, it failed to create a diabetic retinopathy feature selection system for transparently diagnosing the disease state. Also the diagnosis of diseases did not employ machine learning methods to categorize candidate fundus images into true positive and true negative ratio. Several candidate fundus images did not include more detailed feature selection technique for diabetic retinopathy. To apply machine learning methods and classify the candidate fundus images on the basis of sliding window a method called, Diabetic Fundus Image Recuperation (DFIR) is designed in this paper. The initial phase of DFIR method select the feature of optic cup in digital retinal fundus images based on Sliding Window Approach. With this, the disease state for diabetic retinopathy is assessed. The feature selection in DFIR method uses collection of sliding windows to obtain the features based on the histogram value. The histogram based feature selection with the aid of Group Sparsity Non-overlapping function provides more detailed information of features. Using Support Vector Model in the second phase, the DFIR method based on Spiral Basis Function effectively ranks the diabetic retinopathy diseases. The ranking of disease level for each candidate set provides a much promising result for developing practically automated diabetic retinopathy diagnosis system. Experimental work on digital fundus images using the DFIR method performs research on the factors such as sensitivity, specificity rate, ranking efficiency and feature selection time. PMID:25974230

  4. Multimodal Retinal Vessel Segmentation from Spectral-Domain Optical Coherence Tomography and Fundus Photography

    PubMed Central

    Hu, Zhihong; Niemeijer, Meindert; Abràmoff, Michael D.; Garvin, Mona K.

    2014-01-01

    Segmenting retinal vessels in optic nerve head (ONH) centered spectral-domain optical coherence tomography (SD-OCT) volumes is particularly challenging due to the projected neural canal opening (NCO) and relatively low visibility in the ONH center. Color fundus photographs provide a relatively high vessel contrast in the region inside the NCO, but have not been previously used to aid the SD-OCT vessel segmentation process. Thus, in this paper, we present two approaches for the segmentation of retinal vessels in SD-OCT volumes that each take advantage of complimentary information from fundus photographs. In the first approach (referred to as the registered-fundus vessel segmentation approach), vessels are first segmented on the fundus photograph directly (using a k-NN pixel classifier) and this vessel segmentation result is mapped to the SD-OCT volume through the registration of the fundus photograph to the SD-OCT volume. In the second approach (referred to as the multimodal vessel segmentation approach), after fundus-to-SD-OCT registration, vessels are simultaneously segmented with a k-NN classifier using features from both modalities. Three-dimensional structural information from the intraretinal layers and neural canal opening obtained through graph-theoretic segmentation approaches of the SD-OCT volume are used in combination with Gaussian filter banks and Gabor wavelets to generate the features. The approach is trained on 15 and tested on 19 randomly chosen independent image pairs of SD-OCT volumes and fundus images from 34 subjects with glaucoma. Based on a receiver operating characteristic (ROC) curve analysis, the present registered-fundus and multimodal vessel segmentation approaches [area under the curve (AUC) of 0.85 and 0.89, respectively] both perform significantly better than the two previous OCT-based approaches (AUC of 0.78 and 0.83, p < 0.05). The multimodal approach overall performs significantly better than the other three approaches (p < 0

  5. A Novel Image Recuperation Approach for Diagnosing and Ranking Retinopathy Disease Level Using Diabetic Fundus Image

    PubMed Central

    2015-01-01

    Retinal fundus images are widely used in diagnosing and providing treatment for several eye diseases. Prior works using retinal fundus images detected the presence of exudation with the aid of publicly available dataset using extensive segmentation process. Though it was proved to be computationally efficient, it failed to create a diabetic retinopathy feature selection system for transparently diagnosing the disease state. Also the diagnosis of diseases did not employ machine learning methods to categorize candidate fundus images into true positive and true negative ratio. Several candidate fundus images did not include more detailed feature selection technique for diabetic retinopathy. To apply machine learning methods and classify the candidate fundus images on the basis of sliding window a method called, Diabetic Fundus Image Recuperation (DFIR) is designed in this paper. The initial phase of DFIR method select the feature of optic cup in digital retinal fundus images based on Sliding Window Approach. With this, the disease state for diabetic retinopathy is assessed. The feature selection in DFIR method uses collection of sliding windows to obtain the features based on the histogram value. The histogram based feature selection with the aid of Group Sparsity Non-overlapping function provides more detailed information of features. Using Support Vector Model in the second phase, the DFIR method based on Spiral Basis Function effectively ranks the diabetic retinopathy diseases. The ranking of disease level for each candidate set provides a much promising result for developing practically automated diabetic retinopathy diagnosis system. Experimental work on digital fundus images using the DFIR method performs research on the factors such as sensitivity, specificity rate, ranking efficiency and feature selection time. PMID:25974230

  6. Reproducibility of Neonate Ocular Circulation Measurements Using Laser Speckle Flowgraphy.

    PubMed

    Matsumoto, Tadashi; Itokawa, Takashi; Shiba, Tomoaki; Katayama, Yuji; Arimura, Tetsushi; Mizukaki, Norio; Yoda, Hitoshi; Hori, Yuichi

    2015-01-01

    Measuring the ocular blood flow in neonates may clarify the relationships between eye diseases and ocular circulation abnormalities. However, no method for noninvasively measuring ocular circulation in neonates is established. We used laser speckle flowgraphy (LSFG) modified for neonates to measure their ocular circulation and investigated whether this method is reproducible. During their normal sleep, we studied 16 subjects (adjusted age of 34-48 weeks) whose blood flow could be measured three consecutive times. While the subjects slept in the supine position, three mean blur rate (MBR) values of the optic nerve head (ONH) were obtained: the MBR-A (mean of all values), MBR-V (vessel mean), and MBR-T (tissue mean), and nine blood flow pulse waveform parameters in the ONH were examined. We analyzed the coefficient of variation (COV) and the intraclass correlation coefficient (ICC) for each parameter. The COVs of the MBR values were all ≤ 10%. The ICCs of the MBR values were all >0.8. Good COVs were observed for the blowout score, blowout time, rising rate, falling rate, and acceleration time index. Although the measurement of ocular circulation in the neonates was difficult, our results exhibited reproducibility, suggesting that this method could be used in clinical research. PMID:26557689

  7. Reproducibility of Neonate Ocular Circulation Measurements Using Laser Speckle Flowgraphy

    PubMed Central

    Matsumoto, Tadashi; Itokawa, Takashi; Shiba, Tomoaki; Katayama, Yuji; Arimura, Tetsushi; Mizukaki, Norio; Yoda, Hitoshi; Hori, Yuichi

    2015-01-01

    Measuring the ocular blood flow in neonates may clarify the relationships between eye diseases and ocular circulation abnormalities. However, no method for noninvasively measuring ocular circulation in neonates is established. We used laser speckle flowgraphy (LSFG) modified for neonates to measure their ocular circulation and investigated whether this method is reproducible. During their normal sleep, we studied 16 subjects (adjusted age of 34–48 weeks) whose blood flow could be measured three consecutive times. While the subjects slept in the supine position, three mean blur rate (MBR) values of the optic nerve head (ONH) were obtained: the MBR-A (mean of all values), MBR-V (vessel mean), and MBR-T (tissue mean), and nine blood flow pulse waveform parameters in the ONH were examined. We analyzed the coefficient of variation (COV) and the intraclass correlation coefficient (ICC) for each parameter. The COVs of the MBR values were all ≤10%. The ICCs of the MBR values were all >0.8. Good COVs were observed for the blowout score, blowout time, rising rate, falling rate, and acceleration time index. Although the measurement of ocular circulation in the neonates was difficult, our results exhibited reproducibility, suggesting that this method could be used in clinical research. PMID:26557689

  8. Ocular Motor Function in Patients with Bilateral Vestibular Weakness

    PubMed Central

    Ghazizadeh Hashemi, Seyyed Amir Hossein; Jafarzadeh, Sadegh; Haddadi Aval, Majid; Hosseinabadi, Reza

    2016-01-01

    Introduction: Patients with bilateral weakness (BW) have many difficulties in gaze stability that interfere with their normal function. The aim of this study was to evaluate ocular motor functions in patients with BW to better understand the problem of gaze instability in these patients. Materials and Methods: Patients were referred from the Otolaryngology Department for Vestibular Assessment to our clinic between November 2014 and March 2015. We assessed ocular motor function (gaze, saccade, and smooth pursuit) in patients over the age of 18 years with BW, as verified by a caloric test. Results: Seventy-eight patients completed all the tests. The mean age of patients was 51.9 (±15.9) years, and 47 (60%) were female. Abnormal results were found in five (6.4%), 32 (41%), and seven (9%) patients with respect to gaze, smooth pursuit, and saccade, respectively. There were positive but relatively weak relationships between age and ocular motor results. Conclusion: Patients with BW suffer from dizziness and unsteadiness. These patients have abnormal function in ocular motor (especially smooth pursuit) tests. The ocular motor dysfunction is responsible for gaze instability in static positions such as standing. PMID:27429945

  9. A Novel Device to Exploit the Smartphone Camera for Fundus Photography.

    PubMed

    Russo, Andrea; Morescalchi, Francesco; Costagliola, Ciro; Delcassi, Luisa; Semeraro, Francesco

    2015-01-01

    Purpose. To construct an inexpensive, convenient, and portable attachment for smartphones for the acquisition of still and live retinal images. Methods. A small optical device based on the principle of direct ophthalmoscopy was designed to be magnetically attached to a smartphone. Representative images of normal and pathological fundi were taken with the device. Results. A field-of-view up to ~20° was captured at a clinical resolution for each fundus image. The cross-polarization technique adopted in the optical design dramatically diminished corneal Purkinje reflections, making it possible to screen patients even through undilated pupils. Light emission proved to be well within safety limits. Conclusions. This optical attachment is a promising, inexpensive, and valuable alternative to the direct ophthalmoscope, potentially eliminating problems of poor exam skills and inexperienced observer bias. Its portability, together with the wireless connectivity of smartphones, presents a promising platform for screening and telemedicine in nonhospital settings. Translational Relevance. Smartphones have the potential to acquire retinal imaging for a portable ophthalmoscopy. PMID:26137320

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

    PubMed Central

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

    2015-01-01

    Purpose. To determine the diagnostic accuracy for glaucoma of a set of criteria with nonmydriatic monoscopic fundus photography (NMFP) in diabetics. Methods. Diabetics recruited from a screening program for diabetic retinopathy and diabetic glaucoma patients recruited from our glaucoma unit were included. Any patient with evidence of diabetic retinopathy was excluded. Diabetic patients had to have no visual field defects to be included as controls. Glaucoma patients had to have a glaucomatous field defect in at least one eye to be included. One NMFP was taken per eye for all subjects. These photographs were evaluated by two masked glaucoma specialists for the presence of the following: bilateral cup to disc (C/D) ratio ≥0.6, notching or thinning of the neuroretinal rim, disc hemorrhages, and asymmetry in the C/D ratio between both eyes ≥0.2. This evaluation led to a dichotomous classification: if any of the above criteria was present, the patient was classified as glaucoma. If none were present, the patient was classified as normal. Results. 72 control subjects and 72 glaucoma patients were included. Evaluation of NMFP had a sensitivity of 79.17% and a specificity of 80.56% for specialist 1 and a sensitivity of 72.22% and a specificity of 88.88% for specialist 2 for the detection of glaucoma. The overall accuracy was 79.83% and 80.55%, respectively. Discussion. NMFP evaluation by a glaucoma specialist may be useful for the detection of glaucoma in diabetics. PMID:26557709

  11. A Novel Device to Exploit the Smartphone Camera for Fundus Photography

    PubMed Central

    Morescalchi, Francesco; Semeraro, Francesco

    2015-01-01

    Purpose. To construct an inexpensive, convenient, and portable attachment for smartphones for the acquisition of still and live retinal images. Methods. A small optical device based on the principle of direct ophthalmoscopy was designed to be magnetically attached to a smartphone. Representative images of normal and pathological fundi were taken with the device. Results. A field-of-view up to ~20° was captured at a clinical resolution for each fundus image. The cross-polarization technique adopted in the optical design dramatically diminished corneal Purkinje reflections, making it possible to screen patients even through undilated pupils. Light emission proved to be well within safety limits. Conclusions. This optical attachment is a promising, inexpensive, and valuable alternative to the direct ophthalmoscope, potentially eliminating problems of poor exam skills and inexperienced observer bias. Its portability, together with the wireless connectivity of smartphones, presents a promising platform for screening and telemedicine in nonhospital settings. Translational Relevance. Smartphones have the potential to acquire retinal imaging for a portable ophthalmoscopy. PMID:26137320

  12. Retinal nerve fiber layer retardation measurements using a polarization-sensitive fundus camera

    NASA Astrophysics Data System (ADS)

    Fukuma, Yasufumi; Okazaki, Yoshio; Shioiri, Takashi; Iida, Yukio; Kikuta, Hisao; Shirakashi, Motohiro; Yaoeda, Kiyoshi; Abe, Haruki; Ohnuma, Kazuhiko

    2011-07-01

    To measure the retardation distribution of the optic retinal nerve fiber layer (RNFL) from a single image, we have developed a new polarization analysis system that is able to detect the Stokes vector using a fundus camera. The polarization analysis system is constructed with a CCD area image sensor, a linear polarizing plate, a microphase plate array, and a circularly polarized light illumination unit. In this system, the Stokes vector expressing the whole state of polarization is detected, and the influence of the background scattering in the retina and of the retardation caused by the cornea are numerically eliminated. The measurement method is based on the hypothesis that the retardation process of the eye optics can be quantified by a numerical equation that consists of a retardation matrix of all the polarization components. We show the method and the measurement results for normal eyes. Our results indicate that the present method may provide a useful means for the evaluation of retardation distribution of the RNFL.

  13. The Role of Fundus Autofluorescence in Late-Onset Retinitis Pigmentosa (LORP) Diagnosis

    PubMed Central

    Lee, Tamara J.; Hwang, John C.; Chen, Royce W. S.; Lima, Luiz H.; Wang, Nan-Kai; Tosi, Joaquin; Freund, K. Bailey; Yannuzzi, Lawrence A.; Tsang, Stephen H.

    2015-01-01

    Purpose To demonstrate the utility and characteristics of fundus autofluorescence in late-onset retinitis pigmentosa. Methods Observational case series. Patients diagnosed with late-onset retinitis pigmentosa were identified retrospectively in an institutional setting. Twelve eyes of six patients were identified and medical records were reviewed. Results All patients presented with slowly progressive peripheral field loss and initial clinical examination revealed only subtle retinal changes. There was a notable lack of intraretinal pigment migration in all patients. Five out of six patients underwent magnetic resonance imaging of the brain to rule out intracranial processes and all were referred from another ophthalmologist for further evaluation. Fundus autofluorescence was ultimately employed in all patients and revealed more extensive retinal pathology than initially appreciated on clinical examination. Fundus autofluorescence directed the workup toward a retinal etiology in all cases and led to the eventual diagnosis of late-onset retinitis pigmentosa through electroretinogram testing. Conclusion Fundus autofluorescence may be a more sensitive marker for retinal pathology than stereo fundus biomicroscopy alone in late-onset retinitis pigmentosa. Early use of fundus autofluorescence imaging in the evaluation of patients with subtle retinal lesions and complaints of peripheral field loss may be an effective strategy for timely and cost-efficient diagnosis. PMID:23899229

  14. Quantitative Fundus Autofluorescence for the Evaluation of Retinal Diseases.

    PubMed

    Armenti, Stephen T; Greenberg, Jonathan P; Smith, R Theodore

    2016-01-01

    The retinal pigment epithelium (RPE) is juxtaposed to the overlying sensory retina, and supports the function of the visual system. Among the tasks performed by the RPE are phagocytosis and processing of outer photoreceptor segments through lysosome-derived organelles. These degradation products, stored and referred to as lipofuscin granules, are composed partially of bisretinoids, which have broad fluorescence absorption and emission spectra that can be detected clinically as fundus autofluorescence with confocal scanning laser ophthalmoscopy (cSLO). Lipofuscin accumulation is associated with increasing age, but is also found in various patterns in both acquired and inherited degenerative diseases of the retina. Thus, studying its pattern of accumulation and correlating such patterns with changes in the overlying sensory retina are essential to understanding the pathophysiology and progression of retinal disease. Here, we describe a technique employed by our lab and others that uses cSLO in order to quantify the level of RPE lipofuscin in both healthy and diseased eyes. PMID:27023389

  15. Multispectral fundus imaging for early detection of diabetic retinopathy

    NASA Astrophysics Data System (ADS)

    Beach, James M.; Tiedeman, James S.; Hopkins, Mark F.; Sabharwal, Yashvinder S.

    1999-04-01

    Functional imaging of the retina and associated structures may provide information for early assessment of risks of developing retinopathy in diabetic patients. Here we show results of retinal oximetry performed using multi-spectral reflectance imaging techniques to assess hemoglobin (Hb) oxygen saturation (OS) in blood vessels of the inner retina and oxygen utilization at the optic nerve in diabetic patients without retinopathy and early disease during experimental hyperglycemia. Retinal images were obtained through a fundus camera and simultaneously recorded at up to four wavelengths using image-splitting modules coupled to a digital camera. Changes in OS in large retinal vessels, in average OS in disk tissue, and in the reduced state of cytochrome oxidase (CO) at the disk were determined from changes in reflectance associated with the oxidation/reduction states of Hb and CO. Step to high sugar lowered venous oxygen saturation to a degree dependent on disease duration. Moderate increase in sugar produced higher levels of reduced CO in both the disk and surrounding tissue without a detectable change in average tissue OS. Results suggest that regulation of retinal blood supply and oxygen consumption are altered by hyperglycemia and that such functional changes are present before clinical signs of retinopathy.

  16. Robust Multiscale Stereo Matching from Fundus Images with Radiometric Differences

    PubMed Central

    Tang, Li; Garvin, Mona K.; Lee, Kyungmoo; Alward, Wallace L.M.; Kwon, Young H.; Abràmoff, Michael D.

    2013-01-01

    A robust multiscale stereo matching algorithm is proposed to find reliable correspondences between low contrast and weakly textured retinal image pairs with radiometric differences. Existing algorithms designed to deal with piecewise planar surfaces with distinct features and Lambertian reflectance do not apply in applications such as 3D reconstruction of medical images including stereo retinal images. In this paper, robust pixel feature vectors are formulated to extract discriminative features in the presence of noise in scale space, through which the response of low-frequency mechanisms alter and interact with the response of high-frequency mechanisms. The deep structures of the scene are represented with the evolution of disparity estimates in scale space, which distributes the matching ambiguity along the scale dimension to obtain globally coherent reconstructions. The performance is verified both qualitatively by face validity and quantitatively on our collection of stereo fundus image sets with ground truth, which have been made publicly available as an extension of standard test images for performance evaluation. PMID:21464502

  17. Yellowish dots in the retina: a finding of ocular syphilis?

    PubMed

    Rodrigues, Renan Albert Mendonça; Nascimento, Heloisa Moraes do; Muccioli, Cristina

    2014-10-01

    Here we report the occurrence of pale yellowish perivascular preretinal dots in 12 patients with ocular syphilis. A case series of these patients was examined between March and October 2012 at the Uveitis Sector of Universidade Federal de São Paulo. After diagnostic confirmation of syphilis, fundus photographs and optical coherence tomography (OCT) were performed to verify the localization of the dots, and patients were treated with IV crystalline penicillin for 14 days. The study comprised 11 men (91.6%), 19 eyes, median presentation age of 38.1 years, and panuveitis as the main clinical manifestation (seven patients, 58.3%), being bilateral in four. Ten patients were taking oral prednisone (83.3%). Serum panels performed by the Venereal Disease Research Laboratory (VDRL) showed positive results in eight patients (66.7%), whereas VDRL cerebrospinal fluid (CSF) tests were negative in seven of nine collected (77.8%). However, serum FTA-Abs was positive in 100% of patients, and eight patients (66.7%) had HIV infection. The best corrected visual acuity (BCVA) presented after treatment improved in 10 eyes (55.6%), did not change in seven eyes (38.9%), and worsened in one eye (5.6%). Although not yet acknowledged in the literature as a typical manifestation of ocular syphilis, these are very common findings in clinical practice. We believe that preretinal dots are due to perivasculitis secondary to treponema infection. It is important recognize them and remember that syphilis can present in several forms, including the one presented in this study. PMID:25494381

  18. Ocular Health and Safety Assessment among Mechanics of the Cape Coast Metropolis, Ghana

    PubMed Central

    Abu, Emmanuel Kwasi; Boadi-Kusi, Samuel Bert; Opuni, Prince Quarcoo; Kyei, Samuel; Owusu-Ansah, Andrew; Darko-Takyi, Charles

    2016-01-01

    Purpose: To conduct an ocular health and safety assessment among mechanics in the Cape Coast Metropolis, Ghana. Methods: This descriptive cross sectional study included 500 mechanics using multistage sampling. All participants filled a structured questionnaire on demographic data, occupational history and ocular health history. Study participants underwent determination of visual acuity (VA) using LogMAR chart, external eye examination with a handheld slit lamp biomicroscope, dilated fundus examination, applanation tonometry and refraction. Results: Out of 500 mechanics, 433 were examined (response rate, 87%) comprised of 408 (94.2%) male and 25 (5.8%) female subjects. The prevalence of visual impairment (i.e. presenting VA < 6/18) among the respondents was 2.1%. Eye injuries were reported in 171 (39.5%) mechanics probably due to the large number of workers, 314 (72.5%), who did not use eye protective devices. Mechanics in the auto welding category were at the highest risk of sustaining an eye injury (odds ratio [OR], 13.4; P < 0.001). Anterior segment ocular disorders were mostly pterygia while posterior segment eye disorders included glaucoma suspects and retinochoroidal lesions. The development of pterygia was associated with the number of years a mechanic stayed on the job. Eye care seeking behavior among the participants was poor. Conclusion: Eye injuries were prevalent among the mechanics as the use of eye protection was low. Eye safety should be made an integral part of the public health agenda in the Cape Coast Metropolis. PMID:27195090

  19. Comparison of Structural and Functional Ocular Outcomes Between 14- and 70 Day Bed Rest

    NASA Technical Reports Server (NTRS)

    Cromwell, R. L.; Taibbi, G.; Zanello, S. B.; Yarbough, P. O.; Ploutz-Snyder, R. J.; Vizzeri, G.

    2016-01-01

    Purpose: To compare structural and functional ocular outcomes in healthy human subjects undergoing 14- and/or 70-day head-down-tilt bed rest (HDTBR). We hypothesized the amount of HDTBR-induced ocular changes be affected by the HDTBR duration. Methods: The studies were conducted at the NASA Flight Analogs Research Unit, The University of Texas Medical Branch at Galveston, Galveston, TX. Participants were selected using NASA standard screening procedures. Standardized NASA screening procedures and bed rest conditions (e.g., strict sleep-wake cycle, standardized diet, continuous video monitoring) were implemented in both studies. Participants maintained a 6deg HDTBR position for 14 and/or 70 consecutive days and did not engage in exercise. Weekly ophthalmological examinations were conducted in the sitting (pre/post-bed rest only) and HDT positions. Ocular outcomes of interest included: near best-corrected visual acuity (BCVA); spherical equivalent, as determined by cycloplegic autorefraction; Goldmann applanation tonometry and iCare (Icare Finland Oy, Espoo, Finland) intraocular pressure (IOP) measurement; color vision; red dot test; modified Amsler grid test; confrontational visual field; stereoscopic color fundus photography; Spectralis OCT (Heidelberg Engineering, GmbH, Heidelberg, Germany) retinal nerve fiber layer thickness (RNFLT), peripapillary and macular retinal thicknesses. Mixed-effects linear models were used to compare pre- and post-HDTBR observations between 14- and 70-day HDTBR for our continuously scaled outcomes.

  20. Fundus oculi pigmentation studies simulating the fs-LASIK process Fundus oculi pigmentation studies simulating the fs-LASIK process

    NASA Astrophysics Data System (ADS)

    Sander, M.; Minet, O.; Zabarylo, U.; Müller, M.; Tetz, M. R.

    2012-06-01

    The femtosecond-laser in situ keratomileusis (fs-LASIK) technique has successfully entered the refractive surgery market to correct ametropia by cutting transparent corneal tissue with ultra-short laser pulses based on photodisruption. The laser pulses in the near infrared range (NIR) generate a laser-induced breakdown (LIOB) in the cornea. By propagating through the eye, a certain amount of the pulse is deposited in the cornea and the remaining energy interacts with the strong absorbing tissue behind. Due to the absorption by the retinal pigment epithelium and the transfer of the thermal energy to surrounding tissue, the transmitted energy can induce damage to the retina. The aim of this project was to find out the threshold influences concerning the tissue and the correlation between the results of the macroscopical appraisal and the fundus oculi pigmentation by simulating the fs-LASIK procedure with two various laser systems in the continuous wave (CW) and fs-regime. Therefore ex-vivo determinations were carried out macroscopically and histopathologically on porcine tissue.

  1. Endothelial TWIST1 Promotes Pathological Ocular Angiogenesis

    PubMed Central

    Li, Jie; Liu, Chi-Hsiu; Sun, Ye; Gong, Yan; Fu, Zhongjie; Evans, Lucy P.; Tian, Katherine T.; Juan, Aimee M.; Hurst, Christian G.; Mammoto, Akiko; Chen, Jing

    2014-01-01

    Purpose. Pathological neovessel formation impacts many blinding vascular eye diseases. Identification of molecular signatures distinguishing pathological neovascularization from normal quiescent vessels is critical for developing new interventions. Twist-related protein 1 (TWIST1) is a transcription factor important in tumor and pulmonary angiogenesis. This study investigated the potential role of TWIST1 in modulating pathological ocular angiogenesis in mice. Methods. Twist1 expression and localization were analyzed in a mouse model of oxygen-induced retinopathy (OIR). Pathological ocular angiogenesis in Tie2-driven conditional Twist1 knockout mice were evaluated in both OIR and laser-induced choroidal neovascularization models. In addition, the effects of TWIST1 on angiogenesis and endothelial cell function were analyzed in sprouting assays of aortic rings and choroidal explants isolated from Twist1 knockout mice, and in human retinal microvascular endothelial cells treated with TWIST1 small interfering RNA (siRNA). Results. TWIST1 is highly enriched in pathological neovessels in OIR retinas. Conditional Tie2-driven depletion of Twist1 significantly suppressed pathological neovessels in OIR without impacting developmental retinal angiogenesis. In a laser-induced choroidal neovascularization model, Twist1 deficiency also resulted in significantly smaller lesions with decreased vascular leakage. In addition, loss of Twist1 significantly decreased vascular sprouting in both aortic ring and choroid explants. Knockdown of TWIST1 in endothelial cells led to dampened expression of vascular endothelial growth factor receptor 2 (VEGFR2) and decreased endothelial cell proliferation. Conclusions. Our study suggests that TWIST1 is a novel regulator of pathologic ocular angiogenesis and may represent a new molecular target for developing potential therapeutic treatments to suppress pathological neovascularization in vascular eye diseases. PMID:25414194

  2. Purinergic Receptors in Ocular Inflammation

    PubMed Central

    Guzman-Aranguez, Ana; Gasull, Xavier; Diebold, Yolanda; Pintor, Jesús

    2014-01-01

    Inflammation is a complex process that implies the interaction between cells and molecular mediators, which, when not properly “tuned,” can lead to disease. When inflammation affects the eye, it can produce severe disorders affecting the superficial and internal parts of the visual organ. The nucleoside adenosine and nucleotides including adenine mononucleotides like ADP and ATP and dinucleotides such as P1,P4-diadenosine tetraphosphate (Ap4A), and P1,P5-diadenosine pentaphosphate (Ap5A) are present in different ocular locations and therefore they may contribute/modulate inflammatory processes. Adenosine receptors, in particular A2A adenosine receptors, present anti-inflammatory action in acute and chronic retinal inflammation. Regarding the A3 receptor, selective agonists like N6-(3-iodobenzyl)-5′-N-methylcarboxamidoadenosine (CF101) have been used for the treatment of inflammatory ophthalmic diseases such as dry eye and uveoretinitis. Sideways, diverse stimuli (sensory stimulation, large intraocular pressure increases) can produce a release of ATP from ocular sensory innervation or after injury to ocular tissues. Then, ATP will activate purinergic P2 receptors present in sensory nerve endings, the iris, the ciliary body, or other tissues surrounding the anterior chamber of the eye to produce uveitis/endophthalmitis. In summary, adenosine and nucleotides can activate receptors in ocular structures susceptible to suffer from inflammatory processes. This involvement suggests the possible use of purinergic agonists and antagonists as therapeutic targets for ocular inflammation. PMID:25132732

  3. Radiotherapy for ocular tumours.

    PubMed

    Stannard, C; Sauerwein, W; Maree, G; Lecuona, K

    2013-02-01

    Ocular tumours present a therapeutic challenge because of the sensitive tissues involved and the necessity to destroy the tumour while minimising visual loss. Radiotherapy (RT) is one of several modalites used apart from surgery, laser, cryotherapy, and chemotherapy. Both external beam RT (EBRT) and brachytherapy are used. Tumours of the bulbar conjunctiva, squamous carcinoma and malignant melanoma, can be treated with a radioactive plaque: strontium-90, ruthenium-106 (Ru-106), or iodine-125 (I-125), after excision. If the tumour involves the fornix or tarsal conjunctiva, proton therapy can treat the conjunctiva and spare most of the eye. Alternatively, an I-125 interstitial implant can be used with shielding of the cornea and lens. Conjunctival mucosal-associated lymphoid tissue lymphoma can be treated with an anterior electron field with lens shielding and 25-30 Gray (Gy) in 2 Gy fractions. Discrete retinoblastoma (RB), too large for cryotherapy or thermolaser, or recurrent after these modalities, can be treated with plaque therapy, I-125, or Ru-106. For large RB, multiple tumours, or vitreous seeds the whole eye can be treated with an I-125 applicator, sparing the bony orbit, or with EBRT, under anaesthetic, using X-rays or proton therapy with vacuum contact lenses to fix the eyes in the required position. Post-enucleated orbits at risk for recurrent RB can be treated with an I-125 implant with shielding to reduce the dose to the bony orbit. Uveal malignant melanomas can be treated with plaque or proton therapy with excellent local control. Preservation of vision will depend on the initial size and location of the tumour. PMID:23174750

  4. Radiotherapy for ocular tumours

    PubMed Central

    Stannard, C; Sauerwein, W; Maree, G; Lecuona, K

    2013-01-01

    Ocular tumours present a therapeutic challenge because of the sensitive tissues involved and the necessity to destroy the tumour while minimising visual loss. Radiotherapy (RT) is one of several modalites used apart from surgery, laser, cryotherapy, and chemotherapy. Both external beam RT (EBRT) and brachytherapy are used. Tumours of the bulbar conjunctiva, squamous carcinoma and malignant melanoma, can be treated with a radioactive plaque: strontium-90, ruthenium-106 (Ru-106), or iodine-125 (I-125), after excision. If the tumour involves the fornix or tarsal conjunctiva, proton therapy can treat the conjunctiva and spare most of the eye. Alternatively, an I-125 interstitial implant can be used with shielding of the cornea and lens. Conjunctival mucosal-associated lymphoid tissue lymphoma can be treated with an anterior electron field with lens shielding and 25–30 Gray (Gy) in 2 Gy fractions. Discrete retinoblastoma (RB), too large for cryotherapy or thermolaser, or recurrent after these modalities, can be treated with plaque therapy, I-125, or Ru-106. For large RB, multiple tumours, or vitreous seeds the whole eye can be treated with an I-125 applicator, sparing the bony orbit, or with EBRT, under anaesthetic, using X-rays or proton therapy with vacuum contact lenses to fix the eyes in the required position. Post-enucleated orbits at risk for recurrent RB can be treated with an I-125 implant with shielding to reduce the dose to the bony orbit. Uveal malignant melanomas can be treated with plaque or proton therapy with excellent local control. Preservation of vision will depend on the initial size and location of the tumour. PMID:23174750

  5. Ocular Decompression Retinopathy Following Canaloplasty for Primary Open Angle Glaucoma

    PubMed Central

    Li, Gai-yun; Alantaree, Samer; Wang, Jun-ming; Zhang, Hong

    2016-01-01

    Abstract Ocular decompression retinopathy (ODR), a rare postoperative complication following glaucoma surgery, is characterized by the transient appearance of scattered retinal hemorrhages. Here, we present a unique case of ODR in a patient with primary open angle glaucoma who underwent canaloplasty. A 31-year-old male patient presented with an intraocular pressure (IOP) of 60 mm Hg in the right eye. The IOP remained over 40 mm Hg, even when treated with maximum tolerated antiglaucoma medication. Canaloplasty drastically lowered IOP in the right eye from 40 to 7 mm Hg. However, fundus examination revealed ODR after surgery. The patient was treated with tobramycin and dexamethasone. Three months after canaloplasty, IOP remained in control at 16 mm Hg and all retinal hemorrhages had completely resolved. This case demonstrates that ODR can occur following canaloplasty and physicians should be aware of this potential complication in patients with severely elevated IOP. Sufficiently lowering IOP before surgery and gradually decreasing IOP during surgery may prevent ODR from occurring. PMID:26945386

  6. The Tennessee Mouse Genome Consortium: Identification of ocular mutants

    SciTech Connect

    Jablonski, Monica M.; Wang, Xiaofei; Lu, Lu; Miller, Darla R; Rinchik, Eugene M; Williams, Robert; Goldowitz, Daniel

    2005-06-01

    The Tennessee Mouse Genome Consortium (TMGC) is in its fifth year of a ethylnitrosourea (ENU)-based mutagenesis screen to detect recessive mutations that affect the eye and brain. Each pedigree is tested by various phenotyping domains including the eye, neurohistology, behavior, aging, ethanol, drug, social behavior, auditory, and epilepsy domains. The utilization of a highly efficient breeding protocol and coordination of various universities across Tennessee makes it possible for mice with ENU-induced mutations to be evaluated by nine distinct phenotyping domains within this large-scale project known as the TMGC. Our goal is to create mutant lines that model human diseases and disease syndromes and to make the mutant mice available to the scientific research community. Within the eye domain, mice are screened for anterior and posterior segment abnormalities using slit-lamp biomicroscopy, indirect ophthalmoscopy, fundus photography, eye weight, histology, and immunohistochemistry. As of January 2005, we have screened 958 pedigrees and 4800 mice, excluding those used in mapping studies. We have thus far identified seven pedigrees with primary ocular abnormalities. Six of the mutant pedigrees have retinal or subretinal aberrations, while the remaining pedigree presents with an abnormal eye size. Continued characterization of these mutant mice should in most cases lead to the identification of the mutated gene, as well as provide insight into the function of each gene. Mice from each of these pedigrees of mutant mice are available for distribution to researchers for independent study.

  7. 21 CFR 886.1040 - Ocular esthesiometer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1040 Ocular esthesiometer. (a) Identification. An ocular esthesiometer is a device, such as a single-hair brush, intended to touch the cornea...

  8. 21 CFR 886.1040 - Ocular esthesiometer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1040 Ocular esthesiometer. (a) Identification. An ocular esthesiometer is a device, such as a single-hair brush, intended to touch the cornea...

  9. 21 CFR 886.1040 - Ocular esthesiometer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1040 Ocular esthesiometer. (a) Identification. An ocular esthesiometer is a device, such as a single-hair brush, intended to touch the cornea...

  10. 21 CFR 886.1040 - Ocular esthesiometer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1040 Ocular esthesiometer. (a) Identification. An ocular esthesiometer is a device, such as a single-hair brush, intended to touch the cornea...

  11. Ocular Immune Privilege and Transplantation

    PubMed Central

    Taylor, Andrew W.

    2016-01-01

    Allografts are afforded a level of protection from rejection within immune-privileged tissues. Immune-privileged tissues involve mechanisms that suppress inflammation and promote immune tolerance. There are anatomical features, soluble factors, membrane-associated proteins, and alternative antigen-presenting cells (APC) that contribute to allograft survival in the immune-privileged tissue. This review presents the current understanding of how the mechanism of ocular immune privilege promotes tolerogenic activity by APC, and T cells in response to the placement of foreign antigen within the ocular microenvironment. Discussed will be the unique anatomical, cellular, and molecular mechanisms that lessen the chance for graft destroying immune responses within the eye. As more is understood about the molecular mechanisms of ocular immune privilege greater is the potential for using these molecular mechanisms in therapies to prevent allograft rejection. PMID:26904026

  12. [Ocular immune reconstitution inflammatory syndrome].

    PubMed

    Ma, N; Ye, J J

    2016-02-11

    Immune reconstitution inflammatory syndrome (IRIS) is a collection of inflammatory disorders associated with paradoxical worsening of preexisting infectious processes or emerging diseases or even dead after the initiation of highly active antiretroviral therapy (HAART) in human immunodeficiency virus (HIV) infected individuals in a period of recovery of immune function. Ocular immune reconstitution inflammatory syndrome is mainly caused by cytomegalovirus which performing a series of ocular inflammation accompanied with the increase of CD4+ T lymphocytes, such as cytomegalovirus retinitis, after HAART. With HAART widely used, the patients of IRIS gradually increased. But the clinical presentations of IRIS were various because of different pathogens. This review summarized the clinical manifestations, risk factors, diagnosis and treatment of ocular IRIS.(Chin J Ophthalmol, 2016, 51: 150-153). PMID:26906710

  13. Air bags and ocular injuries.

    PubMed Central

    Stein, J D; Jaeger, E A; Jeffers, J B

    1999-01-01

    PURPOSE: This investigation retrospectively examined ocular injuries associated with air bag deployment to gain a better appreciation of potential risk factors in motor vehicle accidents. National statistics regarding the efficacy of air bags were reviewed. METHODS: Review of the literature from 1991 to 1998 identified 44 articles describing 97 patients with air-bag-induced ocular injuries. Variables extracted from each case were age, sex, height, position in the car, eye wear, vehicle impact speed, visual acuity, and specific ocular injuries. RESULTS: Corneal abrasions occurred in 49% of occupants, hyphemas in 43%, vitreous or retinal hemorrhages in 25%, and retinal tears or detachments in 15%. The globe was ruptured in 10 patients. Patients involved in higher-speed accidents (over 30 mph) sustained a greater percentage of vitreous or retinal hemorrhages and traumatic cataracts, while those at slower speeds were more prone to retinal tears or detachments. In a subset of 14 patients with serious ocular injuries, the impact speed of 11 patients was recorded at 30 mph or less. Slower speed may be a risk factor for some ocular injuries. Occupant height was not a significant factor. National statistics confirm that air bags reduce fatalities in motor vehicle accidents. However, children sitting in the front seat without a seat belt and infants in passenger-side rear-facing car seats are at risk for fatal injury. CONCLUSION: Air bags combined with seat belts are an effective means of reducing injury and death in adults during motor vehicle accidents. However, this study has documented a wide variety of ocular injuries associated with air bag deployment. It is hoped that researchers can develop modifications that continue to save lives while minimizing additional harm. Images FIGURE 1 FIGURE 2A FIGURE 2B FIGURE 2C FIGURE 2D FIGURE 3A FIGURE 3B FIGURE 4 FIGURE 5 FIGURE 7 FIGURE 8 PMID:10703118

  14. [Adverse ocular effects of vaccinations].

