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

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