Predicting Visual Outcomes in Central Retinal Vein Occlusion (CRVO) with Vascular Metrics and Non-Perfusion Area (NPA) Measured by Wide-Field Swept-Source OCT-Angiography (WF SS-OCTA)

Abstract

Purpose : Previous studies have used optical coherence tomography angiography (OCTA) to evaluate CRVOs using smaller sized angiograms, namely 3x3 mm and 6x6 mm. We used WF SS-OCTA to quantify macular vascular metrics following CRVO and used these to model the observed visual acuity (VA).

Methods : 109 eyes of 59 patients, (59 eyes with CRVO- 9 ischemic, and 50 fellow eyes) were imaged using WF SS-OCTA (PLEX® Elite 9000, Carl Zeiss Meditec) between March 2019 and October 2021. We analyzed 12x12mm angiograms centered on the fovea using ARI Network (Zeiss Portal) Macular Density Algorithm (v0.7.3) for vessel density (VD), vessel skeleton density (VSD), foveal avascular zone (FAZ) area, circularity, and perimeter. The NPA of each macula was calculated using ImageJ. We performed mixed effects multivariate regression analyses.

Results : Our study population consisted of 33 Male (55.93%) patients with a median age of 63 years (21-86). The median logMAR visual acuity for CRVO eyes was 0.24 (20/35) vs. 0.03 (20/21) in the fellow eye (p<0.0001). CRVO eyes had larger NPAs than fellow eyes (median (m) 27.5, 7.16; Interquartile Range (IQR) 23.98, 8.47; P<0.0001), and greater irregularity of the FAZ (m 0.53, 0.79; IQR 0.25, 0.15; P=0.005). We did not detect a statistical difference in FAZ area (m 0.90, 0.27; IQR 0.29, 0.25, P=0.66) or perimeter (m 4.35, 1.23; IQR 1.88, 1.23; P=0.2).

Our regression analyses suggest that after controlling for age, ischemic CRVOs (ß= 0.35, p=0.006), larger NPAs (ß=0.007, p<0.0001), and larger FAZ area (ß= 0.048, p=0.008) were associated with worse VA. On receiver operating curve (ROC) analysis, wide-field NPA was the best OCTA metric in predicting VA worse than 20/50, area under the curve (AUC) 0.91.

Conclusions : In patients with CRVO, the WF SS-OCTA allows for quantification of NPAs in a larger region of the macula, while still providing useful information pertaining to the perifoveal vascularity. Our study reinforces prior reports that larger NPAs and larger FAZ area are associated with worse VA. WF SS-OCTA could therefore contribute to the evaluation, management, and counseling of a patient with CRVO, by identifying factors associated with worse visual outcomes following the diagnosis.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.