Quantitative WF SS-OCTA and visual outcomes in RAO

Abstract

Purpose : Retinal artery occlusion (RAO) is an emergency that can lead to poor visual outcomes and is associated with an increased risk of cerebral stroke and cardiovascular events. Fluorescein angiography is the traditional diagnostic tool for RAO; however, wide-field swept-source optical coherence tomography angiography (WF SS-OCTA) is able to provide quick and non-invasive angiographic information with a wide field of view. In this study, we looked for associations between OCT-A vascular metrics and visual acuity (VA) in patients with prior diagnosis of RAO.

Methods : Patients with diagnoses of central or branched RAO were included. A 6 x 6mm Angio and a 15 x 15mm AngioPlex Montage OCT-A image were obtained for both eyes in each patient using the Zeiss Plex Elite 9000 WF SS-OCTA device. Each 6 x 6mm image was divided into nine Early Treatment Diabetic Retinopathy Study (ETDRS) subfields. The average measurement of the central foveal subfield, inner ring, and outer ring was calculated for each parameter. Non-perfusion area (NPA) was manually measured using 15 x 15mm Montage images. A linear regression model was utilized to identify a correlation between the imaging metrics and VA. A P-value less than 0.05 was considered to be statistically significant.

Results : 25 subjects were included in the study. For RAO eyes, there was a statistically significant negative correlation between VA and retinal thickness as well as superficial capillary plexus vessel density (VD). A negative correlation was found between VA and deep capillary plexus VD without statistical significance. There was a positive correlation between VA and choroidal thickness as well as choroidal volume without statistical significance. No significant correlation was found between VA and the above metrics in contralateral eyes. For NPA measurements, no significant correlation was found.

Conclusions : This is the first study to investigate the utility of WF SS-OCTA in RAO and to demonstrate correlations between various retinal vascular imaging metrics and visual outcomes. Further investigations should explore the associations between these imaging findings and cardiovascular risk as RAO patients are at elevated risk for symptomatic stroke. The results of this study provide a basis to understand the structural changes involved in visual outcomes in RAO. Furthermore, they may help guide management of RAO and prevention of cerebral stroke and cardiovascular accidents in patients with RAO.

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