Regional Retinal Vessel Diameter and Progression Risk of Diabetic Retinopathy on Ultrawide Field Images

Abstract

Purpose : To describe the relationship between regional retinal vessel diameters (RVD) on ultrawide field images (UWFI) and the 3-year risk of progression of diabetic retinopathy (DR) among eyes with early DR.

Methods : Retinal images from eyes with mild and moderate nonproliferative DR (NPDR) were graded at a centralized reading center for ≥1-step DR progression from baseline to 3-year follow-up based on the clinical Early Treatment Diabetic Retinopathy Study (ETDRS) severity scale. A customized semi-automated tool (AVRTool) measured RVD at 1 DD (inner) and 3.5 DD (outer) from the optic nerve. Mean arteriole and venule diameter (µm) in the inner and outer zones (IA/IV, OA/OV) were assessed. Demographic, refraction and systemic risk factors were retrieved from the electronic medical record.

Results : A total of 838 unique UWFI were evaluated [458 (54.7%) with mild NPDR, 380 (45.3%) with moderate NPDR, 51.7% progressors]. Mean time to DR progression was 2.1±0.9 years, and mean follow-up for nonprogressors was 3.1±0.5 years. Increasing DR severity was associated with decreasing arteriolar and increasing venular diameter in both inner and outer zones (mild/mod/p-value: OA-104.7/102.6/0.02, OV-117.0/120.1/<0.0001, IA-105.4/102.4/0.0003, IV 124.9/126.3/0.04). Progression was associated with increasing outer venular diameters and decreasing inner arteriolar diameter (nonprog/prog/p-value: OA-103.5/103.7/0.26, OV-117.4/120.0, 0.0006, IA-104.9/102.6/0.03, IV 125.6/125.6/0.30). After correcting for baseline differences in age, gender, sex, diabetes duration, spherical equivalent, HbA1c, hypertension, renal and cardiac disease, increased outer venular (p=0.0008) and decreased inner arteriolar diameter (p=0.0048) remained significantly associated with progression

Conclusions : This study demonstrates that changes in regional retinal vessel diameters are associated with increasing DR severity. Furthermore, the risk of DR progression over 3 years was highly associated with outer venular dilation and inner arteriolar narrowing. These findings suggest that such measures derived from UWFI may potentially be used as markers for eventual disease progression. Such markers would allow improved early detection and targeted management strategies in individuals with early NPDR.

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