Quantitative Ultra-Widefield Angiographic Features and Associations with Diabetic Macular Edema

Abstract

Purpose: To examine the relationship between diabetic macular edema (DME) and quantitative ultra-widefield fluorescein angiography (UWFA) metrics of ischemia, leakage, and microaneurysms.

Design: Retrospective image analysis study.

Participants: Eyes with diabetic retinopathy that had undergone spectral-domain OCT, UWFA, and ultra-widefield fundus photography.

Methods: OCT images were analyzed to determine the presence or absence of DME, central subfield thickness (CST), and subretinal fluid. Using a semiautomated analysis platform, UWFA images were segmented for ischemia, leakage, and microaneurysms with manual correction as needed. Clinical variables, including age, gender, race, hemoglobin A1C levels, blood pressure, cholesterol levels, use of blood thinners, smoking status, and lens status also were evaluated.

Main outcome measures: Factors associated with the presence and severity of DME.

Results: A total of 304 eyes (156 right eyes, 148 left eyes) from 178 diabetic patients were analyzed in the study. Panretinal leakage index, microaneurysm count, and ischemic index were not significantly different between eyes with and without DME in univariate assessment. Zonal assessments of macular microaneurysms and macular leakage index values revealed that eyes with DME showed a significantly higher microaneurysm count (P = 0.001) and leakage index (P < 0.0001) in the posterior pole compared with eyes without DME. Severity of macular thickening (i.e., CST) was associated significantly with macular leakage index and posterior pole microaneurysm count (P = 0.0002 and P = 0.03, respectively). In addition to posterior pole leakage index and microaneurysm count, DME was associated with older age (P < 0.01), higher systolic blood pressure (P < 0.001), and white race (P = 0.03). Multivariate assessment confirmed the independent association of presence of DME with macular leakage index and macular microaneurysm count (P < 0.01).

Conclusions: Quantitative measures of leakage index and microaneurysm count in the posterior pole on UWFA images were associated with the presence and severity of DME. Panretinal analyses were not linked to DME as strongly. Additional research is needed to determine the role of quantitative UWFA in predicting DME development and characterizing patient prognosis.