Longitudinal Automated Ellipsoid Zone Mapping Assessment in Retinal Vein Occlusions

Abstract

Purpose : To evaluate the longitudinal quantitative dynamics of the ellipsoid zone (EZ) during management of macular edema in retinal vein occlusion (RVO) and the impact of EZ dynamics on functional outcomes.

Methods : In this IRB-approved retrospective study, a novel retinal layer analysis tool is utilized to evaluate the EZ characteristics longitudinally during the treatment of macular edema secondary to RVO. Inclusion criteria included RVO diagnosis, the presence of macular edema, and a minimum follow-up of 3-months (n=236). Exclusion criteria included lack of macular cube scans at baseline and 3-month follow-up periods (n=54). All eyes underwent macular OCT (Cirrus, Zeiss) at each follow-up interval. Macular cube scans were exported into a novel retinal layer analysis software and EZ parameters were evaluated with an automated platform. Expert reader review was performed on each scan to confirm accurate segmentation. The en face characteristics that were evaluated included percent of area with EZ-retinal pigment epithelium (RPE) attenuation (EZ-RPE thickness < 20 µm), percent of area with EZ-RPE total attenuation (EZ-RPE thickness = 0 µm), EZ-RPE volume, juxtafoveal EZ-RPE thickness, and central foveal EZ-RPE area and thickness. These EZ mapping parameters were analyzed for correlation with clinical data.

Results : One hundred eighty-two eyes were included in this study. All eyes were treated with anti-VEGF therapy at presentation. Initial visual acuity improved from 20/87 at baseline to 20/52 at 3-months (p<0.0001). The mean line change was +2.3 at 3-months. Following initiation of anti-VEGF therapy, EZ attenuation and total attenuation significantly improved by 8.2% (16.4 to 8.2%, p<0.0001) and 7.5% (12.9 to 5.4%, p<0.0001) respectively. The improvement in en face parameters significantly correlated with visual acuity improvement at 3 months. Visual recovery at each time point (e.g., 3, 6, and 12 months) was also strongly associated with improved central foveal EZ-RPE area (0.151mm² to 0.180 mm², p<0.0001) and increased EZ-RPE volume (1.044 mm³ to 1.134 mm³, p<0.0001).

Conclusions : EZ parameters and longitudinal dynamics are directly correlated to functional outcomes in the RVO. Further research is needed to better elucidate the predictive value of these parameters on overall outcomes and the role for assessment in disease management.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.