    PubMed

    Ness, T; Hengel, H

    2016-07-01

    Vaccinations are very effective measures for prevention of infections but are also associated with a long list of possible side effects. Adverse ocular effects following vaccination have been rarely reported or considered to be related to vaccinations. Conjunctivitis is a frequent sequel of various vaccinations. Oculorespiratory syndrome and serum sickness syndrome are considered to be related to influenza vaccinations. The risk of reactivation or initiation of autoimmune diseases (e. g. uveitis) cannot be excluded but has not yet been proven. Overall the benefit of vaccination outweighs the possible but very low risk of ocular side effects. PMID:27357302

  15. Tear evaporation from the ocular surface.

    PubMed

    Tsubota, K; Yamada, M

    1992-09-01

    A simple method was developed to measure tear evaporation. A sensor was inserted into a chamber covering the eye. The humidity inside each chamber then was measured every 10 sec for 2 min with both eyes either closed or open but allowing normal blinking. The difference between these conditions represented evaporation from the ocular surface. Using this method, the tear evaporation rate at 40% ambient humidity (TEROS 40) was calculated. The average TEROS 40 in normal subjects (n = 43) was 15.6 +/- 3.8 x 10(-7) g/sec. It was 9.5 +/- 5.6 x 10(-7) g/sec in patients with dry eye symptoms (n = 72, P less than 0.001). The insertion of lacrimal collagen implants in one group of such patients (n = 10) increased the TEROS 40 from 10.2 +/- 5.5 x 10(-7) g/sec to 18.2 +/- 4.8 x 10(-7) g/sec (P less than 0.01). The instillation of eye drops increased the TEROS 40 significantly in patients with dry eye symptoms for at least 1 min (n = 10, P less than 0.01); a continued effect depended on the type of eye drop. Increased TEROS 40 still was observed 5 min after instillation of viscous eye drops (0.1% and 0.3% sodium hyaluronic acid); the TEROS 40 returned to original levels within 5 min after instillation of artificial tears of normal viscosity with or without 0.05% sodium hyaluronate. In all cases, TEROS 40 returned to original levels within 10 min. This was a quick reliable method for measuring tear evaporation from the ocular surface, and it can be applied to evaluate tear dynamics and subclassifications of dry eyes. PMID:1526744

  16. Ocular accommodative changes in humans induced by positional changes with respect to gravity

    NASA Technical Reports Server (NTRS)

    Markham, C. H.; Diamond, S. G.; Simpson, N. E.

    1977-01-01

    Results are presented for an experimental study concerning ocular accommodation measurements in normal human subjects while they were rotated at a speed of 1 deg/sec about their naso-occipital axis. A few rotations were done about an interaural axis. It is shown that altering the head position with respect to gravity is followed by a change in ocular refraction, with the major change being in a lens-thickening or accommodative direction. Reasons for ascribing these changes to reflex changes in ocular accommodation are given. Arguments are presented relating this accommodative response to the utricles, which are nearly parallel to the earth horizontal.

  17. 21 CFR 886.1040 - Ocular esthesiometer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ocular esthesiometer. 886.1040 Section 886.1040...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1040 Ocular esthesiometer. (a) Identification. An ocular esthesiometer is a device, such as a single-hair brush, intended to touch the cornea...

  18. Automatic detection of age-related macular degeneration pathologies in retinal fundus images.

    PubMed

    Güven, Ayşegül

    2013-04-01

    Advanced techniques in image processing and analysis are being extensively studied to assist clinical diagnoses. Digital colour retinal fundus images are widely utilised to investigate various eye diseases. In this paper, we describe the detection of optic disc (OD), macula and age-related macular degeneration (ARMD) pathologies of the macular regions in colour fundus images. ARMD causes the loss of central vision in older adults. If the disease is detected early and treated promptly, much of the vision loss can be prevented. Eighty colour retinal fundus images were tested using our proposed algorithm. The Hough transform was employed for OD determination. A fundus coordinate system was established based on the macula location. An ARMD pathology detection methodology using a subtraction process after contrast-limited adaptive histogram equalisation operations was proposed. The accuracies of the automated segmentations of the OD, macula and ARMD pathologies obtained were 100%, 100% and 95.49%, respectively. These results show that our algorithm is a useful tool for detecting ARMD in retinal fundus images. The application of our method may reduce the time needed by ophthalmologists to diagnose ARMD pathology while providing dependable detection precision. Integration of our technique into traditional software could be used in clinical implementations as an aid in disease diagnosis and as a tool for quantitative evaluation of treatment effectiveness. PMID:22372623

  19. Diagnosing and Ranking Retinopathy Disease Level Using Diabetic Fundus Image Recuperation Approach

    PubMed Central

    Somasundaram, K.; Alli Rajendran, P.

    2015-01-01

    Retinal fundus images are widely used in diagnosing different types of eye diseases. The existing methods such as Feature Based Macular Edema Detection (FMED) and Optimally Adjusted Morphological Operator (OAMO) effectively detected the presence of exudation in fundus images and identified the true positive ratio of exudates detection, respectively. These mechanically detected exudates did not include more detailed feature selection technique to the system for detection of diabetic retinopathy. To categorize the exudates, Diabetic Fundus Image Recuperation (DFIR) method based on sliding window approach is developed in this work to select the features of optic cup in digital retinal fundus images. The DFIR feature selection uses collection of sliding windows with varying range to obtain the features based on the histogram value using Group Sparsity Nonoverlapping Function. Using support vector model in the second phase, the DFIR method based on Spiral Basis Function effectively ranks the diabetic retinopathy disease level. The ranking of disease level on each candidate set provides a much promising result for developing practically automated and assisted diabetic retinopathy diagnosis system. Experimental work on digital fundus images using the DFIR method performs research on the factors such as sensitivity, ranking efficiency, and feature selection time. PMID:25945362

  20. Evidence suggesting individual ocular motor control of each eye (muscle).

    PubMed

    Dell'Osso, L F

    1994-01-01

    Current models of the ocular motor system are usually presented in their most reduced form, are unilateral in architecture, and precise yoking is presumed. Although this simplifies the models, it does not accurately simulate the actual neuroanatomy and limits the models to simple, stereotyped responses. Studies of normal humans and monkeys have demonstrated striking disconjugacies in normal responses. Normal saccades may be disconjugate, or 1 eye may exhibit a dynamic overshoot. Asymmetric vergence can result in disconjugate saccades, unequal magnification spectacles cause differential saccadic gain adjustment, and saccades to unequal disparities also cause unequal saccades in the 2 eyes. In strabismus, deviated eyes typically do not mimic the movements of the fixating eye nor do their latent or congenital nystagmus waveforms duplicate those of the fixating eye. In spasmus nutans, each eye oscillates independently of the other. In achiasmatic dogs, uni-ocular saccades and uni-ocular nystagmus waveforms are seen; the same may be true in human achiasma. These data from both normals and those with abnormalities suggest that current models for ocular motor control are inadequate representations of the actual system. The inability of unilateral, yoked control (or even bilateral, yoked control) system models to duplicate the ocular motor responses of binocular mammals suggests that their ocular motor systems evolved from the bilateral, independent control systems seen in chameleons. One need only postulate a yoking overlay superimposed on two independent control systems to achieve conjugacy (bilateral, yoked, independent control) of the eyes. Abnormalities producing grossly disconjugate eye movements may then be simulated using the independent control of each eye released by a deficiency in the yoking overlay. Independent control of each eye coupled with the essential bilateral brain stem architecture implies that each individual muscle is driven by independent

  1. The significance of some observations on African ocular onchocerciasis described by Jean Hissette (1888-1965).

    PubMed

    Kluxen, G; Hoerauf, A

    2008-01-01

    One of the most significant contributions to tropical medicine and ophthalmology was made by Jean Hissette: African ocular onchocerciasis. During his extensive investigations in the Babindi country, he found numerous adults with river blindness. Their eye disease was caused by the filaria Onchocerca volvulus Leuckart. He noticed the signs of interstitial keratitis and band keratopathy, faint iritis or iridocyclitis, posterior synechiae and often a downward distortion of the pupil. He was the first to describe chorioretinal scarring of the fundus, what became known as the Hissette-Ridley fundus. People reported to him their entoptic phenomena which he unequivocally interpreted to be the images of microfilariae in the patient's own eye. During his stay in Belgium in 1932, he elucidated the pathogenesis of blindness since he was able to provide histological proof of the presence of microfilariae in various ocular tissues of an enucleated eye from a patient living near the Sankuru river. Like other serious health impairments, the severe inflammatory lesions in the eye occurred only after the microfilariae had died. Hence he realized that dying microfilariae play a key role in the mechanisms leading to blindness. Hissette's precise descriptions were the logical fruit of his outstanding observational abilities and enabled him as a man of great intuition to speculate about causal relationships. He evidently benefited from the fact that he took the native Africans seriously and asked them their opinion. In 1933, his friend and teacher Dr. De Mets in Antwerp already wrote on Hissette's discovery in the Belgian Congo: "This study is of exceptional value to specialists which is not only a tribute to its author, but to our common native country (Belgium)." PMID:18546927

  2. Therapeutical Management for Ocular Rosacea

    PubMed Central

    López-Valverde, Gloria; Garcia-Martin, Elena; Larrosa-Povés, José Manuel; Polo-Llorens, Vicente; Pablo-Júlvez, Luis E.

    2016-01-01

    Purpose The purpose of this study is to describe a case of ocular rosacea with a very complex evolution. Rosacea is a chronic dermatological disease that may affect the ocular structures up to 6-72% of all cases. This form is often misdiagnosed, which may lead to long inflammatory processes with important visual consequences for affected patients. Therefore, an early diagnosis and an adequate treatment are important. Methods We report the case of a 43-year-old patient who had several relapses of what seemed an episode of acute bacterial conjunctivitis. Two weeks later, he developed a corneal ulcer with a torpid evolution including abundant intrastromal infiltrators and calcium deposits. He was diagnosed with ocular rosacea and treated with systemic doxycycline and topical protopic. Results A coating with amniotic membrane was placed in order to heal the ulcer, but a deep anterior lamellar keratoplasty to restore the patient's vision because of the corneal transparency loss was necessary. Conclusions Ocular rosacea includes multiple ophthalmic manifestations ranging from inflammation of the eyelid margin and blepharitis to serious corneal affectations. A delayed diagnosis can result in chronic inflammatory conditions including keratinization and loss of corneal transparency, which lead to important visual sequelae for affected patients. PMID:27462249

  3. Ocular Toxoplasmosis: Lessons from Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    • A new attention to post-natally acquired infections. Previously, most attention was focused on infection during pregnancy, and the risk of congenital disease, with the feeling that infection in older individuals was benign, without a substantial risk of disease morbidity, such as ocular involvemen...

  4. Adverse ocular reactions to drugs.

    PubMed Central

    Spiteri, M. A.; James, D. G.

    1983-01-01

    Drugs acting on various parts of the body may also affect the eye insidiously. Increased awareness of such drug toxicity by the prescribing doctor should encourage him to consider effects on the cornea, lens, retina, optic nerve and elsewhere when checking the patient's progress. The following review concerns adverse ocular effects of systemic drug administration. PMID:6356101

  5. Ultraviolet light and ocular diseases.

    PubMed

    Yam, Jason C S; Kwok, Alvin K H

    2014-04-01

    The objective of this study is to review the association between ultraviolet (UV) light and ocular diseases. The data are sourced from the literature search of Medline up to Nov 2012, and the extracted data from original articles, review papers, and book chapters were reviewed. There is a strong evidence that ultraviolet radiation (UVR) exposure is associated with the formation of eyelid malignancies [basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)], photokeratitis, climatic droplet keratopathy (CDK), pterygium, and cortical cataract. However, the evidence of the association between UV exposure and development of pinguecula, nuclear and posterior subcapsular cataract, ocular surface squamous neoplasia (OSSN), and ocular melanoma remained limited. There is insufficient evidence to determine whether age-related macular degeneration (AMD) is related to UV exposure. It is now suggested that AMD is probably related to visible radiation especially blue light, rather than UV exposure. From the results, it was concluded that eyelid malignancies (BCC and SCC), photokeratitis, CDK, pterygium, and cortical cataract are strongly associated with UVR exposure. Evidence of the association between UV exposure and development of pinguecula, nuclear and posterior subcapsular cataract, OSSN, and ocular melanoma remained limited. There is insufficient evidence to determine whether AMD is related to UV exposure. Simple behaviural changes, appropriate clothing, wearing hats, and UV blocking spectacles, sunglasses or contact lens are effective measures for UV protection. PMID:23722672

  6. Ocular manifestations of feline viral diseases.

    PubMed

    Stiles, Jean

    2014-08-01

    Feline viral diseases are common and cats can be presented with a variety of clinical manifestations. Ocular disease associated with viral pathogens is not unusual, particularly with viruses causing upper respiratory tract disease in cats, such as feline herpesvirus type 1 and feline calicivirus. These agents mainly cause ocular surface disease. Other viruses, such as feline immunodeficiency virus and feline coronavirus, can cause uveitis, while feline leukemia virus can induce ocular lymphosarcoma. This review covers the most common viral pathogens of cats that cause ocular manifestations, the specific features of the ocular diseases caused by these viruses and therapeutic recommendations. PMID:24461645

  7. Topical administration of a suppressor of cytokine signaling-1 (SOCS1) mimetic peptide inhibits ocular inflammation and mitigates ocular pathology during mouse uveitis.

    PubMed

    He, Chang; Yu, Cheng-Rong; Sun, Lin; Mahdi, Rashid M; Larkin, Joseph; Egwuagu, Charles E

    2015-08-01

    Uveitis is a diverse group of potentially sight-threatening intraocular inflammatory diseases and pathology derives from sustained production of pro-inflammatory cytokines in the optical axis. Although topical or systemic steroids are effective therapies, their adverse effects preclude prolonged usage and are impetus for seeking alternative immunosuppressive agents, particularly for patients with refractory uveitis. In this study, we synthesized a 16 amino acid membrane-penetrating lipophilic suppressor of cytokine signaling 1 peptide (SOCS1-KIR) that inhibits JAK/STAT signaling pathways and show that it suppresses and ameliorates experimental autoimmune uveitis (EAU), the mouse model of human uveitis. Fundus images, histological and optical coherence tomography analysis of eyes showed significant suppression of clinical disease, with average clinical score of 0.5 compared to 2.0 observed in control mice treated with scrambled peptide. We further show that SOCS1-KIR conferred protection from ocular pathology by inhibiting the expansion of pathogenic Th17 cells and inhibiting trafficking of inflammatory cells into the neuroretina during EAU. Dark-adapted scotopic and photopic electroretinograms further reveal that SOCS1-KIR prevented decrement of retinal function, underscoring potential neuroprotective effects of SOCS1-KIR in uveitis. Importantly, SOCS1-KIR is non-toxic, suggesting that topical administration of SOCS1-Mimetics can be exploited as a non-invasive treatment for uveitis and for limiting cytokine-mediated pathology in other ocular inflammatory diseases including scleritis. PMID:26094775

  8. Infantile-onset saccade initiation delay (congenital ocular motor apraxia).

    PubMed

    Salman, Michael S

    2015-05-01

    Infantile-onset saccade initiation delay, also known as congenital ocular motor apraxia, typically presents in early infancy with horizontal head thrusts once head control is achieved. Defective initiation of horizontal saccades and saccade hypometria with normal saccadic velocity are characteristic findings. Isolated impairment of vertical saccades is rare. Impaired smooth ocular pursuit may be seen. Other relatively common features include developmental delay, hypotonia, ataxia, or clumsiness. Brain MRI may be normal or show a diverse range of abnormalities, most commonly involving the cerebellum. Defective slow phases of the optokinetic response are commonly associated with brain MRI abnormalities. Isolated defect of vertical saccade initiation may indicate supratentorial brain abnormalities on MRI. Joubert syndrome, a developmental midbrain-hindbrain malformation, and ataxia telangiectasia are both commonly associated with defective volitional and reflexive saccade initiation, saccade hypometria, and head thrusts. Both horizontal and vertical saccades are impaired in these two disorders. PMID:25783597

  9. Ocular pneumoplethysmography can help in the diagnosis of giant-cell arteritis.

    PubMed

    Bosley, T M; Savino, P J; Sergott, R C; Eagle, R C; Sandy, R; Gee, W

    1989-03-01

    We compared the results of ocular pneumoplethysmography in nine patients who had a temporal artery biopsy (TAB) diagnostic of giant-cell arteritis with results of ocular pneumoplethysmography in nine patients with normal TAB results and 112 patients with anterior ischemic optic neuropathy or central retinal artery occlusion assumed to be nonarteritic. The mean +/- SD ocular pulse amplitude with ocular pneumoplethysmography was 3.9 +/- 1.8 mm in the group with abnormal TAB results and 10.6 +/- 4.0 mm in the group with normal TAB results. Every patient with abnormal TAB results had an average calculated ocular blood flow less than 0.60 mL/min, while only one patient with normal TAB results fell in this range. The average calculated ocular blood flow had a sensitivity of 100% and a specificity of 93.4% in the diagnosis of giant-cell arteritis, with a diagnostic accuracy of 93.9%. These results rival the diagnostic accuracy of the erythrocyte sedimentation rate and TAB results. PMID:2923561

  10. Progenitor cells for ocular surface regenerative therapy.

    PubMed

    Casaroli-Marano, Ricardo P; Nieto-Nicolau, Nuria; Martínez-Conesa, Eva M

    2013-01-01

    The integrity and normal function of the corneal epithelium are essential for maintaining the cornea's transparency and vision. The existence of a cell population with progenitor characteristics in the limbus maintains a dynamic of constant epithelial repair and renewal. Currently, cell-based therapies for bio-replacement, such as cultured limbal epithelial transplantation and cultured oral mucosal epithelial transplantation, present very encouraging clinical results for treating limbal stem cell deficiencies. Another emerging therapeutic strategy consists of obtaining and implementing human progenitor cells of different origins using tissue engineering methods. The development of cell-based therapies using stem cells, such as human adult mesenchymal stromal cells, represents a significant breakthrough in the treatment of certain eye diseases and also offers a more rational, less invasive and more physiological approach to ocular surface regeneration. PMID:23257987

  11. Effect of gravitoinertial force on ocular counterrolling.

    NASA Technical Reports Server (NTRS)

    Miller, E. F., II; Graybiel, A.

    1971-01-01

    The effect of G loading on the magnitude of ocular counterrolling at various angles of tilt up to 63 deg. was measured on normal subjects and compared with the effect on persons with severe or complete loss of vestibular function. The group of six normal subjects manifested a compensatory eye roll which increased as a direct and essentially linear function of the component of the gravitoinertial force acting laterally on the subject. This increase in response was not observed in the five deaf subjects with severe or complete bilateral loss of their vestibular organs. These findings confirmed similar results found by other authors using other measuring techniques which show that the reflex eye movement is dependent on and limited to the magnitude of the gravitoinertial stimulus (within the range used) when the otolithocular system is functioning normally. However when this function is severely impaired or lost, the magnitude of the compensatory eye roll is limited to that manifested at 1 G and possibly to nonotolithic contributions. These findings offer means for differentiation between otolithic-defective and ?normal' persons who exhibit little counterrolling.

  12. Preliminary study on differentiation between glaucomatous and non-glaucomatous eyes on stereo fundus images using cup gradient models

    NASA Astrophysics Data System (ADS)

    Muramatsu, Chisako; Hatanaka, Yuji; Ishida, Kyoko; Sawada, Akira; Yamamoto, Tetsuya; Fujita, Hiroshi

    2014-03-01

    Glaucoma is one of the leading causes of blindness in Japan and the US. One of the indices for diagnosis of glaucoma is the cup-to-disc ratio (CDR). We have been developing a computerized method for measuring CDR on stereo fundus photographs. Although our previous study indicated that the method may be useful, cup determination was not always successful, especially for the normal eyes. In this study, we investigated a new method to quantify the likelihood of glaucomatous disc based on the similarity scores to the glaucoma and non-glaucoma models. Eighty-seven images, including 40 glaucomatous eyes, were used in this study. Only one eye from each patient was used. Using a stereo fundus camera, two images were captured from different angles, and the depth image was created by finding the local corresponding points. One of the characteristics of a glaucomatous disc can be not only that the cup is enlarged but it has an acute slope. On the other hand, a non-glaucomatous cup generally has a gentle slope. Therefore, our models were constructed by averaging the depth gradient images. In order to account for disc size, disc outline was automatically detected, and all images were registered by warping the disc outline to a circle with a predetermined diameter using thin plate splines. Similarity scores were determined by multiplying a test case with both models. At the sensitivity of 90.0%, the specificity was improved from 83.0% using the CDR to 97.9% by the model-based method. The proposed method may be useful for differentiation of glaucomatous eyes.

  13. Systemic and Ocular Hemodynamic Risk Factors in Glaucoma

    PubMed Central

    Choi, Jaewan; Kook, Michael S.

    2015-01-01

    Primary open angle glaucoma (POAG) is a multifactorial disease characterized by progressive retinal ganglion cell death and visual field loss. It is known that alterations in intraocular pressure (IOP), blood pressure (BP), and ocular perfusion pressure (OPP) can play a significant role in the pathogenesis of the disease. Impaired autoregulatory capacity of ocular blood vessels may render tissues vulnerable to OPP changes and potentially harmful tissue ischemia-reperfusion damage. Vascular risk factors should be considered more important in a subgroup of patients with POAG, and especially in patients with normal tension glaucoma (NTG) with evidence of unphysiological BP response. For example, reduction of BP during the nighttime has an influence on OPP, and increased circadian OPP fluctuation, which might stand for unstable ocular blood flow, has been found to be the consistent risk factor for NTG development and progression. Central visual field may be affected more severely than peripheral visual field in NTG patients with higher 24-hour fluctuation of OPP. This review will discuss the current understanding of allegedly major systemic and ocular hemodynamic risk factors for glaucoma including systemic hypertension, arterial stiffness, antihypertensive medication, exaggerated nocturnal hypotension, OPP, and autonomic dysregulation. PMID:26557650

  14. [Nutritional status of vitamin A in preschoolers with ocular diseases].

    PubMed

    Villaseñor-Fierro, Emma T; Vásquez-Garibay, Edgar; Romero-Velarde, Enrique; Kumazawa-Ichikawa, Miguel; Villalpando-Hernández, Salvador; Vélez-Gómez, Ezequiel

    2009-09-01

    The purpose was to evaluate the nutritional status of vitamin A in preschool children with ocular diseases attending to the Hospital Civil of Guadalajara. In a cross sectional design 100 preschool children between 24 and 71 mo of age with ocular diseases were included. Vitamin A intake was evaluated by 24 h dietetic recall, plasma Retinol concentration by high pressure liquid chromatography (HPLC); and, conjunctiva impression cytology (CIC) was carried out by a trained pathologist. ANOVA and U Mann Whitney tests, and also Spearman correlations were estimated. There were 44.1% females and 55,9% males. Strabismus was the most common disease (41,9%), conjunctivitis (19,4%), and congenital diseases (17,2%). The mean intake of Vitamin A was 374 microg/d +/- 706 and the serum concentration of retinol was of 30 microg/dL +/- 7,6; CIC was normal in 75,6%. The percentage of vitamin A deficiency was 3,2% according to the serum concentration of Retinol and 3,5% to the CIC criteria. It was not association between the nutritional status of vitamin A and ocular diseases. A positive correlation between vitamin A intake and weight/height index (r = 0,244) was found. In conclusion, most preschool children covered the dietary reference intake recommendation of vitamin A; deficiency of this vitamin was lower and, it was not associated to ocular diseases. PMID:19886511

  15. Telemedicine in the control of intra-ocular pressure.

    PubMed

    Michelson, G; Striebel, W; Prihoda, W; Schmidt, V

    2000-01-01

    Glaucoma is one of the most common causes of blindness in the Western world and a major risk factor is increased intra-ocular pressure. We therefore used telemedicine in its control. Patients measured their intra-ocular pressure several times a day with a portable instrument and the values were then entered into a portable digital assistant. These data were transmitted by a modem to a central server. If the intra-ocular pressure was pathologically high, an email message was automatically sent to the ophthalmologist. The pressure curve, including a statistical analysis, was displayed in an easily readable chart format. Ten patients with glaucoma participated in a trial. Self-tonometry with telemedicine enabled continuous evaluation of the patient by the ophthalmologist. This approach offered the advantage of controlling the treatment remotely. Advantages for the patient were that the measurements were easily done at home under normal conditions, and the patient could control when the measurement and data transmission would be performed. Telemedicine is a cost-effective technique enabling the early diagnosis of pathologically increased intra-ocular pressure. PMID:10793996

  16. Automated multimodality concurrent classification for segmenting vessels in 3D spectral OCT and color fundus images

    NASA Astrophysics Data System (ADS)

    Hu, Zhihong; Abràmoff, Michael D.; Niemeijer, Meindert; Garvin, Mona K.

    2011-03-01

    Segmenting vessels in spectral-domain optical coherence tomography (SD-OCT) volumes is particularly challenging in the region near and inside the neural canal opening (NCO). Furthermore, accurately segmenting them in color fundus photographs also presents a challenge near the projected NCO. However, both modalities also provide complementary information to help indicate vessels, such as a better NCO contrast from the NCO-aimed OCT projection image and a better vessel contrast inside the NCO from fundus photographs. We thus present a novel multimodal automated classification approach for simultaneously segmenting vessels in SD-OCT volumes and fundus photographs, with a particular focus on better segmenting vessels near and inside the NCO by using a combination of their complementary features. In particular, in each SD-OCT volume, the algorithm pre-segments the NCO using a graph-theoretic approach and then applies oriented Gabor wavelets with oriented NCO-based templates to generate OCT image features. After fundus-to-OCT registration, the fundus image features are computed using Gaussian filter banks and combined with OCT image features. A k-NN classifier is trained on 5 and tested on 10 randomly chosen independent image pairs of SD-OCT volumes and fundus images from 15 subjects with glaucoma. Using ROC analysis, we demonstrate an improvement over two closest previous works performed in single modal SD-OCT volumes with an area under the curve (AUC) of 0.87 (0.81 for our and 0.72 for Niemeijer's single modal approach) in the region around the NCO and 0.90 outside the NCO (0.84 for our and 0.81 for Niemeijer's single modal approach).

  17. A Health Insurance Portability and Accountability Act–Compliant Ocular Telehealth Network for the Remote Diagnosis and Management of Diabetic Retinopathy

    PubMed Central

    Li, Yaqin; Karnowski, Thomas P.; Tobin, Kenneth W.; Giancardo, Luca; Morris, Scott; Sparrow, Sylvia E.; Garg, Seema; Fox, Karen

    2011-01-01

    Abstract In this article, we present the design and implementation of a regional ocular telehealth network for remote assessment and management of diabetic retinopathy (DR), including the design requirements, network topology, protocol design, system work flow, graphics user interfaces, and performance evaluation. The Telemedical Retinal Image Analysis and Diagnosis Network is a computer-aided, image analysis telehealth paradigm for the diagnosis of DR and other retinal diseases using fundus images acquired from primary care end users delivering care to underserved patient populations in the mid-South and southeastern United States. PMID:21819244

  18. Comparison of Drusen Area Detected by Spectral Domain Optical Coherence Tomography and Color Fundus Imaging

    PubMed Central

    Yehoshua, Zohar; Gregori, Giovanni; Sadda, SriniVas R.; Penha, Fernando M.; Goldhardt, Raquel; Nittala, Muneeswar G.; Konduru, Ranjith K.; Feuer, William J.; Gupta, Pooja; Li, Ying; Rosenfeld, Philip J.

    2013-01-01

    Purpose. To compare the measurements of drusen area from manual segmentation of color fundus photographs with those generated by an automated algorithm designed to detect elevations of the retinal pigment epithelium (RPE) on spectral domain optical coherence tomography (SD-OCT) images. Methods. Fifty eyes with drusen secondary to nonexudative age-related macular degeneration were enrolled. All eyes were imaged with a high-definition OCT instrument using a 200 × 200 A-scan raster pattern covering a 6 mm × 6 mm area centered on the fovea. Digital color fundus images were taken on the same day. Drusen were traced manually on the fundus photos by graders at the Doheny Image Reading Center, whereas quantitative OCT measurements of drusen were obtained by using a fully automated algorithm. The color fundus images were registered to the OCT data set and measurements within corresponding 3- and 5-mm circles centered at the fovea were compared. Results. The mean areas (±SD [range]) for the 3-mm circles were SD-OCT = 1.57 (±1.08 [0.03–4.44]); 3-mm color fundus = 1.92 (±1.08 [0.20–3.95]); 5-mm SD-OCT = 2.12 (±1.55 [0.03–5.40]); and 5-mm color fundus = 3.38 (±1.90 [0.39–7.49]). The mean differences between color images and the SD-OCT (color − SD-OCT) were 0.36 (±0.93) (P = 0.008) for the 3-mm circle and 1.26 (±1.38) (P < 0.001) for the 5-mm circle measurements. Intraclass correlation coefficients of agreements for 3- and 5-mm measurements were 0.599 and 0.540, respectively. Conclusions. There was only fair agreement between drusen area measurements obtained from SD-OCT images and color fundus photos. Drusen area measurements on color fundus images were larger than those with SD-OCT scans. This difference can be attributed to the fact that the OCT algorithm defines drusen in terms of RPE deformations above a certain threshold, and will not include small, flat drusen and subretinal drusenoid deposits. The two approaches provide complementary information about

  19. Comparing the utility of the non-mydriatic fundus camera to the direct ophthalmoscope for medical education.

    PubMed

    Chen, Ming; Swinney, Christian; Chen, Mindy; Bal, Minder; Nakatsuka, Austin

    2015-03-01

    Visualization of the fundus is an important component of any ophthalmologic exam. Students are taught to visualize the fundus using a direct handheld ophthalmoscope. However, this device has many limitations, which may be a detriment to medical education and patient care. The invention of the non-mydriatic automatic fundus camera could significantly improve medical education. Our study examined the ability of a group of 5 medical students to visualize pathology and form a diagnosis with a traditional handheld ophthalmoscope and an automatic fundus camera. With the direct ophthalmoscope, none of the students were able to visualize the macula, a crucial aspect of the ophthalmologic exam. With the automatic fundus camera, all students were able to visualize the fundus. The latter modality also increased the proportion of students that was able to correctly diagnose the patients with diabetic retinopathy, 100% vs 40%. On average, students were also more confident in their ability to visualize basic retinal anatomy with the automatic fundus camera, 9.6/10 vs 6.4/10. Thus, incorporating the non-mydriatic automatic fundus camera into medical education, alongside the handheld ophthalmoscope, has the potential to improve both learning outcomes and patient care. PMID:25821651

  20. Comparing the Utility of the Non-Mydriatic Fundus Camera to the Direct Ophthalmoscope for Medical Education

    PubMed Central

    Chen, Ming; Chen, Mindy; Bal, Minder; Nakatsuka, Austin

    2015-01-01

    Visualization of the fundus is an important component of any ophthalmologic exam. Students are taught to visualize the fundus using a direct handheld ophthalmoscope. However, this device has many limitations, which may be a detriment to medical education and patient care. The invention of the non-mydriatic automatic fundus camera could significantly improve medical education. Our study examined the ability of a group of 5 medical students to visualize pathology and form a diagnosis with a traditional handheld ophthalmoscope and an automatic fundus camera. With the direct ophthalmoscope, none of the students were able to visualize the macula, a crucial aspect of the ophthalmologic exam. With the automatic fundus camera, all students were able to visualize the fundus. The latter modality also increased the proportion of students that was able to correctly diagnose the patients with diabetic retinopathy, 100% vs 40%. On average, students were also more confident in their ability to visualize basic retinal anatomy with the automatic fundus camera, 9.6/10 vs 6.4/10. Thus, incorporating the non-mydriatic automatic fundus camera into medical education, alongside the handheld ophthalmoscope, has the potential to improve both learning outcomes and patient care. PMID:25821651

  1. Ocular surface foreign bodies: novel findings mimicking ocular malignant melanoma

    PubMed Central

    Maudgil, A; Wagner, B E; Rundle, P; Rennie, I G; Mudhar, H S

    2014-01-01

    Purpose Malignant melanoma of the eye is an uncommon condition that is important to recognise. We describe three cases in which ocular foreign bodies have masqueraded as ocular malignant melanoma. Methods Interventional case reports. Results Case 1 describes diathermy-induced carbon particle implantation, during plaque therapy for the treatment of uveal melanoma, mimicking recurrence with extra-scleral invasion. Case 2 shows a foreign body called ‘mullite' mimicking conjunctival melanoma. Case 3 demonstrates a conjunctival foreign body called ‘illite' that mimicked a limbal melanocytic lesion, clinically thought to be either melanocytoma or melanoma. Conclusion This report highlights the importance of careful history taking, examination, and appropriate biopsy in cases of suspected malignant melanoma, to prevent unnecessary and potentially radical treatment. PMID:25104745

  2. Optic disc boundary segmentation from diffeomorphic demons registration of monocular fundus image sequences versus 3D visualization of stereo fundus image pairs for automated early stage glaucoma assessment

    NASA Astrophysics Data System (ADS)

    Gatti, Vijay; Hill, Jason; Mitra, Sunanda; Nutter, Brian

    2014-03-01

    Despite the current availability in resource-rich regions of advanced technologies in scanning and 3-D imaging in current ophthalmology practice, world-wide screening tests for early detection and progression of glaucoma still consist of a variety of simple tools, including fundus image-based parameters such as CDR (cup to disc diameter ratio) and CAR (cup to disc area ratio), especially in resource -poor regions. Reliable automated computation of the relevant parameters from fundus image sequences requires robust non-rigid registration and segmentation techniques. Recent research work demonstrated that proper non-rigid registration of multi-view monocular fundus image sequences could result in acceptable segmentation of cup boundaries for automated computation of CAR and CDR. This research work introduces a composite diffeomorphic demons registration algorithm for segmentation of cup boundaries from a sequence of monocular images and compares the resulting CAR and CDR values with those computed manually by experts and from 3-D visualization of stereo pairs. Our preliminary results show that the automated computation of CDR and CAR from composite diffeomorphic segmentation of monocular image sequences yield values comparable with those from the other two techniques and thus may provide global healthcare with a cost-effective yet accurate tool for management of glaucoma in its early stage.

  3. Understanding Ocular Discomfort and Dryness Using the Pain Sensitivity Questionnaire

    PubMed Central

    Li, Wing; Graham, Andrew D.

