Macular telangiectasia type 2 is a bilateral disease of unknown cause with characteristic alterations of the macular capillary network and neurosensory atrophy. Its prevalence may be underestimated and has recently been shown to be as high as 0.1% in persons 40 years and older. Biomicroscopy may show reduced retinal transparency, crystalline deposits, mildly ectatic capillaries, blunted venules, retinal pigment plaques, foveal atrophy, and neovascular complexes. Fluorescein angiography shows telangiectatic capillaries predominantly temporal to the foveola in the early phase and a diffuse hyperfluorescence in the late phase. High-resolution optical coherence tomography (OCT) may reveal disruption of the photoreceptor inner segment-outer segment border, hyporeflective cavities at the level of the inner or outer retina, and atrophy of the retina in later stages. Macular telangiectasia type 2 shows a unique depletion of the macular pigment in the central retina and recent therapeutic trials showed that such depleted areas cannot re-accumulate lutein and zeaxanthin after oral supplementation. There have been various therapeutic approaches with limited or no efficacy. Recent clinical trials with compounds that block vascular endothelial growth factor (VEGF) have established the role of VEGF in the pathophysiology of the disease, but have not shown significant efficacy, at least for the non-neovascular disease stages. Recent progress in structure-function correlation may help to develop surrogate outcome measures for future clinical trials. In this review article, we summarize the current knowledge on macular telangiectasia type 2, including the epidemiology, the genetics, the clinical findings, the staging and the differential diagnosis of the disease. Findings using retinal imaging are discussed, including fluorescein angiography, OCT, adaptive optics imaging, confocal scanning laser ophthalmoscopy, and fundus autofluorescence, as are the findings using visual function testing including visual acuity and fundus-controlled microperimetry. We provide an overview of the therapeutic approaches for both non-neovascular and neovascular disease stages and provide a perspective of future directions including animal models and potential therapeutic approaches.

ObjectiveTo report the 2-year outcomes of the BOLT study, a prospective randomized controlled trial evaluating intravitreous bevacizumab and modified Early Treatment Diabetic Retinopathy Study (ETDRS) macular laser therapy (MLT) in patients with persistent clinically significant macular edema (CSME).MethodsIn a 2-year, single-center, randomized controlled trial, 80 patients with center-involving CSME and visual acuity of 20/40 to 20/320 were randomized to receive either bevacizumab or MLT.Main Outcome MeasuresPrimary outcome: difference in ETDRS best-corrected visual acuity (BCVA) between arms. Secondary outcomes: mean change in BCVA, proportion gaining at least 15 and at least 10 ETDRS letters, losing fewer than 15 and at least 30 letters, change in central macular thickness, ETDRS retinopathy severity, and safety outcomes.ResultsAt 2 years, mean (SD) ETDRS BCVA was 64.4 (13.3) (ETDRS equivalent Snellen fraction: 20/50) in the bevacizumab arm and 54.8 (12.6) (20/80) in the MLT arm (P = .005). The bevacizumab arm gained a median of 9 ETDRS letters vs 2.5 letters for MLT (P = .005), with a mean gain of 8.6 letters for bevacizumab vs a mean loss of 0.5 letters for MLT. Forty-nine percent of patients gained 10 or more letters (P = .001) and 32% gained at least 15 letters (P = .004) for bevacizumab vs 7% and 4% for MLT. Percentage who lost fewer than 15 letters in the MLT arm was 86% vs 100% for bevacizumab (P = .03). Mean reduction in central macular thickness was 146 μm in the bevacizumab arm vs 118 μm in the MLT arm. The median number of treatments over 24 months was 13 for bevacizumab and 4 for MLT.ConclusionsThis study provides evidence supporting longer-term use of intravitreous bevacizumab for persistent center-involving CSME.Application to Clinical PracticeImprovements in BCVA and central macular thickness seen with bevacizumab at 1 year were maintained over the second year with a mean of 4 injections.Trial Registrationeudract.ema.europa.eu Identifier: 2007-000847-89

Background Within a surveillance of the prevalence and causes of vision impairment in high-income regions and Central/Eastern Europe, we update figures through 2015 and forecast expected values in 2020. Methods Based on a systematic review of medical literature, prevalence of blindness, moderate and severe vision impairment (MSVI), mild vision impairment and presbyopia was estimated for 1990, 2010, 2015, and 2020. Results Age-standardised prevalence of blindness and MSVI for all ages decreased from 1990 to 2015 from 0.26% (0.10–0.46) to 0.15% (0.06–0.26) and from 1.74% (0.76–2.94) to 1.27% (0.55–2.17), respectively. In 2015, the number of individuals affected by blindness, MSVI and mild vision impairment ranged from 70 000, 630 000 and 610 000, respectively, in Australasia to 980 000, 7.46 million and 7.25 million, respectively, in North America and 1.16 million, 9.61 million and 9.47 million, respectively, in Western Europe. In 2015, cataract was the most common cause for blindness, followed by age-related macular degeneration (AMD), glaucoma, uncorrected refractive error, diabetic retinopathy and cornea-related disorders, with declining burden from cataract and AMD over time. Uncorrected refractive error was the leading cause of MSVI. Conclusions While continuing to advance control of cataract and AMD as the leading causes of blindness remains a high priority, overcoming barriers to uptake of refractive error services would address approximately half of the MSVI burden. New data on burden of presbyopia identify this entity as an important public health problem in this population. Additional research on better treatments, better implementation with existing tools and ongoing surveillance of the problem is needed.