Background: Optical coherence tomography angiography (OCT-A) has emerged as a novel, fast, safe and non-invasive imaging technique of analyzing the retinal and choroidal microvasculature in vivo. OCT-A captures multiple sequential B-scans performed repeatedly over a specific retinal area at high speed, thus enabling the composition of a vascular map with areas of contrast change (high flow zones) and areas of steady contrast (slow or no flow zones). It therefore provides unique insight into the exact retinal or choroidal layer and location at which abnormal blood flow develops. OCTA has evolved into a useful tool for understanding a number of retinal pathologies such as diabetic retinopathy, age-related macular degeneration, central serous chorioretinopathy, vascular occlusions, macular telangiectasia and choroidal neovascular membranes of other causes. OCT-A technology is also increasingly being used in the evaluation of optic disc perfusion and has been suggested as a valuable tool in the early detection of glaucomatous damage and monitoring progression. Objective: To review the existing literature on the applications of optical coherence tomography angiography in neurodegenerative diseases. Summary: A meticulous literature was performed until the present day. Google Scholar, PubMed, Mendeley search engines were used for this purpose. We used 123 published manuscripts as our references. OCT-A has been utilized so far to describe abnormalities in multiple sclerosis (MS), Alzheimer's disease, arteritic and non-arteritic optic neuropathy (AION and NAION), Leber's hereditary optic neuropathy (LHON) papilloedema, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis (ALS), Wolfram syndrome, migraines, lesions of the visual pathway and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). It appears that OCT-A findings correlate quite well with the severity of the aforementioned diseases. However, OCT-A has its own limitations, namely its lack of wide-field view of the peripheral retina and the inaccurate interpretation due to motion artifacts in uncooperative groups of patients (e.g. children). Larger prospective longitudinal studies will need to be conducted in order to eliminate the aforementioned limitations.

Purpose: To describe long-term outcomes with intravitreal Bevacizumab for choroidal neovascularization secondary to Sorsby fundus dystrophy. Materials/methods: Observational case series. Results: Two sisters of the same family formally diagnosed with Sorsby fundus dystrophy were followed-up for 12 years. The elder sister (S1) presented with significant decline in vision due to choroidal neovascularization in her right eye (OD). She developed choroidal neovascularization 3 years later in her left eye (OS). She was treated with Bevacizumab intravitreal injections on a on a pro-re-nata (PRN) until April 2015, when a treat-and-extend (T&E) approach was adopted. Best corrected visual acuities at the time of switch to T&E were 1.09 OD and 0.85 LogMar OS. Best corrected visual acuities at the last follow-up were LogMar 1.1 OD and 0.82 OS. Her younger sister (S2) presented with best corrected visual acuities of LogMar 0.1 OD and 0.0 OS. She developed choroidal neovascularization 5 years later in both eyes. OS developed choroidal neovascularization 18 months after her right eye. She received Bevacizumab on a pro re nata basis until April 2015 when a switch to a T&E was performed. Best corrected visual acuity in the left eye at the switch to T&E was 0.34 LogMar. At the last follow-up, best corrected visual acuities were LogMar 1.2 OD and 0.29 OS. Conclusion: Bevacizumab is an effective therapy for choroidal neovascularization secondary to Sorsby fundus dystrophy. A T&E protocol appears more effective compared to pro re nata protocol in minimizing recurrence of choroidal neovascularization with potential secondary scar formation or atrophy.

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Sorsby fundus dystrophy (SFD) is a rare autosomal dominant disorder with complete penetrance affecting the macula. This is caused by a mutation in the TIMP-3. This objective narrative review aims to provide an overview of the pathophysiology, current treatment modalities, and future perspectives. A literature search was performed using "PubMed," "Web of Science," "Scopus," "ScienceDirect," "Google Scholar," "medRxiv," and "bioRxiv." The molecular mechanisms underlying SFD are not completely understood. Novel advancements in cell culture techniques, including induced pluripotent stem cells, may enable more reliable modeling of SFD. These cell culture techniques aim to shed more light on the pathophysiology of SFD, and hopefully, this may lead to the future development of treatment strategies for SFD. Currently, no gene therapy is available. The main treatment is the use of anti-vascular endothelial growth factors (anti-VEGF) to treat secondary choroidal neovascular membrane (CNV), which is a major complication observed in this condition. If CNV is detected and treated promptly, patients with SFD have a good chance of maintaining a functional central vision. Other treatment modalities have been tried but have shown limited benefit, and therefore, have not managed to be more widely accepted. In summary, although there is no definitive cure yet, the use of anti-VEGF treatment for secondary CNV has provided the opportunity to maintain functional vision in individuals with SFD, provided CNV is detected and treated early.Abbreviations: AMD = age-related macular degeneration, CNV = choroidal neovascular membrane, iPSC = induced pluripotent stem cells, LogMAR = logarithm of Minimum angle of resolution, PDT = photodynamic therapy, PRN = pro re nata, RPE = retinal pigment epithelium, SFD = Sorsby fundus dystrophy, T&E = treat and extend, TIMP-3 = tissue inhibitor of metallproteinase-3, TNF-α = tumor necrosis factor-α, VEGF = vascular endothelial growth factor, VEGFR = vascular endothelial growth factor receptor.