Evaluation of diabetic microaneurysm leakage status through multimodal imaging

Abstract

Purpose : To compare microaneurysm (MA) detection rates and association of MA detectability with MA leakage status on fluorescein angiography (FA) with high-speed megahertz optical coherence tomography angiography (MHz-OCTA) en face images and color fundus photography (CF) in patients with diabetic retinopathy (DR).

Methods : Patients with severe non-proliferative and proliferative DR were recruited at the Department of Ophthalmology at the Medical University of Vienna for this exploratory cross-sectional study. MHz-OCTA data were acquired with a swept-source OCT prototype (A-scan rate: 1.7MHz). FA and CF imaging was performed using Optos® California. MA count was manually evaluated on en face MHz-OCTA/FA/CF images within a field of view of 12 mm. Detectability of MAs visible on FA images was evaluated on corresponding MHz-OCTA and CF images. MA leakage status, determined on early- and late-phase FA images, was correlated with MA detectability on OCTA and CF imaging.

Results : 47 eyes with severe non-proliferative (n=12) and proliferative DR (n=35) were included. A median of 125 (range: 13-591) MAs were detected on ground-truth FA images per eye with 92.3% of MAs showing leakage. MHz-OCTA and CF imaging detected on average 56% and 36% of MAs. 55% of leaking and 53% of non-leaking MAs were detected using MHz-OCTA. There was no statistically significant association between MA detectability on MHz-OCTA images and leakage status on FA images (1.15 [0.96; 1.37], p=0.13). On CF images 35% of MAs with leakage and 40% without leakage were detected. The odds for MA detection were significantly lower for leaking MAs than non-leaking ones (0.79 [0.66; 0.95], p=0.012) with CF imaging.

Conclusions : More MAs were detected on MHz-OCTA en face images than on CF images. Detection rate was lower for leaking MAs than for non-leaking ones on CF imaging, while leakage status did not influence detectability on MHz-OCTA.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.