    2016-01-01

    Purpose To utilize the Pain Sensitivity Questionnaire (PSQ) to assess the influence of pain sensitivity on perceptions of ocular discomfort and dryness. Methods Subjects completed a battery of questionnaires, including history of ocular and general health, contact lens wear history, the Ocular Surface Disease Index (OSDI) questionnaire, visual analog scale (VAS) 100-point rating scales to assess severity and frequency of average and end of day (EOD) discomfort and dryness, and the PSQ to assess pain sensitivity level. Masked subjects were then instructed to wear one inverted and one normally oriented soft contact lens contralaterally for 30 minutes to induce an inter-eye difference in comfort and dryness sensations. Subjects rated comfort and dryness in each eye on VAS every 5 minutes during contact lens wear. A slit lamp examination was performed to evaluate ocular surface health and to assess contact lens fit. Results One hundred and fifty-three subjects (111 females, 42 males) completed the study. In separate models, a higher PSQ score was significantly associated with higher OSDI score (p = 0.002), lower average and EOD comfort (p = 0.005 and 0.001, respectively), and greater EOD dryness (p = 0.04). The minimum (0.14) and maximum (7.14) PSQ scores observed in our subject cohort (i.e., from the subjects who were the least and most sensitive to pain, respectively) corresponded to an estimated difference of 11 points on the OSDI, 20 points on the VAS scale for average comfort, 31 points for EOD comfort and 17 points for EOD dryness. In a mixed effects model, a higher PSQ score was significantly associated with a greater inter-eye difference in comfort (p = 0.013) and dryness (p = 0.010) during CL wear. Conclusions Pain sensitivity influences perceptions of ocular discomfort and dryness, and should be taken into account when evaluating subjective assessments of these symptoms. PMID:27137908

  4. Antibiotic therapy for ocular infection.

    PubMed Central

    Snyder, R W; Glasser, D B

    1994-01-01

    Infections of the eye can rapidly damage important functional structures and lead to permanent vision loss or blindness. Broad-spectrum antibiotics should be administered to the appropriate site of infection as soon as a diagnosis is made. Topical drops are preferred for corneal and conjunctival infections. Intravitreal antibiotics, and possibly subconjunctival and parenteral antibiotics, are preferred for endophthalmitis. Parenteral antibiotics are recommended for infection in deep adnexal structures. We review specific aspects of antibiotic therapy for ocular and periocular infection. PMID:7856158

  5. Ocular toxoplasmosis in AIDS patients.

    PubMed Central

    Gagliuso, D J; Teich, S A; Friedman, A H; Orellana, J

    1990-01-01

    We describe 16 cases of ocular and, in some patients, associated CNS toxoplasmosis in AIDS patients. T gondii is commonly associated with infection in the immunocompromised host. The lesions are most often seen in the CNS and eyes; involvement in the brain, heart, lung, liver, spleen, and lymph nodes may be observed. CNS involvement by toxoplasmosis may be an initial manifestation of AIDS and may be associated with discrete or diffuse lesions. CT scan and MR imaging may demonstrate a multitude of lesions often displaying the characteristic ring-shaped enhancement after contrast injection. Ocular involvement by toxoplasmosis, though less common than CNS involvement, is characterized by several features. These may be manifested as single or multifocal retinal lesions in one or both eyes or massive areas of retinal necrosis. Invariably these lesions are unassociated with a pre-existing retinochoroidal scar suggesting that the lesions are a manifestation of acquired rather than congenital disease. Presence of IgM antibodies may support this observation although antibody levels in AIDS patients may not reflect the magnitude of disease. Vitreous reaction is often minimal. Anterior uveitis has been reported in one case. Treatment of the ocular infection with pyrimethamine, clindamycin and sulfadiazine is effective in over 75% of patients. Once resolution of the ocular infection is observed, maintenance therapy is continued as relapses occur in the absence of treatment. Corticosteroid treatment is unnecessary and its use has been associated with the development of CMV retinitis. Other retinal infections in AIDS patients which should be considered in the differential diagnosis include CMV, herpetic-associated ARN and syphilis. Concomitant CMV and toxoplasmosis in the same eye have been seen. Images FIGURE 1 FIGURE 2 A FIGURE 2 B FIGURE 3 A FIGURE 3 B FIGURE 4 A FIGURE 4 B FIGURE 5 A FIGURE 5 B FIGURE 6 FIGURE 7 FIGURE 8 A FIGURE 8 B FIGURE 9 A FIGURE 9 B FIGURE 9 C PMID

  6. Murine fundus fluorescein angiography: An alternative approach using a handheld camera.

    PubMed

    Ehrenberg, Moshe; Ehrenberg, Scott; Schwob, Ouri; Benny, Ofra

    2016-07-01

    In today's modern pharmacologic approach to treating sight-threatening retinal vascular disorders, there is an increasing demand for a compact, mobile, lightweight and cost-effective fluorescein fundus camera to document the effects of antiangiogenic drugs on laser-induced choroidal neovascularization (CNV) in mice and other experimental animals. We have adapted the use of the Kowa Genesis Df Camera to perform Fundus Fluorescein Angiography (FFA) in mice. The 1 kg, 28 cm high camera has built-in barrier and exciter filters to allow digital FFA recording to a Compact Flash memory card. Furthermore, this handheld unit has a steady Indirect Lens Holder that firmly attaches to the main unit, that securely holds a 90 diopter lens in position, in order to facilitate appropriate focus and stability, for photographing the delicate central murine fundus. This easily portable fundus fluorescein camera can effectively record exceptional central retinal vascular detail in murine laser-induced CNV, while readily allowing the investigator to adjust the camera's position according to the variable head and eye movements that can randomly occur while the mouse is optimally anesthetized. This movable image recording device, with efficiencies of space, time, cost, energy and personnel, has enabled us to accurately document the alterations in the central choroidal and retinal vasculature following induction of CNV, implemented by argon-green laser photocoagulation and disruption of Bruch's Membrane, in the experimental murine model of exudative macular degeneration. PMID:27260483

  7. Quality Enhancement and Nerve Fibre Layer Artefacts Removal in Retina Fundus Images by Off Axis Imaging

    SciTech Connect

    Giancardo, Luca; Meriaudeau, Fabrice; Karnowski, Thomas Paul; Li, Yaquin; Tobin Jr, Kenneth William; Chaum, Edward

    2011-01-01

    Retinal fundus images acquired with non-mydriatic digital fundus cameras are a versatile tool for the diagnosis of various retinal diseases. Because of the ease of use of newer camera models and their relative low cost, these cameras are employed worldwide by retina specialists to diagnose diabetic retinopathy and other degenerative diseases. Even with relative ease of use, the images produced by these systems sometimes suffer from reflectance artefacts mainly due to the nerve fibre layer (NFL) or other camera lens related reflections. We propose a technique that employs multiple fundus images acquired from the same patient to obtain a single higher quality image without these reflectance artefacts. The removal of bright artefacts, and particularly of NFL reflectance, can have great benefits for the reduction of false positives in the detection of retinal lesions such as exudate, drusens and cotton wool spots by automatic systems or manual inspection. If enough redundant information is provided by the multiple images, this technique also compensates for a suboptimal illumination. The fundus images are acquired in straightforward but unorthodox manner, i.e. the stare point of the patient is changed between each shot but the camera is kept fixed. Between each shot, the apparent shape and position of all the retinal structures that do not exhibit isotropic reflectance (e.g. bright artefacts) change. This physical effect is exploited by our algorithm in order to extract the pixels belonging to the inner layers of the retina, hence obtaining a single artefacts-free image.

  8. Bone Remodeling in Choroidal Osteoma Monitored by Fundus Photography and Spectral-Domain Optical Coherence Tomography

    PubMed Central

    Kamalden, Tengku Ain; Lingam, Gopal; Sundar, Gangadhara

    2014-01-01

    Choroidal osteoma is a benign ossifying tumor of the choroid, consisting of mature bone tissue. It has been described to enlarge and evolve at varying rates over time. Here, we report and quantify the progression of a unilateral choroidal osteoma in a 7-year-old boy by fundus photography, and document tumor remodeling by spectral domain optical coherence tomography images. PMID:27175357

  9. Differential gene expression in the murine gastric fundus lacking interstitial cells of Cajal

    PubMed Central

    Daigo, Yataro; Takayama, Ichiro; Ponder, Bruce AJ; Caldas, Carlos; Ward, Sean M; Sanders, Kenton M; Fujino, Masayuki A

    2003-01-01

    Background The muscle layers of murine gastric fundus have no interstitial cells of Cajal at the level of the myenteric plexus and only possess intramuscular interstitial cells and this tissue does not generate electric slow waves. The absence of intramuscular interstitial cells in W/WV mutants provides a unique opportunity to study the molecular changes that are associated with the loss of these intercalating cells. Method The gene expression profile of the gastric fundus of wild type and W/WV mice was assayed by murine microarray analysis displaying a total of 8734 elements. Queried genes from the microarray analysis were confirmed by semi-quantitative reverse transcription-polymerase chain reaction. Results Twenty-one genes were differentially expressed in wild type and W/WV mice. Eleven transcripts had 2.0–2.5 fold higher mRNA expression in W/WV gastric fundus when compared to wild type tissues. Ten transcripts had 2.1–3.9 fold lower expression in W/WV mutants in comparison with wild type animals. None of these genes have ever been implicated in any bowel motility function. Conclusions These data provides evidence that several important genes have significantly changed in the murine fundus of W/WV mutants that lack intramuscular interstitial cells of Cajal and have reduced enteric motor neurotransmission. PMID:12795813

  10. Facial asymmetry in ocular torticollis.

    PubMed

    Akbari, Mohammad Reza; Khorrami Nejad, Masoud; Askarizadeh, Farshad; Pour, Fatemeh Farahbakhsh; Ranjbar Pazooki, Mahsa; Moeinitabar, Mohamad Reza

    2015-01-01

    Torticollis can arise from nonocular (usually musculoskeletal) and ocular conditions. Some facial asymmetries are correlated with a history of early onset ocular torticollis supported by the presence of torticollis on reviewing childhood photographs. When present in an adult, this type of facial asymmetry with an origin of ocular torticollis should help to confirm the chronicity of the defect and prevent unnecessary neurologic evaluation in patients with an uncertain history. Assessment of facial asymmetry consists of a patient history, physical examination, and medical imaging. Medical imaging and facial morphometry are helpful for objective diagnosis and measurement of the facial asymmetry, as well as for treatment planning. The facial asymmetry in congenital superior oblique palsy is typically manifested by midfacial hemihypoplasia on the side opposite the palsied muscle, with deviation of the nose and mouth toward the hypoplastic side. Correcting torticollis through strabismus surgery before a critical developmental age may prevent the development of irreversible facial asymmetry. Mild facial asymmetry associated with congenital torticollis has been reported to resolve with continued growth after early surgery, but if asymmetry is severe or is not treated in the appropriate time, it might remain even with continued growth after surgery. PMID:27239567

  11. Transplant related ocular surface disorders: Advanced techniques for ocular surface rehabilitation after ocular complications secondary to hematopoietic stem cell transplantation.

    PubMed

    Stahl, Erin D; Mahomed, Faheem; Hans, Amneet K; Dalal, Jignesh D

    2016-05-01

    HSCT has been linked to the development of an assortment of ocular surface complications with the potential to lead to permanent visual impairment if left untreated or if not treated early in the course of disease. Strategies for therapy include maintenance of lubrication and tear preservation, prevention of evaporation, decreasing inflammation, and providing epithelial support. The ultimate aim of treatment is to prevent permanent ocular sequelae through prompt ophthalmology consultation and the use of advanced techniques for ocular surface rehabilitation. We describe several rehabilitation options of ocular surface complications occurring secondarily during the post-HSCT course. PMID:26869458

  12. Role of Telokin in Regulating Murine Gastric Fundus Smooth Muscle Tension

    PubMed Central

    An, Changlong; Bhetwal, Bhupal P.; Sanders, Kenton M.; Somlyo, Avril V.; Perrino, Brian A.

    2015-01-01

    Telokin phosphorylation by cyclic GMP-dependent protein kinase facilitates smooth muscle relaxation. In this study we examined the relaxation of gastric fundus smooth muscles from basal tone, or pre-contracted with KCl or carbachol (CCh), and the phosphorylation of telokin S13, myosin light chain (MLC) S19, MYPT1 T853, T696, and CPI-17 T38 in response to 8-Bromo-cGMP, the NO donor sodium nitroprusside (SNP), or nitrergic neurotransmission. We compared MLC phosphorylation and the contraction and relaxation responses of gastric fundus smooth muscles from telokin-/- mice and their wild-type littermates to KCl or CCh, and 8-Bromo-cGMP, SNP, or nitrergic neurotransmission, respectively. We compared the relaxation responses and telokin phosphorylation of gastric fundus smooth muscles from wild-type mice and W/WV mice which lack ICC-IM, to 8-Bromo-cGMP, SNP, or nitrergic neurotransmission. We found that telokin S13 is basally phosphorylated and that 8-Bromo-cGMP and SNP increased basal telokin phosphorylation. In muscles pre-contracted with KCl or CCh, 8-Bromo-cGMP and SNP had no effect on CPI-17 or MYPT1 phosphorylation, but increased telokin phosphorylation and reduced MLC phosphorylation. In telokin-/- gastric fundus smooth muscles, basal tone and constitutive MLC S19 phosphorylation were increased. Pre-contracted telokin-/- gastric fundus smooth muscles have increased contractile responses to KCl, CCh, or cholinergic neurotransmission and reduced relaxation to 8-Bromo-cGMP, SNP, and nitrergic neurotransmission. However, basal telokin phosphorylation was not increased when muscles were stimulated with lower concentrations of SNP or when the muscles were stimulated by nitrergic neurotransmission. SNP, but not nitrergic neurotransmission, increased telokin Ser13 phosphorylation in both wild-type and W/WV gastric fundus smooth muscles. Our findings indicate that telokin may play a role in attenuating constitutive MLC phosphorylation and provide an additional mechanism to

  13. [Diagnosis and treatment of ocular hypertension].

    PubMed

    Sun, Y Y; Chen, W W; Wang, N L

    2016-07-01

    Ocular hypertension is popular among people, with a prevalence of 3% to 10% in those older than 40 years old. Without proper intervention, over 10% of the patients with ocular hypertension would develop glaucoma in the following 5 to 10 years. Glaucoma has become one of the leading causes of blindness all over the world, which makes it essential for us to pay enough attention to the prevention and treatment of ocular hypertension. However, it is not cost-effective to treat all the patients with ocular hypertension. Certain side effects may also be caused with long-term medical treatment. Therefore, it is of great importance for ophthalmologists to identify the right time and use appropriate therapeutic methods. To introduce the knowledge of ocular hypertension, the definition, epidemiology, diagnosis, risk factors and treatment of ocular hypertension are reviewed in this article. (Chin J Ophthalmol, 2016, 52: 542-546). PMID:27531115

  14. Ocular Toxicity of Tyrosine Kinase Inhibitors

    PubMed Central

    Davis, Mary Elizabeth

    2016-01-01

    Purpose/Objectives To review common tyrosine kinase inhibitors, as well as their ocular side effects and management. Data Sources A comprehensive literature search was conducted using cINahl®, Pubmed, and cochrane databases for articles published since 2004 with the following search terms: ocular toxicities, tyrosine kinase inhibitors, ophthalmology, adverse events, eye, and vision. Data Synthesis Tyrosine kinase inhibitors can cause significant eye toxicity. Conclusions Given the prevalence of new tyrosine kinase inhibitor therapies and the complexity of possible pathogenesis of ocular pathology, oncology nurses can appreciate the occurrence of ocular toxicities and the role of nursing in the management of these problems. Implications for Nursing Knowledge of the risk factors and etiology of ocular toxicity of targeted cancer therapies can guide nursing assessment, enhance patient education, and improve care management. Including a review of eye symptoms and vision issues in nursing assessment can enhance early detection and treatment of ocular toxicity. PMID:26906134

  15. Tumors of the ocular surface: A review

    PubMed Central

    Honavar, Santosh G; Manjandavida, Fairooz P

    2015-01-01

    Tumors of the Ocular Surface clinically manifest with a very wide spectrum and include several forms of epithelial, stromal, caruncular, and secondary tumors. As a group, these tumors are seen commonly in the clinical practice of a comprehensive ophthalmologist, cornea specialist, and an ocular oncologist. This review is aimed to discuss the common tumors of the ocular surface and emphasize on their clinical diagnosis and appropriate management. PMID:25971163

  16. Review of external ocular compression: clinical applications of the ocular pressure estimator

    PubMed Central

    Korenfeld, Michael S; Dueker, David K

    2016-01-01

    mmHg (SEM) and the mean trough pressure was 15±2 mmHg (SEM). There was a 78% agreement between the eye that was reported to be dependent during sleep and the eye with the larger vertical cup-to-disc ratio, for eyes with at least a 0.10 cup-to-disc ratio difference, P=0.001, n=137. The OPE estimated an average induced IOP during typical DOM of 104±8 mmHg (SEM), with each compression having an average range of 17±3 mmHg (SEM). After coaching, and a 5-minute waiting period, the average induced IOP reduced to 95±3 mmHg (SEM) with a reduced average range of IOP to 11±1 mmHg. Conclusion The OPE was successfully used to estimate the IOP while subjects experienced EOC during normal sleep postures. These EOC-induced elevations of IOP were considerable, and likely contribute to significant ocular pathology, not only for glaucoma, but for retinal vascular occlusive diseases, retinal vascular leakage, and the induction of the ocular-cardiac reflex in infants, as well. The correlation of a larger vertical cup-to-disc ratio in patients with a sleep posture preference suggests a causal relationship, since patients with other conditions known to be associated with cup-to disc ratio asymmetry were excluded from this study. The OPE is a useful device to teach DOM to surgeons and patients for home use. PMID:26966349

  17. Ocular manifestations of infectious skin diseases.

    PubMed

    Sadowska-Przytocka, Anna; Czarnecka-Operacz, Magdalena; Jenerowicz, Dorota; Grzybowski, Andrzej

    2016-01-01

    Ocular complications of infectious skin diseases are a common occurrence. Managing the inflamed or infected eye in the emergency setting presents a diagnostic and therapeutic challenge to the emergency physician. Infectious agents may affect any part of the eye. Ocular findings may be the first sign of many infectious diseases, such as, for example, gonorrhea or chlamydia infection. Understanding the various forms of ocular involvement in these conditions is important, because untreated ophthalmic involvement can lead to severe vision loss. This review focuses on the significant ocular manifestations of the most common infectious diseases, including bacterial, viral, fungal, and parasitic infections, that both ophthalmologists and dermatologists may encounter. PMID:26903179

  18. [Glaucoma medications, preservatives and the ocular surface.

    PubMed

    Aptel, F; Labbé, A; Baudouin, C; Bron, A; Lachkar, Y; Sellem, E; Renard, J-P; Nordmann, J-P; Rouland, J-F; Denis, P

    2014-10-14

    Several clinical and experimental studies have demonstrated that ocular surface disease is common in glaucoma patients receiving chronic glaucoma drops, and that the preservatives in these drops play a major role in the occurrence of ocular surface disease. These ocular surface changes may induce both symptoms reported by the patients and anterior segment clinical signs, and should be systematically assessed by history and exam in all glaucoma patients. In these patients with ocular surface disease, reducing the amount of preservatives administered to the eye should be strived for, rather than adding additional eye drops to alleviate or mask the side effects of the glaucoma drops. PMID:25440185

  19. Scleral Mechanisms Underlying Ocular Growth and Myopia

    PubMed Central

    Metlapally, Ravi; Wildsoet, Christine F.

    2015-01-01

    In the regulation of ocular growth, scleral events critically determine eye size and thus the refractive status of the eye. Increased scleral matrix remodeling can lead to exaggerated eye growth causing myopia and additionally increased risk of ocular pathological complications. Thus, therapies targeting these changes in sclera hold potential to limit such complications since sclera represents a relatively safe and accessible drug target. Understanding the scleral molecular mechanisms underlying ocular growth is essential to identifying plausible therapeutic targets in the sclera. This section provides a brief update on molecular studies that pertain to the sclera in the context of ocular growth regulation and myopia. PMID:26310158

  20. [Principles of treatment in ocular burns regarding the ocular surface and limbal stem cells].

    PubMed

    Potop, V; Dumitrache, Marieta

    2005-01-01

    The term ocular surface emphasizes the functional interdependence of the nonkeratinizing epithelium of cornea and conjunctiva. The limbal stem cells are responsible for replacement of corneal epithelium following ocular surface injuries. Over the past decades important advances in the management of chemical injury have occurred based on the application of theories on ocular surface and limbal stem cells. PMID:16245740

  1. Crowdsourcing as a Novel Technique for Retinal Fundus Photography Classification: Analysis of Images in the EPIC Norfolk Cohort on Behalf of the UKBiobank Eye and Vision Consortium

    PubMed Central

    Mitry, Danny; Peto, Tunde; Hayat, Shabina; Morgan, James E.; Khaw, Kay-Tee; Foster, Paul J.

    2013-01-01

    Aim Crowdsourcing is the process of outsourcing numerous tasks to many untrained individuals. Our aim was to assess the performance and repeatability of crowdsourcing for the classification of retinal fundus photography. Methods One hundred retinal fundus photograph images with pre-determined disease criteria were selected by experts from a large cohort study. After reading brief instructions and an example classification, we requested that knowledge workers (KWs) from a crowdsourcing platform classified each image as normal or abnormal with grades of severity. Each image was classified 20 times by different KWs. Four study designs were examined to assess the effect of varying incentive and KW experience in classification accuracy. All study designs were conducted twice to examine repeatability. Performance was assessed by comparing the sensitivity, specificity and area under the receiver operating characteristic curve (AUC). Results Without restriction on eligible participants, two thousand classifications of 100 images were received in under 24 hours at minimal cost. In trial 1 all study designs had an AUC (95%CI) of 0.701(0.680–0.721) or greater for classification of normal/abnormal. In trial 1, the highest AUC (95%CI) for normal/abnormal classification was 0.757 (0.738–0.776) for KWs with moderate experience. Comparable results were observed in trial 2. In trial 1, between 64–86% of any abnormal image was correctly classified by over half of all KWs. In trial 2, this ranged between 74–97%. Sensitivity was ≥96% for normal versus severely abnormal detections across all trials. Sensitivity for normal versus mildly abnormal varied between 61–79% across trials. Conclusions With minimal training, crowdsourcing represents an accurate, rapid and cost-effective method of retinal image analysis which demonstrates good repeatability. Larger studies with more comprehensive participant training are needed to explore the utility of this compelling technique in

  2. Significance of the disc damage likelihood scale objectively measured by a non-mydriatic fundus camera in preperimetric glaucoma

    PubMed Central

    Pahlitzsch, Milena; Torun, Necip; Erb, Carl; Bruenner, Jeanette; Maier, Anna Karina B; Gonnermann, Johannes; Bertelmann, Eckart; Klamann, Matthias K J

    2015-01-01

    Purpose To assess the correlation between the disc damage likelihood scale (DDLS) objectively measured by a non-mydriatic fundus camera, Heidelberg Retina Tomograph 3, and optic coherence tomography in preperimetric glaucoma. Methods One-hundred-twenty-five patients with preperimetric primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (n=30) were included (mean age 58.9±15.9 years). All three devices graded the optic disc topography: Diagnosis 1 was defined as “outside normal limits”, while Diagnosis 2 as “borderline or outside normal limits”. Results For Diagnosis 1, a significant correlation was shown between DDLS and Moorfields regression analysis (P=0.022), and for Diagnosis 2 with glaucoma probability score analysis (P=0.024), in POAG. In pseudoexfoliation glaucoma, DDLS did not correlate significantly with Heidelberg Retina Tomograph 3 and optic coherence tomography. Regarding the area under the curve the highest predictive power was demonstrated by the objective DDLS (0.513–0.824) compared to Burk (0.239–0.343) and Mikelberg (0.093–0.270) coefficients. Conclusions The DDLS showed a significant correlation to the Moorfields regression analysis in preperimetric POAG. The objective DDLS showed the highest predictive power and thus is an additive tool in diagnosing preperimetric glaucoma. PMID:26640365

  3. Usefulness of laser speckle flowgraphy for the assessment of ocular blood flow in extracranial-intracranial bypass.

    PubMed

    Omodaka, Shunsuke; Endo, Hidenori; Doi, Hiroshi; Shimizu, Hiroaki; Fujimura, Miki; Aizawa, Naoko; Nakazawa, Toru; Tominaga, Teiji

    2014-01-01

    Laser speckle flowgraphy (LSFG) is a noninvasive technique that can measure relative blood flow velocity in the optic fundus. The authors present a case of symptomatic internal carotid artery occlusion treated with superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in which an improvement of ocular circulation was confirmed by LSFG. A 47-year-old man presented with a 1-month history of repeated left blurred vision and motor weakness of the right leg. Diffusion-weighted magnetic resonance imaging revealed a small infarction in the left frontal lobe. Carotid angiography revealed that the left internal carotid artery was occluded at the C4 portion. Single-photon emission computed tomography indicated that the cerebral blood flow in the left MCA territory was markedly impaired. Ophthalmologic examination revealed ischemic change of the left optic fundi, and LSFG revealed decreased blood flow around the left optic disc. Left STA-MCA bypass was successfully performed. Both ischemic ocular symptoms and the ischemic symptoms of the right leg were completely recovered after surgery. Postoperative ophthalmologic examination revealed improvement of both ischemic changes of the left optic fundi. Moreover, LSFG revealed improvement of the blood flow around the left optic disc. LSFG can be a promising clinical tool for the assessment of ocular circulation before and after bypass surgery for occlusive cerebrovascular disease. PMID:25238922

  4. Ocular hazards of light

    NASA Technical Reports Server (NTRS)

    Sliney, David H.

    1994-01-01

    The eye is protected against bright light by the natural aversion response to viewing bright light sources. The aversion response normally protects the eye against injury from viewing bright light sources such as the sun, arc lamps and welding arcs, since this aversion limits the duration of exposure to a fraction of a second (about 0.25 s). The principal retinal hazard resulting from viewing bright light sources is photoretinitis, e.g., solar retinitis with an accompanying scotoma which results from staring at the sun. Solar retinitis was once referred to as 'eclipse blindness' and associated 'retinal burn'. Only in recent years has it become clear that photoretinitis results from a photochemical injury mechanism following exposure of the retina to shorter wavelengths in the visible spectrum, i.e., violet and blue light. Prior to conclusive animal experiments at that time, it was thought to be a thermal injury mechanism. However, it has been shown conclusively that an intense exposure to short-wavelength light (hereafter referred to as 'blue light') can cause retinal injury. The product of the dose-rate and the exposure duration always must result in the same exposure dose (in joules-per-square centimeter at the retina) to produce a threshold injury. Blue-light retinal injury (photoretinitis) can result from viewing either an extremely bright light for a short time, or a less bright light for longer exposure periods. This characteristic of photochemical injury mechanisms is termed reciprocity and helps to distinguish these effects from thermal burns, where heat conduction requires a very intense exposure within seconds to cause a retinal coagulation otherwise, surrounding tissue conducts the heat away from the retinal image. Injury thresholds for acute injury in experimental animals for both corneal and retinal effects have been corroborated for the human eye from accident data. Occupational safety limits for exposure to UVR and bright light are based upon this

  5. Ocular biocompatibility evaluation of hydroxyl-functionalized graphene.

    PubMed

    Lin, Mimi; Zou, Ruitao; Shi, Haiyan; Yu, Shanshan; Li, Xiaojian; Guo, Rui; Yan, Lu; Li, Guoxing; Liu, Yong; Dai, Liming

    2015-05-01

    We have presented our recent efforts on genotoxicity and intraocular biocompatibility of hydroxylated graphene (G-OH) prepared by ball milling. We have previously demonstrated that the as-synthesized G-OH could be considered as an excellent alternative for graphene oxide which had been applied widely. Following our last report on G-OH, we carried out detailed studies on genotoxicity and in vivo biocompatibility of G-OH in this work. Less than 5% enhanced caspase-3 level was observed for cells exposed to more than 50 μg/mL G-OH over 72 h, suggesting G-OH caused cell apoptosis was slight. The G-OH induced DNA damage was also found to be mild since expression of p53 and ROS regeneration level was quite low even at high concentration of G-OH over a long time. Cell viability was found to be higher than 90% with 50 μg/mL G-OH and 80% with 100 μg/mL G-OH using flow cytometry. Comet results suggested that less than 5% tail could be found with 100 μg/mL G-OH. TEM results confirmed that G-OH could penetrate into and out of the cytoplasm by means of endocytosis and exocytosis without causing damage on cell membranes. In vivo biocompatibility of G-OH was studied by intravitreal injection of G-OH into rabbits. The ocular fundus photography results showed that G-OH could be diffused in the vitreous body gradually without any damage caused. Injection of G-OH had caused few damages on eyesight related functions such as intraocular pressure, electroretinogram and histological structures of the retina. PMID:25746274

  6. Chronic ocular hypertension alters local retinal responsiveness.

    PubMed Central

    Ofri, R; Dawson, W W; Foli, K; Gelatt, K N

    1993-01-01

    Electrophysiological responses of the retina and visual cortex to a series of grating stimuli (6-768 minutes of arc) were recorded in seven sessions using normal beagles, 21 sessions using beagles afflicted with inherited ocular hypertension, and 12 sessions using rhesus monkeys. A 15 degrees field centred around the animal's area centralis or fovea was used to stimulate the central retina. A 30 degrees field, centred on the same spot, was then used to stimulate the larger area. Two recording series were completed on each animal, with both field sizes presented in each recording session. The first recording took place 30 minutes after and the second 2 hours after the injection of thiamylal sodium. Only the signals from the toroidal 15 degrees of the retina of the hypertensive dogs were remarkably larger during the second recording (p = 0.001). No significant differences were found between the two recordings from the retinas of normal dogs or monkeys, nor were there any significant differences between the two recordings from above the cortex in any group. Several hypotheses are proposed to explain the basis for the interaction of thiamylal with the more peripheral retinal function in clinically glaucomatous dogs. PMID:8025048

  7. Inverse image alignment method for image mosaicing and video stabilization in fundus indocyanine green angiography under confocal scanning laser ophthalmoscope.

    PubMed

    Zhou, Yongjin; Xue, Hui; Wan, Mingxi

    2003-01-01

    An efficient image registration algorithm, the Inverse Compositional image alignment method based on minimization of Sum of Squared Differences of images, is applied in fundus blood vessel angiography under confocal scanning laser ophthalmoscope, to build image mosaics which have larger field of view without loss of resolution to assist diagnosis. Furthermore, based on similar technique, the angiography video stabilization algorithm is implemented for fundus documenting. The actual underlying models of motion between images and corresponding convergence criteria are also discussed. The experiment results in fundus images demonstrate the effectiveness of the registration scheme. PMID:14575786

  8. Ocular drug delivery systems: An overview

    PubMed Central

    Patel, Ashaben; Cholkar, Kishore; Agrahari, Vibhuti; Mitra, Ashim K

    2014-01-01

    The major challenge faced by today’s pharmacologist and formulation scientist is ocular drug delivery. Topical eye drop is the most convenient and patient compliant route of drug administration, especially for the treatment of anterior segment diseases. Delivery of drugs to the targeted ocular tissues is restricted by various precorneal, dynamic and static ocular barriers. Also, therapeutic drug levels are not maintained for longer duration in target tissues. In the past two decades, ocular drug delivery research acceleratedly advanced towards developing a novel, safe and patient compliant formulation and drug delivery devices/techniques, which may surpass these barriers and maintain drug levels in tissues. Anterior segment drug delivery advances are witnessed by modulation of conventional topical solutions with permeation and viscosity enhancers. Also, it includes development of conventional topical formulations such as suspensions, emulsions and ointments. Various nanoformulations have also been introduced for anterior segment ocular drug delivery. On the other hand, for posterior ocular delivery, research has been immensely focused towards development of drug releasing devices and nanoformulations for treating chronic vitreoretinal diseases. These novel devices and/or formulations may help to surpass ocular barriers and associated side effects with conventional topical drops. Also, these novel devices and/or formulations are easy to formulate, no/negligibly irritating, possess high precorneal residence time, sustain the drug release, and enhance ocular bioavailability of therapeutics. An update of current research advancement in ocular drug delivery necessitates and helps drug delivery scientists to modulate their think process and develop novel and safe drug delivery strategies. Current review intends to summarize the existing conventional formulations for ocular delivery and their advancements followed by current nanotechnology based formulation developments

  9. Ocular perfusion pressure and ocular blood flow in glaucoma

    PubMed Central

    Cherecheanu, A Popa; Garhofer, G; Schmidl, D; Werkmeister, R; Schmetterer, L

    2013-01-01

    Glaucoma is a progressive optic neuropathy of unknown origin. It has been hypothesized that a vascular component is involved in glaucoma pathophysiology. This hypothesis has gained support from studies showing that reduced ocular perfusion pressure is a risk factor for the disease. The exact nature of the involvement is, however, still a matter of debate. Based on recent evidence we propose a model including primary and secondary insults in glaucoma. The primary insult appears to happen at the optic nerve head. Increased intraocular pressure and ischemia at the post-laminar optic nerve head affects retinal ganglion cell axons. Modulating factors are the biomechanical properties of the tissues and cerebrospinal fluid pressure. After this primary insult retinal ganglion cells function at a reduced energy level and are sensitive to secondary insults. These secondary insults may happen if ocular perfusion pressure falls below the lower limit of autoregulation or if neurovascular coupling fails. Evidence for both faulty autoregulation and reduced hyperemic response to neuronal stimulation has been provided in glaucoma patients. The mechanisms appear to involve vascular endothelial dysfunction and impaired astrocyte-vessel signaling. A more detailed understanding of these pathways is required to direct neuroprotective strategies via the neurovascular pathway. PMID:23009741

  10. Ocular perfusion pressure and ocular blood flow in glaucoma.

    PubMed

    Cherecheanu, A Popa; Garhofer, G; Schmidl, D; Werkmeister, R; Schmetterer, L

    2013-02-01

    Glaucoma is a progressive optic neuropathy of unknown origin. It has been hypothesized that a vascular component is involved in glaucoma pathophysiology. This hypothesis has gained support from studies showing that reduced ocular perfusion pressure is a risk factor for the disease. The exact nature of the involvement is, however, still a matter of debate. Based on recent evidence we propose a model including primary and secondary insults in glaucoma. The primary insult appears to happen at the optic nerve head. Increased intraocular pressure and ischemia at the post-laminar optic nerve head affects retinal ganglion cell axons. Modulating factors are the biomechanical properties of the tissues and cerebrospinal fluid pressure. After this primary insult retinal ganglion cells function at a reduced energy level and are sensitive to secondary insults. These secondary insults may happen if ocular perfusion pressure falls below the lower limit of autoregulation or if neurovascular coupling fails. Evidence for both faulty autoregulation and reduced hyperemic response to neuronal stimulation has been provided in glaucoma patients. The mechanisms appear to involve vascular endothelial dysfunction and impaired astrocyte-vessel signaling. A more detailed understanding of these pathways is required to direct neuroprotective strategies via the neurovascular pathway. PMID:23009741

  11. Translational models of ocular disease.

    PubMed

    Zeiss, Caroline J

    2013-07-01

    Animals provide indispensable models to translate basic mechanistic discoveries and realize their therapeutic potential in humans. Conversely, advances in human medicine often inform management of similar conditions in clinical veterinary medicine. In this paper, key experimental model species are introduced, with emphasis on genetic contributions of the mouse. Its role and those of larger animal models are described in common ocular research areas including intraocular neoplasia, corneal epithelial and stromal disease, cataract, uveitis, glaucoma, and retinal dystrophies. Emphasis is placed on those conditions shared by humans and domestic animals, with the intent of exploring how the study of comparable conditions in humans, domestic animals, and laboratory animals informs one another. PMID:23750503

  12. Anomalous phosphenes in ocular protontherapy

    NASA Astrophysics Data System (ADS)

    Khan, E.; Maréchal, F.; Dendale, R.; Mabit, C.; Calugaru, V.; Desjardin, L.; Narici, L.

    2010-04-01

    We have undertaken a clinical ground study of proton-induced light flashes (phosphenes). Patients treated at the Institut Curie - Centre de Protonthérapie in Orsay, France, received radiation therapy to cure ocular and skull-base cancers. Sixty percent of the patients treated for choroidal melanomas using 73 MeV protons report anomalous phosphenes. Delivering a radiation dose on the retina only is not sufficient to trigger the light flash. The present study may be the first indication of phosphenes triggered by protons of few tens of MeV.

