Abstract
Purpose :
Optical coherence tomography angiography (OCT-A) offers the opportunity to safely and routinely image the choriocapillaris (CC), which is unable to be visualized by the established technique of fluorescein angiography. We performed a retrospective cohort study to compare the CC vascular flow area between diabetic patients with differing degrees of clinical diabetic retinopathy (DR) severity. We hypothesize that blood flow area in the CC can be used as a biomarker to correlate with clinical severity of DR.
Methods :
This retrospective cohort study analyzed the measured flow area of the CC on quality OCT-A scans in non-diabetic control patients (n=206), diabetic patients without retinopathy (n=47), and diabetic patients with mild non-proliferative DR (NPDR) (n=40), moderate to severe NPDR (n=144), and proliferative DR (PDR) (n=81). A two-sample t-test was completed to compare CC flow area between control patients and diabetic patients with at least one quality OCT-A scan. A multivariate linear regression analysis was performed to compare CC flow area to clinical DR diagnosis when controlling for age, gender, and visual acuity in patients with at least one quality OCT-A scan.
Results :
There was found to be a statistically significant decreased CC flow area (p<0.05) in diabetic patients compared to patients without diabetes. In comparison to diabetic patients without retinopathy, mild NPDR patients revealed an insignificantly increased CC flow area of 0.253 (p=0.53), while moderate to severe NPDR patients revealed a significantly decreased CC flow area of 0.691 (p=0.04) and PDR patients revealed a significantly decreased CC flow area of 1.11 (p<0.01).
Conclusions :
CC vascular flow area, as measured by OCT-A, shows promise for the diagnosis and monitoring of DR as a biomarker of clinical disease severity. Future studies investigating longitudinal CC blood flow changes after anti-VEGF injections may be helpful in better understanding the treatment’s effects.
This is a 2021 ARVO Annual Meeting abstract.