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Gyrate atrophy (GA) of the choroid and retina is a rare autosomal recessive genetic condition characterized by elevation of the plasma level of the amino acid ornithine due to deficiency of the enzyme ornithine ketoacid aminotransferase. Accumulation of ornithine occurs in various body tissues but leads primarily to characteristic ophthalmic manifestations including myopia, cataract, progressive chorioretinal atrophy, and macular changes. Patients usually present with night blindness that starts in the first decade of life followed by visual field constriction and eventually diminution of the central visual acuity and blindness. The condition has been reported worldwide and its differential diagnosis is broad and includes choroideremia and retinitis pigmentosa. Treatment currently depends on life-long dietary modifications including restriction of the amino acid arginine in diet. This article describes in detail the pathogenesis, clinical features, multimodal imaging findings, and treatment options for GA of the choroid and retina and its complications.

Background. Diabetic macular edema (DME) is a major cause of vision loss in diabetics that is currently mainly treated by antivascular endothelial growth factor (VEGF) agents. The effect of these agents on macular perfusion (MP) is a current concern. Optical coherence tomography angiography (OCTA) is an imaging modality that allows noninvasive high-resolution retinal microvasculature imaging. Several recent studies evaluated the effect of anti-VEGF agents on the MP of DME patients using OCTA. Our aim is to provide a systematic review of these studies. Methods. Multiple databases were searched including PubMed, Ovid Medline, EMBASE, and Google Scholar for relevant studies published between January 2016 and November 2020 which were included in this review. Studies were compared regarding their design, the number of included patients, the machine and scanning protocol used, the inclusion and exclusion criteria, the number of injections given, the type of anti-VEGF agent used, the outcome measures assessed, and the effect of injections on different MP parameters. Results. A total of 16 studies were included. The studies assessed various OCTA parameters that define MP including the foveal avascular zone area and superficial and deep vascular density and yielded conflicting results. Seven studies showed stable or improved MP following treatment, while 7 studies showed worsening MP following treatment, and 2 studies showed inconclusive results. This could have been due to differences in study design, inclusion criteria, type of anti-VEGF agents used, treatment duration, and methods of image analysis and vascular density quantification. All identified studies were noncomparative case series, and 14 of them (87.5%) used the RTVue XR Avanti OCTA machine. Only one study compared OCTA to fluorescein angiography findings. Conclusion. Analysis of MP changes following VEGF inhibition for DME could benefit from a unified scanning protocol and analysis approach that uses similar study designs to eliminate potential sources of bias. This may provide more definitive conclusions regarding the effect of treatment on MP.

Traumatic chiasm transection is a rare condition characterized by bitemporal hemianopsia following head trauma. In a study of visual complications following head trauma, only 4.4% of patients suffered from chiasmal injuries. Complete transection of the chiasm is even more rare and best visualized using magnetic resonance imaging (MRI). We report the one-year follow-up of clinical, visual field, and MRI findings of a patient with complete transection of the optic chiasm following head trauma.

Background: In the current coronavirus disease 2019 (COVID-19) pandemic, health systems are struggling to prioritize care for affected patients, however, physicians globally are also attempting to maintain care for other lessthreatening medical conditions that may lead to permanent disabilities if untreated. Idiopathic intracranial hypertension (IIH) is a relatively common condition affecting young females that could lead to permanent blindness if not properly treated. In this article, we provide some insight and recommendations regarding the management of IIH during the pandemic. Methods: The diagnosis, follow-up, and treatment methods of IIH during the COVID-19 pandemic period are reviewed. COVID-19 as a mimic of IIH is also discussed. Results: Diagnosis and follow-up of papilledema due to IIH during the COVID-19 pandemic can be facilitated by nonmydriatic fundus photography and optical coherence tomography. COVID-19 may mimic IIH by presenting as cerebral venous sinus thrombosis, papillophlebitis, or meningoencephalitis, so a high index of suspicious is required in these cases. When surgical treatment is indicated, optic nerve sheath fenestration may be the primary procedure of choice during the pandemic period. Conclusion: IIH is a serious vision threatening condition that could lead to permanent blindness and disability at a relatively young age if left untreated. It could be the first presentation of a COVID-19 infection. Certain precautions during the diagnosis and management of this condition could be taken that may allow appropriate care to be delivered to these patients while minimizing the risk of coronavirus infection.

Background: Diabetic macular edema (DME) is a major cause of vision loss in diabetics worldwide. Anti-vascular endothelial growth factor (anti-VEGF) agents have become the mainstay of treatment of vision loss due to DME. Long-term effects of these agents on the macular perfusion (MP) are a current concern. Objective: To review recently published studies that evaluated the effect of intravitreal injection of anti-VEGF agents on the MP of diabetics with DME. Methods: Different databases were searched including PubMed, Medline, Ovid, Science Direct, and Google Scholar for relevant studies published between 2010 and 2019. All studies found were compared regarding methodology and results and included in this review. Some studies relating to retinal perfusion in general and not strictly MP were also included for comprehensiveness. Results: Several studies utilizing different anti-VEGF agents were identified. All the large randomized controlled clinical trials identified utilized primarily fluorescein angiography (FA) and human graders and found generally no worsening of MP associated with anti-VEGF agents use in diabetic patients with DME. Some of these studies, however, depended on post-hoc analysis. Several more recent, but smaller case series, have utilized the relatively new and non-invasive optical coherence tomography angiography in this evaluation and found more conflicting results. Conclusion: The large clinical trials recently performed depended mainly on FA in the analysis of MP changes following injections and generally found no worsening of MP. More recently, smaller case series have utilized OCTA in this analysis, yielding more conflicting results. Large randomized controlled trials using OCTA are thus needed.

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