  13. A case of ocular cardiac reflex in a child with blunt ocular trauma.

    PubMed

    Reddy, Soma Sekhara; Landry, Jonathan P; Douglass, Kate; Venugopalan, Poovathum Parambil

    2014-01-01

    An 11-year-old boy re-presented with refractory vomiting 18 h after blunt facial and head trauma. Initial CT of the brain performed at his first visit was normal. He was found to have a heart rate of 56 bpm (age appropriate 65-100 bpm) with a blood pressure 90/60 mm Hg. Physical examination revealed an injected sclera and limited vertical movement of the left eye. Neurological examination revealed no focal deficits, but a Glasgow Coma Scale of 14, with mild confusion, depressed mental status and diplopia on upward gaze. Performing upward gaze extra ocular movements exacerbated the patient's bradycardia and confirmed the presence of the oculocardiac reflex. High-resolution CT of orbits demonstrated a left orbital floor fracture with entrapment of the left inferior rectus muscle. Surgical correction resolved his bradycardia. PMID:25422334

  14. An effective fovea detection and automatic assessment of diabetic maculopathy in color fundus images.

    PubMed

    Medhi, Jyoti Prakash; Dandapat, Samarendra

    2016-07-01

    Prolonged diabetes causes severe damage to the vision through leakage of blood and blood constituents over the retina. The effect of the leakage becomes more threatening when these abnormalities involve the macula. This condition is known as diabetic maculopathy and it leads to blindness, if not treated in time. Early detection and proper diagnosis can help in preventing this irreversible damage. To achieve this, the possible way is to perform retinal screening at regular intervals. But the ratio of ophthalmologists to patients is very small and the process of evaluation is time consuming. Here, the automatic methods for analyzing retinal/fundus images prove handy and help the ophthalmologists to screen at a faster rate. Motivated from this aspect, an automated method for detection and analysis of diabetic maculopathy is proposed in this work. The method is implemented in two stages. The first stage involves preprocessing required for preparing the image for further analysis. During this stage the input image is enhanced and the optic disc is masked to avoid false detection during bright lesion identification. The second stage is maculopathy detection and its analysis. Here, the retinal lesions including microaneurysms, hemorrhages and exudates are identified by processing the green and hue plane color images. The macula and the fovea locations are determined using intensity property of processed red plane image. Different circular regions are thereafter marked in the neighborhood of the macula. The presence of lesions in these regions is identified to confirm positive maculopathy. Later, the information is used for evaluating its severity. The principal advantage of the proposed algorithm is, utilization of the relation of blood vessels with optic disc and macula, which enhances the detection process. Proper usage of various color plane information sequentially enables the algorithm to perform better. The method is tested on various publicly available databases

  15. Pattern and distribution of ocular morbidity in primary school children of rural Delhi.

    PubMed

    Chaturvedi, S; Aggarwal, O P

    1999-01-01

    A total of 679 primary school children drawn from developed southern parts and underdeveloped eastern parts of Delhi were examined for ocular morbidity. Their age range was 5-15 years and both sexes had almost equal representation. The prevalence of eye diseases was relatively high. Over 40 percent of all the children studied had one or more ocular problems. Trachoma (18%) was the most common ocular morbidity followed by vitamin A deficiency (10.6%), visual acuity < 6/9 (7.4%) and apparent/latent squint (7.4%). In most of these eye disorders, the majority of the children came from the underdeveloped eastern parts of Delhi. Ocular morbidity seems to be unevenly distributed in rural Delhi with a significantly worse picture in the underdeveloped eastern parts, across the river 'Yamuna'. Though blinding trachoma may cease to be a major problem in India, the country continues to have endemic pockets of its non-blinding form. One puzzling observation was that children with protein-energy malnutrition (PEM) did not show any specific vulnerability to ocular diseases. In fact, those with normal weight-height index were having a higher share of eye diseases. Though this issue needs to be explored further in the light of biological plausibility, it appears that children who do not have PEM are also exposed to ocular diseases at least with comparable risk. PMID:10829825

  16. Meibomian glands and ocular surface inflammation.

    PubMed

    Suzuki, Tomo; Teramukai, Satoshi; Kinoshita, Shigeru

    2015-04-01

    The purpose of this review was to systematically analyze publications related to the role of meibomian gland disease in ocular surface inflammation, with special reference to meibomitis as an inflammatory form of meibomian gland dysfunction (MGD). Meibomian gland inflammation is often present with the ocular surface inflammation in conditions such as blepharokeratoconjunctivitis, ocular rosacea, and phlyctenular keratitis, but its contribution is often overlooked, especially in younger subjects. This can result in misdiagnosis, mistreatment, and, sometimes, severe visual impairment. We identified a related disease entity, seen predominantly in young patients, of ocular surface inflammation associated with meibomitis, which we termed meibomitis-related keratoconjunctivitis. Its specific clinical features are similar to those observed in the above-mentioned diseases, and the inflammatory form of MGD was found to be closely involved in the ocular surface inflammation seen in those four diseases, based on our statistical evaluation. The diagnosis and management of meibomitis, an inflammatory form of MGD, is vital for the successful treatment of the induced ocular surface inflammation. We propose that the ocular surface and the adnexal meibomian glands should be considered as one unit, i.e., the "meibomian gland and ocular surface" (MOS), when encountered in the clinical setting. PMID:25881997

  17. Clinical evaluation of accommodation and ocular surface stability relavant to visual asthenopia with 3D displays

    PubMed Central

    2014-01-01

    Background To validate the association between accommodation and visual asthenopia by measuring objective accommodative amplitude with the Optical Quality Analysis System (OQAS®, Visiometrics, Terrassa, Spain), and to investigate associations among accommodation, ocular surface instability, and visual asthenopia while viewing 3D displays. Methods Fifteen normal adults without any ocular disease or surgical history watched the same 3D and 2D displays for 30 minutes. Accommodative ability, ocular protection index (OPI), and total ocular symptom scores were evaluated before and after viewing the 3D and 2D displays. Accommodative ability was evaluated by the near point of accommodation (NPA) and OQAS to ensure reliability. The OPI was calculated by dividing the tear breakup time (TBUT) by the interblink interval (IBI). The changes in accommodative ability, OPI, and total ocular symptom scores after viewing 3D and 2D displays were evaluated. Results Accommodative ability evaluated by NPA and OQAS, OPI, and total ocular symptom scores changed significantly after 3D viewing (p = 0.005, 0.003, 0.006, and 0.003, respectively), but yielded no difference after 2D viewing. The objective measurement by OQAS verified the decrease of accommodative ability while viewing 3D displays. The change of NPA, OPI, and total ocular symptom scores after 3D viewing had a significant correlation (p < 0.05), implying direct associations among these factors. Conclusions The decrease of accommodative ability after 3D viewing was validated by both subjective and objective methods in our study. Further, the deterioration of accommodative ability and ocular surface stability may be causative factors of visual asthenopia in individuals viewing 3D displays. PMID:24612686

  18. Clinical and Immunological Responses in Ocular Demodecosis

    PubMed Central

    Kim, Jae Hoon; Chun, Yeoun Sook

    2011-01-01

    The purpose of this study was to investigate clinical and immunological responses to Demodex on the ocular surface. Thirteen eyes in 10 patients with Demodex blepharitis and chronic ocular surface disorders were included in this study and treated by lid scrubbing with tea tree oil for the eradication of Demodex. We evaluated ocular surface manifestations and Demodex counts, and analyzed IL-1β, IL-5, IL-7, IL-12, IL-13, IL-17, granulocyte colony-stimulating factor, and macrophage inflammatory protein-1β in tear samples before and after the treatment. All patients exhibited ocular surface manifestations including corneal nodular opacity, peripheral corneal vascularization, refractory corneal erosion and infiltration, or chronic conjunctival inflammatory signs before treatment. After treatment, Demodex was nearly eradicated, tear concentrations of IL-1β and IL-17 were significantly reduced and substantial clinical improvement was observed in all patients. In conclusion, we believe that Demodex plays an aggravating role in inflammatory ocular surface disorders. PMID:21935281

  19. Ocular diseases: immunological and molecular mechanisms

    PubMed Central

    Song, Jing; Huang, Yi-Fei; Zhang, Wen-Jing; Chen, Xiao-Fei; Guo, Yu-Mian

    2016-01-01

    Many factors, such as environmental, microbial and endogenous stress, antigen localization, can trigger the immunological events that affect the ending of the diverse spectrum of ocular disorders. Significant advances in understanding of immunological and molecular mechanisms have been researched to improve the diagnosis and therapy for patients with ocular inflammatory diseases. Some kinds of ocular diseases are inadequately responsive to current medications; therefore, immunotherapy may be a potential choice as an alternative or adjunctive treatment, even in the prophylactic setting. This article first provides an overview of the immunological and molecular mechanisms concerning several typical and common ocular diseases; second, the functions of immunological roles in some of systemic autoimmunity will be discussed; third, we will provide a summary of the mechanisms that dictate immune cell trafficking to ocular local microenvironment in response to inflammation. PMID:27275439

  20. Custom Ocular Prosthesis: A Palliative Approach

    PubMed Central

    Thakkar, Prachi; Patel, JR; Sethuraman, Rajesh; Nirmal, Narendra

    2012-01-01

    The goal of palliative care is the achievement of the best quality of life for patients and their families. Eyes are generally the first features of the face to be noticed. Loss of an eye is a traumatic event which has a crippling effect on the psychology of the patient. Several ocular and orbital disorders require surgical intervention that may result in ocular defects. An ocular prosthesis is fabricated to restore the structure, function, and cosmetics of the defects created by such conditions. Although an implant eye prosthesis has a superior outcome, due to economic factors it may not be a feasible option for all patients. Therefore, a custom-made ocular prosthesis is a good alternative. This case report presents a palliative treatment for a patient with an enucleated eye by fabricating a custom ocular prosthesis which improved his psychological, physical, social, functional, emotional and spiritual needs. PMID:22837616

  1. Ocular manifestations of frontonasal dysplasia.

    PubMed

    Roarty, J D; Pron, G E; Siegel-Bartelt, J; Posnick, J C; Buncic, J R

    1994-01-01

    The ophthalmologic findings associated with frontonasal dysplasia have not been defined previously in a large series of untreated children. We reviewed the ophthalmic manifestations of a series of patients with frontonasal dysplasia who were seen as part of their craniofacial evaluation. All had undergone a complete ophthalmologic examination before any manipulation of either the orbits or the soft tissues of the orbital contents. From 1986 to 1991, 23 patients with frontonasal dysplasia were seen; ophthalmologic abnormalities were found in 20 (87 percent). Abnormalities included significant refractive errors, strabismus, nystagmus, and eyelid ptosis. Three patients had amblyopia, a treatable cause of visual loss, from strabismus or anisometropia. Ten eyes in seven patients (30 percent) had severe structural anomalies, such as optic nerve hypoplasia, optic nerve colobomas, microphthalmia, cataract, corneal dermoid, or inflammatory retinopathy, that resulted in an acuity of 20/100 or worse. The high incidence of ocular abnormalities indicates that early assessment by an ophthalmologist should be part of the initial evaluation of patients with frontonasal dysplasia to detect treatable visual or ocular problems. PMID:8278482

  2. Pharmacotherapy of vestibular and ocular motor disorders, including nystagmus.

    PubMed

    Strupp, Michael; Thurtell, Matthew J; Shaikh, Aasef G; Brandt, Thomas; Zee, David S; Leigh, R John

    2011-07-01

    We review current pharmacological treatments for peripheral and central vestibular disorders, and ocular motor disorders that impair vision, especially pathological nystagmus. The prerequisites for successful pharmacotherapy of vertigo, dizziness, and abnormal eye movements are the "4 D's": correct diagnosis, correct drug, appropriate dosage, and sufficient duration. There are seven groups of drugs (the "7 A's") that can be used: antiemetics; anti-inflammatory, anti-Ménière's, and anti-migrainous medications; anti-depressants, anti-convulsants, and aminopyridines. A recovery from acute vestibular neuritis can be promoted by treatment with oral corticosteroids. Betahistine may reduce the frequency of attacks of Ménière's disease. The aminopyridines constitute a novel treatment approach for downbeat and upbeat nystagmus, as well as episodic ataxia type 2 (EA 2); these drugs may restore normal "pacemaker" activity to the Purkinje cells that govern vestibular and cerebellar nuclei. A limited number of trials indicate that baclofen improves periodic alternating nystagmus, and that gabapentin and memantine improve acquired pendular and infantile (congenital) nystagmus. Preliminary reports suggest suppression of square-wave saccadic intrusions by memantine, and ocular flutter by beta-blockers. Thus, although progress has been made in the treatment of vestibular neuritis, some forms of pathological nystagmus, and EA 2, controlled, masked trials are still needed to evaluate treatments for many vestibular and ocular motor disorders, including betahistine for Ménière's disease, oxcarbazepine for vestibular paroxysmia, or metoprolol for vestibular migraine. PMID:21461686

  3. Lacritin and other autophagy associated proteins in ocular surface health.

    PubMed

    Karnati, Roy; Talla, Venu; Peterson, Katherine; Laurie, Gordon W

    2016-03-01

    Advantage may be taken of macroautophagy ('autophagy') to promote ocular health. Autophagy continually captures aged or damaged cellular material for lysosomal degradation and recyling. When autophagic flux is chronically elevated, or alternatively deficient, health suffers. Chronic elevation of flux and stress are the consequence of inflammatory cytokines or of dry eye tears but not normal tears invitro. Exogenous tear protein lacritin transiently accelerates flux to restore homeostasis invitro and corneal health invivo, and yet the monomeric active form of lacritin appears to be selectively deficient in dry eye. Tissue transglutaminase-dependent cross-linking of monomer decreases monomer quantity and monomer affinity for coreceptor syndecan-1 thereby abrogating activity. Tissue transglutaminase is elevated in dry eye. Mutation of arylsulfatase A, arylsulfatase B, ceroid-lipofuscinosis neuronal 3, mucolipin, or Niemann-Pick disease type C1 respectively underlie several diseases of apparently insufficient autophagic flux that affect the eye, including: metachromatic leukodystrophy, mucopolysaccharidosis type VI, juvenile-onset Batten disease, mucolipidosis IV, and Niemann-Pick type C associated with myelin sheath destruction of corneal sensory and ciliary nerves and of the optic nerve; corneal clouding, ocular hypertension, glaucoma and optic nerve atrophy; accumulation of 'ceroid-lipofuscin' in surface conjunctival cells, and in ganglion and neuronal cells; decreased visual acuity and retinal dystrophy; and neurodegeneration. For some, enzyme or gene replacement, or substrate reduction, therapy is proving to be successful. Here we discuss examples of restoring ocular surface homeostasis through alteration of autophagy, with particular attention to lacritin. PMID:26318608

  4. Bio-medical imaging: Localization of main structures in retinal fundus images

    NASA Astrophysics Data System (ADS)

    Basit, A.; Egerton, S. J.

    2013-12-01

    Retinal fundus images have three main structures, the optic disk, fovea and blood vessels. By examining fundus images, an ophthalmologist can diagnose various clinical disorders of the eye and the body, typically indicated by changes in the diameter, area, branching angles and tortuosity of the three ma in retinal structures. Knowledge of the optic disk position is an important diagnostic index fo r many diseases related to the retina. In this paper, localization of optic disc is discussed. Optic disk detection is based on morphological operationsand smoothing filters. Blood vessels are extracted using the green component of a colour retinal image with the help of a median filter. Maximum intensity values are validated with blood vessels to localize the optic disk location. The proposed method has shown significant improvements in results.

  5. Investigating the influence of chromatic aberration and optical illumination bandwidth on fundus imaging in rats

    NASA Astrophysics Data System (ADS)

    Li, Hao; Liu, Wenzhong; Zhang, Hao F.

    2015-10-01

    Rodent models are indispensable in studying various retinal diseases. Noninvasive, high-resolution retinal imaging of rodent models is highly desired for longitudinally investigating the pathogenesis and therapeutic strategies. However, due to severe aberrations, the retinal image quality in rodents can be much worse than that in humans. We numerically and experimentally investigated the influence of chromatic aberration and optical illumination bandwidth on retinal imaging. We confirmed that the rat retinal image quality decreased with increasing illumination bandwidth. We achieved the retinal image resolution of 10 μm using a 19 nm illumination bandwidth centered at 580 nm in a home-built fundus camera. Furthermore, we observed higher chromatic aberration in albino rat eyes than in pigmented rat eyes. This study provides a design guide for high-resolution fundus camera for rodents. Our method is also beneficial to dispersion compensation in multiwavelength retinal imaging applications.

  6. Investigating the influence of chromatic aberration and optical illumination bandwidth on fundus imaging in rats.

    PubMed

    Li, Hao; Liu, Wenzhong; Zhang, Hao F

    2015-10-01

    Abstract. Rodent models are indispensable in studying various retinal diseases. Noninvasive, high-resolution retinal imaging of rodent models is highly desired for longitudinally investigating the pathogenesis and therapeutic strategies. However, due to severe aberrations, the retinal image quality in rodents can be much worse than that in humans. We numerically and experimentally investigated the influence of chromatic aberration and optical illumination bandwidth on retinal imaging. We confirmed that the rat retinal image quality decreased with increasing illumination bandwidth. We achieved the retinal image resolution of 10  μm using a 19 nm illumination bandwidth centered at 580 nm in a home-built fundus camera. Furthermore, we observed higher chromatic aberration in albino rat eyes than in pigmented rat eyes. This study provides a design guide for high-resolution fundus camera for rodents. Our method is also beneficial to dispersion compensation in multiwavelength retinal imaging applications. PMID:26502233

  7. Unusual optical coherence tomography and fundus autofluorescence findings of eclipse retinopathy.

    PubMed

    Li, Kun-Hsien; Chen, San-Ni; Hwang, Jiunn-Feng; Lin, Chun-Ju

    2012-01-01

    A 63-year-old female patient complained of dimness in the central field of vision in the left eye after viewing an annular partial eclipse without adequate eye protection on 22 July 2009. Fundoscopy showed a wrinkled macular surface. Fundus autofluorescence study revealed well-demarcated hyperautofluorescence at the fovea. Optical coherence tomography demonstrated tiny intraretinal cysts. Fluorescein angiography and indocyanine green angiography were unremarkable. Epimacular membrane developed in the following month with deteriorated vision. Vitrectomy, epiretinal membrane and internal limiting membrane peeling were performed. Vision was restored to 20/20 after the operation. Direct sun-gazing may damage the retinal structures resulting in macular inflammation and increased focal metabolism, which explains the hyperautofluorescence. It may also induce epimacular membrane. Fundus autofluorescence might represent a useful technique to detect subtle solar-induced injuries of the retina. The visual prognosis is favorable but prevention remains the mainstay of treatment. Public health education is mandatory in reducing visual morbidity. PMID:23202400

  8. Simultaneous hand-held contact color fundus and SD-OCT imaging for pediatric retinal diseases (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Ruggeri, Marco; Hernandez, Victor; De Freitas, Carolina; Relhan, Nidhi; Silgado, Juan; Manns, Fabrice; Parel, Jean-Marie

    2016-03-01

    Hand-held wide-field contact color fundus photography is currently the standard method to acquire diagnostic images of children during examination under anesthesia and in the neonatal intensive care unit. The recent development of portable non-contact hand-held OCT retinal imaging systems has proved that OCT is of tremendous help to complement fundus photography in the management of pediatric patients. Currently, there is no commercial or research system that combines color wide-field digital fundus and OCT imaging in a contact-fashion. The contact of the probe with the cornea has the advantages of reducing motion experienced by the photographer during the imaging and providing fundus and OCT images with wider field of view that includes the periphery of the retina. In this study we produce proof of concept for a contact-type hand-held unit for simultaneous color fundus and OCT live view of the retina of pediatric patients. The front piece of the hand-held unit consists of a contact ophthalmoscopy lens integrating a circular light guide that was recovered from a digital fundus camera for pediatric imaging. The custom-made rear piece consists of the optics to: 1) fold the visible aerial image of the fundus generated by the ophthalmoscopy lens on a miniaturized level board digital color camera; 2) conjugate the eye pupil to the galvanometric scanning mirrors of an OCT delivery system. Wide-field color fundus and OCT images were simultaneously obtained in an eye model and sequentially obtained on the eye of a conscious 25 year-old human subject with healthy retina.

  9. Design, simulation and experimental analysis of an anti-stray-light illumination system of fundus camera

    NASA Astrophysics Data System (ADS)

    Ma, Chen; Cheng, Dewen; Xu, Chen; Wang, Yongtian

    2014-11-01

    Fundus camera is a complex optical system for retinal photography, involving illumination and imaging of the retina. Stray light is one of the most significant problems of fundus camera because the retina is so minimally reflective that back reflections from the cornea and any other optical surface are likely to be significantly greater than the light reflected from the retina. To provide maximum illumination to the retina while eliminating back reflections, a novel design of illumination system used in portable fundus camera is proposed. Internal illumination, in which eyepiece is shared by both the illumination system and the imaging system but the condenser and the objective are separated by a beam splitter, is adopted for its high efficiency. To eliminate the strong stray light caused by corneal center and make full use of light energy, the annular stop in conventional illumination systems is replaced by a fiber-coupled, ring-shaped light source that forms an annular beam. Parameters including size and divergence angle of the light source are specially designed. To weaken the stray light, a polarized light source is used, and an analyzer plate is placed after beam splitter in the imaging system. Simulation results show that the illumination uniformity at the fundus exceeds 90%, and the stray light is within 1%. Finally, a proof-of-concept prototype is developed and retinal photos of an ophthalmophantom are captured. The experimental results show that ghost images and stray light have been greatly reduced to a level that professional diagnostic will not be interfered with.

  10. Computer-aided diagnosis of proliferative diabetic retinopathy via modeling of the major temporal arcade in retinal fundus images.

    PubMed

    Oloumi, Faraz; Rangayyan, Rangaraj M; Ells, Anna L

    2013-12-01

    Monitoring the openness of the major temporal arcade (MTA) and how it changes over time could facilitate diagnosis and treatment of proliferative diabetic retinopathy (PDR). We present methods for user-guided semiautomated modeling and measurement of the openness of the MTA based on Gabor filters for the detection of retinal vessels, morphological image processing, and a form of the generalized Hough transform for the detection of parabolas. The methods, implemented via a graphical user interface, were tested with retinal fundus images of 11 normal individuals and 11 patients with PDR in the present pilot study on potential clinical application. A method of arcade angle measurement was used for comparative analysis. The results using the openness parameters of single- and dual-parabolic models as well as the arcade angle measurements indicate areas under the receiver operating characteristics of A z = 0.87, 0.82, and 0.80, respectively. The proposed methods are expected to facilitate quantitative analysis of the architecture of the MTA, as well as assist in detection and diagnosis of PDR. PMID:23579735

  11. Image processing based automatic diagnosis of glaucoma using wavelet features of segmented optic disc from fundus image.

    PubMed

    Singh, Anushikha; Dutta, Malay Kishore; ParthaSarathi, M; Uher, Vaclav; Burget, Radim

    2016-02-01

    Glaucoma is a disease of the retina which is one of the most common causes of permanent blindness worldwide. This paper presents an automatic image processing based method for glaucoma diagnosis from the digital fundus image. In this paper wavelet feature extraction has been followed by optimized genetic feature selection combined with several learning algorithms and various parameter settings. Unlike the existing research works where the features are considered from the complete fundus or a sub image of the fundus, this work is based on feature extraction from the segmented and blood vessel removed optic disc to improve the accuracy of identification. The experimental results presented in this paper indicate that the wavelet features of the segmented optic disc image are clinically more significant in comparison to features of the whole or sub fundus image in the detection of glaucoma from fundus image. Accuracy of glaucoma identification achieved in this work is 94.7% and a comparison with existing methods of glaucoma detection from fundus image indicates that the proposed approach has improved accuracy of classification. PMID:26574297

  12. Optic disc detection in color fundus images using ant colony optimization.

    PubMed

    Pereira, Carla; Gonçalves, Luís; Ferreira, Manuel

    2013-03-01

    Diabetic retinopathy has been revealed as the most common cause of blindness among people of working age in developed countries. However, loss of vision could be prevented by an early detection of the disease and, therefore, by a regular screening program to detect retinopathy. Due to its characteristics, the digital color fundus photographs have been the easiest way to analyze the eye fundus. An important prerequisite for automation is the segmentation of the main anatomical features in the image, particularly the optic disc. Currently, there are many works reported in the literature with the purpose of detecting and segmenting this anatomical structure. Though, none of them performs as needed, especially when dealing with images presenting pathologies and a great variability. Ant colony optimization (ACO) is an optimization algorithm inspired by the foraging behavior of some ant species that has been applied in image processing with different purposes. In this paper, this algorithm preceded by anisotropic diffusion is used for optic disc detection in color fundus images. Experimental results demonstrate the good performance of the proposed approach as the optic disc was detected in most of all the images used, even in the images with great variability. PMID:23160896

  13. [New Approach of Fundus Image Segmentation Evaluation Based on Topology Structure].

    PubMed

    Sheng, Hanwei; Dai, Peishan; Liu, Zhihang; Zhang-Wen, Miaoyun; Zhao, Yali; Fan, Min

    2015-10-01

    In view of the evaluation of fundus image segmentation, a new evaluation method was proposed to make up insufficiency of the traditional evaluation method which only considers the overlap of pixels and neglects topology structure of the retinal vessel. Mathematical morphology and thinning algorithm were used to obtain the retinal vascular topology structure. Then three features of retinal vessel, including mutual information, correlation coefficient and ratio of nodes, were calculated. The features of the thinned images taken as topology structure of blood vessel were used to evaluate retinal image segmentation. The manually-labeled images and their eroded ones of STARE database were used in the experiment. The result showed that these features, including mutual information, correlation coefficient and ratio of nodes, could be used to evaluate the segmentation quality of retinal vessel on fundus image through topology structure, and the algorithm was simple. The method is of significance to the supplement of traditional segmentation evaluation of retinal vessel on fundus image. PMID:26964319

  14. Multimodal segmentation of optic disc and cup from stereo fundus and SD-OCT images

    NASA Astrophysics Data System (ADS)

    Miri, Mohammad Saleh; Lee, Kyungmoo; Niemeijer, Meindert; Abràmoff, Michael D.; Kwon, Young H.; Garvin, Mona K.

    2013-03-01

    Glaucoma is one of the major causes of blindness worldwide. One important structural parameter for the diagnosis and management of glaucoma is the cup-to-disc ratio (CDR), which tends to become larger as glaucoma progresses. While approaches exist for segmenting the optic disc and cup within fundus photographs, and more recently, within spectral-domain optical coherence tomography (SD-OCT) volumes, no approaches have been reported for the simultaneous segmentation of these structures within both modalities combined. In this work, a multimodal pixel-classification approach for the segmentation of the optic disc and cup within fundus photographs and SD-OCT volumes is presented. In particular, after segmentation of other important structures (such as the retinal layers and retinal blood vessels) and fundus-to-SD-OCT image registration, features are extracted from both modalities and a k-nearest-neighbor classification approach is used to classify each pixel as cup, rim, or background. The approach is evaluated on 70 multimodal image pairs from 35 subjects in a leave-10%-out fashion (by subject). A significant improvement in classification accuracy is obtained using the multimodal approach over that obtained from the corresponding unimodal approach (97.8% versus 95.2%; p < 0:05; paired t-test).

  15. Ocular dominance plasticity disrupts binocular inhibition-excitation matching in visual cortex

    PubMed Central

    Saiepour, M. Hadi; Rajendran, Rajeev; Omrani, Azar; Ma, Wen-pei; Tao, Huizhong W.; Heimel, J. Alexander; Levelt, Christiaan N.

    2015-01-01

    Background To ensure that neuronal networks function in a stable fashion, neurons receive balanced inhibitory and excitatory inputs. In various brain regions this balance has been found to change temporarily during plasticity. Whether changes in inhibition have an instructive or permissive role in plasticity remains unclear. Several studies have addressed this question using ocular dominance plasticity in the visual cortex as a model, but so far it remains controversial whether changes in inhibition drive this form of plasticity by directly affecting eye-specific responses or through increasing the plasticity potential of excitatory connections. Results We tested how three major classes of interneurons affect eye-specific responses in normally reared or monocularly deprived mice by optogenetically suppressing their activity. We find that in contrast to somatostatin or vasoactive intestinal polypeptide expressing interneurons, parvalbumin (PV)-expressing interneurons strongly inhibit visual responses. In individual neurons of normal mice, inhibition and excitation driven by either eye are balanced and suppressing PV interneurons does not alter ocular preference. Monocular deprivation disrupts the binocular balance of inhibition and excitation in individual neurons, causing suppression of PV interneurons to change their ocular preference. Importantly however, these changes do not consistently favor responses to one of the eyes at the population level. Conclusion Monocular deprivation disrupts the binocular balance of inhibition and excitation of individual cells. This disbalance does not affect the overall expression of ocular dominance. Our data therefore support a permissive rather than an instructive role of inhibition in ocular dominance plasticity. PMID:25754642

  16. Expression of mutant and wild-type TIMP3 in primary gingival fibroblasts from Sorsby's fundus dystrophy patients.

    PubMed

    Arris, Christine E; Bevitt, Debra J; Mohamed, Jeseem; Li, Zheng; Langton, Kevin P; Barker, Michael D; Clarke, Michael P; McKie, Norman

    2003-05-20

    Gingival fibroblast cell lines were derived from Sorsby's fundus dystrophy (SFD) patients carrying the S181C TIMP3 and the E139X TIMP3 mutations. These cell lines were grown in culture to study expression of the wild-type and mutant tissue inhibitor of metalloproteinase 3 (TIMP3) alleles from a normal diploid cell type. Firstly, patient cells were found to co-express the wild-type and mutant TIMP3 alleles, S181C TIMP3 or E139X TIMP3, at the mRNA level using restriction fragment length polymorphism (RFLP) analysis. A SpeI RFLP for E139X TIMP3 is described. Low levels of endogenous TIMP3 protein expression were elevated using the natural polysaccharide calcium pentosan polysulfate (CaPPs) in combination with the cytokine IL-1alpha. Immunoblotting detected protein expression from both wild-type and mutant alleles, S181C TIMP3 or E139X TIMP3. S181C TIMP3 from these cells was found to dimerise and retain MMP2 inhibitory activity. To facilitate studies of the E139X TIMP3 protein, the allele was expressed using HighFive insect cells. In this cell type, the E139X TIMP3 was synthesised as a mixture of monomer and dimer. Both monomeric and dimeric E139X TIMP3 protein retained MMP2 inhibitory activity in gelatin zymography. Expression of mutant E139X or S181C TIMP3 protein from a normal diploid patient-derived fibroblast cell had no effect on either MMP2 or MMP9 expression or activation whilst transcribed from their normal promoter context. PMID:12757930

  17. ETS-1 and ETS-2 are upregulated in a transgenic mouse model of pigmented ocular neoplasm

    PubMed Central

    De la Houssaye, G.; Vieira, V.; Masson, C.; Beermann, F.; Dufier, J.L.; Menasche, M.

    2008-01-01

    Purpose Choroidal melanoma is the most common primary malignant ocular tumor in human adults. Relevant mouse models of human uveal melanoma still remain to be developed. We have studied the transgenic mouse strain, Tyrp-1-TAg, to try to gain insight into possible molecular mechanisms common to pigmented ocular neoplasms occurring spontaneously in the eyes of these mice and human choroidal melanoma. The role of two members of the ETS (E26 avian leukemia oncogene) family of transcription factors, ETS-1 and ETS-2, has been investigated in many cancers but has not yet been studied in ocular tumors. Methods This is the first study describing the production and distribution of ETS-1 and ETS-2 mRNAs and proteins using in situ hybridization and immunohistochemistry in murine ocular tissue sections of normal control eyes and tumoral eyes from mice of the same age. Using semi-quantitative reverse-transcription polymerase chain reaction (RT–PCR) and western blots experiments, we compared changes in ETS-1 and ETS-2 expression, their protein levels, and the regulation of some of their target gene expressions at different stages of the ocular tumoral progression in the transgenic mouse model, Tyrp-1-TAg, with those in normal eyes from control mice of the same age. Results In normal control adult mouse eyes, ETS-1 was mostly present in the nuclei of all neuroretinal layers whereas ETS-2 was mostly localized in the cytosol of the cell bodies of these layers with a smaller amount present in the nuclei. Both were found in the retinal pigmentary epithelium (RPE). ETS-1 and ETS-2 mRNA and protein levels were much higher in the ocular tissues of Tyrp-1-TAg mice than in control ocular tissues from wild-type mice. This upregulation was correlated with tumor progression. We also demonstrated upregulation of ETS-1 and ETS-2 target expressions in Tyrp-1-TAg mice when comparing with the same target expressions in control mice. Conclusions Our findings suggest that ETS-1 and ETS-2 are

  18. Variability of Ocular Deviation in Strabismus

    PubMed Central

    Economides, John R.; Adams, Daniel L.; Horton, Jonathan C.

    2015-01-01

    IMPORTANCE In strabismus, the fixating eye conveys the direction of gaze while the fellow eye points at a peripheral location in space. The stability of the eyes may be reduced by the absence of a common target. OBJECTIVE To quantify the stability of eye position in strabismus and to measure variability in the ocular deviation. DESIGN, SETTING, AND PARTICIPANTS From 2010 to 2014, a prospective comparative case study of 25 patients with alternating exotropia with normal visual acuity in each eye and 25 control individuals was conducted in a laboratory at a tertiary eye center. A video eye tracker was used to measure the position of each eye while participants alternated fixation on the center of a cross under dichoptic conditions or scanned pictures of natural scenes. MAIN OUTCOMES AND MEASURES Spatial and temporal variability in the position of the fixating eye and the nonfixating eye in patients with strabismus and control individuals, quantified by the log area of ellipses containing 95% of eye positions or mean SDs of eye position. RESULTS In the 25 patients with strabismus, the mean (SD) age was 28 (14) years (range, 8–55 years) and the mean (SD) ocular deviation was 14.2° (5.9°) (range, 4.4°–22.4°). In the patients with strabismus, the mean position variability (1.80 log units; 95% CI, 1.66–1.93) for the deviating eye was greater than for the fixating eye (1.26 log units; 95% CI, 1.17–1.35) (P < .001). The fixating eye of patients with strabismus was more variable in position than the fixating eye of individuals without strabismus (0.98 log units; 95% CI, 0.88–1.08) (P < .005). CONCLUSIONS AND RELEVANCE In patients with strabismus, even without amblyopia, the deviated eye is more variable in position than the fixating eye. Both eyes are less stable in position than the eyes of control individuals, which indicates that strabismus impairs the ability to fixate targets steadily. Saccades contribute to variability of the deviation angle because they

  19. Functional Roles of Bestrophins in Ocular Epithelia

    PubMed Central

    Marmorstein, Alan D.; Cross, Harold E.; Peachey, Neal S.

    2009-01-01

    There are four members of the bestrophin family of proteins in the human genome, of which two are known to be expressed in the eye. The gene BEST1 (formerly VMD2) which encodes the protein bestrophin-1 (Best1) was first identified in 1998. Mutations in this gene have now been associated with four clinically distinguishable human eye diseases, collectively referred to as “bestrophinopathies”. Over the last decade, laboratories have sought to understand how Best1 mutations could result in eye diseases that range in presentation from macular degeneration to nanophthalmos. The majority of our knowledge comes from studies that have sought to understand how Best1 mutations or dysfunction could induce the classical symptoms of the most common of these diseases: Best vitelliform macular dystrophy (BVMD). BVMD is a dominant trait that is characterized electrophysiologically by a diminished electrooculogram light peak with a normal clinical electroretinogram. This together with the localization of Best1 to the retinal pigment epithelium (RPE) basolateral plasma membrane and data from heterologous expression studies, have led to the proposal that Best1 generates the light peak, and that bestrophins are a family of Ca2+ activated Cl- channels (CaCCs). However, data from Best1 knock-out and knock-in mice, coupled with the recent discovery of a recessive bestrophinopathy suggest that Best1 does not generate the light peak. Recently Best2 was found to be expressed in non-pigmented epithelia in the ciliary body. However, aqueous dynamics in Best2 knock-out mice do not support a role for Best2 as a Cl- channel. Thus, the purported CaCC function of the bestrophins and how loss of this function relates to clinical disease needs to be reassessed. In this article, we examine data obtained from tissue-type and animal models and discuss the current state of bestrophin research, what roles Best1 and Best2 may play in ocular epithelia and ocular electrophysiology, and how perturbation

  20. Free radicals and ocular disease.

    PubMed

    Anderson, R E; Kretzer, F L; Rapp, L M

    1994-01-01

    Ames, Shigenaga, and Hagen recently published a thorough review of the relationship between oxidants, antioxidants, and degenerative diseases of ageing. They point out that only 9% of Americans daily consume the two fruits and three vegetables recommended by the National Cancer Institute and the National Research Council/National Academy of Science. In addition to antioxidants, these foodstuffs contain many essential micronutrients. To date, specific recommendations for antioxidant supplementation have not been made by any governmental agency or professional association. A number of clinical, basic, and epidemiological studies have implicated free radical induced lipid peroxidation in various ocular disorders. It would seem prudent that those persons at greatest risk for these disorders take some precautions, which could include sunglasses that filter ultraviolet light; hats that shield the eyes from direct sunlight; and the ingestion of fruits, vegetables, and antioxidants. PMID:7771292

  1. Immunomodulation on the ocular surface: a review

    PubMed Central

    Szaflik, Jerzy; Szaflik, Jacek P.; Ambroziak, Maciej; Witkiewicz, Jan; Skopiński, Piotr

    2016-01-01

    The increasing understanding of immune mechanisms changed our perception of the ocular surface, which is now considered a compartment of the common mucosal immune system. It offered the possibility to alter the physiological immune response on the ocular surface and effectively combat inflammation, which impairs stability of the tear film and causes tear hyperosmolarity, causing symptoms of dry eye disease. The paper provides an overview of ocular surface anatomy and physiology, explains the underlying mechanisms of dry eye disease and discusses novel and promising treatment modalities, such as cyclosporine A, biological therapies using autologous serum and various growth factors as well as experimental treatment methods which are currently being investigated. PMID:27536206

  2. [Case of Fisher syndrome with ocular flutter].

    PubMed

    Nakayasu, Koki; Sakimoto, Tohru; Minami, Masayuki; Shigihara, Syuntaro; Ishikawa, Hiroshi

    2010-06-01

    We report a case of Fisher syndrome accompanied by ocular flutter. A 19-year-old man presented with diplopia and vertigo, associated with preceding symptoms of common cold. Since symmetric weakness of abduction in both eyes, truncal ataxia, diminution of tendon reflexes, and gaze nystagmus were noted, he was diagnosed as having Fisher syndrome. Ocular flutter also was noticed during horizontal gaze. Serum anti-GQ1b antibody and anti-GM1 antibody were detected. He was followed without therapy and the symptoms resolved. The accompanying ocular flutter may suggest that a central nervous system disorder may also be present in Fisher syndrome. PMID:20593660

  3. Ocular chemical injuries and their management

    PubMed Central

    Singh, Parul; Tyagi, Manoj; Kumar, Yogesh; Gupta, K. K.; Sharma, P. D.

    2013-01-01

    Chemical burns represent potentially blinding ocular injuries and constitute a true ocular emergency requiring immediate assessment and initiation of treatment. The majority of victims are young and exposure occurs at home, work place and in association with criminal assaults. Alkali injuries occur more frequently than acid injuries. Chemical injuries of the eye produce extensive damage to the ocular surface epithelium, cornea, anterior segment and limbal stem cells resulting in permanent unilateral or bilateral visual impairment. Emergency management if appropriate may be single most important factor in determining visual outcome. This article reviews the emergency management and newer techniques to improve the prognosis of patients with chemical injuries. PMID:24082664

  4. OCULAR SYPHILIS IN A KIDNEY TRANSPLANT RECIPIENT

    PubMed Central

    ROMAO, Elen A.; BOLELLA, Valdes R.; NARDIN, Maria Estela P.; HABIB-SIMAO, Maria Lucia; FURTADO, João Marcelo; MOYSES-NETO, Miguel

    2016-01-01

    We present a case of ocular syphilis after a renal transplantation involving progressive vision loss without clinically identifiable ocular disease. Electroretinography showed signs of ischemia, especially in the internal retina. A serological test was positive for syphilis. Lumbar puncture revealed lymphocytic meningitis and a positive serologic test for syphilis in the cerebrospinal fluid. The patient was treated with penicillin, and had a quick vision improvement. In the case of transplant recipients, clinicians should always consider the diagnosis of ocular syphilis in cases with unexplained visual acuity decrement, as this condition may cause serious complications if not treated. PMID:27253748

  5. Gender Disparities in Ocular Inflammatory Disorders*

    PubMed Central

    Sen, Hatice Nida; Davis, Janet; Ucar, Didar; Fox, Austin; Chan, Chi Chao; Goldstein, Debra A.

