Jerome Sherman

Buried disc drusen have hypo-reflective appearance on SD-OCT.

Purpose. Buried disc drusen are an important differential diagnosis for papilledema. Spectral domain optical coherence tomography (SD-OCT) affords clinicians with new non-invasive opportunities to probe below the surface of the optic nerve. Clinicians may use the knowledge of this appearance to rule out buried disc drusen in patients with irregular optic nerve borders or a bulging, hyperemic appearance. Methods. SD-OCTs were obtained in a patient with one surfacing disc druse, identifying the nature of the appearance of this disc druse and others in this and the contralateral eye when imaged with this technology. B-scan ultrasonography was used to confirm the presence of disc drusen. Additional scans in multiple patients with confirmed buried drusen were obtained for comparison. Results. Drusen appear as rounded hyporeflectant areas on SD-OCT, similar in appearance to blood vessels. They share the appearance of cysts but show a fine hyperreflective border anteriorly. These same discrete hyporeflective areas were found at various depths within optic nerve heads with confirmed buried disc drusen. Conclusions. The hyporeflective appearance may not be anticipated by clinicians, as B-scans show calcified drusen as hyperreflective on echo. It is hypothesized that the hyporeflectant appearance of drusen is due to a constancy in refractive index through the druse, as OCT detects changes in optical reflectivity. Thus, drusen are likely dense and homogenous. SD-OCT may be more useful in those patients with buried disc drusen which are not calcified as B-scan often contributes little in such cases.

Flash visual evoked potential (VEP) in amblyopia and optic nerve disease.

Amblyopia and optic atrophy are two very different causes of unilateral long-standing visual impairment. Yet, in some patients the differential diagnosis is not always manifest and standard clinical tests may fail to provide accurate information. We tested the efficacy of a nonstandard clinical test [flash visual evoked potentials (VEPs)] and quantitative ultivariate statistical techniques as aids in the assessment of this differential. Thirty-three patients were separated into four groups (normal, anisometropic amblyopia, strabismic amblyopia, and unilateral optic atrophy). Nonpatterned flash VEPs were obtained using several different temporal frequency rates. Patients with optic atrophy had significantly reduced VEPs in the affected eye at all temporal frequencies. Strabismic amblyopes, but not anisometropic amblyopes, often showed upranormal responses in the affected eye at the higher temporal frequencies. Finally, by using discriminant analysis (DA) we were able to classify correctly almost 70% of the patients, well above chance level of 25%. This DA provided very good sensitivity and specificity. We have shown that the use of flash VEPs and of multivariate statistical techniques may provide an effective way to diagnose amblyopia differentially from optic atrophy.

Discordance between structure and function in glaucoma: Possible anatomical explanations.

PURPOSE The aim of this study was to analyze glaucomatous eyes that show discordance between structure and function and hypothesize plausible anatomical explanations for discordance. METHODS Fifty eyes from 50 consecutive subjects with glaucoma (which was diagnosed according to multicenter criteria) were studied. One eye from each subject was selected randomly for inclusion, counterbalancing right eye (O.D.) and left eye (O.S.). By comparing the available structural information (from clinical disc assessment as well as GDx retinal nerve fiber layer [RNFL] measurements) to the Swedish Interactive Threshold Algorithm (SITA) Standard 24-2 (SS24-2) visual field results, study eyes were assigned to the following categories: (1) positive structure-function correlation, (2) structural abnormalities with no functional deficits, and (3) functional abnormalities with no structural deficits. Structure and function also were compared on a statistical basis, utilizing the nerve fiber indicator (NFI) of the GDx and the mean deviation (MD) and pattern standard deviation (PSD) of SS24-2 visual fields. RESULTS Forty-four eyes were classified in category 1, 5 eyes in category 2, and 1 eye in category 3. Scatter plots showing the relationship between the NFI and MD and between the NFI and PSD depict a positive correlation in the 44 category 1 eyes with R(2) values of 0.465 and 0.322, respectively. The remaining 6 eyes with discordant structural and functional findings were analyzed in detail. CONCLUSION The majority (88%) of glaucoma cases show concordance between structural loss and functional deficits. The primary proposed explanations for discordance include (1) visual field sampling and test selection limitations (i.e., the SS24-2 samples only axons that are anatomically connected to photoreceptors in the central retina, whereas the GDx samples virtually all axons) and (2) GDx measurement limitations in the papillo-macula bundle (i.e., the GDx has difficulty differentiating the normally thin RNFL from the pathologically even thinner RNFL). Tests of both structure and function are recommended in glaucoma suspects and patients, as neither mode is capable of identifying all glaucomatous deficits. Due to the apparent diagnostic benefit that the peripheral functional data may provide, we strongly recommend that future studies evaluating the structure-function relationship in glaucoma record peripheral (60-4) visual fields for all subjects at the outset of the study.

