Retinal vascular calibers are not predictive for long-term progression to proliferative diabetic retinopathy

Abstract

Purpose : To evaluate if retinal vascular calibers in patients with no or minimal diabetic retinopathy (DR) can predict risk of long-term progression to proliferative diabetic retinopathy (PDR).

Methods : This was a 1:2 DR-matched case-control study of patients with diabetes having no or minimal DR at baseline, but with (cases) or without (controls) subsequent development of PDR (cases). The patients could contribute in the study with two independent eyes and we used cluster robust standard error to account for the symmetry introduced by this fact. We collected six-field, 45-degree retinal images, demographic and clinical data from the Funen Diabetes Database. A trained grader assessed fundal images for correct International Clinical Diabetic Retinopathy grading and used the semi-automatic software VAMPIRE (Vessel assessment and Measurement Platform for Images of the Retina) to analyze retinal vascular calibers.

Results : We included 53 eyes from 40 cases and 100 eyes from 90 controls. Cases had higher HbA1c (73 vs. 55 mmol/mol; p <0.001), but we found no differences in sex (53.8% vs. 54.7% female; p = 0.93), age (median 42 vs. 35 years; p = 0.75), type of diabetes (64.1% vs. 64.0% type 1 diabetes; p = 0.99) or observation time (10.8 years vs. 10.5 years; p = 0.94). Likewise, cases and controls did not differ according to the calibers of the retinal arterioles (35.4 vs. 35.0 pixels; p = 0.51), venules (44.6 vs. 44.9 pixels; p = 0.83) or the arterio-venular-ratio (0.8 vs. 0.8; p = 0.94).
In an age and sex adjusted logistic regression model with cluster robust standard error, HbA1c (OR 1.56 per 10 mmol/mol; 95%-CI: 1.25 to 1.96; p <0.001), triglyceride (OR 1.72 per 1 mmol/L; 95%-CI: 1.18 to 1.2.50; p = 0.005) and diastolic blood pressure (OR 1.24 per 5 mmHg; 95%-CI: 1.01 to 1.52 ; p = 0.04) were the only risk factors for upcoming PDR.

Conclusions : In a long-term study of patients with no or minimal DR, calibers of the retinal arterioles and venules were not able to predict subsequent progression to PDR in contrast to well-established risk factors like HbA1c, triglyceride and diastolic blood pressure.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.