Hyperreflective Ganglion Cell Layer Band in Gyrate Atrophy.

We have described the hyperreflective ganglion cell layer band (HGCB) in a series of cases of gyrate atrophy. Clinical fundus examination and multimodal imaging which included optical coherence tomography (OCT) was done in all cases. Four patients (one male, three female) were studied. In all four cases, a hyperreflective band was noted in the ganglion cell layer. In three patients, the band was continuous, and in one patient, the band was patchy. To conclude, HGCB is a novel OCT sign in gyrate atrophy and can be valuable in prognostication of disease. [Ophthalmic Surg Lasers Imaging Retina 2024;55:XX-XX.].

Pupil vignetting artifact on optical coherence tomography angiography.

PURPOSE: To discuss the features of an artifact on optical coherence tomography angiography (OCTA), termed "pupil vignetting artifact," and describe how it may masquerade as true chorioretinal pathology. DESIGN: This was a retrospective, observational case series. METHODS: The authors studied 12 eyes at a vitreoretinal clinic in Eastern India, reviewing a dark shadow such as an artifact on OCTA images. RESULTS: In all 12 eyes, there was an appearance of a dark shadow on OCTA imaging, located at the macula, superior, superotemporal, or superonasal to the fovea, which did not correspond to any ischemic area responsible for flow-void or any media opacity casting a posterior shadow. It was believed to be an artifact caused by the vignetting effect of the pupil as the incident OCT beam clips the iris during OCTA scanning, and therefore reduces the amount of total light incident on the retina. The variability in the size, shape, and location of the artifact is contributed by a few factors such as variable angle of incident light on the pupil, pupillary dynamics, and curvature of the retinal surface. CONCLUSION: Pupil vignetting artifact is a unique undescribed phenomenon appearing at the macula on OCTA imaging that can masquerade as numerous true chorioretinal pathologies. This article aims to describe this artifact to avoid misinterpretation and further confusion in real-life clinical practice.

Multicolor imaging: Current clinical applications.

Multicolor (MC) imaging is an innovative pseudocolor fundus imaging modality based on confocal scanning laser ophthalmoscopy. It effectively scans the retina at different depths to create a composite image. The green reflectance image depicts the middle retinal while blue reflectance image provides images of the retinal surface. The infrared reflectance image depicts retinal structures at the level of outer retina and choroid. We systematically analyze published case reports, case series, and original articles on MC imaging where it has helped in discovering additional clinical features of retinal diseases not readily apparent on conventional color fundus photography and played a role in monitoring the response to treatment.

Angular Sign of Henle Fiber Layer Hyperreflectivity in Purtscher and Purtscher like Retinopathy.

ABSTRACT: Angular Sign of Henle Fiber Layer Hyperreflectivity (ASHH) is a marker of Henle Fibre layer ischemia. Our aim is to describe ASHH as a novel OCT sign in Purtscher and Purtscher like retinopathy. Here we present 3 Cases, one classical Purtscher Retinopathy and 2 Purtscher like Retinopathy who had ASHH on SD OCT imaging. Modalities like Colour fundus photography, cross-sectional OCT, OCT angiography (OCTA) and fluorescein angiography were used. Presence ASHH in Purtscher Retinopathy and Purtscher like retinopathy points towards a deep capillary plexus insult and has prognostic implications.

Structural and functional phenotypic features and molecular analysis of Indian patients with Bietti crystalline dystrophy.

Purpose: Bietti crystalline dystrophy (BCD) is a rare retinal dystrophy, uncommon in Indians. This study describes the various phenotypic features seen in the Indian population. Methods: In this retrospective, descriptive case series, records of patients with either clinical or molecular diagnosis of BCD from 2009 to 2020 were perused. Phenotypic and genotype information was collected and analyzed. Results: This study included 58 patients of BCD (31 males) aged 21-79 years (mean: 47 ± 14 years). The age at onset ranged from 7 to 41 years (mean: 28.8 ± 5.1 years). Vision ranged from 20/20 to counting fingers. There were 18 (31%) patients with stage 1 with crystals and mild retinochoroidal atrophy, 22 (38%) with stage 2 with atrophy extending beyond arcades, and 18 (31%) with absent crystals and extensive atrophy of stage 3. Choroidal neovascular membrane was seen in four patients. The optical coherence tomography showed retinochoroidal thinning (84.6%), outer retinal tubulations (71.8%), and paradoxical foveal thickening with interlaminar bridges (7.7%). Electrophysiology and visual fields showed reduced responses in advanced retinochoroidal changes. Molecular confirmation was available in five patients; five mutations were seen in the CYP4V2. Conclusion: A wide variation is seen in the phenotypic picture of BCD. A molecular diagnosis is helpful in differentiating from other retinal dystrophies. The OCT shows the peculiar feature of the interlaminar bridge in early cases with photoreceptor loss. Further investigations into this OCT feature may provide insights into the pathogenesis of BCD. A genotype-phenotype correlation could not be done.

Histopathology and Molecular Biology Study of an Eyeball of a Case of Acute Retinal Necrosis.

PURPOSE: To report a histopathology and molecular biology study of an eyeball of a case of acute retinal necrosis (ARN). METHODS: Histopathology, immunohistochemistry and molecular biology of an enucleated globe of acute retinal necrosis 6 years after the onset of ARN. RESULTS: Histopathology showed persistence of chronic inflammatory cells with herpes virus inclusion body. Semi nested polymerase chain reaction showed varicella zoster virus. CONCLUSIONS: Chronic inflammatory cells and viral genome can be persistent even after 6 years after the onset of ARN.