Visual acuity recovery in a case of idiopathic retinal vasculitis aneurysms and neuroretinitis.

Purpose. To describe the visual recovery after intravitreal injections of the antivascular endothelial growth factor, bevacizumab, in a case of vaso obliteration from idiopathic retinal vasculitis, aneurysm, and neuroretinitis (IRVAN). The name IRVAN was given to the condition to highlight the key findings present in the disease. IRVAN is a severe, sight threatening condition that can lead to peripheral capillary non-perfusion and vision loss from the ischemic sequelae of vascular occlusion. Panretinal photocoagulation (PRP) is the current standard of care for IRVAN but visual outcome is poor if PRP is initiated after neovascularization develops. Intravitreal bevacizumab has success at treating neovascularization from other ischemic retinopathies and inflammatory retinal conditions that have similar characteristics to IRVAN. Case Report. This case report describes a patient with decreased vision in the OS. The patient presented with best-corrected visual acuity of 20/20 in the OD and count fingers at 4 ft in the OS. Evaluation revealed findings consistent with an advanced stage of IRVAN. Anterior and posterior neovascularization had developed from extensive capillary non-perfusion in both retinas. A dense vitreous hemorrhage blocked vision OS. Bilateral intravitreal injections of bevacizumab and extensive PRP were given in the area of retinal ischemia for treatment. After 4 months, the patients vision had improved from count fingers in the OS to 20/40. Conclusions. IRVAN has favorable outcomes when treated with a combination of PRP and intravitreal injections of antivascular endothelial growth factor. This case demonstrates the effectiveness of this combination treatment in a case of IRVAN with both posterior and anterior neovascularization.

Central Pigmentary Sheen Dystrophy

Three members from two successive generations demonstrated a bilateral, symmetric pigmentary maculopathy consisting of a diffuse yellowish sheen of the posterior pole. The visual acuity was variable (20/25 to 10/400) and visual function tests indicated a localized disorder. Historic information suggests the disorder is slowly progressive. On the basis of mode of inheritance, fundus and angiographic appearance, and visual function testing this appears to be a newly described disorder.

Ectopia lentis, chorioretinal dystrophy and myopia A new autosomal recessive syndrome

Four of five siblings born of a consanguineous marriage demonstrated abnormalities of the lens (ectopia lentis and dense cataracts) and retina (generalized tapetoretinal dystrophy and total retinal detachment) associated with myopia. This association in an autosomal recessive pedigree has not been previously noted.

Sensitivity and specificity of the iVue iWellnessExam™ in detecting retinal and optic nerve disorders

