Abstract
Purpose :
Optical coherence tomography angiography (OCTA) is a novel non-invasive imaging modality of the retinal vasculature which has had limited utility in the diagnosis of retinal vasculitis (RV) due to innate challenges with the detection of perivascular leakage. In a prior proof-of-concept paper by the author, a custom segmentation OCTA protocol that simulates perivascular leakage was able to identify and monitor changes in RV. We tested the sensitivity and specificity of this custom OCTA protocol in detecting small vessel RV (defined as third-order vessels and smaller) as compared to the gold standard fluorescein angiography (FA) with three masked retina graders who evaluated OCTA and FA images from eyes with and without retinal vasculitis.
Methods :
Retrospective cross-sectional chart review of patients at a single institution from January 2021 to June 2021. 34 eyes with retinal vasculitis (infectious and non-infectious etiologies of posterior and pan-uveitis) and 18 control eyes were studied. Three retina specialists (1 uveitis/medical retina, 1 surgical retina, 1 medical retina) underwent a one-hour training session using a custom segmentation OCTA protocol to identify features suspicious for retinal vasculitis on OCTA. These masked retina specialists graded SD- OCTA 8x8mm en face scans (blood flow, structural, and B scans centered on the fovea) to identify the presence of retinal vasculitis and rule out mimickers of perivascular thickening. The primary outcome measure was the sensitivity and specificity of SD-OCTA in the identification of RV compared to the gold standard FA.
Results :
The average sensitivity of identifying RV on OCTA by the masked graders was 84%, and the specificity was 76% compared to FA. The positive predictive value of SD-OCTA to detect RV was 85%, and the negative predictive value was 74%. The presence of cystoid macular edema and optic nerve head leakage/staining on FA did not increase the statistical likelihood of a false positive result on OCTA. Higher signal strengths (above 5/10) of the SD-OCTA scans did not correlate with a higher likelihood of a correct SD-OCTA interpretation.
Conclusions :
SD-OCTA imaging may serve as a useful alternative to FA in identifying retinal vasculitis. The use of different SD-OCTA imaging features may help to decrease the risk of incorrectly identifying or missing retinal vasculitis in patients.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.