    2014-01-01

    Ocular inflammatory disorders disproportionately affect women, and the majority of affected women are of childbearing age. The role of sex or reproductive hormones has been proposed in many other inflammatory or autoimmune disorders, and findings from non-ocular autoimmune diseases suggest a complex interaction between sex hormones, genetic factors and the immune system. However, despite the age and sex bias, factors that influence this disparity are complicated and unclear. This review aims to evaluate the gender disparities in prevalence, incidence and severity of the most common infectious and non-infectious ocular inflammatory disorders. PMID:24987987

  6. Immunomodulation on the ocular surface: a review.

    PubMed

    Ambroziak, Anna M; Szaflik, Jerzy; Szaflik, Jacek P; Ambroziak, Maciej; Witkiewicz, Jan; Skopiński, Piotr

    2016-01-01

    The increasing understanding of immune mechanisms changed our perception of the ocular surface, which is now considered a compartment of the common mucosal immune system. It offered the possibility to alter the physiological immune response on the ocular surface and effectively combat inflammation, which impairs stability of the tear film and causes tear hyperosmolarity, causing symptoms of dry eye disease. The paper provides an overview of ocular surface anatomy and physiology, explains the underlying mechanisms of dry eye disease and discusses novel and promising treatment modalities, such as cyclosporine A, biological therapies using autologous serum and various growth factors as well as experimental treatment methods which are currently being investigated. PMID:27536206

  7. OCULAR SYPHILIS IN A KIDNEY TRANSPLANT RECIPIENT.

    PubMed

    Romao, Elen A; Bolella, Valdes R; Nardin, Maria Estela P; Habib-Simao, Maria Lucia; Furtado, João Marcelo; Moyses-Neto, Miguel

    2016-01-01

    We present a case of ocular syphilis after a renal transplantation involving progressive vision loss without clinically identifiable ocular disease. Electroretinography showed signs of ischemia, especially in the internal retina. A serological test was positive for syphilis. Lumbar puncture revealed lymphocytic meningitis and a positive serologic test for syphilis in the cerebrospinal fluid. The patient was treated with penicillin, and had a quick vision improvement. In the case of transplant recipients, clinicians should always consider the diagnosis of ocular syphilis in cases with unexplained visual acuity decrement, as this condition may cause serious complications if not treated. PMID:27253748

  8. Imaging of ocular melanoma metastasis.

    PubMed

    Balasubramanya, Rashmi; Selvarajan, Santosh Kumar; Cox, Mougnyan; Joshi, Ganesh; Deshmukh, Sandeep; Mitchell, Donald G; O'Kane, Patrick

    2016-09-01

    Ocular melanoma is the most common adult primary intraocular tumour. Although <1% of patients have metastatic disease at the time of initial diagnosis, most will develop metastasis at varying lengths of time. Metastasis surveillance is therefore critical in the follow-up of patients with ocular melanoma. Liver is the most common site of metastasis and prognosis is based on the treatment of liver metastasis. Hence, imaging of liver metastasis is vital. MRI is the most specific modality for imaging liver metastasis and is at least as sensitive as CT. Extrahepatic metastasis such as retroperitoneal nodules and bone metastases are also better evaluated on MRI. Gadolinium-based contrast agents are extremely helpful for detecting liver lesions. In particular, newer hepatobiliary contrast agents which offer an additional hepatobiliary phase of excretion help in the detection of even tiny liver metastases. Diffusion-weighted imaging is helpful when an i.v. contrast cannot be administered. Treated lesions are also better evaluated with MRI. CT is useful for evaluating lung nodules, large liver metastasis or in patients in whom MRI is medically contraindicated. The disadvantage lies in its inability to detect small liver metastasis and the radiation dose involved. The lesions treated with iodized oil as part of chemoembolization procedures can be followed on CT. Ultrasound can be used only for detecting hepatic metastases. However, it is heavily operator dependent, technically challenging and time consuming especially in patients who are large. Extrahepatic metastasis cannot be seen on ultrasound. Its utility is primarily for the biopsy of liver lesions. Positron emission tomography (PET)-CT can detect lung nodules and large liver lesions but is insensitive to small liver lesions. Moreover, the high radiation dose is a major disadvantage. PMID:27168029

  9. Color Fundus Photography versus Fluorescein Angiography in Identification of the Macular Center and Zone in Retinopathy of Prematurity

    PubMed Central

    Patel, Samir N.; Klufas, Michael A.; Ryan, Michael C.; Jonas, Karyn E.; Ostmo, Susan; Martinez-Castellanos, Maria Ana; Berrocal, Audina M.; Chiang, Michael F.; Chan, R.V. Paul

    2016-01-01

    Purpose To examine the utility of fluorescein angiography (FA) in identification of the macular center and the diagnosis of zone in patients with retinopathy of prematurity (ROP). Design Validity and reliability analysis of diagnostic tools Methods 32 sets (16 color fundus photographs; 16 color fundus photographs paired with the corresponding FA) of wide-angle retinal images obtained from 16 eyes of eight infants with ROP were compiled on a secure web site. 9 ROP experts (3 pediatric ophthalmologists; 6 vitreoretinal surgeons) participated in the study. For each image set, experts identified the macular center and provided a diagnosis of zone. Main Outcome Measures (1) Sensitivity and specificity of zone diagnosis (2) “Computer facilitated diagnosis of zone,” based on precise measurement of the macular center, optic disc center, and peripheral ROP. Results Computer facilitated diagnosis of zone agreed with the expert’s diagnosis of zone in 28/45 (62%) cases using color fundus photographs and in 31/45 (69%) cases using FA. Mean (95% CI) sensitivity for detection of zone I by experts as compared to a consensus reference standard diagnosis when interpreting the color fundus images alone versus interpreting the color fundus photographs and FA was 47% (35.3% – 59.3%) and 61.1% (48.9% – 72.4%), respectively, (t(9) ≥ (2.063), p = 0.073). Conclusions There is a marginally significant difference in zone diagnosis when using color fundus photographs compared to using color fundus photographs and the corresponding fluorescein angiograms. There is inconsistency between traditional zone diagnosis (based on ophthalmoscopic exam and image review) compared to a computer-facilitated diagnosis of zone. PMID:25637180

  10. Ocular Complications of Diabetes and Therapeutic Approaches

    PubMed Central

    Vieira-Potter, Victoria J.; Karamichos, Dimitrios; Lee, Darren J.

    2016-01-01

    Diabetes mellitus (DM) is a metabolic disease defined by elevated blood glucose (BG). DM is a global epidemic and the prevalence is anticipated to continue to increase. The ocular complications of DM negatively impact the quality of life and carry an extremely high economic burden. While systemic control of BG can slow the ocular complications they cannot stop them, especially if clinical symptoms are already present. With the advances in biodegradable polymers, implantable ocular devices can slowly release medication to stop, and in some cases reverse, diabetic complications in the eye. In this review we discuss the ocular complications associated with DM, the treatments available with a focus on localized treatments, and what promising treatments are on the horizon. PMID:27119078

  11. Ocular Complications of Diabetes and Therapeutic Approaches.

    PubMed

    Vieira-Potter, Victoria J; Karamichos, Dimitrios; Lee, Darren J

    2016-01-01

    Diabetes mellitus (DM) is a metabolic disease defined by elevated blood glucose (BG). DM is a global epidemic and the prevalence is anticipated to continue to increase. The ocular complications of DM negatively impact the quality of life and carry an extremely high economic burden. While systemic control of BG can slow the ocular complications they cannot stop them, especially if clinical symptoms are already present. With the advances in biodegradable polymers, implantable ocular devices can slowly release medication to stop, and in some cases reverse, diabetic complications in the eye. In this review we discuss the ocular complications associated with DM, the treatments available with a focus on localized treatments, and what promising treatments are on the horizon. PMID:27119078

  12. The effect of uterine motion and uterine margins on target and normal tissue doses in intensity modulated radiation therapy of cervical cancer

    NASA Astrophysics Data System (ADS)

    Gordon, J. J.; Weiss, E.; Abayomi, O. K.; Siebers, J. V.; Dogan, N.

    2011-05-01

    In intensity modulated radiation therapy (IMRT) of cervical cancer, uterine motion can be larger than cervix motion, requiring a larger clinical target volume to planning target volume (CTV-to-PTV) margin around the uterine fundus. This work simulates different motion models and margins to estimate the dosimetric consequences. A virtual study used image sets from ten patients. Plans were created with uniform margins of 1 cm (PTVA) and 2.4 cm (PTVC), and a margin tapering from 2.4 cm at the fundus to 1 cm at the cervix (PTVB). Three inter-fraction motion models (MM) were simulated. In MM1, all structures moved with normally distributed rigid body translations. In MM2, CTV motion was progressively magnified as one moved superiorly from the cervix to the fundus. In MM3, both CTV and normal tissue motion were magnified as in MM2, modeling the scenario where normal tissues move into the void left by the mobile uterus. Plans were evaluated using static and percentile DVHs. For a conventional margin (PTVA), quasi-realistic uterine motion (MM3) reduces fundus dose by about 5 Gy and increases normal tissue volumes receiving 30-50 Gy by ~5%. A tapered CTV-to-PTV margin can restore fundus and CTV doses, but will increase normal tissue volumes receiving 30-50 Gy by a further ~5%.

  13. Ocular cytokinome is linked to clinical characteristics in ocular toxoplasmosis

    PubMed Central

    de-la-Torre, Alejandra; Pfaff, Alexander W.; Grigg, Michael E.; Villard, Odile; Candolfi, Ermanno; Gomez-Marin, Jorge E.

    2016-01-01

    Purpose To determine the cytokine levels in aqueous humor (AH) of Colombian patients with active ocular toxoplasmosis (OT), and to correlate them with their clinical characteristics. Methods 27 Cytokines/chemokines were assayed in 15 AH samples (nine patients with diagnosis of OT biologically-confirmed and six controls that underwent cataract surgery). Correlations were assessed between cytokine/chemokine levels, type of inflammatory response (Th1, Th2, Th17, Treg), and clinical characteristics. Results Th2 predominant response was related to more severe clinical features. The presence of VEGF and IL-5 was related to higher number of recurrences. Growth factors (VEGF, FGF, PDGF-β), were related to higher number of lesions. Patients infected by type-I/III strains had a particular intraocular cytokine-pattern. Conclusions Th2 response was related to more severe clinical characteristics in patients infected by Type I/III strains. IL-5 and VEGF were associated with recurrences. We correlate for the first time, specific cytokine-patterns with clinical characteristics and with the infecting Toxoplasma strain. PMID:24787053

  14. Gender Differences in Ocular Blood Flow

    PubMed Central

    Schmidl, Doreen; Garhöfer, Gerhard; Popa-Cherecheanu, Alina

    2015-01-01

    Gender medicine has been a major focus of research in recent years. The present review focuses on gender differences in the epidemiology of the most frequent ocular diseases that have been found to be associated with impaired ocular blood flow, such as age-related macular degeneration, glaucoma and diabetic retinopathy. Data have accumulated indicating that hormones have an important role in these diseases, since there are major differences in the prevalence and incidence between men and pre- and post-menopausal women. Whether this is related to vascular factors is, however, not entirely clear. Interestingly, the current knowledge about differences in ocular vascular parameters between men and women is sparse. Although little data is available, estrogen, progesterone and testosterone are most likely important regulators of blood flow in the retina and choroid, because they are key regulators of vascular tone in other organs. Estrogen seems to play a protective role since it decreases vascular resistance in large ocular vessels. Some studies indicate that hormone therapy is beneficial for ocular vascular disease in post-menopausal women. This evidence is, however, not sufficient to give any recommendation. Generally, remarkably few data are available on the role of sex hormones on ocular blood flow regulation, a topic that requires more attention in the future. PMID:24892919

  15. [Ocular involvement in familial amyloid polyneuropathy].

    PubMed

    Rousseau, A; Kaswin, G; Adams, D; Cauquil, C; Théaudin, M; Mincheva, Z; M'garrech, M; Labetoulle, M; Barreau, E

    2013-11-01

    Familial amyloid polyneuropathy (FAP) or transthyretin (TTR) amyloid polyneuropathy is a progressive sensorimotor and autonomic neuropathy of adult onset, which is transmitted as an autosomal dominant trait. In addition to neurologic symptoms, FAP may be associated with weight loss, cardiac and renal failure and ocular complications. FAP is a devastating disease, causing death within 10years after the first symptoms. The TTR Val30Met mutation is the most common of more than 100 amyloidogenic mutations identified worldwide. Liver transplantation (LT) is currently the only treatment for preventing synthesis of the amyloidogenic variants of TTR. LT can halt progression of the neuropathy in up to 70% of cases and doubles the overall median survival of young Val30Met patients. Oral administration of tafamidis, which prevents deposition of mutated TTR, is now available to delay neurologic complications in early stages of the disease. Ocular manifestations of FAP are frequent and mainly include keratoconjunctivitis sicca, secondary glaucoma, vitreous deposits and pupillary abnormalities. Retinal and choroidal vascular abnormalities are more rare. Since ocular TTR is synthesized, at least in part, in the retinal pigment epithelium, LT does not influence the course of ocular involvement. The effects of tafamidis on the latter are still unknown. Because LT and symptomatic treatments greatly improve life expectancy of patients with FAP, ocular involvement is becoming a more frequent challenge to address. This review summarizes the pathophysiology, clinical findings and possible treatments of ocular manifestations of FAP. PMID:24144522

  16. Effect of Brij-78 on systemic delivery of insulin from an ocular device.

    PubMed

    Lee, Y C; Simamora, P; Yalkowsky, S H

    1997-04-01

    An ocular insert is developed for the controlled systemic delivery of insulin. Commercially available Gelfoam absorbable gelatin sponge, USP, is used in the fabrication of the ocular insert in the form of a matrix system. Two eyedrop formulations and 13 eye device formulations were evaluated. The efficacy of insulin ocular delivery was quantitated by monitoring the changes in its pharmacological response (i.e., blood glucose lowering). The in vivo results from devices containing 0.5 or 1.0 mg of insulin with 20 micrograms of polyoxyethylene-20-stearyl ether (Brij-78) give a substantial improvement in insulin activity and a significant prolongation in its duration compared with the eyedrops. In addition, the mean blood glucose concentration returns to nearly normal levels within 60 min after the removal of the device. Overall, the application of the Gelfoam device makes it feasible to obtain a prolonged systemic delivery of insulin within the desired therapeutic levels without the risk of hypoglycemia. PMID:9109043

  17. Ocular motility, visual acuity and dysfunction of neuropsychological impairment in children with shunted uncomplicated hydrocephalus.

    PubMed

    Zeiner, H K; Prigatano, G P; Pollay, M; Biscoe, C B; Smith, R V

    1985-01-01

    Children with shunted, uncomplicated, communicating hydrocephalus were tested to determine (1) the persistence of neuropsychological impairment and (2) the relationship between neuropsychological functioning, ocular motility, and acuity abnormalities. Eighteen hydrocephalic and 18 individually age- and sex-matched controls were given a neuropsychological battery, repeated after an interval of 1 year. Hydrocephalic children were also tested at the beginning of the second year for strabismus, amblyopia and visual acuity. Their medical records were reviewed for history of ocular motility and/or acuity abnormalities. Hydrocephalic children with normal range IQ were found to have lower verbal IQ, memory, and fine motor skills compared to controls. A history of ocular motility and acuity abnormalities was associated with impaired visuospatial and verbal problem-solving skills. PMID:4005882

  18. Endothelial microRNA-150 is an intrinsic suppressor of pathologic ocular neovascularization

    PubMed Central

    Liu, Chi-Hsiu; Sun, Ye; Li, Jie; Gong, Yan; Tian, Katherine T.; Evans, Lucy P.; Morss, Peyton C.; Fredrick, Thomas W.; Saba, Nicholas J.; Chen, Jing

    2015-01-01

    Pathologic ocular neovascularization commonly causes blindness. It is critical to identify the factors altered in pathologically proliferating versus normally quiescent vessels to develop effective targeted therapeutics. MicroRNAs regulate both physiological and pathological angiogenesis through modulating expression of gene targets at the posttranscriptional level. However, it is not completely understood if specific microRNAs are altered in pathologic ocular blood vessels, influencing vascular eye diseases. Here we investigated the potential role of a specific microRNA, miR-150, in regulating ocular neovascularization. We found that miR-150 was highly expressed in normal quiescent retinal blood vessels and significantly suppressed in pathologic neovessels in a mouse model of oxygen-induced proliferative retinopathy. MiR-150 substantially decreased endothelial cell function including cell proliferation, migration, and tubular formation and specifically suppressed the expression of multiple angiogenic regulators, CXCR4, DLL4, and FZD4, in endothelial cells. Intravitreal injection of miR-150 mimic significantly decreased pathologic retinal neovascularization in vivo in both wild-type and miR-150 knockout mice. Loss of miR-150 significantly promoted angiogenesis in aortic rings and choroidal explants ex vivo and laser-induced choroidal neovascularization in vivo. In conclusion, miR-150 is specifically enriched in quiescent normal vessels and functions as an endothelium-specific endogenous inhibitor of pathologic ocular neovascularization. PMID:26374840

  19. Endothelial microRNA-150 is an intrinsic suppressor of pathologic ocular neovascularization.

    PubMed

    Liu, Chi-Hsiu; Sun, Ye; Li, Jie; Gong, Yan; Tian, Katherine T; Evans, Lucy P; Morss, Peyton C; Fredrick, Thomas W; Saba, Nicholas J; Chen, Jing

    2015-09-29

    Pathologic ocular neovascularization commonly causes blindness. It is critical to identify the factors altered in pathologically proliferating versus normally quiescent vessels to develop effective targeted therapeutics. MicroRNAs regulate both physiological and pathological angiogenesis through modulating expression of gene targets at the posttranscriptional level. However, it is not completely understood if specific microRNAs are altered in pathologic ocular blood vessels, influencing vascular eye diseases. Here we investigated the potential role of a specific microRNA, miR-150, in regulating ocular neovascularization. We found that miR-150 was highly expressed in normal quiescent retinal blood vessels and significantly suppressed in pathologic neovessels in a mouse model of oxygen-induced proliferative retinopathy. MiR-150 substantially decreased endothelial cell function including cell proliferation, migration, and tubular formation and specifically suppressed the expression of multiple angiogenic regulators, CXCR4, DLL4, and FZD4, in endothelial cells. Intravitreal injection of miR-150 mimic significantly decreased pathologic retinal neovascularization in vivo in both wild-type and miR-150 knockout mice. Loss of miR-150 significantly promoted angiogenesis in aortic rings and choroidal explants ex vivo and laser-induced choroidal neovascularization in vivo. In conclusion, miR-150 is specifically enriched in quiescent normal vessels and functions as an endothelium-specific endogenous inhibitor of pathologic ocular neovascularization. PMID:26374840

  20. Ocular Surface Immunity: Homeostatic Mechanisms and Their Disruption in Dry Eye Disease

    PubMed Central

    Barabino, Stefano; Chen, Yihe; Chauhan, Sunil; Dana, Reza

    2012-01-01

    The tear film, lacrimal glands, corneal and conjunctival epithelia and Meibomian glands work together as a lacrimal functional unit (LFU) to preserve the integrity and function of the ocular surface. The integrity of this unit is necessary for the health and normal function of the eye and visual system. Nervous connections and systemic hormones are well known factors that maintain the homeostasis of the ocular surface. They control the response to internal and external stimuli. Our and others’ studies show that immunological mechanisms also play a pivotal role in regulating the ocular surface environment. Our studies demonstrate how anti-inflammatory factors such as the expression of vascular endothelial growth factor receptor-3 (VEGFR-3) in corneal cells, immature corneal resident antigen-presenting cells, and regulatory T cells play an active role in protecting the ocular surface. Dry eye disease (DED) affects millions of people worldwide and negatively influences the quality of life for patients. In its most severe forms, DED may lead to blindness. The etiology and pathogenesis of DED remain largely unclear. Nonetheless, in this review we summarize the role of the disruption of afferent and efferent immunoregulatory mechanisms that are responsible for the chronicity of the disease, its symptoms, and its clinical signs. We illustrate current anti-inflammatory treatments for DED and propose that prevention of the disruption of immunoregulatory mechanisms may represent a promising therapeutic strategy towards controlling ocular surface inflammation. PMID:22426080

  1. Overview of biopolymers as carriers of antiphlogistic agents for treatment of diverse ocular inflammations.

    PubMed

    Sharma, Anil Kumar; Arya, Amit; Sahoo, Pravat Kumar; Majumdar, Dipak Kanti

    2016-10-01

    Inflammation of the eye is a usual clinical condition that can implicate any part of the eye. The nomenclature of variety of such inflammations is based on the ocular part involved. These diseases may jeopardize normal functioning of the eye on progression. In general, corticosteroids, antihistamines, mast cell stabilizers and non-steroidal anti-inflammatory drugs (NSAIDs) are used to treat inflammatory diseases/disorders of the eye. There have been several attempts via different approaches of drug delivery to overcome the low ocular bioavailability resulting from shorter ocular residence time. The features like safety, ease of elimination and ability to sustain drug release have led to application of biopolymers in ocular therapeutics. Numerous polymers of natural origin such as gelatin, collagen, chitosan, albumin, hyaluronic acid, alginates etc. have been successfully employed for preparation of different ocular dosage forms. Chitosan is the most explored biopolymer amongst natural biopolymers because of its inherent characteristics. The emergence of synthetic biopolymers (like PVP, PACA, PCL, POE, polyanhydrides, PLA, PGA and PLGA) has also added new dimensions to the drug delivery strategies meant for treatment of ophthalmic inflammations. The current review is an endeavor to describe the utility of a variety of biomaterials/polymers based drug delivery systems as carrier for anti-inflammatory drugs in ophthalmic therapeutics. PMID:27287177

  2. Normal faults, normal friction?

    NASA Astrophysics Data System (ADS)

    Collettini, Cristiano; Sibson, Richard H.

    2001-10-01

    Debate continues as to whether normal faults may be seismically active at very low dips (δ < 30°) in the upper continental crust. An updated compilation of dip estimates (n = 25) has been prepared from focal mechanisms of shallow, intracontinental, normal-slip earthquakes (M > 5.5; slip vector raking 90° ± 30° in the fault plane) where the rupture plane is unambiguously discriminated. The dip distribution for these moderate-to-large normal fault ruptures extends from 65° > δ > 30°, corresponding to a range, 25° < θr < 60°, for the reactivation angle between the fault and inferred vertical σ1. In a comparable data set previously obtained for reverse fault ruptures (n = 33), the active dip distribution is 10° < δ = θr < 60°. For vertical and horizontal σ1 trajectories within extensional and compressional tectonic regimes, respectively, dip-slip reactivation is thus restricted to faults oriented at θr ≤ 60° to inferred σ1. Apparent lockup at θr ≈ 60° in each dip distribution and a dominant 30° ± 5° peak in the reverse fault dip distribution, are both consistent with a friction coefficient μs ≈ 0.6, toward the bottom of Byerlee's experimental range, though localized fluid overpressuring may be needed for reactivation of less favorably oriented faults.

  3. Myosin light chain phosphatase activation is involved in the hydrogen sulfide-induced relaxation in mouse gastric fundus.

    PubMed

    Dhaese, Ingeborg; Lefebvre, Romain A

    2009-03-15

    The relaxant effect of hydrogen sulfide (H(2)S) in the vascular tree is well established but its influence and mechanism of action in gastrointestinal smooth muscle was hardly investigated. The influence of H(2)S on contractility in mouse gastric fundus was therefore examined. Sodium hydrogen sulfide (NaHS; H(2)S donor) was administered to prostaglandin F(2alpha) (PGF(2alpha))-contracted circular muscle strips of mouse gastric fundus, before and after incubation with interfering drugs. NaHS caused a concentration-dependent relaxation of the pre-contracted mouse gastric fundus strips. The K(+) channels blockers glibenclamide, apamin, charybdotoxin, 4-aminopyridin and barium chloride had no influence on the NaHS-induced relaxation. The relaxation by NaHS was also not influenced by L-NAME, ODQ and SQ 22536, inhibitors of the cGMP and cAMP pathway, by nerve blockers capsazepine, omega-conotoxin and tetrodotoxin or by several channel and receptor blockers (ouabain, nifedipine, 2-aminoethyl diphenylborinate, ryanodine and thapsigargin). The myosin light chain phosphatase (MLCP) inhibitor calyculin-A reduced the NaHS-induced relaxation, but the Rho-kinase inhibitor Y-27632 had no influence. We show that NaHS is able to relax PGF(2alpha)-contracted mouse gastric fundus strips. The results suggest that in the mouse gastric fundus, H(2)S causes relaxation at least partially via activation of MLCP. PMID:19374871

  4. Nitrergic and purinergic interplay in inhibitory transmission in rat gastric fundus.

    PubMed

    Vetri, T; Bonvissuto, F; Marino, A; Postorino, A

    2007-07-01

    1 This study was undertaken to analyse the involvement of ATP in non-adrenergic non- cholinergic (NANC) relaxation and possible interplay between nitrergic and purinergic systems in rat gastric fundus. 2 Experiments were performed in vitro on strips of longitudinal muscle from rat gastric fundus, recording the mechanical activity as changes in isometric force. In addition, NO release induced by different experimental conditions was assayed. 3 Under NANC conditions in serotonin-precontracted strips, electrical field stimulation (EFS) elicited a tetrodotoxin (TTX)-sensitive relaxation accompanied by nitric oxide (NO) release. This effect was antagonized by pretreatment with the NO synthase antagonist Nomega-nitro-L-arginine (L-NA) or by desensitization of purinergic receptors. Purinergic desensitization was also able to further antagonize the residual EFS-induced relaxation remaining after L-NA treatment. Exogenously applied NO [delivered as sodium nitroprusside (SNP)] or ATP (and related purines) induced concentration-dependent, TTX-insensitive relaxant responses. ATP also induced the release of NO. A reduction in the responses to ATP was observed in the presence of L-NA. In contrast, SNP-induced relaxation remained unchanged after desensitization of purinergic receptors. Finally, apamin, a blocker of the small conductance Ca2+ -dependent K+ channels, reduced the amplitude of the muscular relaxation evoked by either EFS, ATP or SNP. 4 In conclusion, this study provides evidence that in rat gastric fundus, ATP is one of the inhibitory transmitters released from NANC intramural neurones acting directly on the muscle, through receptors coupled to apamin-sensitive Ca2+ -dependent K+ channels and, indirectly, through the stimulation of NO production. PMID:17584445

  5. Detection of retinal capillary nonperfusion in fundus fluorescein angiogram of diabetic retinopathy

    PubMed Central

    Rasta, Seyed Hossein; Nikfarjam, Shima; Javadzadeh, Alireza

    2015-01-01

    Introduction: Retinal capillary nonperfusion (CNP) is one of the retinal vascular diseases in diabetic retinopathy (DR) patients. As there is no comprehensive detection technique to recognize CNP areas, we proposed a different method for computing detection of ischemic retina, non-perfused (NP) regions, in fundus fluorescein angiogram (FFA) images. Methods: Whilst major vessels appear as ridges, non-perfused areas are usually observed as ponds that are surrounded by healthy capillaries in FFA images. A new technique using homomorphic filtering to correct light illumination and detect the ponds surrounded in healthy capillaries on FFA images was designed and applied on DR fundus images. These images were acquired from the diabetic patients who had referred to the Nikookari hospital and were diagnosed for diabetic retinopathy during one year. Our strategy was screening the whole image with a fixed window size, which is small enough to enclose areas with identified topographic characteristics. To discard false nominees, we also performed a thresholding operation on the screen and marked images. To validate its performance we applied our detection algorithm on 41 FFA diabetic retinopathy fundus images in which the CNP areas were manually delineated by three clinical experts. Results: Lesions were found as smooth regions with very high uniformity, low entropy, and small intensity variations in FFA images. The results of automated detection method were compared with manually marked CNP areas so achieved sensitivity of 81%, specificity of 78%, and accuracy of 91%.The result was present as a Receiver operating character (ROC) curve, which has an area under the curve (AUC) of 0.796 with 95% confidence intervals. Conclusion: This technique introduced a new automated detection algorithm to recognize non-perfusion lesions on FFA. This has potential to assist detecting and managing of ischemic retina and may be incorporated into automated grading diabetic retinopathy structures

  6. ROPtool analysis of images acquired using a noncontact handheld fundus camera (Pictor)--a pilot study.

    PubMed

    Vickers, Laura A; Freedman, Sharon F; Wallace, David K; Prakalapakorn, S Grace

    2015-12-01

    The presence of plus disease is the primary indication for treatment of retinopathy of prematurity (ROP), but its diagnosis is subjective and prone to error. ROPtool is a semiautomated computer program that quantifies vascular tortuosity and dilation. Pictor is an FDA-approved, noncontact, handheld digital fundus camera. This pilot study evaluated ROPtool's ability to analyze high-quality Pictor images of premature infants and its accuracy in diagnosing plus disease compared to clinical examination. In our small sample of images, ROPtool could trace and identify the presence of plus disease with high accuracy. PMID:26691046

  7. Elliptical Local Vessel Density: a Fast and Robust Quality Metric for Fundus Images

    SciTech Connect

    Giancardo, Luca; Chaum, Edward; Karnowski, Thomas Paul; Meriaudeau, Fabrice; Tobin Jr, Kenneth William; Abramoff, M.D.

    2008-01-01

    A great effort of the research community is geared towards the creation of an automatic screening system able to promptly detect diabetic retinopathy with the use of fundus cameras. In addition, there are some documented approaches to the problem of automatically judging the image quality. We propose a new set of features independent of Field of View or resolution to describe the morphology of the patient's vessels. Our initial results suggest that they can be used to estimate the image quality in a time one order of magnitude shorter respect to previous techniques.

  8. Ocular Biometric Changes after Trabeculectomy

    PubMed Central

    Alvani, Azam; Pakravan, Mohammad; Esfandiari, Hamed; Safi, Sare; Yaseri, Mehdi; Pakravan, Parastou

    2016-01-01

    This review article aimed to evaluate ocular biometric changes after trabeculectomy. The PubMed database was searched using the keywords “axial length” (AL), “anterior chamber depth” (ACD), “corneal astigmatism,” “corneal topography” and “trabeculectomy.” The extracted studies were categorized based on the evaluated parameters and the biometry method (contact and non-contact). Comparable studies with respect to their sample size were combined for statistical analysis. Twenty-five studies including 690 individuals which met the inclusion criteria were selected. After trabeculectomy, a significant and persistent AL reduction, with a range of 0.1-0.19 and 0.1-0.9 mm measured with contact and non-contact methods, respectively, was observed. With respect to topographic changes, 0.38-1.4 diopters (D) with-the-rule (WTR) astigmatism was induced postoperatively. All studies revealed ACD reduction immediately after surgery, which gradually deepened and approximated its preoperative levels on day 14. ACD reduction was not significant after that period in the majority of cases. In conclusion, changes in ACD is of small amount and of short period, thus it can be ignored; however, reported changes in AL and keratometry are of sufficient magnitude and can affect the refractive prediction of combined cataract surgery and trabeculectomy. PMID:27621788

  9. Cockpit Ocular Recording System (CORS)

    NASA Technical Reports Server (NTRS)

    Rothenheber, Edward; Stokes, James; Lagrossa, Charles; Arnold, William; Dick, A. O.

    1990-01-01

    The overall goal was the development of a Cockpit Ocular Recording System (CORS). Four tasks were used: (1) the development of the system; (2) the experimentation and improvement of the system; (3) demonstrations of the working system; and (4) system documentation. Overall, the prototype represents a workable and flexibly designed CORS system. For the most part, the hardware use for the prototype system is off-the-shelf. All of the following software was developed specifically: (1) setup software that the user specifies the cockpit configuration and identifies possible areas in which the pilot will look; (2) sensing software which integrates the 60 Hz data from the oculometer and heat orientation sensing unit; (3) processing software which applies a spatiotemporal filter to the lookpoint data to determine fixation/dwell positions; (4) data recording output routines; and (5) playback software which allows the user to retrieve and analyze the data. Several experiments were performed to verify the system accuracy and quantify system deficiencies. These tests resulted in recommendations for any future system that might be constructed.

  10. Ocular Biometric Changes after Trabeculectomy.

    PubMed

    Alvani, Azam; Pakravan, Mohammad; Esfandiari, Hamed; Safi, Sare; Yaseri, Mehdi; Pakravan, Parastou

    2016-01-01

    This review article aimed to evaluate ocular biometric changes after trabeculectomy. The PubMed database was searched using the keywords "axial length" (AL), "anterior chamber depth" (ACD), "corneal astigmatism," "corneal topography" and "trabeculectomy." The extracted studies were categorized based on the evaluated parameters and the biometry method (contact and non-contact). Comparable studies with respect to their sample size were combined for statistical analysis. Twenty-five studies including 690 individuals which met the inclusion criteria were selected. After trabeculectomy, a significant and persistent AL reduction, with a range of 0.1-0.19 and 0.1-0.9 mm measured with contact and non-contact methods, respectively, was observed. With respect to topographic changes, 0.38-1.4 diopters (D) with-the-rule (WTR) astigmatism was induced postoperatively. All studies revealed ACD reduction immediately after surgery, which gradually deepened and approximated its preoperative levels on day 14. ACD reduction was not significant after that period in the majority of cases. In conclusion, changes in ACD is of small amount and of short period, thus it can be ignored; however, reported changes in AL and keratometry are of sufficient magnitude and can affect the refractive prediction of combined cataract surgery and trabeculectomy. PMID:27621788

  11. Deep neural network and random forest hybrid architecture for learning to detect retinal vessels in fundus images.

    PubMed

    Maji, Debapriya; Santara, Anirban; Ghosh, Sambuddha; Sheet, Debdoot; Mitra, Pabitra

    2015-08-01

    Vision impairment due to pathological damage of the retina can largely be prevented through periodic screening using fundus color imaging. However the challenge with large-scale screening is the inability to exhaustively detect fine blood vessels crucial to disease diagnosis. In this work we present a computational imaging framework using deep and ensemble learning based hybrid architecture for reliable detection of blood vessels in fundus color images. A deep neural network (DNN) is used for unsupervised learning of vesselness dictionaries using sparse trained denoising auto-encoders (DAE), followed by supervised learning of the DNN response using a random forest for detecting vessels in color fundus images. In experimental evaluation with the DRIVE database, we achieve the objective of vessel detection with max. avg. accuracy of 0.9327 and area under ROC curve of 0.9195. PMID:26736930

  12. Classification of abnormal fundus autofluorescence patterns in the junctional zone of geographic atrophy in patients with age related macular degeneration

    PubMed Central

    Bindewald, A; Schmitz-Valckenberg, S; Jorzik, J J; Dolar-Szczasny, J; Sieber, H; Keilhauer, C; Weinberger, A W A; Dithmar, S; Pauleikhoff, D; Mansmann, U; Wolf, S; Holz, F G

    2005-01-01

    Aim: To describe and classify patterns of abnormal fundus autofluorescence (FAF) in the junctional zone of geographic atrophy (GA) in patients with age related macular degeneration. Methods: Digital FAF images were recorded in 164 eyes of 107 patients using a confocal scanning laser ophthalmoscope (cSLO; excitation 488 nm, detection above 500 nm) as part of a prospective multicentre natural history study (FAM Study). FAF images were obtained in accordance with a standardised protocol for digital image acquisition and generation of mean images after automated alignment. Results: Image quality was sufficient for classification of FAF patterns in 149 eyes (90.9%) with lens opacities being the most common reason for insufficient image quality. Abnormal FAF outside GA in 149 eyes was classified into four patterns: focal (12.1%), banded (12.8%), patchy (2.0%), and diffuse (57.0%), whereby 12.1% had normal background FAF in the junctional zone. In 4% there was no predominant pattern. The diffuse pattern was subdivided into four groups including reticular (4.7%), branching (27.5%), fine granular (18.1%), and fine granular with peripheral punctate spots (6.7%). Conclusions: Different phenotypic patterns of abnormal FAF in the junctional zone of GA can be identified with cSLO FAF imaging. These distinct patterns may reflect heterogeneity at a cellular and molecular level in contrast with a non-specific ageing process. A refined phenotypic classification may be helpful to identify prognostic determinants for the spread of atrophy and visual loss, for identification of genetic risk factors as well as for the design of future interventional trials. PMID:15965170

  13. Radial fundus autofluorescence in the periphery in patients with X-linked retinitis pigmentosa

    PubMed Central

    Ogino, Ken; Oishi, Maho; Oishi, Akio; Morooka, Satoshi; Sugahara, Masako; Gotoh, Norimoto; Kurimoto, Masafumi; Yoshimura, Nagahisa

    2015-01-01

    Purpose To describe the peripheral autofluorescence images and clinical features of patients with retinal dystrophy who showed radial fundus autofluorescence (FAF) at the posterior pole. Methods The authors retrospectively reviewed pooled wide-field FAF images of 711 patients with retinal dystrophy and 56 family members. Results Eleven eyes of seven women exhibited radial FAF at the posterior pole. Wide-field FAF showed extension of the radial pattern to the periphery in all eyes except one. One woman showed radial hyper-FAF only in the periphery, not at the posterior pole. These eight individuals were X-linked retinitis pigmentosa patients or carriers. The tapetal-like reflex was not observed in their color fundus photographs. The peripheral visual field showed wedge-shaped restriction in some individuals. Conclusion Wide-field FAF imaging can depict radial FAF not only at the posterior pole but also in the periphery in X-linked retinitis pigmentosa carriers. The authors therefore agree with previous reports that radial FAF may be a hallmark of X-linked retinitis pigmentosa. PMID:26316687

  14. Pilot Study on Visual Function and Fundus Autofluorescence Assessment in Diabetic Patients

    PubMed Central

    Calvo-Maroto, Ana M.; Esteve-Taboada, José J.; Pérez-Cambrodí, Rafael J.; Madrid-Costa, David; Cerviño, Alejandro

    2016-01-01

    Purpose. Evaluate optimized fundus autofluorescence (FAF) imaging in early stages of diabetic retinopathy (DR) and relate findings with conventional colour fundus imaging and visual function in diabetic patients and control subjects. Materials and Methods. FAF and colour images were obtained using the CR-2 Plus digital nonmydriatic retinal camera in seven diabetic patients and thirteen control subjects. Visual-Functioning Questionnaire-25 (VFQ-25) and Diabetes Self-Management Questionnaire (DSMQ) were used to assess the quality of life and diabetes self-care. Contrast sensitivity function (CSF) was evaluated with the Vistech 6500 chart. Results. FAF and optimized-FAF imaging showed more retinal alterations related to DR than colour imaging. In diabetic patients, compatible signs with microaneurysms, capillary dilations, and haemorrhages were less numerous in colour imaging than optimized-FAF and FAF imaging in areas analysed. Control subjects at risk of developing DM showed more retinal pigment epithelium defects than those without risk in all retinal areas. Significant differences were not found in VFQ-25 and CSF between diabetic patients and control subjects. Conclusions. FAF and optimized-FAF imaging showed significant alterations related to DR not observed in colour imaging. FAF and optimized-FAF images could be a useful complementary tool for detecting early alterations associated with the development and progression of DR. PMID:26977312

  15. Automatic multiresolution age-related macular degeneration detection from fundus images

    NASA Astrophysics Data System (ADS)

    Garnier, Mickaël.; Hurtut, Thomas; Ben Tahar, Houssem; Cheriet, Farida

    2014-03-01

    Age-related Macular Degeneration (AMD) is a leading cause of legal blindness. As the disease progress, visual loss occurs rapidly, therefore early diagnosis is required for timely treatment. Automatic, fast and robust screening of this widespread disease should allow an early detection. Most of the automatic diagnosis methods in the literature are based on a complex segmentation of the drusen, targeting a specific symptom of the disease. In this paper, we present a preliminary study for AMD detection from color fundus photographs using a multiresolution texture analysis. We analyze the texture at several scales by using a wavelet decomposition in order to identify all the relevant texture patterns. Textural information is captured using both the sign and magnitude components of the completed model of Local Binary Patterns. An image is finally described with the textural pattern distributions of the wavelet coefficient images obtained at each level of decomposition. We use a Linear Discriminant Analysis for feature dimension reduction, to avoid the curse of dimensionality problem, and image classification. Experiments were conducted on a dataset containing 45 images (23 healthy and 22 diseased) of variable quality and captured by different cameras. Our method achieved a recognition rate of 93:3%, with a specificity of 95:5% and a sensitivity of 91:3%. This approach shows promising results at low costs that in agreement with medical experts as well as robustness to both image quality and fundus camera model.

