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Purpose To evaluate the agreement between clinical examination, spectral-domain ocular coherence tomography (SD OCT), and fluorescein angiography (FA) in diagnosing intraretinal microvascular abnormality (IRMA) and neovascularization elsewhere (NVE) and define the SD OCT features that differentiate NVEs from IRMAs. Design Retrospective study. Methods Data were collected from 23 lesions from 8 diabetic patients, seen from July 2012 through October 2013 at Moorfields Eye Hospital, United Kingdom. Main outcomes were SD OCT features and FA leakage of IRMA and neovascular complex. The agreement between 3 evaluations was analyzed by Fleiss' kappa. Results The following 5 SD OCT features significantly differentiated IRMAs from NVEs: (1) hyperreflective dots in superficial inner retina ( P = .002); (2) the outpouching of internal limiting membrane (ILM) ( P = .004); (3) the breach of ILM ( P = .004); (4) the breach of posterior hyaloid ( P = .0005); (5) hyperreflective dots in vitreous ( P = .008). The agreement was moderate between 3 evaluations (κ = 0.48, P = 7.11 × 10 −5 ) but substantial between clinical and SD OCT evaluation (κ = 0.72, P = .00055). There was no significant agreement between OCT evaluation and FA leakage (κ = 0.249, P = .232). Conclusions SD OCT will be a valuable adjunct in evaluating IRMA and NVE, since it can verify the histopathologic correlate. SD OCT provides subtle anatomic insights and may be more accurate than clinical examination or leakage on FA, our current method of diagnosing this important endpoint, which has implications in future trial design for proliferative diabetic retinopathy prevention.

Purpose To investigate the association between peripheral and central ischemia in diabetic retinopathy. Design Retrospective, cross-sectional. Methods Consecutive ultra-widefield fluorescein angiography images were collected from patients with diabetes over a 12-month period. Parameters quantified include the foveal avascular zone (FAZ) area, peripheral ischemic index, peripheral leakage index, and central retinal thickness measurements, as well as visual acuity. The peripheral ischemia or leakage index was calculated as the area of capillary nonperfusion or leakage, expressed as a percentage of the total retinal area. Results Forty-seven eyes of 47 patients were included. A moderate correlation was observed between the peripheral ischemia index and FAZ area (r = 0.49, P = .0001). A moderate correlation was also observed between the peripheral leakage index and FAZ area, but only in eyes that were laser naive (r = 0.44, P = .02). A thinner retina was observed in eyes with macular ischemia (217 ± 81.8 μm vs 272 ± 36.0 μm) ( P = .02), but not peripheral ischemia (258 ± 76.3 μm vs 276 ± 68.0 μm) ( P = .24). The relationships between different patterns of peripheral and central macular pathology and visual acuity were evaluated in a step-wise multivariable regression model, and the variables that remained independently associated were age (r = 0.33, P = .03), FAZ area (r = 0.45, P = .02), and central retinal thickness (r = 0.38, P = .01), (R 2 -adjusted = 0.36). Conclusions Ultra-widefield fluorescein angiography provides an insight into the relationships between diabetic vascular complications in the retinal periphery and central macula. Although we observed relationships between ischemia and vascular leakage in the macula and periphery, it was only macular ischemia and retinal thinning that was independently associated with a reduced visual function.

Purpose To investigate the predictive factors for diabetic macular ischemia progression through the analysis of fluorescein angiography (FA) parameters. Design Retrospective, longitudinal study. Methods Data were collected from 79 eyes of 79 patients with type 2 diabetes mellitus. Macular ischemia severity was assessed using Early Treatment Diabetic Retinopathy Study (ETDRS) protocols and custom software used to quantify the foveal avascular zone (FAZ) area. Patients with ischemia grades "mild," "moderate," or "severe" and at least 2 macula-centered FA images over a minimum of 6 months were included. Main outcome measures were change in macular ischemia grades and FAZ enlargement rate (mm 2 /year). Results The median FAZ areas in mild, moderate, and severe ischemia grades at baseline were 0.28, 0.37, and 0.73 mm 2 , and significantly increased at the final FA (0.31, 0.41, and 1.23 mm 2 ) ( P = .001). The median duration of follow-up was 27.5, 31.0, and 24.0 months, and was not significantly different between groups. FAZ enlargement rates were higher in the more advanced ischemia grades—"severe" (0.073 mm 2 [10.4%]/year) compared to "mild" (0.021 mm 2 [7.50%]/year) ( P = .02) or "moderate" (0.019 [5.13%] mm 2 /year) ( P = .03). A greater ischemia severity grade was predictive for progression (odds ratio [OR] = 2.47, confidence interval [CI] = 1.21-5.05, P = .02). Macular ischemia progression itself was an independent predictive factor for visual acuity loss (OR = 4.60, CI = 1.54-13.7, P = .03). Conclusions The rate of FAZ enlargement ranges from 5%-10% of baseline FAZ area per year in eyes with established ischemia. A greater macular ischemia grade was independently predictive for progression, and diabetic macular ischemia progression itself was predictive of the loss of visual function.