Abstract
Purpose :
Early detection of diabetic retinopathy (DR) is vital in preventing poor visual outcomes and is done with ultra-widefield color fundus photos (CFP) and fluorescein angiography (FA). Optical coherence tomography angiography (OCTA) may have a role but limited literature exists. Here we aim to determine the potential utility of OCTA in DR screening.
Methods :
This is an IRB-approved retrospective image analysis of subjects with type 1 or 2 diabetes mellitus with or without DR at a single academic center. Subjects received FA and CFP (OPTOS, UK) and OCTA (Plex-Elite, Zeiss, Germany) in the same eye, same day. The arteriovenous and late phase frames were used for FA and 12x12mm vitreo-retinal interface (VRI) and superficial plexus slabs for OCTA. Images were analyzed by three masked graders on Imagivault (Melbourne, Australia). Graders evaluated for enlarged/irregular foveal avascular zone (FAZ), venous beading (VB), intraretinal microvascular abnormalities (IRMA), microaneurysms (MA), nonperfusion (NP), and neovascularization elsewhere (NVE) or disc (NVD). Images with poor quality or artifacts were excluded. We estimated sensitivities and specificities of features against FA as gold standard and Fleiss Kappa for intergrader agreement and reliability.
Results :
From 43 total eyes, 36 met inclusion criteria. Mean age was 57 with 14 mild, moderate, or severe NPDR, 19 PDR, and 3 no DR. OCTA sensitivity was 0.94-1.00 for all features and specificity 0.75-1.00 in detection of MA, IRMA, NVE, NVD, NPA, and VB. CFP had sensitivity in detecting VB, MA, NVE, and NVD from 0.89 to 1.00 and specificity in detecting MA, VB, NVE, and NVD from 0.91-1.00. Inter-grader agreement showed FA was highest in detecting MA (89%, kappa 0.53) and NVD (89%, kappa 0.81). CFP had highest agreement in number of IRMA (75%, kappa 0.18); OCTA had highest agreement in IRMA (72%, kappa 0.63), MA (72%, kappa 0.45), and number of NVE (75%, kappa 0.47).
Conclusions :
In our study OCTA outperformed FA in sensitivity and repeatability of detecting FAZ enlargement/irregularity and IRMAs. In addition, OCTA had comparable performance in detecting neovascularization. CFP overall was least able to accurately and reliably detect a variety of diabetic lesions. These findings highlight OCTA strengths in the evaluation of DR.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.