  16. Bright Retinal Lesions Detection using Colour Fundus Images Containing Reflective Features

    SciTech Connect

    Giancardo, Luca; Karnowski, Thomas Paul; Chaum, Edward; Meriaudeau, Fabrice; Tobin Jr, Kenneth William; Li, Yaquin

    2009-01-01

    In the last years the research community has developed many techniques to detect and diagnose diabetic retinopathy with retinal fundus images. This is a necessary step for the implementation of a large scale screening effort in rural areas where ophthalmologists are not available. In the United States of America, the incidence of diabetes is worryingly increasing among the young population. Retina fundus images of patients younger than 20 years old present a high amount of reflection due to the Nerve Fibre Layer (NFL), the younger the patient the more these reflections are visible. To our knowledge we are not aware of algorithms able to explicitly deal with this type of reflection artefact. This paper presents a technique to detect bright lesions also in patients with a high degree of reflective NFL. First, the candidate bright lesions are detected using image equalization and relatively simple histogram analysis. Then, a classifier is trained using texture descriptor (Multi-scale Local Binary Patterns) and other features in order to remove the false positives in the lesion detection. Finally, the area of the lesions is used to diagnose diabetic retinopathy. Our database consists of 33 images from a telemedicine network currently developed. When determining moderate to high diabetic retinopathy using the bright lesions detected the algorithm achieves a sensitivity of 100% at a specificity of 100% using hold-one-out testing.

  17. Automatic Screening and Grading of Age-Related Macular Degeneration from Texture Analysis of Fundus Images.

    PubMed

    Phan, Thanh Vân; Seoud, Lama; Chakor, Hadi; Cheriet, Farida

    2016-01-01

    Age-related macular degeneration (AMD) is a disease which causes visual deficiency and irreversible blindness to the elderly. In this paper, an automatic classification method for AMD is proposed to perform robust and reproducible assessments in a telemedicine context. First, a study was carried out to highlight the most relevant features for AMD characterization based on texture, color, and visual context in fundus images. A support vector machine and a random forest were used to classify images according to the different AMD stages following the AREDS protocol and to evaluate the features' relevance. Experiments were conducted on a database of 279 fundus images coming from a telemedicine platform. The results demonstrate that local binary patterns in multiresolution are the most relevant for AMD classification, regardless of the classifier used. Depending on the classification task, our method achieves promising performances with areas under the ROC curve between 0.739 and 0.874 for screening and between 0.469 and 0.685 for grading. Moreover, the proposed automatic AMD classification system is robust with respect to image quality. PMID:27190636

  18. Pilot Study on Visual Function and Fundus Autofluorescence Assessment in Diabetic Patients.

    PubMed

    Calvo-Maroto, Ana M; Esteve-Taboada, José J; Pérez-Cambrodí, Rafael J; Madrid-Costa, David; Cerviño, Alejandro

    2016-01-01

    Purpose. Evaluate optimized fundus autofluorescence (FAF) imaging in early stages of diabetic retinopathy (DR) and relate findings with conventional colour fundus imaging and visual function in diabetic patients and control subjects. Materials and Methods. FAF and colour images were obtained using the CR-2 Plus digital nonmydriatic retinal camera in seven diabetic patients and thirteen control subjects. Visual-Functioning Questionnaire-25 (VFQ-25) and Diabetes Self-Management Questionnaire (DSMQ) were used to assess the quality of life and diabetes self-care. Contrast sensitivity function (CSF) was evaluated with the Vistech 6500 chart. Results. FAF and optimized-FAF imaging showed more retinal alterations related to DR than colour imaging. In diabetic patients, compatible signs with microaneurysms, capillary dilations, and haemorrhages were less numerous in colour imaging than optimized-FAF and FAF imaging in areas analysed. Control subjects at risk of developing DM showed more retinal pigment epithelium defects than those without risk in all retinal areas. Significant differences were not found in VFQ-25 and CSF between diabetic patients and control subjects. Conclusions. FAF and optimized-FAF imaging showed significant alterations related to DR not observed in colour imaging. FAF and optimized-FAF images could be a useful complementary tool for detecting early alterations associated with the development and progression of DR. PMID:26977312

  19. Accurate and reliable segmentation of the optic disc in digital fundus images

    PubMed Central

    Giachetti, Andrea; Ballerini, Lucia; Trucco, Emanuele

    2014-01-01

    Abstract. We describe a complete pipeline for the detection and accurate automatic segmentation of the optic disc in digital fundus images. This procedure provides separation of vascular information and accurate inpainting of vessel-removed images, symmetry-based optic disc localization, and fitting of incrementally complex contour models at increasing resolutions using information related to inpainted images and vessel masks. Validation experiments, performed on a large dataset of images of healthy and pathological eyes, annotated by experts and partially graded with a quality label, demonstrate the good performances of the proposed approach. The method is able to detect the optic disc and trace its contours better than the other systems presented in the literature and tested on the same data. The average error in the obtained contour masks is reasonably close to the interoperator errors and suitable for practical applications. The optic disc segmentation pipeline is currently integrated in a complete software suite for the semiautomatic quantification of retinal vessel properties from fundus camera images (VAMPIRE). PMID:26158034

  20. Accurate and reliable segmentation of the optic disc in digital fundus images.

    PubMed

    Giachetti, Andrea; Ballerini, Lucia; Trucco, Emanuele

    2014-07-01

    We describe a complete pipeline for the detection and accurate automatic segmentation of the optic disc in digital fundus images. This procedure provides separation of vascular information and accurate inpainting of vessel-removed images, symmetry-based optic disc localization, and fitting of incrementally complex contour models at increasing resolutions using information related to inpainted images and vessel masks. Validation experiments, performed on a large dataset of images of healthy and pathological eyes, annotated by experts and partially graded with a quality label, demonstrate the good performances of the proposed approach. The method is able to detect the optic disc and trace its contours better than the other systems presented in the literature and tested on the same data. The average error in the obtained contour masks is reasonably close to the interoperator errors and suitable for practical applications. The optic disc segmentation pipeline is currently integrated in a complete software suite for the semiautomatic quantification of retinal vessel properties from fundus camera images (VAMPIRE). PMID:26158034

  1. Automatic Screening and Grading of Age-Related Macular Degeneration from Texture Analysis of Fundus Images

    PubMed Central

    Phan, Thanh Vân; Seoud, Lama; Chakor, Hadi; Cheriet, Farida

    2016-01-01

    Age-related macular degeneration (AMD) is a disease which causes visual deficiency and irreversible blindness to the elderly. In this paper, an automatic classification method for AMD is proposed to perform robust and reproducible assessments in a telemedicine context. First, a study was carried out to highlight the most relevant features for AMD characterization based on texture, color, and visual context in fundus images. A support vector machine and a random forest were used to classify images according to the different AMD stages following the AREDS protocol and to evaluate the features' relevance. Experiments were conducted on a database of 279 fundus images coming from a telemedicine platform. The results demonstrate that local binary patterns in multiresolution are the most relevant for AMD classification, regardless of the classifier used. Depending on the classification task, our method achieves promising performances with areas under the ROC curve between 0.739 and 0.874 for screening and between 0.469 and 0.685 for grading. Moreover, the proposed automatic AMD classification system is robust with respect to image quality. PMID:27190636

  2. Optoelectrophysiological stimulation of the human eye using fundus-controlled silent substitution technique

    NASA Astrophysics Data System (ADS)

    Klee, Sascha; Link, Dietmar; Bessler, Patrick; Haueisen, Jens

    2011-01-01

    We design, characterize, and apply a novel optoelectrophysiological setup for a fundus-controlled silent substitution technique that accounts for interindividual variability in retina morphology and simultaneously monitors the stimulation site under investigation. We connect a digital color liquid crystal on silicon projector, an electron-multiplying imager, and a light-emitting diode to a fundus camera. The temporal and spatial characterization reveal a maximal contrast loss of 7% for the highest stimulation frequency (30 Hz) and maximum cutoff spatial frequencies of ~120 cycles/deg. Two silent substitution flash sequences are applied to modulate selective activity in the short-wavelength-sensitive cone (S-cone) and combined long- and middle-wavelength-sensitive cone (LM-cone) pathways. Simultaneously, the visual evoked potentials are recorded. The data are compared to the grand average responses from a previous study that employed standard computer-screen presentation and showed very good latency matches. All the volunteers in the present examination exhibit differences between the S-cone and LM-cone evoked potentials (parameters mean values: peak-to-peak amplitude, N1 latency, and P1 latency for S-cone/LM-cone responses: 8 μV/15 μV, 113 ms/89 ms, 170 ms/143 ms). We demonstrate that the developed optoelectrophysiological setup simultaneously provides imaging, functional stimulation, and electrophysiological investigation of the retina.

  3. Ocular Findings in Volcanic Fog Induced Conjunctivitis

    PubMed Central

    Lagunzad, John Kenneth D

    2011-01-01

    Objective To describe the ocular signs and symptoms of patients complaining of eye irritation due to volcanic fog (vog). Methods The study utilized a non-comparative, retrospective chart review of 30 patients who had a chief complaint of eye irritation, which the subjects attributed to vog. Ocular signs and symptoms are described and related to the ambient concentration of sulfur dioxide (SO2), particulate matter sized 2.5 microns (PM2.5), and vog visibility in O‘ahu during the period of the study. Results Ocular signs noted were conjunctival injection (100%), clear mucous discharge (100%), papillary reaction (100%), punctal edema (80%), eyelid swelling (73.3%) and chemosis (63.3%). Ocular symptoms were itchiness (100%), foreign body sensation (100%), tearing (96.6%) and burning sensation (90%). All patients had concurrent respiratory symptoms. During the period of study, the highest 24-hour average concentration of particulate matter sized 2.5 microns (PM2.5) was 49.04 µg/m3 and vog was visually present. Conclusions Patients complaining of eye irritation due to vog have observable ocular signs and symptoms. PMID:22187513

  4. Ocular toxicity from systemically administered xenobiotics

    PubMed Central

    Gokulgandhi, Mitan R; Vadlapudi, Aswani Dutt; Mitra, Ashim K

    2015-01-01

    Introduction The eye is considered as the most privileged organ because of the blood–ocular barrier that acts as a barrier to systemically administered xenobiotics. However, there has been a significant increase in the number of reports on systemic drug-induced ocular complications. If such complications are left untreated, then it may cause permanent damage to vision. Hence, knowledge of most recent updates on ever-increasing reports of such toxicities has become imperative to develop better therapy while minimizing toxicities. Areas covered The article is mainly divided into anterior and posterior segment manifestations caused by systemically administered drugs. The anterior segment is further elaborated on corneal complications where as the posterior segment is focused on optic nerve, retinal and vitreous complications. Furthermore, this article includes recent updates on acute and chronic ocular predicaments, in addition to discussing various associated symptoms caused by drugs. Expert opinion Direct correlation of ocular toxicities due to systemic drug therapy is evident from current literature. Therefore, it is necessary to have detailed documentation of these complications to improve understanding and predict toxicities. We made an attempt to ensure that the reader is aware of the characteristic ocular complications, the potential for irreversible drug toxicity and indications for cessation. PMID:22803583

  5. Trans-palpebral illumination: an approach for wide-angle fundus photography without the need for pupil dilation.

    PubMed

    Toslak, Devrim; Thapa, Damber; Chen, Yanjun; Erol, Muhammet Kazim; Paul Chan, R V; Yao, Xincheng

    2016-06-15

    It is technically difficult to construct wide-angle fundus imaging devices due to the complexity of conventional transpupillary illumination and imaging mechanisms. We report here a new method, i.e., trans-palpebral illumination, for wide-angle fundus photography without the need for pupil dilation. By constructing a smartphone-based prototype imaging device, we demonstrated a 152° view in a single-shot image. The unique combination of low-cost smartphone design and automatic illumination optimization promises an affordable solution to conduct telemedicine assessment of eye diseases, which will improve access to eye care for patients in rural and underserved areas. PMID:27304264

  6. Trans-palpebral illumination: an approach for wide-angle fundus photography without the need for pupil dilation

    PubMed Central

    Toslak, Devrim; Thapa, Damber; Chen, Yanjun; Erol, Muhammet Kazim; Paul Chan, R. V.; Yao, Xincheng

    2016-01-01

    It is technically difficult to construct wide-angle fundus imaging devices due to the complexity of conventional transpupillary illumination and imaging mechanisms. We report here a new method, i.e., trans-palpebral illumination, for wide-angle fundus photography without the need for pupil dilation. By constructing a smartphone-based prototype imaging device, we demonstrated a 152° view in a single-shot image. The unique combination of low-cost smartphone design and automatic illumination optimization promises an affordable solution to conduct telemedicine assessment of eye diseases, which will improve access to eye care for patients in rural and underserved areas. PMID:27304264

  7. Human ocular torsion during parabolic flights: an analysis with scleral search coil

    NASA Technical Reports Server (NTRS)

    Cheung, B. S.; Money, K.; Howard, I.; Kirienko, N.; Johnson, W.; Lackner, J.; Dizio, P.; Evanoff, J.

    1992-01-01

    Rotation of the eyes about the visual axis is known as ocular torsion. A lateral inclination (a "roll") of the head induces ocular torsion in the opposite direction, a response known as ocular counterrolling. For six subjects, we recorded the static (head still) and dynamic (head in oscillatory roll motion) ocular torsion in normal 1 g condition and also during the microgravity and hypergravity periods of parabolic flight, using the electromagnetic scleral search coil technique. With the head still, the direction and magnitude of torsion that occurred in response to microgravity and hypergravity differed substantially from one individual to another, but there was a significant difference in torsional magnitude between the microgravity and hypergravity periods, for all static head positions including the upright position. Under normal 1 g conditions, counterrolling compensated for about 16% of (voluntary) static head roll, while dynamic counterroll was much larger, up to 36% of head roll at 0.55 Hz. With increasing frequency of head oscillation between 0.33 Hz and 0.55 Hz, the gain of counterrolling increased and there was no change in the phase relationship. The gain of dynamic counterroll (in response to voluntary head rolling) was not significantly less in hypogravity, suggesting that on the ground at these frequencies the contribution of gravity and gravity receptors to this reflex is redundant: this reflex is probably driven by the semicircular canals. In some subjects, the torsional displacement in microgravity is accompanied by micro-torsional oscillatory motion.

  8. Ocular Decompression Retinopathy Following Canaloplasty for Primary Open Angle Glaucoma: A Case Report.

    PubMed

    Li, Gai-Yun; Alantaree, Samer; Wang, Jun-Ming; Zhang, Hong

    2016-03-01

    Ocular decompression retinopathy (ODR), a rare postoperative complication following glaucoma surgery, is characterized by the transient appearance of scattered retinal hemorrhages.Here, we present a unique case of ODR in a patient with primary open angle glaucoma who underwent canaloplasty. A 31-year-old male patient presented with an intraocular pressure (IOP) of 60 mm Hg in the right eye. The IOP remained over 40 mm Hg, even when treated with maximum tolerated antiglaucoma medication. Canaloplasty drastically lowered IOP in the right eye from 40 to 7 mm Hg. However, fundus examination revealed ODR after surgery. The patient was treated with tobramycin and dexamethasone. Three months after canaloplasty, IOP remained in control at 16 mm Hg and all retinal hemorrhages had completely resolved.This case demonstrates that ODR can occur following canaloplasty and physicians should be aware of this potential complication in patients with severely elevated IOP. Sufficiently lowering IOP before surgery and gradually decreasing IOP during surgery may prevent ODR from occurring. PMID:26945386

  9. Knowledge-based image processing for proton therapy planning of ocular tumors

    NASA Astrophysics Data System (ADS)

    Noeh, Sebastian; Haarbeck, Klaus; Bornfeld, Norbert; Tolxdorff, Thomas

    1998-06-01

    Our project is concerned with the improvement of radiation treatment procedures for ocular tumors. In this context the application of proton beams offers new possibilities to considerably enhance precision and reliability of current radiation treatment systems. A precise model of the patient's eye and the tumor is essential for determining the necessary treatment plan. Current treatment systems base their irradiation plan calculations mainly on schematic eye models (e.g., Gullstrand's schematic eye). The adjustment of the model to the patient's anatomy is done by distorting the model according to information from ultrasound and/or CT images. In our project a precise model of the orbita is determined from CT, high resolution MRT, ultrasound (A-mode depth images and/or 2D B-mode images) and photographs of the fundus. The results from various segmentation and image analysis steps performed on all the data are combined to achieve an eye model of improved precision. By using a proton cannon for the therapy execution, the high precision of the model can be exploited, thus achieving a basic improvement of the therapy. Control over the destruction of the tumor can be increased by maximizing the dose distributions within the target volume keeping the damage in the surrounding tissue to a minimum. This article is concerned with the image processing to generate an eye model on which treatment planning is based.

  10. A Case of a Newborn with Agenesis of the Corpus Callosum Complicated with Ocular Albinism

    PubMed Central

    Miki, Michiko; Miyamoto, Makiko; Mitsutsuji, Tatsuma; Watanabe, Hiroko; Shimizu, Kazuhiro; Matsuo, Junko; Tonari, Masahiro; Kida, Teruyo; Sugasawa, Jun; Ikeda, Tsunehiko

    2016-01-01

    Purpose To report a case of ocular albinism found in a newborn infant in whom agenesis of the corpus callosum (ACC) was indicated in utero. Case Report This study involved a female newborn who was delivered after a gestational period of 41 weeks. The patient was referred to the Obstetrics Department at Takatsuki Hospital, Takatsuki City, Japan, after the indication of ACC by magnetic resonance imaging (MRI) at a nearby clinic during the fetal period. At birth, the baby's weight was 2,590 g, and ACC and ventricular enlargement were found by cranial sonography and cranial MRI. While initial ophthalmic findings noted partial loss of pigmentation of the iris and hypopigmentation of broad areas of the fundus in both eyes, nystagmus was not observed. The patient's hair pigment was slightly diluted, and the color of her skin was slightly off-white. At 2 years after birth, obvious mental retardation was observed. With regard to other systemic findings, no apparent heart, kidney, or immune system abnormalities were found. Conclusion Although the patient in question is presently growing without any major systemic problems, it will be necessary in the future to pay attention to any changes in systemic and ophthalmic findings. PMID:27462254

  11. [Ocular perfusion pressure and its relevance for glaucoma].

    PubMed

    Schmidl, D; Werkmeister, R; Garhöfer, G; Schmetterer, L

    2015-02-01

    Ocular perfusion pressure is defined as the difference between arterial and venous pressure in ocular vessels. In practice, mean arterial pressure is used to substitute for arterial pressure in ocular vessels while intraocular pressure gives an estimate for ocular venous pressure. This results in a value that is easy to calculate and which is of importance since several studies have shown that it is correlated to the prevalence, incidence and progression of primary open angle glaucoma. Today, ocular perfusion pressure is used to estimate individual risks. Since no target value for ocular perfusion pressure can be defined, direct therapeutic intervention is difficult. Still, it has to be kept in mind that lowering intraocular pressure automatically leads to an increase in ocular perfusion pressure. The present article also points out problems and limitations in the concept of ocular perfusion pressure and suggests possible solutions for these problems in the future. PMID:25700252

  12. Genetics Home Reference: ocular albinism

    MedlinePlus

    ... are cellular structures that produce and store a pigment called melanin. Melanin is the substance that gives ... and eyes their color. In the retina, this pigment also plays a role in normal vision. Most ...

  13. Developments in Ocular Genetics: 2013 Annual Review

    PubMed Central

    Aboobakar, Inas F.; Allingham, R. Rand

    2014-01-01

    Purpose To highlight major advancements in ocular genetics from the year 2013. Design Literature review. Methods A literature search was conducted on PubMed to identify articles pertaining to genetic influences on human eye diseases. This review focuses on manuscripts published in print or online in the English language between January 1, 2013 and December 31, 2013. A total of 120 papers from 2013 were included in this review. Results Significant progress has been made in our understanding of the genetic basis of a broad group of ocular disorders, including glaucoma, age-related macular degeneration, cataract, diabetic retinopathy, keratoconus, Fuchs’ endothelial dystrophy, and refractive error. Conclusions The latest next-generation sequencing technologies have become extremely effective tools for identifying gene mutations associated with ocular disease. These technological advancements have also paved the way for utilization of genetic information in clinical practice, including disease diagnosis, prediction of treatment response and molecular interventions guided by gene-based knowledge. PMID:25097799

  14. Lymphocyte transformation in presumed ocular histoplasmosis

    SciTech Connect

    Ganley, J.P.; Nemo, G.J.; Comstock, G.W.; Brody, J.A.

    1981-08-01

    Lymphocytes from individuals with inactive macular disciform lesions of presumed ocular histoplasmosis challenged with three histoplasmin antigens incorporated tritiated thymidine at a significantly higher rate than histoplasmin-stimulated lymphocytes of matched control and peripheral scar groups. This finding is consistent with the etiologic association of the disciform ocular syndrome and previous systemic infection with Histoplasma capsulatum. The disciform group had a higher mean response than the other two groups to pokeweed mitogen but not to phytohemagglutinin and had higher mean counts per minute to the specific antigens Toxoplasma gondii, Blastomyces dermatitidis, Cryptococcus neoformans, Mycobacterium tuberculosis, M battery, and M gaus, but not to Candida albicans. These data would suggest that individuals with the disciform lesion of presumed ocular histoplasmosis have a hyperreactive cellular immune response; this response may play an important role in the development of the disciform.

  15. Ocular Dipping in Creutzfeldt-Jakob Disease

    PubMed Central

    Llamas, Sara; Gonzalo, Juan Francisco; Sánchez Sánchez, Carmen

    2014-01-01

    Background Ocular dipping (OD), or inverse ocular bobbing, consists of slow, spontaneous downward eye movements with rapid return to the primary position. It has been mainly reported following hypoxic-ischemic encephalopathy, but has also been described in association with other types of diffuse or multifocal encephalopathies and structural brainstem damage. Case Report We report the case of a previously asymptomatic 66-year-old woman who presented with confusion, recent memory disturbances, and abnormal involuntary movements, followed by a coma. Abnormal spontaneous vertical eye movements consistent with OD developed from the fourth day after admission, and the patient died 20 days later. The pathological examination of the brain confirmed the diagnosis of Creutzfeldt-Jakob disease. Conclusions The precise location of damage causing OD is unknown. In contrast to ocular bobbing, OD has no localizing value itself, but structural brainstem damage is likely when it appears combined with other spontaneous vertical eye movements. PMID:24829603

  16. Optic Neuritis as Isolated Manifestation of Leptomeningeal Carcinomatosis: A Case Report and Systematic Review of Ocular Manifestations of Neoplastic Meningitis

    PubMed Central

    Basilico, Paola; Trezzi, Ilaria; Borellini, Linda; Franco, Giulia; Civelli, Vittorio; Bresolin, Nereo; Baron, Pierluigi

    2013-01-01

    Introduction. Leptomeningeal carcinomatosis occurs in about 5% of cancer patients. Ocular involvement is a common clinical manifestation and often the presenting clinical feature. Materials and Methods. We report the case of a 52-year old lady with optic neuritis as isolated manifestation of neoplastic meningitis and a review of ocular involvement in neoplastic meningitis. Ocular symptoms were the presenting clinical feature in 34 patients (83%) out of 41 included in our review, the unique manifestation of meningeal carcinomatosis in 3 patients (7%). Visual loss was the presenting clinical manifestation in 17 patients (50%) and was the most common ocular symptom (70%). Other ocular signs were diplopia, ptosis, papilledema, anisocoria, exophthalmos, orbital pain, scotomas, hemianopsia, and nystagmus. Associated clinical symptoms were headache, altered consciousness, meningism, limb weakness, ataxia, dizziness, seizures, and other cranial nerves involvement. All patients except five underwent CSF examination which was normal in 1 patient, pleocytosis was found in 11 patients, increased protein levels were observed in 16 patients, and decreased glucose levels were found in 8 patients. Cytology was positive in 29 patients (76%). Conclusion. Meningeal carcinomatosis should be considered in patients with ocular symptoms even in the absence of other suggestive clinical symptoms. PMID:24223306

  17. Optic neuritis as isolated manifestation of leptomeningeal carcinomatosis: a case report and systematic review of ocular manifestations of neoplastic meningitis.

    PubMed

    Lanfranconi, Silvia; Basilico, Paola; Trezzi, Ilaria; Borellini, Linda; Franco, Giulia; Civelli, Vittorio; Pallotti, Francesco; Bresolin, Nereo; Baron, Pierluigi

    2013-01-01

    Introduction. Leptomeningeal carcinomatosis occurs in about 5% of cancer patients. Ocular involvement is a common clinical manifestation and often the presenting clinical feature. Materials and Methods. We report the case of a 52-year old lady with optic neuritis as isolated manifestation of neoplastic meningitis and a review of ocular involvement in neoplastic meningitis. Ocular symptoms were the presenting clinical feature in 34 patients (83%) out of 41 included in our review, the unique manifestation of meningeal carcinomatosis in 3 patients (7%). Visual loss was the presenting clinical manifestation in 17 patients (50%) and was the most common ocular symptom (70%). Other ocular signs were diplopia, ptosis, papilledema, anisocoria, exophthalmos, orbital pain, scotomas, hemianopsia, and nystagmus. Associated clinical symptoms were headache, altered consciousness, meningism, limb weakness, ataxia, dizziness, seizures, and other cranial nerves involvement. All patients except five underwent CSF examination which was normal in 1 patient, pleocytosis was found in 11 patients, increased protein levels were observed in 16 patients, and decreased glucose levels were found in 8 patients. Cytology was positive in 29 patients (76%). Conclusion. Meningeal carcinomatosis should be considered in patients with ocular symptoms even in the absence of other suggestive clinical symptoms. PMID:24223306

  18. Ocular findings in the Hermansky-Pudlak syndrome.

    PubMed Central

    Izquierdo, N J; Townsend, W; Hussels, I E

    1995-01-01

    BACKGROUND: The Hermansky-Pudlak syndrome (HPS) is defined by the autosomal recessively inherited triad of tyrosinase-positive oculocutaneous albinism, bleeding diathesis and accumulation of ceroid in tissues. Late complications include: interstitial pulmonary fibrosis; inflammatory bowel disease; and renal failure. PATIENTS AND METHODS: We undertook a non-concurrent prospective study of 55 Puerto Rican patients with HPS (age range 1 to 54 yrs; mean = 19.7 yrs). These patients had a comprehensive ocular examination and a systemic evaluation for HPS. RESULTS: Visual acuities ranged from 20/50 to 5/200. All patients had nystagmus. Forty-three patients had strabismus; esotropia was found in 24 patients; exotropia in 18 patients; and one patient had hypertropia. Posterior embryotoxon occurred in 15 patients and Axenfeld anomaly in 4 patients. Iris pigmentation varied from minimal to almost completely normal. Three patients had cataract formation. The retina was typically albinotic with macular hypoplasia. All patients had cutaneous albinism, bleeding diathesis and various systemic manifestations as part of HPS. CONCLUSION: Ocular findings in HPS include reduced visual acuity; congenital nystagmus, strabismus and cataract. Diagnosis of the syndrome ought to be made preoperatively to help minimize the potential complications associated with bleeding diathesis at the time of extraocular muscle and intraocular surgery in patients with HPS. PMID:8719678

  19. Penicillin-induced liver injury during treatment for ocular neurosyphilis.

    PubMed

    Wilkinson, Janelle; Zainal, Abir; Naqvi, Syed Yaseen

    2016-01-01

    A 51-year-old man, homosexual, recently diagnosed with ocular neurosyphilis, presented to the emergency room with a 1-day history of fevers and chills. His vital signs were significant for a temperature of 102.8°F and tachycardia of 125 bpm. The patient had experienced blurred vision in his left eye and was diagnosed with ocular neurosyphilis 10 days prior to the current presentation. He was treated with a 14-day course of high-dose intravenous penicillin and oral prednisone. His laboratory studies were significant for transaminitis, with an aspartate aminotransferase of 1826 U/L, alanine aminotransferase of 1743 U/L, total bilirubin of 1.2 mg/dL and alkaline phosphatase of 68 U/L. After ruling out viral aetiologies and toxin-induced hepatic injury, penicillin was discontinued on the day following admission and transaminases promptly improved with resolution of symptoms. The patient's vision returned to normal within 2 weeks after discharge from hospital. PMID:27389728

  20. Instability of Ocular Alignment in Childhood Esotropia

    PubMed Central

    2008-01-01

    Objective Instability of ocular alignment may cause surgeons to delay surgical correction of childhood esotropia. We investigated the stability of ocular alignment over 18 weeks in children with infantile esotropia (IET), acquired non-accommodative esotropia (ANAET), or acquired partially-accommodative esotropia (APAET). Design Prospective observational study Participants Two hundred thirty-three children aged 2 months to <5 years with IET, ANAET, or APAET of less than 6 months duration Methods Ocular alignment was measured at baseline and at six-week intervals for 18 weeks. Main Outcome Measure Using definitions derived from a nested test-retest study and computer simulation modeling, ocular alignment was classified as ‘unstable’ if there was a change of ≥ 15 prism diopters (PD) between any two of the four measurements, as ‘stable’ if all four measurements were within ≤ 5 PD of one another, or as ‘uncertain’ if neither criteria was met. Results Of those who completed all three follow-up visits within time windows for analysis, 27 (46%) of 59 subjects with IET had ocular alignment classified as unstable (95% confidence interval (CI) = 33 to 59%), 20% as stable (95% CI = 11 to 33%), and 34% as uncertain (95% CI = 22 to 47%). Thirteen (22%) of 60 subjects with ANAET had ocular alignment classified as unstable (95% confidence interval (CI) = 12 to 34%), 37% as stable (95% CI = 25 to 50%), and 42% as uncertain (95% CI = 29 to 55%). Six (15%) of 41 subjects with APAET had ocular alignment classified as unstable (95% CI = 6 to 29%), 39% as stable (95% CI = 24 to 56%), and 46% as uncertain (95% CI = 31 to 63%). For IET, subjects who were older at presentation were less likely to have unstable angles than subjects who were younger at presentation (risk ratio for unstable vs. stable per additional month of age = 0.85, 99% CI = 0.74 to 0.99). Conclusions Ocular alignment instability is common in children with IET, ANAET and APAET. The impact of this finding

  1. Dry Eye: an Inflammatory Ocular Disease

    PubMed Central

    Hessen, Michelle; Akpek, Esen Karamursel

    2014-01-01

    Keratoconjunctivitis sicca, or dry eye, is a common ocular disease prompting millions of individuals to seek ophthalmological care. Regardless of the underlying etiology, dry eye has been shown to be associated with abnormalities in the pre-corneal tear film and subsequent inflammatory changes in the entire ocular surface including the adnexa, conjunctiva and cornea. Since the recognition of the role of inflammation in dry eye, a number of novel treatments have been investigated designed to inhibit various inflammatory pathways. Current medications that are used, including cyclosporine A, corticosteroids, tacrolimus, tetracycline derivatives and autologous serum, have been effective for management of dry eye and lead to measurable clinical improvement. PMID:25279127

  2. Ocular motor abnormalities in neurodegenerative disorders

    PubMed Central

    Antoniades, C A; Kennard, C

    2015-01-01

    Eye movements are a source of valuable information to both clinicians and scientists as abnormalities of them frequently act as clues to the localization of a disease process. Classically, they are divided into two main types: those that hold the gaze, keeping images steady on the retina (vestibulo-ocular and optokinetic reflexes) and those that shift gaze and redirect the line of sight to a new object of interest (saccades, vergence, and smooth pursuit). Here we will review some of the major ocular motor abnormalities present in neurodegenerative disorders. PMID:25412716

  3. Ocular autofluorescence in diabetes mellitus. A review.

    PubMed

    Calvo-Maroto, Ana M; Perez-Cambrodi, Rafael J; Garcia-Lazaro, Santiago; Ferrer-Blasco, Teresa; Cerviño, Alejandro

    2016-09-01

    Diabetes mellitus is a metabolic disease with a considerable impact on healthcare owing to its increased prevalence and high mortality rate. Structural, morphological, and physiological changes in each of the ocular components have been described in detail. Autofluorescence has been described as a good indicator of metabolic activity. The aim of the present review is to provide an overview of ocular endogenous fluorophores in the cornea, the crystalline lens, and the retinal pigment epithelium, the effects of diabetes mellitus and therefore the potential of autofluorescence assessment for screening and monitoring changes in diabetic patients. PMID:27147470

  4. [Ocular findings in leukemia in childhood].

    PubMed

    Rochels, R; Heiland, I

    1987-11-01

    Primary and therapy-induced ocular manifestations of leukemia in 25 of 103 children suffering from the disease (60 patients with ALL, eight with AML, two with CML, 33 with NHL) were kept under observation for an average period of five years. The lens was involved in 10%, the retina in 9%, the optic nerve in 7%, and the orbit in 4% of these cases. The present authors' findings concurred with those published in the literature to date, in that they could not find a pathognomonic combination or a specific frequency of ocular symptoms related to one of the four types of leukemia. PMID:3481001

  5. Ocular manifestations of genetic skin disorders.

    PubMed

    Jen, Melinda; Nallasamy, Sudha

    2016-01-01

    Genetic skin diseases, or genodermatoses, often have extracutaneous manifestations. Ocular manifestations in particular can have significant clinical implications, like blindness. Other manifestations, such as the corneal opacities that occur in X-linked ichthyosis, are asymptomatic but characteristic of a particular genodermatosis. Ophthalmologic examination can aid in diagnosis when characteristic findings are seen. The genodermatoses with ocular manifestations will be reviewed, but neurocutaneous, syndromes, genetic pigmentary disorders, and genetic metabolic diseases are not included because they are covered elsewhere in this issue. PMID:26903188

  6. Modification of the Cervico-ocular Reflex by Canal Plugging

    PubMed Central

    Yakushin, Sergei B.; Tarasenko, Yelena; Raphan, Theodore; Suzuki, Jun-Ichi; Della Santina, Charles C.; Minor, Lloyd B.; Cohen, Bernard

    2016-01-01

    The cervico-ocular reflex (COR) has a low gain in normal animals. In this study, we determined whether COR gain increases were specific to the low/midband frequency range, which is the range over which the angular vestibulo-ocular reflex (aVOR) is compromised by plugging. The gain and phase of the yaw and pitch COR and aVOR were compared in normal monkeys and those with all six semicircular canals or only the lateral canal plugged. During experiments animals sat with the body fixed to a chair and the head fixed in space. The body was oscillated about body-yaw and body-pitch axes over a frequency range of 0.05–6 Hz, with amplitude <10°. For normal animals, both yaw and pitch eye velocities were compensatory to the relative velocity of the head with respect to the body. The gains were 0.1–0.2 at frequencies below 1 Hz and decreased to zero as stimulus frequency increased above 1 Hz. Canal-plugged animals had COR gains close to 1.0 at low frequencies, decreasing to ≈0.6 at 0.5 Hz and to 0.2 for stimulus frequencies above 3 Hz. The phase of eye velocity was 180° relative to head-re-body velocity at frequencies below 0.5 Hz and shifted toward 270° as frequencies were increased to 4 Hz. This study demonstrates that adaptation of COR gain is tuned to a frequency range at which the aVOR is compromised by the canal plugging. PMID:19645881

  7. 21 CFR 886.4610 - Ocular pressure applicator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ocular pressure applicator. 886.4610 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4610 Ocular pressure applicator. (a) Identification. An ocular pressure applicator is a manual device that consists of a sphygmomanometer-type...

  8. 21 CFR 886.4610 - Ocular pressure applicator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ocular pressure applicator. 886.4610 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4610 Ocular pressure applicator. (a) Identification. An ocular pressure applicator is a manual device that consists of a sphygmomanometer-type...

  9. 21 CFR 886.4610 - Ocular pressure applicator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ocular pressure applicator. 886.4610 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4610 Ocular pressure applicator. (a) Identification. An ocular pressure applicator is a manual device that consists of a sphygmomanometer-type...

  10. 21 CFR 886.4610 - Ocular pressure applicator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ocular pressure applicator. 886.4610 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4610 Ocular pressure applicator. (a) Identification. An ocular pressure applicator is a manual device that consists of a sphygmomanometer-type...