BACKGROUND The purpose of this study was to assess the specificity and sensitivity of the iWellnessExam™ screening protocol available on iVue® spectral domain optical coherence tomography (SD-OCT), in a cohort of confirmed normal subjects and subjects with confirmed disease. METHODS In total, 126 of 132 confirmed normal subjects and 101 of 107 subjects with confirmed disease were included for analysis. Of the patients with confirmed disease, 67 had retinal disease, 50 had optic nerve disease, and 16 had both retinal and optic nerve pathology. All subjects were screened on the iWellnessExam protocol. Screen shots of the OD, OS, and OU comparison data were obtained and deidentified for reviewer analysis. Based on these data alone, each subject was sorted by a well trained eye care clinician into one of four categories (1, normal; 2, retinal disease; 3, optic nerve disease; 4, retinal and optic nerve disease). RESULTS Of the confirmed normal subjects, 125 of 126 were correctly identified as normal (specificity 99%). Retinal and/or optic nerve disease was correctly detected in 97 of 101 patients with confirmed disease (category 2, 3, 4), retinal pathology was correctly detected in 64 of 67 patients with retinal disease (category 2, 4), and optic nerve pathology was properly detected in 45 of 50 patients with optic nerve disease (category 3, 4), with a sensitivity of 96%, 95.5%, and 90%, respectively. CONCLUSION The iWellnessExam offers the health care provider an excellent method for identifying eyes at risk using very reliable technology. High specificity and sensitivity was obtained when reviewed by a well trained eye care clinician. It would be valuable to repeat the study with a novice and/or student clinician reviewing the same data set to ascertain interobserver variability, as well as the impact of clinical experience on accurate referral, based on the screening data.

OCT in a Myelinated Retinal Nerve Fiber Syndrome with Reduced Vision.

Purpose The prognosis of success with vision therapy in refractive “amblyopia” associated with the syndrome of myelinated nerve fibers (MRNF), optic disc hypoplasia, and myopia is reported to be poorer than that of anisomyopic amblyopia without these features. The reason for the poorer prognosis has not been well understood. The purpose of this study was to perform spectral domain (SD) ocular coherence tomography (OCT) to determine if there is a structural etiology that may explain the poorer prognosis. Case Reports Case 1 was a 12-year-old male patient with anisometropic “amblyopia” in the right eye, MRNF denser superiorly, a hypoplastic disc, and a myopic fundus with a flat intact macula. The OCT demonstrated an attenuated photoreceptor integrity line (PIL) in the macula. Case 2 was a 10-year-old male patient with a constant left esotropia, MRNF denser superiorly, a hypoplastic disc, and a myopic fundus with a flat intact macula. The OCT demonstrated an absent PIL. Case 3 was a 58-year-old female patient with a history of diabetic retinopathy OU, long-standing reduced vision in the right eye, MRNF denser superiorly, optic nerve hypoplasia, and a myopic fundus with an intact macula. The OCT demonstrated an absent PIL in the macula. Conclusions This case series identifies three patients with the syndrome of MRNF, optic nerve hypoplasia, and anisomyopia in one eye with reduced vision and reports OCT findings using SD-OCT systems. All three patients demonstrated an absence or attenuation of the photoreceptor integrity line (PIL) in the macula in the affected eye. To our knowledge, there is no known association between this syndrome and abnormality of the PIL reported in the literature. Patients with this syndrome may have a guarded prognosis in the success of vision therapy.

Visual evoked potential (VEP) delays in tilted and/or oblique entrance of the optic nerve head

Although VEP delays to pattern stimulation were once considered to be a specific finding in demyelinating optic neuropathy, such delays have more recently been reported in non-demyelinating optic neuropathy and in both wet and dry maculopathies. One major group of conditions not well documented in the clinical VEP literature is congenital anomalies of the optic nerve. The authors evaluated ten consecutive patients with the congenital optic nerve anomaly consisting of tilted and/or oblique entrance of the optic nerve in one or both eyes. The visual acuity ranged from 20/20-20/400. No patient had any symptom or clinical evidence of demyelinating disease and the VA was stable in each case. VEPs were recorded to pattern stimuli of 14,28, and 56 minute of arc checks reversing at 1.88 Hz and 7.5 Hz at 76% contrast and mean luminance of 25 cd/m2. The VEPs were delayed in 60%-70% of eyes tested depending upon the specific stimulus parameters utilized. In addition, VEPs were reduced and delayed in some patients wi...