Distribution of Nonperfusion Area on Ultra-widefield Fluorescein Angiography in Eyes With Diabetic Macular Edema: DAVE Study

Abstract

Purpose: To explore the distribution of nonperfusion area (NPA) in eyes with diabetic macular edema (DME) and its relationship with the severity of DME.

Design: Prospective, observational case series.

Methods: Forty eyes of 29 patients with treatment-naïve DME who participated in the DAVE study (NCT01552408) were included. Ultra-widefield fluorescein angiography images were sent to the Doheny Image Reading Center, where they were montaged and corrected using stereographic projection to adjust for peripheral distortion. Two experienced, independent/masked certified graders manually segmented the NPA and the total visible retinal area (TRA), and computed the NPA and TRA in square millimeters (mm²). The ischemic index (ISI) was calculated. The distributions of NPA and ISI within different retinal zones were correlated with the severity of DME.

Results: In 40 eyes with treatment-naïve DME (mean age, 55.8 years) visual acuity (VA) (mean 59.6 EDTRS letters) was correlated with central macular thickness (CMT) (mean 536.9 μm, R = -0.418, P = .008) and macular volume (MV) (mean 11.9 mm³, R = -0.449, P = .004). The NPA and ISI among the different retinal zones were significantly different (NPA: P < .001; ISI: P = .005). The NPA and ISI in the midperiphery were negatively associated with CMT (NPA: P = .04; ISI: P = .02). However, the global NPA and ISI for the entire retina were not associated with CMT or MV (P > .05).

Conclusion: In eyes with DME, the ISI increases with increasing distance from the fovea. The severity of DME does not appear to correlate with global NPA and ISI.