  11. 21 CFR 886.4360 - Ocular surgery irrigation device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ocular surgery irrigation device. 886.4360 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4360 Ocular surgery irrigation device. (a) Identification. An ocular surgery irrigation device is a device intended to be suspended over...

  12. 21 CFR 886.4360 - Ocular surgery irrigation device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ocular surgery irrigation device. 886.4360 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4360 Ocular surgery irrigation device. (a) Identification. An ocular surgery irrigation device is a device intended to be suspended over...

  13. 21 CFR 886.4360 - Ocular surgery irrigation device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ocular surgery irrigation device. 886.4360 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4360 Ocular surgery irrigation device. (a) Identification. An ocular surgery irrigation device is a device intended to be suspended over...

  14. 21 CFR 886.4360 - Ocular surgery irrigation device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ocular surgery irrigation device. 886.4360 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4360 Ocular surgery irrigation device. (a) Identification. An ocular surgery irrigation device is a device intended to be suspended over...

  15. 21 CFR 886.4360 - Ocular surgery irrigation device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ocular surgery irrigation device. 886.4360 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4360 Ocular surgery irrigation device. (a) Identification. An ocular surgery irrigation device is a device intended to be suspended over...

  16. KV7 channels regulate muscle tone and nonadrenergic noncholinergic relaxation of the rat gastric fundus.

    PubMed

    Ipavec, V; Martire, M; Barrese, V; Taglialatela, M; Currò, D

    2011-10-01

    Voltage-dependent type 7 K+ (KV7) channels play important physiological roles in neurons and muscle cells. The aims of the present study were to investigate the motor effects of KV7 channel modulators in the rat gastric fundus and the expression of KV7 channels in this tissue. Muscle tone and electrical field stimulation (EFS)-evoked relaxations of precontracted longitudinal muscle strips of the rat gastric fundus were investigated under nonadrenergic noncholinergic conditions by organ bath studies. Gene expression was studied by real-time PCR and tissue localization of channels was investigated by immunohistochemistry. The KV7 channel blocker XE-991 induced concentration-dependent contractions, with mean pD2 and Emax of 5.4 and 48% of the maximal U46619-induced contraction, respectively. The KV7 channel activators retigabine and flupirtine concentration-dependently relaxed U46619-precontracted strips, with pD2s of 4.7 and 4.4 and Emax of 93% and 91% of the maximal relaxation induced by papaverine, respectively. XE-991 concentration-dependently inhibited retigabine-induced relaxation with a pIC50 of 6.2. XE-991 and DMP-543, another KV7 channel blocker, increased by 13-25% or reduced by 11-21% the relaxations evoked by low- or high-frequency EFS, respectively. XE-991 also reduced the relaxation induced by vasoactive intestinal polypeptide (VIP) by 33% of controls. Transcripts encoded by all KV7 genes were detected in the fundus, with 7.4 and 7.5 showing the highest expression levels. KV7.4 and 7.5 channels were visualized by confocal immunofluorescence in both circular and longitudinal muscle layers. In conclusion, in the rat proximal stomach, KV7 channels appear to contribute to the resting muscle tone and to VIP- and high-frequency EFS-induced relaxation. KV7 channel activators could be useful relaxant agents of the gastric smooth muscle. PMID:21740972

  17. Changes to the ocular biota with time in extended- and daily-wear disposable contact lens use.

    PubMed

    Stapleton, F; Willcox, M D; Fleming, C M; Hickson, S; Sweeney, D F; Holden, B A

    1995-11-01

    Gram-negative bacteria may play a role in the etiology of certain soft contact lens (SCL)-related diseases. Contact lens (CL) wear may modify the normal ocular biota, providing a more favorable environment for potential pathogens. This study reports temporal changes in ocular biota in daily-wear (DW) and extended-wear (EW) disposable SCL use in experienced and neophyte wearers. Lid margin and bulbar conjunctival biota were sampled prior to CL fitting in 26 previous DW SCL users, 18 previous EW SCL users, and 26 neophytes. Wearers were fitted with an etafilcon A CL in one eye and a polymacon CL in the fellow eye. Lenses were worn on a daily basis by the 26 previous DW SCL wearers and on an EW basis by the remaining 44 subjects. The ocular biota was further sampled after 1, 3, 6, 9, and 12 months of wear. The ocular biota consisted of coagulase-negative staphylococci, Corynebacterium spp., Micrococcus spp., and Propionibacterium spp. Potential pathogens were rarely isolated at baseline. No significant trend of increasing ocular colonization was shown for extended CL wear. Lid and conjunctival colonization increased with DW SCL use (P < 0.001), although this increase occurred for nonpathogenic species only. Fewer potential pathogens were isolated from DW SCL than from EW SCL users (P < 0.05). The lid margin consistently showed greater colonization than the conjunctiva and may be a source of potential pathogens during CL wear. Hydrogel CL wear appears to modify the ocular biota. An increased number of commensal organisms were present in DW SCL use. EW SCL use altered the spectrum of organisms isolated. These alterations may suppress the normal ocular defense mechanisms and may be relevant in the pathogenesis of CL-related disease. PMID:7591092

  18. The Measurement of Ocular Dominance in Infants.

    ERIC Educational Resources Information Center

    Coren, Stanley

    A simple test of ocular dominance in infants is described. In the test, a small point of light is gradually brought closer to the observer along the medial plane. As the light draws closer, in typical cases, one eye will cease to converge, or frequently, it will break from convergence suddenly. The eye which ceases converging or breaks away from…

  19. Evolution of the vestibulo-ocular system

    NASA Technical Reports Server (NTRS)

    Fritzsch, B.

    1998-01-01

    The evolutionary and developmental changes in the eye muscle innervation, the inner ear, and the vestibulo-ocular reflex are examined. Three eye muscle patterns, based on the innervation by distinct ocular motoneurons populations, can be identified: a lamprey, an elasmobranch, and a bony fish/tetrapod pattern. Four distinct patterns of variation in the vestibular system are described: a hagfish pattern, a lamprey pattern, an elasmobranch pattern, and a bony fish/tetrapod pattern. Developmental data suggest an influence of the hindbrain on ear pattern formation, thus potentially allowing a concomitant change of eye muscle innervation and ear variation. The connections between the ear and the vestibular nuclei and between the vestibular nuclei and ocular motoneurons are reviewed, and the role of neurotrophins for pattern specification is discussed. Three patterns are recognized in central projections: a hagfish pattern, a lamprey pattern, and a pattern for jawed vertebrates. Second-order connections show both similarities and differences between distantly related species such as lampreys and mammals. For example, elasmobranchs lack an internuclear system, which is at best poorly developed in lampreys. It is suggested that the vestibulo-ocular system shows only a limited degree of variation because of the pronounced functional constraints imposed on it.

  20. 21 CFR 882.1790 - Ocular plethysmograph.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... in the carotid artery). (b) Classification. Class III (premarket approval). (c) Date PMA or notice of completion of PDP is required. A PMA or notice of completion of a PDP is required to be filed with the Food... commercial distribution before May 28, 1976. Any other ocular plethysmograph shall have an approved PMA...

  1. 21 CFR 882.1790 - Ocular plethysmograph.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... in the carotid artery). (b) Classification. Class III (premarket approval). (c) Date PMA or notice of completion of PDP is required. A PMA or notice of completion of a PDP is required to be filed with the Food... commercial distribution before May 28, 1976. Any other ocular plethysmograph shall have an approved PMA...

  2. Recent Perspectives in Ocular Drug Delivery

    PubMed Central

    Gaudana, Ripal; Jwala, J.; Boddu, Sai H. S.; Mitra, Ashim K.

    2015-01-01

    Anatomy and physiology of the eye makes it a highly protected organ. Designing an effective therapy for ocular diseases, especially for the posterior segment, has been considered as a formidable task. Limitations of topical and intravitreal route of administration have challenged scientists to find alternative mode of administration like periocular routes. Transporter targeted drug delivery has generated a great deal of interest in the field because of its potential to overcome many barriers associated with current therapy. Application of nanotechnology has been very promising in the treatment of a gamut of diseases. In this review, we have briefly discussed several ocular drug delivery systems such as microemulsions, nanosuspensions, nanoparticles, liposomes, niosomes, dendrimers, implants, and hydrogels. Potential for ocular gene therapy has also been described in this article. In near future, a great deal of attention will be paid to develop non-invasive sustained drug release for both anterior and posterior segment eye disorders. A better understanding of nature of ocular diseases, barriers and factors affecting in vivo performance, would greatly drive the development of new delivery systems. Current momentum in the invention of new drug delivery systems hold a promise towards much improved therapies for the treatment of vision threatening disorders. PMID:18758924

  3. Current and emerging therapies for ocular neovascularisation.

    PubMed

    Reynolds, Alison L; Kent, David; Kennedy, Breandán N

    2014-01-01

    Ocular neovascularisation (ONV) is a pathological feature of many human blinding diseases. Here, we review current pharmacological therapies for these disorders and highlight emerging therapies in clinical trial for ONV. Finally, we discuss desirable characteristics of future ONV therapies, including innovative strategies for novel delivery to the back of the eye. PMID:24664773

  4. Pattern of Ocular Injuries in Owo, Nigeria

    PubMed Central

    Omolase, Charles Oluwole; Omolade, Ericson Oluseyi; Ogunleye, Olakunle Tolulope; Omolase, Bukola Olateju; Ihemedu, Chidi Oliver; Adeosun, Olumuyiwa Adekunle

    2011-01-01

    Purpose To determine the pattern of ocular injuries in patients presenting to the eye clinic and the accident and emergency department of Federal Medical Center, Owo, Ondo State, Nigeria. Methods This prospective study was conducted between January and December 2009. Federal Medical Center, Owo is the only tertiary hospital in Ondo State, Nigeria. The eye center located at this medical center was the only eye care facility in the community at the time of this study. All patients were interviewed with the aid of an interviewer-administered questionnaire and underwent a detailed ocular examination. Results Of 132 patients included in the study, most (84.1%) sustained blunt eye injury while (12.1%) had penetrating eye injury. A considerable proportion of patients (37.9%) presented within 24 hours of injury. Vegetative materials were the most common (42.4%) offending agent, a minority of patients (22%) was admitted and none of the patients had used eye protection at the time of injury. Conclusion In the current series, blunt eye injury was the most common type of ocular trauma. The community should be educated and informed about the importance of preventive measures including protective eye devices during high risk activities. Patients should be encouraged to present early following ocular injury. PMID:22454720

  5. Controlled Ocular Drug Delivery with Nanomicelles

    PubMed Central

    Vaishya, Ravi D.; Khurana, Varun; Patel, Sulabh; Mitra, Ashim K.

    2014-01-01

    Many vision threatening ocular diseases such as age-related macular degeneration (AMD), diabetic retinopathy, glaucoma, and proliferative vitreoretinopathy may result in blindness. Ocular drug delivery specifically to the intraocular tissues remains a challenging task due to the presence of various physiological barriers. Nonetheless, recent advancements in the field of nanomicelle based novel drug delivery system could fulfil these unmet needs. Nanomicelles consists of amphiphilic molecules that self-assemble in aqueous media to form organized supramolecular structures. Micelles can be prepared in various sizes (10 to 1000nm) and shapes depending on the molecular weights of the core and corona forming blocks. Nanomicelles have been an attractive carriers for their potential to solubilize hydrophobic molecules in aqueous solution. In addition, small size in nanometer range and highly modifiable surface properties have been reported to be advantageous in ocular drug delivery. In the present review various factors influencing rationale design of nanomicelles formulation and disposition are discussed along with case studies. Despite the progress in the field, influence of various properties of nanomicelles such as size, shape, surface charge, rigidity of structure on ocular disposition need to be studied in further details to develop an efficient nanocarrier system. PMID:24888969

  6. Myopic anisometropia: ocular characteristics and aetiological considerations.

    PubMed

    Vincent, Stephen J; Collins, Michael J; Read, Scott A; Carney, Leo G

    2014-07-01

    Anisometropia represents a unique example of ocular development, where the two eyes of an individual, with an identical genetic background and seemingly subject to identical environmental influences, can grow asymmetrically to produce significantly different refractive errors. This review provides an overview of the research examining myopic anisometropia, the ocular characteristics underlying the condition and the potential aetiological factors involved. Various mechanical factors are discussed, including corneal structure, intraocular pressure and forces generated during near work that may contribute to development of anisomyopia. Potential visually guided mechanisms of unequal ocular growth are also explored, including the influence of astigmatism, accommodation, higher-order aberrations and the choroidal response to altered visual experience. The association between binocular vision, ocular dominance and asymmetric refraction is also considered, along with a review of the genetic contribution to the aetiology of myopic anisometropia. Despite a significant amount of research into the biomechanical, structural and optical characteristics of anisometropic eyes, there is still no unifying theory, which adequately explains how two eyes within the same visual system grow to different endpoints. PMID:24939167

  7. Ocular findings in conjoined (Siamese) twins.

    PubMed

    Mansour, A M; Mansour, N; Rosenberg, H S

    1991-01-01

    Conjoined twinning is a rare form of congenital anomaly. The ocular findings in six sets of conjoined twins as well as those reported elsewhere include abnormal optic nerve decussation, pseudosynophthalmos, microphthalmia, abnormal eyelids, orbital encephalocele, occipital encephalocele, and eyelid coloboma. These findings are interpreted as due to deformations from appositional fusion-related factors or malformations from developmental factors. PMID:1955960

  8. Fundus optic disc localization and segmentation method based on phase congruency.

    PubMed

    Geng, Lei; Shao, Yi-Ting; Xiao, Zhi-Tao; Zhang, Fang; Wu, Jun; Li, Min; Shan, Chun-Yan

    2014-01-01

    It has been demonstrated that shape, area and depth of the optic disc are relevant indices of diabetic retinopathy. In this paper, we present a new fundus optic disc localization and segmentation method based on phase congruency (PC). Firstly, in order to highlight the optic disc, channel images with the highest contrast between optic disc and background are selected in LAB, YUV, YIQ and HSV spaces respectively. Secondly, with the use of PC, features of four selected channel images can be extracted. Multiplication operation is then used to enhance PC detection results. Thirdly, window scanning and gray accumulating are utilized to locate the optic disc. Finally, iterative OTSU automatic threshold segmentation and Hough transform are performed on location images, before the final optic disc segmentation result can be obtained. The experimental results showed that the proposed method can effectively and accurately perform optic disc location and segmentation. PMID:25227031

  9. An efficient algorithm for measurement of retinal vessel diameter from fundus images based on directional filtering

    NASA Astrophysics Data System (ADS)

    Wang, Xuchu; Niu, Yanmin

    2011-02-01

    Automatic measurement of vessels from fundus images is a crucial step for assessing vessel anomalies in ophthalmological community, where the change in retinal vessel diameters is believed to be indicative of the risk level of diabetic retinopathy. In this paper, a new retinal vessel diameter measurement method by combining vessel orientation estimation and filter response is proposed. Its interesting characteristics include: (1) different from the methods that only fit the vessel profiles, the proposed method extracts more stable and accurate vessel diameter by casting this problem as a maximal response problem of a variation of Gabor filter; (2) the proposed method can directly and efficiently estimate the vessel's orientation, which is usually captured by time-consuming multi-orientation fitting techniques in many existing methods. Experimental results shows that the proposed method both retains the computational simplicity and achieves stable and accurate estimation results.

  10. Optic Disc and Cup Segmentation from Color Fundus Photograph Using Graph Cut with Priors

    PubMed Central

    Zheng, Yuanjie; Stambolian, Dwight; O’Brien, Joan; Gee, James C.

    2014-01-01

    For automatic segmentation of optic disc and cup from color fundus photograph, we describe a fairly general energy function that can naturally fit into a global optimization framework with graph cut. Distinguished from most previous work, our energy function includes priors on the shape & location of disc & cup, the rim thickness and the geometric interaction of “disc contains cup”. These priors together with the effective optimization of graph cut enable our algorithm to generate reliable and robust solutions. Our approach is able to outperform several state-of-the-art segmentation methods, as shown by a set of experimental comparisons with manual delineations and a series of results of correlations with the assessments of a merchant-provided software from Optical Coherence Tomography (OCT) regarding several cup and disc parameters. PMID:24579126

  11. Automatic differentiation of color fundus images containing drusen or exudates using a contextual spatial pyramid approach.

    PubMed

    van Grinsven, Mark J J P; Theelen, Thomas; Witkamp, Leonard; van der Heijden, Job; van de Ven, Johannes P H; Hoyng, Carel B; van Ginneken, Bram; Sánchez, Clara I

    2016-03-01

    We developed an automatic system to identify and differentiate color fundus images containing no lesions, drusen or exudates. Drusen and exudates are lesions with a bright appearance, associated with age-related macular degeneration and diabetic retinopathy, respectively. The system consists of three lesion detectors operating at pixel-level, combining their outputs using spatial pooling and classification with a random forest classifier. System performance was compared with ratings of two independent human observers using human-expert annotations as reference. Kappa agreements of 0.89, 0.97 and 0.92 and accuracies of 0.93, 0.98 and 0.95 were obtained for the system and observers, respectively. PMID:27231583

  12. 3D Reconstruction of the Retinal Arterial Tree Using Subject-Specific Fundus Images

    NASA Astrophysics Data System (ADS)

    Liu, D.; Wood, N. B.; Xu, X. Y.; Witt, N.; Hughes, A. D.; Samcg, Thom

    Systemic diseases, such as hypertension and diabetes, are associated with changes in the retinal microvasculature. Although a number of studies have been performed on the quantitative assessment of the geometrical patterns of the retinal vasculature, previous work has been confined to 2 dimensional (2D) analyses. In this paper, we present an approach to obtain a 3D reconstruction of the retinal arteries from a pair of 2D retinal images acquired in vivo. A simple essential matrix based self-calibration approach was employed for the "fundus camera-eye" system. Vessel segmentation was performed using a semi-automatic approach and correspondence between points from different images was calculated. The results of 3D reconstruction show the centreline of retinal vessels and their 3D curvature clearly. Three-dimensional reconstruction of the retinal vessels is feasible and may be useful in future studies of the retinal vasculature in disease.

  13. Variability in grading diabetic retinopathy from stereo fundus photographs: comparison of physician and lay readers.

    PubMed Central

    Milton, R. C.; Ganley, J. P.; Lynk, R. H.

    1977-01-01

    Two physicians and two lay readers were trained according to a detailed protocol in the grading of 17 lesions found in diabetic retinopathy by evaluation of stereo fundus photographs according to a modified Airlie House classification. Intraobserver and interobserver variability of these readers was assessed by two methods: weighted kappa, and frequency of agreement within one grade. In general, physician readers were found to be less variable on replicate readings than were lay leaders, and had slightly better agreement with each other than with the lay readers. The physiological significance of the direction and magnitude of the difference between physician and lay reader variability for individual lesions was often uncertain. Assessment of contribution to disagreement by individual readers was possible and permits future training directed at reducing disagreement to acceptable values. PMID:851521

  14. Region-based multi-step optic disk and cup segmentation from color fundus image

    NASA Astrophysics Data System (ADS)

    Xiao, Di; Lock, Jane; Manresa, Javier Moreno; Vignarajan, Janardhan; Tay-Kearney, Mei-Ling; Kanagasingam, Yogesan

    2013-02-01

    Retinal optic cup-disk-ratio (CDR) is a one of important indicators of glaucomatous neuropathy. In this paper, we propose a novel multi-step 4-quadrant thresholding method for optic disk segmentation and a multi-step temporal-nasal segmenting method for optic cup segmentation based on blood vessel inpainted HSL lightness images and green images. The performance of the proposed methods was evaluated on a group of color fundus images and compared with the manual outlining results from two experts. Dice scores of detected disk and cup regions between the auto and manual results were computed and compared. Vertical CDRs were also compared among the three results. The preliminary experiment has demonstrated the robustness of the method for automatic optic disk and cup segmentation and its potential value for clinical application.

  15. Automatic differentiation of color fundus images containing drusen or exudates using a contextual spatial pyramid approach

    PubMed Central

    van Grinsven, Mark J. J. P.; Theelen, Thomas; Witkamp, Leonard; van der Heijden, Job; van de Ven, Johannes P. H.; Hoyng, Carel B.; van Ginneken, Bram; Sánchez, Clara I.

    2016-01-01

    We developed an automatic system to identify and differentiate color fundus images containing no lesions, drusen or exudates. Drusen and exudates are lesions with a bright appearance, associated with age-related macular degeneration and diabetic retinopathy, respectively. The system consists of three lesion detectors operating at pixel-level, combining their outputs using spatial pooling and classification with a random forest classifier. System performance was compared with ratings of two independent human observers using human-expert annotations as reference. Kappa agreements of 0.89, 0.97 and 0.92 and accuracies of 0.93, 0.98 and 0.95 were obtained for the system and observers, respectively. PMID:27231583

  16. Obtaining optic disc center and pixel region by automatic thresholding methods on morphologically processed fundus images.

    PubMed

    Marin, Diego; Gegundez-Arias, Manuel E; Suero, Angel; Bravo, Jose M

    2015-02-01

    Development of automatic retinal disease diagnosis systems based on retinal image computer analysis can provide remarkably quicker screening programs for early detection. Such systems are mainly focused on the detection of the earliest ophthalmic signs of illness and require previous identification of fundal landmark features such as optic disc (OD), fovea or blood vessels. A methodology for accurate center-position location and OD retinal region segmentation on digital fundus images is presented in this paper. The methodology performs a set of iterative opening-closing morphological operations on the original retinography intensity channel to produce a bright region-enhanced image. Taking blood vessel confluence at the OD into account, a 2-step automatic thresholding procedure is then applied to obtain a reduced region of interest, where the center and the OD pixel region are finally obtained by performing the circular Hough transform on a set of OD boundary candidates generated through the application of the Prewitt edge detector. The methodology was evaluated on 1200 and 1748 fundus images from the publicly available MESSIDOR and MESSIDOR-2 databases, acquired from diabetic patients and thus being clinical cases of interest within the framework of automated diagnosis of retinal diseases associated to diabetes mellitus. This methodology proved highly accurate in OD-center location: average Euclidean distance between the methodology-provided and actual OD-center position was 6.08, 9.22 and 9.72 pixels for retinas of 910, 1380 and 1455 pixels in size, respectively. On the other hand, OD segmentation evaluation was performed in terms of Jaccard and Dice coefficients, as well as the mean average distance between estimated and actual OD boundaries. Comparison with the results reported by other reviewed OD segmentation methodologies shows our proposal renders better overall performance. Its effectiveness and robustness make this proposed automated OD location and

  17. Automatic classification of pathological myopia in retinal fundus images using PAMELA

    NASA Astrophysics Data System (ADS)

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

    2010-03-01

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

  18. Application of 3-Dimensional Printing Technology to Construct an Eye Model for Fundus Viewing Study

    PubMed Central

    Li, Xinhua; Gao, Zhishan; Yuan, Dongqing; Liu, Qinghuai

    2014-01-01

    Objective To construct a life-sized eye model using the three-dimensional (3D) printing technology for fundus viewing study of the viewing system. Methods We devised our schematic model eye based on Navarro's eye and redesigned some parameters because of the change of the corneal material and the implantation of intraocular lenses (IOLs). Optical performance of our schematic model eye was compared with Navarro's schematic eye and other two reported physical model eyes using the ZEMAX optical design software. With computer aided design (CAD) software, we designed the 3D digital model of the main structure of the physical model eye, which was used for three-dimensional (3D) printing. Together with the main printed structure, polymethyl methacrylate(PMMA) aspherical cornea, variable iris, and IOLs were assembled to a physical eye model. Angle scale bars were glued from posterior to periphery of the retina. Then we fabricated other three physical models with different states of ammetropia. Optical parameters of these physical eye models were measured to verify the 3D printing accuracy. Results In on-axis calculations, our schematic model eye possessed similar size of spot diagram compared with Navarro's and Bakaraju's model eye, much smaller than Arianpour's model eye. Moreover, the spherical aberration of our schematic eye was much less than other three model eyes. While in off- axis simulation, it possessed a bit higher coma and similar astigmatism, field curvature and distortion. The MTF curves showed that all the model eyes diminished in resolution with increasing field of view, and the diminished tendency of resolution of our physical eye model was similar to the Navarro's eye. The measured parameters of our eye models with different status of ametropia were in line with the theoretical value. Conclusions The schematic eye model we designed can well simulate the optical performance of the human eye, and the fabricated physical one can be used as a tool in fundus

  19. Localised calcium release events in cells from the muscle of guinea-pig gastric fundus

    PubMed Central

    Parsons, S P; Bolton, T B

    2004-01-01

    After enzymatic dispersion of the muscle of the guinea-pig gastric fundus, single elongated cells were observed which differed from archetypal smooth muscle cells due to their knurled, tuberose or otherwise irregular surface morphology. These, but not archetypal smooth muscle cells, consistently displayed spontaneous localized (i.e. non-propagating) intracellular calcium ([Ca2+]i) release events. Such calcium events were novel in their magnitude and kinetic profiles. They included short transient events, plateau events and events which coalesced spatially or temporally (compound events). Quantitative analysis of the events with an automatic detection programme showed that their spatio-temporal characteristics (full width and full duration at half-maximum amplitude) were approximately exponentially distributed. Their amplitude distribution suggested the presence of two release modes. Carbachol application caused an initial cell-wide calcium transient followed by an increase in localized calcium release events. Pharmacological analysis suggested that localized calcium release was largely dependent on external calcium entry acting on both inositol trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs) to release stored calcium. Nominally calcium-free external solution immediately and reversibly abolished all localized calcium release without blocking the initial transient calcium release response to carbachol. This was inhibited by 2-APB (100 μm), ryanodine (10 or 50 μm) or U-73122 (1 μm). 2-APB (100 μm), xestospongin C (XeC, 10 μm) or U-73122 (1 μm) blocked both spontaneous localized calcium release and localized release stimulated by 10 μm carbachol. Ryanodine (50 μm) also inhibited spontaneous release, but enhanced localized release in response to carbachol. This study represents the first characterization of localized calcium release events in cells from the gastric fundus. PMID:14608011

  20. Nonmydriatic Fundus Photography for Teleophthalmology Diabetic Retinopathy Screening in Rural and Urban Clinics

    PubMed Central

    Chin, Eric K.; Ventura, Bruna V.; See, Kai-Yin; Seibles, Joann

    2014-01-01

    Abstract Purpose: To evaluate the relative diagnostic value of nonmydriatic fundus photography (nFP) among patients screened for diabetic retinopathy in remote rural medical clinics and an urban academic medical center for nonadherence to recommended annual dilated eye examination. Subjects and Methods: A retrospective cross-sectional study was performed among diabetic patients seen in primary outpatient clinics between 2006 and 2011 who were screened for diabetic retinopathy with nFP for history of nonadherence to recommended annual dilated eye examination. A single nonstereoscopic, 45°, 10-megapixel digital image of the disc and macula of both eyes was obtained locally and transmitted electronically to a retinal specialist for remote review. The results from remote rural Native American Indian reservations were compared with those from an urban academic family practice clinic. The proportion of subjects diagnosed with diabetic retinopathy and the quality of fundus images were compared. Results: Among 872 patients (1,744 eyes) screened from rural sites and 517 subjects (1,034 eyes) screened from an urban site, images were of good quality for evaluation in 82.4% and 85.7% of subjects, respectively. Diabetic retinopathy was noted in 12.6% of rural subjects and 29.6% of urban subjects (p<0.001). Conclusions: nFP can be a useful tool in both rural and urban settings to screen for diabetic retinopathy in patients who are nonadherent to the recommended dilated annual eye exam. In our study population, a surprisingly higher percentage of diabetic subjects screened from the urban clinic had retinopathy compared with subjects screened in rural clinics. PMID:24219153

  1. Detection of necrosis of the gastric fundus after blunt abdominal trauma by PET-CT.

    PubMed

    Hofer, A; Kratochwill, H; Pentsch, A; Gabriel, M

    2015-02-01

    Positron emission tomography with [(18)F]-fluorodeoxyglucose provides functional and anatomic information by visualising the uptake of radiolabelled glucose in tumour and inflammatory cells. We report delayed diagnosis of necrosis of the gastric fundus after blunt abdominal trauma in a 73-year-old man. After a car accident with head-on collision, the patient was stabilised in our emergency room. His femur was treated by internal fixation, his ellbow was stabilised by a fixateur externe. During surgery his status deteriorated. The patient was in need of high dosage of inotrops during the following days. He had a biventricular pacemaker implanted because of ischemic myocardiopathy, and he suffered from renal insufficiency. Over the next days, his haemodynamics improved. A central venous line had to be removed because of ensuing septic fever. The patient complained of upper abdominal pain and nausea. A sonography and computer tomography without contrast medium were performed with negative result. Because of contamination of the central venous line with Staphylococcus epidermidis the pacemaker was evaluated for infection by transoesophageal echocardiography, again without any findings. Because of ongoing fever and positive inflammatory markers a positron emission tomography was indicated, as a contrast examination and a magnetic resonance examination were not feasible because of the renal insufficiency and the pacemaker, respectively. Prophylactic removal of the pacemaker would have been a substantial risk for the patient due to his underlying myocardiopathy. Positron emission tomography showed an increased tracer uptake in the gastric fundus, which turned out to be necrotic by endoscopy. A laparoscopic resection followed, and drainage of an abscess, which had evolved subsequently between stomach and spleen stopped the inflammatory process. This case report demonstrates that positron emission tomography may be an alternative to computer tomography with contrast medium

  2. Ocular myiasis caused by Chrysomya bezziana – a case report

    PubMed Central

    Nene, Amit S; Mishra, Anoop; Dhand, Purnima

    2015-01-01

    Ophthalmomyiasis can have variable presentation depending on the type of fly, structures involved, and level of penetration. A 42-year-old female presented with extensive myiasis of the right eye. A lesion of 3×2 cm was noted at the medial canthus and was infested with maggots. The larvae were removed meticulously and the wound debrided. The larva isolated was that of Chrysomya bezziana (Old World screwworm). Computed tomography (CT) scan was normal. The wound was dressed regularly and healed by secondary intention. Ocular myiasis is a rare disease that can lead to life threatening consequences, such as intracranial extension. Prompt management with debridement and radical antibiotic therapy is essential. PMID:25784787

  3. Recent advances in ocular drug delivery.

    PubMed

    Achouri, Djamila; Alhanout, Kamel; Piccerelle, Philippe; Andrieu, Véronique

    2013-11-01

    Amongst the various routes of drug delivery, the field of ocular drug delivery is one of the most interesting and challenging endeavors facing the pharmaceutical scientist. Recent research has focused on the characteristic advantages and limitations of the various drug delivery systems, and further research will be required before the ideal system can be developed. Administration of drugs to the ocular region with conventional delivery systems leads to short contact time of the formulations on the epithelium and fast elimination of drugs. This transient residence time involves poor bioavailability of drugs which can be explained by the tear production, non-productive absorption and impermeability of corneal epithelium. Anatomy of the eye is shortly presented and is connected with ophthalmic delivery and bioavailability of drugs. In the present update on ocular dosage forms, chemical delivery systems such as prodrugs, the use of cyclodextrins to increase solubility of various drugs, the concept of penetration enhancers and other ocular drug delivery systems such as polymeric gels, bioadhesive hydrogels, in-situ forming gels with temperature-, pH-, or osmotically induced gelation, combination of polymers and colloidal systems such as liposomes, niosomes, cubosomes, microemulsions, nanoemulsions and nanoparticles are discussed. Novel ophthalmic delivery systems propose the use of many excipients to increase the viscosity or the bioadhesion of the product. New formulations like gels or colloidal systems have been tested with numerous active substances by in vitro and in vivo studies. Sustained drug release and increase in drug bioavailability have been obtained, offering the promise of innovation in drug delivery systems for ocular administration. Combining different properties of pharmaceutical formulations appears to offer a genuine synergy in bioavailability and sustained release. Promising results are obtained with colloidal systems which present very comfortable

  4. Epidemiological aspects of ocular superglue injuries

    PubMed Central

    Tabatabaei, Seyed Ali; Modanloo, Shokoufeh; Ghiyasvand, Arezoo Mohammadkhani; Pouryani, Abolghasem; Soleimani, Mohammad; Tabatabaei, Seyed Mehdi; Pakrah, Ahmad Reza; Masarat, Hamideh

    2016-01-01

    AIM To report the frequency, associated risk factors and characteristics of cases referred to Farabi Eye Hospital with ocular superglue injuries. METHODS In a descriptive cross-sectional study conducted between December 2012 and February 2013, patients with ocular superglue injuries were evaluated. Age, sex, educational level, location, time, mechanism, type, site and time of eye injury were gathered through interview using a customized questionnaire. All participants had given consent to undergo thorough eye examination. RESULTS Over the course of three months, 105 patients with ocular superglue injuries enrolled in the study, including 56(53.3%) men and 49(46.7%) women with the mean age of 24.7±11.6 (range, 2 to 53)y. The right eye, left eye and both eyes were involved in 52%, 42% and 6% of the patients, respectively. Most of injuries had occurred at home (72.4%) and at night (55%). More than half of patients (52.4%) did not take any primary aids following the ocular injury. Patient carelessness (78.1%), childhood curiosity and lack of parental supervision (11.4%), storing superglue in inappropriate places and inadvertently using superglue as eye drops due to poor vision (2.9%), inadequate awareness of superglue applications [used to stick on artificial nails (3.8%), artificial eyelashes (1.9%) and broken tooth (1%)] and being assaulted with glue (1%) were common risk factors. CONCLUSION The frequency of ocular superglue injuries in patients referred to Farabi Eye Hospital is relatively high. This finding underlines the importance of public education and awareness about superglue injuries to the eye and taking protective measures and safety strategies in order to prevent these injures. PMID:26949651

  5. Vascular function and ocular involvement in sarcoidosis.

    PubMed

    Siasos, Gerasimos; Paraskevopoulos, Theodoros; Gialafos, Elias; Rapti, Aggeliki; Oikonomou, Evangelos; Zaromitidou, Marina; Mourouzis, Konstantinos; Siasou, Georgia; Gouliopoulos, Nikolaos; Tsalamandris, Sotiris; Vlasis, Konstantinos; Stefanadis, Christodoulos; Papavassiliou, Athanasios G; Tousoulis, Dimitris

    2015-07-01

    Ocular involvement occurs in sarcoidosis (Sar) patients mainly in the form of uveitis. This study was designed to determine if uveitis in Sar patients is associated with vascular impairment. We enrolled 82 Sar patients and 77, age and sex matched, control subjects (Cl). Sar patients were divided into those with ocular sarcoidosis (OS) and those without ocular sarcoidosis (WOS). Endothelial function was evaluated by flow-mediated dilation (FMD). Pulse wave velocity (PWV) was measured as an index of aortic stiffness and augmentation index (AIx) as a measure of arterial wave reflections. Although there was no significant difference in sex, age and mean arterial pressure, patients with OS compared to WOS patients and Cl subjects had impaired FMD (p<0.001), increased AIx (p=0.02) and increased PWV (p=0.001). Interestingly, impaired FMD in Sar patients was independently, from possible covariates (age, sex, smoking habits, arterial hypertension, dyslipidemia), associated with increased odds of ocular involvement (odds ratio=1.69, p=0.001). More precisely ROC curve analysis revealed that FMD had a significant diagnostic ability for the detection of OS (AUC=0.77, p<0.001) with a sensitivity of 79% and a specificity of 68% for an FMD value below 6.00%. To conclude in the present study we have shown that ocular involvement in Sar patients is associated with impaired endothelial function and increased arterial stiffness. These results strengthen the vascular theory which considers uveitis a consequence of vascular dysfunction in Sar patients and reveals a possible clinical importance of the use of endothelial function tests. PMID:25937082

  6. Ocular toxicity of authentic lunar dust

    PubMed Central

    2012-01-01

    Background Dust exposure is a well-known occupational hazard for terrestrial workers and astronauts alike and will continue to be a concern as humankind pursues exploration and habitation of objects beyond Earth. Humankind’s limited exploration experience with the Apollo Program indicates that exposure to dust will be unavoidable. Therefore, NASA must assess potential toxicity and recommend appropriate mitigation measures to ensure that explorers are adequately protected. Visual acuity is critical during exploration activities and operations aboard spacecraft. Therefore, the present research was performed to ascertain the ocular toxicity of authentic lunar dust. Methods Small (mean particle diameter = 2.9 ± 1.0 μm), reactive lunar dust particles were produced by grinding bulk dust under ultrapure nitrogen conditions. Chemical reactivity and cytotoxicity testing were performed using the commercially available EpiOcularTM assay. Subsequent in vivo Draize testing utilized a larger size fraction of unground lunar dust that is more relevant to ocular exposures (particles <120 μm; median particle diameter = 50.9 ± 19.8 μm). Results In vitro testing indicated minimal irritancy potential based on the time required to reduce cell viability by 50% (ET50). Follow-up testing using the Draize standard protocol confirmed that the lunar dust was minimally irritating. Minor irritation of the upper eyelids was noted at the 1-hour observation point, but these effects resolved within 24 hours. In addition, no corneal scratching was observed using fluorescein stain. Conclusions Low-titanium mare lunar dust is minimally irritating to the eyes and is considered a nuisance dust for ocular exposure. No special precautions are recommended to protect against ocular exposures, but fully shielded goggles may be used if dust becomes a nuisance. PMID:22817808

  7. Clinical applications of high-resolution ocular magnetic resonance imaging.

    PubMed

    Tanitame, Keizo; Sone, Takashi; Kiuchi, Yoshiaki; Awai, Kazuo

    2012-11-01

    Magnetic resonance imaging (MRI) using fast sequences with subjects staring at a target can provide motion-free ocular images, and small receiver surface coils make it possible to produce ocular images with high spatial resolution. MRI using half-Fourier single-shot rapid acquisition with a relaxation enhancement sequence as a fast T2-weighted imaging yields useful images for the morphologic diagnosis of ocular diseases, and MRI using a fast spoiled gradient-recalled-echo sequence as a T1-weighted imaging yields additional information by the administration of gadolinium-based contrast material for assessing the vascularity of intraocular tumors. These ocular imaging techniques are useful for the evaluation of patients with angle closure glaucoma, congenital abnormality of ocular globes, intraocular tumors and several types of detachments, as well as patients after ocular surgery. In this pictorial essay, we demonstrate the clinical applications of fast high-resolution ocular MRI with fixation of the subjects' visual foci. PMID:22923185

  8. The albino chick as a model for studying ocular developmental anomalies, including refractive errors, associated with albinism.

    PubMed

    Rymer, Jodi; Choh, Vivian; Bharadwaj, Shrikant; Padmanabhan, Varuna; Modilevsky, Laura; Jovanovich, Elizabeth; Yeh, Brenda; Zhang, Zhan; Guan, Huanxian; Payne, W; Wildsoet, Christine F

    2007-10-01

    Albinism is associated with a variety of ocular anomalies including refractive errors. The purpose of this study was to investigate the ocular development of an albino chick line. The ocular development of both albino and normally pigmented chicks was monitored using retinoscopy to measure refractive errors and high frequency A-scan ultrasonography to measure axial ocular dimensions. Functional tests included an optokinetic nystagmus paradigm to assess visual acuity, and flash ERGs to assess retinal function. The underlying genetic abnormality was characterized using a gene microarray, PCR and a tyrosinase assay. The ultrastructure of the retinal pigment epithelium (RPE) was examined using transmission electron microscopy. PCR confirmed that the genetic abnormality in this line is a deletion in exon 1 of the tyrosinase gene. Tyrosinase gene expression in isolated RPE cells was minimally detectable, and there was minimal enzyme activity in albino feather bulbs. The albino chicks had pink eyes and their eyes transilluminated, reflecting the lack of melanin in all ocular tissues. All three main components, anterior chamber, crystalline lens and vitreous chamber, showed axial expansion over time in both normal and albino animals, but the anterior chambers of albino chicks were consistently shallower than those of normal chicks, while in contrast, their vitreous chambers were longer. Albino chicks remained relatively myopic, with higher astigmatism than the normally pigmented chicks, even though both groups underwent developmental emmetropization. Albino chicks had reduced visual acuity yet the ERG a- and b-wave components had larger amplitudes and shorter than normal implicit times. Developmental emmetropization occurs in the albino chick but is impaired, likely because of functional abnormalities in the RPE and/or retina as well as optical factors. In very young chicks the underlying genetic mutation may also contribute to refractive error and eye shape abnormalities

  9. A Case Report: Anti-Psychotic Agents Related Ocular Toxicity.

    PubMed

    Choy, Bonnie Nga Kwan; Ng, Alex Lap Ki; Shum, Jennifer Wei Huen; Fan, Michelle Ching Yim; Lai, Jimmy Shiu Ming

    2016-04-01

    Chlorpromazine is known to cause ocular pigmentary deposits. However, delayed presentation after cessation of chlorpromazine has not been reported. There are also no reports on whether newer generation of anti-psychotic agents contribute to ocular toxicity. We describe a case of ocular toxicity related to anti-psychotic agents. To the best of our knowledge, this is the first reported case of anterior segment pigmentary deposits associated with olanzapine use, 2 years after the cessation of chlorpromazine.We report a case of ocular toxicity in a patient with history of chlorpromazine usage of 100 mg per day for 13 years and subsequently switched to olanzapine 5 mg for 2 years. There were no signs of ocular toxicity while the patient was on chlorpromazine. However, when the patient switched to olanzapine, she developed the ocular side effect as described for chlorpromazine-induced ocular toxicity, with pigmentary depositions on both corneas and the anterior lens surface and decrease in vision.Olanzapine, a newer anti-psychotic agent, may play a role in the ocular pigmentary deposition, either directly causing pigmentary deposition itself or accentuating the effect of chlorpromazine as the 2 drugs act on the same receptors, although further studies are required to support this hypothesis. As patients with psychiatric conditions may not voluntarily complain of visual symptoms, ocular screening could be considered in these patients receiving chronic anti-psychotic treatment, so that any ocular toxicity could be diagnosed in a timely manner. PMID:27082594

  10. Topical cyclosporine to control ocular surface disease in patients with chronic glaucoma after long-term usage of topical ocular hypotensive medications

    PubMed Central

    Saini, M; Dhiman, R; Dada, T; Tandon, R; Vanathi, M

    2015-01-01

    Purpose To evaluate changes in ocular surface and central corneal sub-basal nerve fiber layer (SBNFL) after topical cyclosporin therapy in chronic glaucoma patients on long-term topical antiglaucoma therapy. Methods A prospective comparative study of ocular surface evaluation of chronic glaucoma patients on long-term topical therapy treated concurrently with a topical cyclosporine 0.05% twice daily for 6 months and controls was done. The study parameters evaluated at recruitment and at the 6-month follow-up included details of topical antiglaucoma medications, visual acuity, intraocular pressure, ocular surface evaluation parameters (TBUT, Schirmers I, ocular surface staining scores and ocular surface disease (OSD) index score (OSDI)), central corneal sensation (Cochet Bonnett aesthesiometer), and central confocal microscopy to study the SBNFL density (SBNFLD). Results Thirty-two eyes of 16 patients with chronic glaucoma and 30 eyes of 15 normal subjects as controls were studied. Mean TBUT, pre/post CsA treatment was 8.67±3.01/12.24±1.83 s (P=0.007). Mean conjunctival/corneal staining scores pre/post CsA treatment were 3.38±1.93/1.50±0.718 (P=0.00) /5.19±1.82/1.81±0.78 (P=0.098), respectively. Mean OSDI pre/post CsA treatment scores were 30.63±14.61/14.76±6.06 (P=0.007). Mean corneal sensations scores pre/post CsA treatment were 4.64±0.46/4.94±0.39 (P=0.002). Central corneal SBNFLD pre and post CsA treatment was 8811.35±2985.29/10335.13±4092.064 μm/mm2 (P=0.0001). Conclusions Schirmer's test, ocular surface staining scores, OSDI, corneal sensations, and corneal SBNFLD showed a statistically significant improvement following a 6-month concurrent topical CsA therapy. PMID:25857609

  11. Ocular myasthenia gravis accompanied by anosmia.

    PubMed

    Chen, Ying; Wang, Li; Zhou, Li; Gao, Ying

    2016-02-01

    We report a case of ocular myasthenia gravis (MG) accompanied by anosmia. A 76-year-old man had idiopathic anosmia of 2-year duration. Four months before consultation, he began to have drooping in the right upper eyelid along with muscle soreness, distension, and pain in the nape. His tongue was dark-red with a thin and white coating; his pulse was wiry and slippery. According to Traditional Chinese Medicine, eyelid drooping and anosmia are the main signs of liver constraint and spleen deficiency. In Western Medicine, the diagnosis was ocular MG and idiopathic anosmia. Our patient, along with the literature, suggests that anosmia may be an early symptom before MG. MG accompanied by anosmia could be a special subtype of MG according to antibody production and symptoms. PMID:26946629

  12. Ocular problems in military free fall parachutists.

    PubMed

    Gruppo, Leonard; Mader, Thomas H; Wedmore, Ian

    2002-10-01

    Military free fall parachutists may be unaware of the risk of corneal freezing and desiccation keratitis should their goggles come off during free fall in subfreezing temperatures. We determine the incidence of ocular difficulties in military free fall parachutists and the role freezing temperatures may play in causing these problems. We found that 79% of those who responded to the survey had lost their goggles at least once during free fall and 69% experienced ocular symptoms after goggle loss. Analysis shows a 30-fold increase in the duration of symptoms in subfreezing vs. above-freezing temperatures, with the odds of the ground mission being affected at 7.3 per 100 jumps in the subfreezing group. The rate of goggles coming off per jump is 3.3 times less with >75 jumps. Contact lenses are not protective and photorefractive keratectomy was not detrimental. PMID:12392242

  13. Ocular Surface as Barrier of Innate Immunity

    PubMed Central

    Bolaños-Jiménez, Rodrigo; Navas, Alejandro; López-Lizárraga, Erika Paulina; de Ribot, Francesc March; Peña, Alexandra; Graue-Hernández, Enrique O; Garfias, Yonathan

    2015-01-01

    Sight is one of the most important senses that human beings possess. The ocular system is a complex structure equipped with mechanisms that prevent or limit damage caused by physical, chemical, infectious and environmental factors. These mechanisms include a series of anatomical, cellular and humoral factors that have been a matter of study. The cornea is not only the most powerful and important lens of the optical system, but also, it has been involved in many other physiological and pathological processes apart from its refractive nature; the morphological and histological properties of the cornea have been thoroughly studied for the last fifty years; drawing attention in its molecular characteristics of immune response. This paper will review the anatomical and physiological aspects of the cornea, conjunctiva and lacrimal apparatus, as well as the innate immunity at the ocular surface. PMID:26161163

  14. Orchestrating epigenetic roles targeting ocular tumors

    PubMed Central

    Wen, Xuyang; Lu, Linna; He, Zhang; Fan, Xianqun

    2016-01-01

    Epigenetics is currently one of the most promising areas of study in the field of biomedical research. Scientists have dedicated their efforts to studying epigenetic mechanisms in cancer for centuries. Additionally, the field has expanded from simply studying DNA methylation to other areas, such as histone modification, non-coding RNA, histone variation, nucleosome location, and chromosome remodeling. In ocular tumors, a large amount of epigenetic exploration has expanded from single genes to the genome-wide level. Most importantly, because epigenetic changes are reversible, several epigenetic drugs have been developed for the treatment of cancer. Herein, we review the current understanding of epigenetic mechanisms in ocular tumors, including but not limited to retinoblastoma and uveal melanoma. Furthermore, the development of new pharmacological strategies is summarized. PMID:27013893

  15. Isolated ocular lichen planus in a child.

    PubMed

    Igras, Estera; Kennedy, Susan; MacDermott, Emma Jane; Murphy, Conor C

    2015-08-01

    Lichen planus (LP) is an autoimmune inflammatory condition of the skin and mucous membranes, of unknown aetiology, that infrequently involves the eye. Ocular LP has not been described in children. We present the case of an 8-year-old girl with severe, filamentous dry eyes and persistent conjunctival hyperemia with bilateral progressive conjunctival symblepharon. Her conjunctival biopsy showed heavy linear fibrinogen deposits along the basement membrane without IgG, IgA, IgM, or C3 deposition, consistent with LP. No skin or other mucosal lesions were present, suggesting a diagnosis of isolated conjunctival LP. Oral and topical cyclosporine combined with methotrexate and low-dose oral steroids led to sustained disease remission. To our knowledge, this is the first case of isolated ocular LP in a child. PMID:26212185

  16. Treatment options for ocular adnexal lymphoma (OAL)

    PubMed Central

    Cohen, Victoria Mary Lendrum

    2009-01-01

    Most lymphomas that involve the ocular adnexal structure are low grade, B cell, non-Hodgkin’s lymphomas. The treatment depends upon the grade and stage of the disease. High grade lymhoma requires treatment with systemic chemotherapy whereas the localized low grade (extranodal marginal zone lymphoma) can be successfully managed with local radiotherapy. Chlamydia psittaci infection is associated with low grade ocular lymphoma; however there is wide geographic variation in the strength of this association. Blanket antibiotic therapy is not advised unless there is proof of an infective agent. The monoclonal antibody, rituximab, may be successful for CD20 positive lymphoma, although it is likely that rituximab will have better long-term results when used in combination with systemic chemotherapy. PMID:20054418

  17. Ocular screening tests of elementary school children

    NASA Technical Reports Server (NTRS)

    Richardson, J.

    1983-01-01

    This report presents an analysis of 507 abnormal retinal reflex images taken of Huntsville kindergarten and first grade students. The retinal reflex images were obtained by using an MSFC-developed Generated Retinal Reflex Image System (GRRIS) photorefractor. The system uses a 35 mm camera with a telephoto lens with an electronic flash attachment. Slide images of the eyes were examined for abnormalities. Of a total of 1835 students screened for ocular abnormalities, 507 were found to have abnormal retinal reflexes. The types of ocular abnormalities detected were hyperopia, myopia, astigmatism, esotropia, exotropia, strabismus, and lens obstuctions. The report shows that the use of the photorefractor screening system is an effective low-cost means of screening school children for abnormalities.

  18. Ocular drift along the mental number line.

    PubMed

    Myachykov, Andriy; Ellis, Rob; Cangelosi, Angelo; Fischer, Martin H

    2016-05-01

    We examined the spontaneous association between numbers and space by documenting attention deployment and the time course of associated spatial-numerical mapping with and without overt oculomotor responses. In Experiment 1, participants maintained central fixation while listening to number names. In Experiment 2, they made horizontal target-direct saccades following auditory number presentation. In both experiments, we continuously measured spontaneous ocular drift in horizontal space during and after number presentation. Experiment 2 also measured visual-probe-directed saccades following number presentation. Reliable ocular drift congruent with a horizontal mental number line emerged during and after number presentation in both experiments. Our results provide new evidence for the implicit and automatic nature of the oculomotor resonance effect associated with the horizontal spatial-numerical mapping mechanism. PMID:26724955

  19. Ocular injuries due to projectile impacts.

    PubMed

    Scott, W R; Lloyd, W C; Benedict, J V; Meredith, R

    2000-01-01

    An animal model has been developed using enucleated porcine eyes to evaluate ocular trauma. The eyes were pressurized to approximately 18 mmHg and mounted in a container with a 10% gelatin mixture. The corneas of sixteen pressurized eyes were impacted by a blunt metal projectile (mass of 2.6 gm, 3.5 gm or 45.5 gm) at velocities of 4.0 to 38.1 m/s. The impacted eyes were evaluated by an ophthalmologist. A numerical classification scheme was used to categorize the severity of the ocular injury. A chi-squared test indicates that the injury level is associated with the kinetic energy (KE) and not the momentum of the projectile. The enucleated eyes began to experience lens dislocations when the KE of the projectile was approximately 0.75 Nm, and retinal injuries when the KE was approximately 1.20 Nm. PMID:11558084

  20. Ocular changes resulting from therapy with amiodarone.

    PubMed Central

    Ingram, D V; Jaggarao, N S; Chamberlain, D A

    1982-01-01

    Amiodarone, a powerful antiarrhythmic agent recently made available in Britain, is known to cause corneal changes, but the clinical implications of this unwanted effect are still controversial. We have made serial observations on 105 patients treated with the drug for periods ranging from 3 months to over 7 years. Corneal abnormalities were detected by slit-lamp examination in 103 patients (98%). These always progressed over several months but subsequently showed a stable pattern which changed only with alteration of dose. The abnormalities regressed and disappeared within 7 months in the 16 patients whose treatment was discontinued for reasons unconnected with ocular changes. No macular changes or permanent sequelae occurred. Ocular symptoms were unusual: 6 patients had reactions in the skin of the eyelids, and 6 others had minor symptoms related to the corneal changes. We do not believe that ophthalmological surveillance is mandatory in asymptomatic patients on long-term amiodarone therapy. Images PMID:7115651

  1. Vestibular-ocular accommodation reflex in man

    NASA Technical Reports Server (NTRS)

    Clark, B.; Randle, R. J.; Stewart, J. D.

    1975-01-01

    Stimulation of the vestibular system by angular acceleration produces widespread sensory and motor effects. The present paper studies a motor effect which has not been reported in the literature, i.e., the influence of rotary acceleration of the body on ocular accommodation. The accommodation of 10 young men was recorded before and after a high-level deceleration to zero velocity following 30 sec of rotating. Accommodation was recorded continuously on an infrared optometer for 110 sec under two conditions: while the subjects observed a target set at the far point, and while they viewed the same target through a 0.3-mm pinhole. Stimulation by high-level rotary deceleration produced positive accommodation or a pseudomyopia under both conditions, but the positive accommodation was substantially greater and lasted much longer during fixation through the pinhole. It is hypothesized that this increase in accommodation is a result of a vestibular-ocular accommodation reflex.

  2. Current concepts of ocular adnexal surgery

    PubMed Central

    Borrelli, Maria; Geerling, Gerd

    2013-01-01

    Ophthalmic Plastic and Reconstructive Surgery is a specialized area of ophthalmology that deals with the management of deformities and abnormalities of the eyelids, lacrimal system and the orbit. An ophthalmoplastic surgeon is able to identify and correct abnormalities of the ocular adnexae such as ectropion, lid retraction, conjunctival scarring with severe entropion, that can cause secondary ocular surface disorders; manage patients with watering eye, and when needed intervene with a dacryocystorhinostomy by external or endonasal approach and moreover minimize disfigurement following enucleation or evisceration and prevent further corneal damage, alleviate complains of tearing and grittiness, but also cosmetic complaints in patients with Graves’ orbitopathy. Aim of this manuscript was to review current established and recently evolving surgical procedures. PMID:26504698

  3. Orchestrating epigenetic roles targeting ocular tumors.

    PubMed

    Wen, Xuyang; Lu, Linna; He, Zhang; Fan, Xianqun

    2016-01-01

    Epigenetics is currently one of the most promising areas of study in the field of biomedical research. Scientists have dedicated their efforts to studying epigenetic mechanisms in cancer for centuries. Additionally, the field has expanded from simply studying DNA methylation to other areas, such as histone modification, non-coding RNA, histone variation, nucleosome location, and chromosome remodeling. In ocular tumors, a large amount of epigenetic exploration has expanded from single genes to the genome-wide level. Most importantly, because epigenetic changes are reversible, several epigenetic drugs have been developed for the treatment of cancer. Herein, we review the current understanding of epigenetic mechanisms in ocular tumors, including but not limited to retinoblastoma and uveal melanoma. Furthermore, the development of new pharmacological strategies is summarized. PMID:27013893

  4. Effects of phacoemulsification surgery on ocular hemodynamics

    PubMed Central

    Turk, Adem; Mollamehmetoglu, Suleyman; Imamoglu, Halil Ibrahim; Kola, Mehmet; Erdol, Hidayet; Akyol, Nurettin

    2013-01-01

    AIM To evaluate the possible effects of phacoemulsification cataract surgery on ocular hemodynamics. METHODS In this prospective study, intraocular pressure (IOP), pulsatile ocular blood flow (POBF), and ocular pulse amplitude (OPA) were measured pre-operatively (baseline) and at 1 week and 3 weeks postoperation in 52 eyes of 26 patients (mean age 63.15±10.25 years) scheduled for unilateral phacoemulsification cataract surgery with intraocular lens implantation. In all of the eyes, a blood flow analyzer (Paradigm DICON; Paradigm Medical Industries Inc.; USA) was used to obtain measurements of IOP, POBF, and OPA. The data obtained from operated eyes were compared statistically to untreated fellow phakic eyes of the patients. RESULTS For operated eyes, the mean baseline IOP, POBF, and OPA values were 15.9±4.64mmHg, 17.41±4.84µL/s, and 2.91±1.12mmHg, respectively. The IOP, POBF, and OPA values were 17.19±4.34mmHg, 17.56±6.46µL/s, and 3.12±1.1mmHg, respectively, in the nonoperated control eyes. Statistically significant differences from baseline measurements were not observed 1 week and 3 weeks postoperation for the operated or nonoperated eyes. There were also no statistically significant differences in any measurements between the operated and nonoperated eyes in all the examination periods (P>0.05 for all). CONCLUSION Uncomplicated phacoemulsification surgery does not affect ocular hemodynamics in normotensive eyes with cataracts. PMID:23991393

  5. [Larva migrans syndrome or ocular toxocariasis].

    PubMed

    Pizzi, D R; Maffrand, R A; De Lisa, I S; Pizzi, H L; Plaza Ontiveros, R G

    2001-01-01

    Thirteen cases of ocular toxocariasis attended in the Oftalmology Service of the Pediatric Hospital "Niño Jesús", from Córdoba; and in the Parasitology and Micology Cathedra of the Medicine Collegue of the University of Córdoba were studied from July 1993 till July 1995. The authors determine the needs of taking into account this parasitosis; above all in children and with the antecedent of contact with pets. PMID:12934266

  6. Ocular quinine toxicity in a sleepwalker.

    PubMed

    Sinha, Amit; Al Husainy, Sahar

    2013-01-01

    A 55-year-old woman presented to the emergency department following an episode of severe visual impairment, headache, dizziness and confusion. The patient had been taking quinine sulfate as long-term medication for leg cramps. During an episode of sleepwalking, the patient had taken an overdose of quinine sulfate. Following a thorough investigation and assessment, a diagnosis of ocular quinine toxicity was made. We present this case and highlight the risks of quinine prescription. PMID:24287479

  7. Ocular quinine toxicity in a sleepwalker

    PubMed Central

    Sinha, Amit; Al Husainy, Sahar

    2013-01-01

    A 55-year-old woman presented to the emergency department following an episode of severe visual impairment, headache, dizziness and confusion. The patient had been taking quinine sulfate as long-term medication for leg cramps. During an episode of sleepwalking, the patient had taken an overdose of quinine sulfate. Following a thorough investigation and assessment, a diagnosis of ocular quinine toxicity was made. We present this case and highlight the risks of quinine prescription. PMID:24287479

  8. Gene-environment interactions in ocular diseases.

    PubMed

    Sacca, S C; Bolognesi, C; Battistella, A; Bagnis, A; Izzotti, A

    2009-07-10

    Degenerative ocular diseases are widespread in the population and represent a major cause of reversible and irreversible blindness. Scientific evidences have been accumulating supporting the role of genotoxic damage and gene environment interactions in the pathogenesis of these diseases mainly including glaucoma, age-related macular degeneration, and cataract. Glaucoma, in its degenerative form, is characterized by the degeneration of the trabecular meshwork, the tissue of the anterior chamber of the eye devoted to aqueous-humour outflow. Such a degenerative process results in intra-ocular pressure increase and progressive damage of optic nerve head. Oxidative stress and DNA damage play an important role in inducing the degeneration of these well differentiated target tissues in which DNA damage results in a progressive cell loss. Macular degeneration is a common age-related disease affecting the central regions of the retina inducing progressive accumulation of oxidized lipoproteins and neovascularization. Environmental genotoxic risk factors include diet, light, and cigarette smoke paralleled by individual susceptibility as determined by adverse genetic assets. Cataract is a progressive opacity of the crystalline lens resulting from molecular damages induced by various risk factors including UV-containing light. This disease has been related to a failure in antioxidant defences. Experimental study provides evidence that cataract patients possess higher basal level of DNA damage, as evaluated by Comet test, in lymphocytes than controls. This finding is paralleled by the higher susceptibility to oxidative stress observed in the same patients. These novel experimental data further support the role of DNA damage as a main factor contributing to cataract onset. In conclusion, the examined degenerative ocular diseases recognise environmental risk factors often displaying genotoxic attitudes. Whenever these factors target individuals who are susceptible due their

  9. Ocular Myasthenia Gravis Associated With Thymic Amyloidosis.

    PubMed

    Chapman, Kristin O; Beneck, Debra M; Dinkin, Marc J

    2016-03-01

    A 45-year-old woman with ptosis and diplopia was found to have myasthenia gravis (MG) associated with amyloidosis of the thymus gland. Systemic MG is frequently associated with thymomas or thymic hyperplasia but has only once previously been reported in association with amyloidosis of the thymus. This case demonstrates that isolated ocular MG rarely may also be associated with amyloidosis of the thymus. PMID:25822660

  10. Central serous chorioretinopathy after ocular trauma in the fellow eye during a water-polo game.

    PubMed

    Moschos, Marilita M; Gouliopoulos, Nikolaos Stefanos

    2015-01-01

    A 35-year-old water polo player was struck in his right eye during a water polo game. At presentation to our hospital, his visual acuity, intraocular pressure, fundus examination and neurological examination were normal. He received the appropriate treatment (no corticosteroids were applied), but 1 week later he reported blurred vision in his left eye. Visual acuity in the left eye was 6/10 Snellen chart, fluorescein angiography showed a focal retinal pigment epithelium leakage, while optical coherence tomography through the macula revealed mild neurosensory retinal detachment with an increase in retinal thickness. Two weeks later, the situation improved, and 1 month later no signs or symptoms of central serous chorioretinopathy were present. Currently, 9 months later, the situation remains unchanged. Post-traumatic stress was recognised as the key factor for development of central serous chorioretinopathy in our patient, since it was followed by excessive release of catecholamines and increased endogenous cortisol levels. PMID:26392445

  11. Nanoparticles in the ocular drug delivery

    PubMed Central

    Zhou, Hong-Yan; Hao, Ji-Long; Wang, Shuang; Zheng, Yu; Zhang, Wen-Song

    2013-01-01

    Ocular drug transport barriers pose a challenge for drug delivery comprising the ocular surface epithelium, the tear film and internal barriers of the blood-aqueous and blood-retina barriers. Ocular drug delivery efficiency depends on the barriers and the clearance from the choroidal, conjunctival vessels and lymphatic. Traditional drug administration reduces the clinical efficacy especially for poor water soluble molecules and for the posterior segment of the eye. Nanoparticles (NPs) have been designed to overcome the barriers, increase the drug penetration at the target site and prolong the drug levels by few internals of drug administrations in lower doses without any toxicity compared to the conventional eye drops. With the aid of high specificity and multifunctionality, DNA NPs can be resulted in higher transfection efficiency for gene therapy. NPs could target at cornea, retina and choroid by surficial applications and intravitreal injection. This review is concerned with recent findings and applications of NPs drug delivery systems for the treatment of different eye diseases. PMID:23826539

  12. Ocular rhinosporidiosis presenting as recurrent chalazion.

    PubMed

    Mukhopadhyay, Somnath; Shome, Subrata; Bar, Prasenjit Kumar; Chakrabarti, Amit; Mazumdar, Swati; De, Avisek; Sadhukhan, Kaushik; Bala, Bivas

    2015-10-01

    Rhinosporidiosis, a granulomatous disease caused by Rhinosporidium seeberi, is widely prevalent in Sri Lanka and southern parts of India. Besides the eye, the lacrimal passage and nasal cavity are affected. The most common ocular involvement is a subconjunctival bleeding mass. Our case, a 9-year-old girl from a rural background with a history of pond water bathing, presented with a marginal chalazion involving the left lower lid. She had a history of chalazion involving the same site three months earlier which was managed by incision and curettage. A decision of surgical exploration was made and the evacuated mass was examined histologically showing evidence of rhinosporidiosis. This type of clinical presentation for ocular rhinosporidiosis (as recurrent chalazion) has not been reported earlier in the literature. This case emphasises that the clinicians from this part of the world must consider ocular rhinosporidiosis as differential diagnosis in cases with recurrent chalazion especially in a rural background with a habit of pond water bathing. PMID:22986579

  13. [Experimental model of ocular ischemic diseases].

    PubMed

    Kiseleva, T N; Chudin, A V

    2014-01-01

    The review presents the most common methods of modeling of retinal ischemia in vitro (chemical ischemia with iodoacetic acid, incubation of the retinal pigment epithelium cells with oligomycin, deprivation of oxygen and glucose) and in vivo (a model with increased intraocular pressure, cerebral artery occlusion, chronic ligation of the carotid arteries, photocoagulation of the retinal vessels, occlusion of the central retinal artery, endothelin-1 administration). Modeling ischemic injury in rats is the most frequently used method in studies, because the blood supply of their eyes is similar to blood flow in the human eyes. Each method has its own advantages and disadvantages. Application of methods depends on the purpose of the experimental study. Currently model of ocular ischemic disease can be obtained easily by injecting vasoconstrictive drug endothelin-1. It is the most widely used method of high intraocular pressure induced ocular ischemic damage similar to glaucoma, occlusion of central retinal artery or ophthalmic artery in human. The development of experimental models of ocular ischemic diseases and detailed investigation of mechanisms of impairment of microcirculation are useful for improve the efficiency of diagnostic and treatment of ischemic diseases of retina and optic nerve. PMID:25971134

  14. Ocular tissue engineering: current and future directions.

    PubMed

    Karamichos, D

    2015-01-01

    Tissue engineering (TE) is a concept that was first emerged in the early 1990s to provide solutions to severe injured tissues and/or organs [1]. The dream was to be able to restore and replace the damaged tissue with an engineered version which would ultimately help overcome problems such as donor shortages, graft rejections, and inflammatory responses following transplantation. While an incredible amount of progress has been made, suggesting that TE concept is viable, we are still not able to overcome major obstacles. In TE, there are two main strategies that researchers have adopted: (1) cell-based, where cells are been manipulated to create their own environment before transplanted to the host, and (2) scaffold-based, where an extracellular matrix is created to mimic in vivo structures. TE approaches for ocular tissues are available and have indeed come a long way, over the last decades; however more clinically relevant ocular tissue substitutes are needed. Figure 1 highlights the importance of TE in ocular applications and indicates the avenues available based on each tissue.[...]. PMID:25695336

  15. Ocular drug delivery of progesterone using nanoparticles.

    PubMed

    Li, V H; Wood, R W; Kreuter, J; Harmia, T; Robinson, J R

    1986-01-01

    The objective of this study was to evaluate ocular delivery of a lipid-soluble drug, [3H]progesterone, using nanoparticles. Polybutylcyanoacrylate nanoparticles loaded with [3H]progesterone were prepared by an emulsion polymerization technique using a hydrophilic continuous phase. The resulting nanoparticle suspension contained 2 x 10(-5) M progesterone. It was found that, at equilibrium, 99 per cent of the progesterone resided in the nanoparticles and the remainder in the aqueous phase indicating an excellent encapsulation efficiency. In addition, an appropriate control solution of progesterone was prepared, which did not contain polybutylcyanoacrylate. Concentrations of [3H]progesterone in various ocular tissues of the albino rabbit were monitored at various times following topical administration of either the nanoparticle suspension or the control solutions. Comparison of the concentration-time profiles indicates that tissue concentration of progesterone following topical administration of nanoparticles is generally four to five times less than that obtained with control solutions. This decreased concentration suggests that, due to the high affinity of progesterone for the nanoparticles, the drug is being made less available for absorption during its residence time in the precorneal area. The utility of nanoparticles as an ocular drug delivery system may depend on optimizing lipophilic-hydrophilic properties of the polymer-drug system, in addition to increasing retention efficiency in the precorneal pocket. PMID:3508187

  16. Theory of ocular dominance pattern formation

    NASA Astrophysics Data System (ADS)

    Scherf, O.; Pawelzik, K.; Wolf, F.; Geisel, T.

    1999-06-01

    We investigate a general and analytically tractable model for the activity-dependent formation of neuronal connectivity patterns. Previous models are contained as limiting cases. As an important example we analyze the formation of ocular dominance patterns in the visual cortex. A linear stability analysis reveals that the model undergoes a Turing-type instability as a function of interaction range and receptive field size. The phase transitions is of second order. After the linear instability the patterns may reorganize which we analyze in terms of a potential for the dynamics. Our analysis demonstrates that the experimentally observed dependency of ocular dominance patterns on interocular correlations of visual experience during development can emerge according to two generic scenarios: either the system is driven through the phase transition during development thereby selecting and stabilizing the first unstable mode or a primary pattern reorganizes towards larger wavelength according their lower energy. Experimentally observing the time course of ocular dominance pattern formation will decide which scenario is realized in the brain.

  17. Myorelaxant activity of 2-t-butyl-4-methoxyphenol (BHA) in guinea pig gastric fundus.

    PubMed

    Fusi, F; Valoti, M; Petkov, G V; Boev, K K; Sgaragli, G P

    1998-10-30

    This study investigates the mechanism whereby the antioxidant 2-t-butyl-4-methoxyphenol (BHA) relaxes guinea pig gastric fundus smooth muscle. In circular smooth muscle strips, 10 microM cyclopiazonic acid, a specific inhibitor of sarcoplasmic reticulum Ca2+-ATPase, induced a prolonged rise in tension which depended on the presence of extracellular Ca2+. BHA (pIC50 = 5.83), sodium nitroprusside (6.85), isoproterenol (7.69) and nifedipine (8.02), but not 2,6-di-t-butyl-4-methoxyphenol (DTBHA) (up to 30 microM), relaxed muscle strips contracted with cyclopiazonic acid. Methyl-1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluoromethylphenyl)-pyri dine-5-carboxylate (Bay K 8644) (1 microM) antagonised the nifedipine- but not the BHA-induced relaxation. Nifedipine and isoproterenol (10 microM) caused a decrease in spontaneous tone, but did not counteract the subsequent rise in tension elicited by 10 microM cyclopiazonic acid. Conversely, 100 microM BHA and 100 microM sodium nitroprusside not only significantly reduced spontaneous tone but also markedly impaired the response of the muscles to cyclopiazonic acid. DTBHA failed to show either effect. When added to preparations completely relaxed by 100 microM BHA, 10 mM tetraethylammonium still elicited nifedipine-sensitive tonic and phasic contractions in the presence or absence of 10 microM cyclopiazonic acid. BHA and DTBHA inhibited, in a concentration-dependent manner, the Ca2+-promoted contraction of strips depolarised by 10 mM tetraethylammonium. The BHA antagonism showed a non-competitive profile while that of DTBHA was competitive. In muscle strips at rest, 10 microM BHA caused a significant increase in tissue cAMP concentration, leaving cGMP unmodified. To conclude, the myorelaxant action of BHA on gastric fundus smooth muscle appears to be mediated partly by an increase in cAMP levels and partly by inhibition of Ca2+ influx from the extracellular space. PMID:9845271

  18. Dissociation between electrical and mechanical responses to nitrergic stimulation in the canine gastric fundus.

    PubMed

    Bayguinov, O; Sanders, K M

    1998-06-01

    1. We examined the relationships between membrane potential, intracellular [Ca2+] ([Ca2+]i), and tension in muscles of the canine gastric fundus in response to nitrergic stimulation by NO donors and electrical field stimulation (EFS) of intrinsic enteric inhibitory neurons when adrenergic and cholinergic responses were blocked. 2. NO donors reduced [Ca2+]i and tension in a concentration-dependent manner. A close relationship was noted between these parameters. 3. In terms of the [Ca2+] vs. force relationship, relaxation responses to EFS differed from responses to NO donors. EFS resulted in smaller decreases in [Ca2+]i to produce a given relaxation compared with responses to NO donors. Thus, muscles stimulated with EFS were less sensitive to [Ca2+]i than muscles stimulated with exogenous NO. 4. When membrane potential, [Ca2+]i and tension were monitored simultaneously in the same muscles, a temporal dissociation was noted between the electrical responses and changes in [Ca2+]i and tension. Brief electrical responses were associated with more sustained changes in [Ca2+]i and tension. 5. Further dissociation between electrical and mechanical effects was noted. Changes in [Ca2+]i and tension caused by sodium nitroprusside and EFS were blocked by arginine analogues and by oxyhaemoglobin, but electrical responses were unaffected. 1H-[1,2,4]oxadiazolo[4, 3-a]quinoxalin-1-one (ODQ), an inhibitor of soluble guanylyl cyclase, also blocked the effects of nitrergic stimulation on [Ca2+]i and tension, without affecting hyperpolarization. Thus, in the presence of continued hyperpolarization, the reductions in [Ca2+]i and tension caused by nitrergic stimulation were blocked. 6. Block of hyperpolarization in response to nitrergic stimulation with tetrapentylammonium chloride (TPEA) had relatively little effect on the [Ca2+]i and tension responses. Thus, hyperpolarization is not required for nitrergic effects on [Ca2+]i and tension. 7. In summary, reduction in [Ca2+]i and tension

  19. Spectral-Domain Optical Coherence Tomography, Wide-Field Photography, and Fundus Autofluorescence Correlation of Posterior Ophthalmomyiasis Interna.

    PubMed

    Paulus, Yannis M; Butler, Nicholas J

    2016-07-01

    Posterior ophthalmomyiasis interna is a rare, potentially devastating infestation of the posterior segment by fly larvae. The authors report the first demonstration of spectral-domain optical coherence tomography (SD-OCT) (Spectralis; Heidelberg Engineering, Heidelberg, Germany), wide-field angiography (Optos, Dunfermline, Scotland) and photography, and fundus autofluorescence with temporal progression during a period of 6 months. A 12-year-old white female presented with acute, painless vision loss with hand motions visual acuity. No larva was visible, so she was treated with oral ivermectin. Visual acuity improved to 20/80. OCT demonstrated hyporeflective spaces of the outer retina and retinal pigment epithelium, which resolved during 1-month period with improved ellipsoid layer by 6 months. Fundus autofluorescence demonstrated linear hypoautofluorescent tracks. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:682-685.]. PMID:27434903

  20. Feasibility of laser targeted photo-occlusion of ocular vessels.

    PubMed Central

    Asrani, S; Zeimer, R

    1995-01-01

    AIMS/BACKGROUND--Neovascularisation occurs in many major ocular diseases such as diabetes, age-related macular degeneration, and sickle cell disease. Laser photocoagulation is typically used to obliterate the vessels but it also causes severe damage to adjacent normal tissues. This is a very significant limitation especially in the treatment of choroidal neovascularisation which often covers large areas of the posterior pole and the fovea. A method, laser targeted delivery, has been developed capable of releasing drugs locally and non-invasively in the choroidal or retinal vasculature. This method could be used to target a photo-sensitiser to neovascular membranes and cause their selective occlusion by irradiating them. The targeting properties of the method promise to yield a treatment for neovascularisation that does not damage adjacent tissues and thus preserves vision. The purpose of the present study was to test the feasibility of occluding ocular vessels with this method. METHOD--The iris vessels of the albino rat were chosen because the treatment could be assessed unequivocally and followed with time. Aluminium phthalocyanine tetrasulphonate was encapsulated in heat sensitive liposomes and administered systemically. The iris vessels were irradiated with a yellow laser to raise their temperature to 41 degrees C, cause a phase transition in the liposomes and thereby locally release the photosensitiser. The laser was also used to excite the released photosensitiser and cause occlusion. The effect was monitored immediately and for 8 months thereafter. Controls for the effect of the laser and the unencapsulated drug were conducted. RESULTS--The results demonstrated that occlusion can be achieved and sustained for the period of follow up. The controls showed that the effect was not due to heat or to the activation of the low dose of free drug. CONCLUSION--These preliminary findings indicate that laser targeted photo-occlusion is a promising new method for the