Abstract
Purpose :
The fellow eyes of patients with unilateral neovascular age-related degeneration (AMD) are known to be at a higher risk for development of late AMD, and the choroid is thought to be important in disease pathogenesis. The aim of this study is to compare the choriocapillaris (CC) in eyes with intermediate AMD, with or without wet AMD in the fellow eye, using optical coherence tomography angiography (OCT-A).
Methods :
In this IRB-approved retrospective analysis, we collected data from 37 eyes with intermediate AMD from 37 patients who had OCT-A obtained using an Optovue XR Avanti OCT. This cohort was divided into two subgroups according to the status of the fellow eye, yielding a group of 12 cases with bilateral intermediate AMD (iAMD group), and 25 cases wet AMD in the fellow eye (nAMD group). An additional control group of 9 eyes from 9 healthy subjects was included for comparison. The CC layer extracted from the OCT-A data was defined as a slab 30 microns thick starting 31 μm posterior to the retinal pigment epithelium – Bruch’s membrane complex. The CC beneath drusen, as well as under superficial retinal vessels, was excluded from the analysis, in order to avoid shadowing or projection artifacts from confounding the analysis. Main outcome measures were: (i) percent non-perfused choriocapillaris area (PNPCA); and (ii) average choriocapillaris flow void size.
Results :
No differences in PNPCA were found among the three groups (2.26±1.35 % in the nAMD group, 1.56±0.98% in the iAMD group, and 1.25±0.48 % in the control group, respectively). The average CC flow void area, however, was significantly increased in nAMD eyes (298.9±82.78 μm2) compared to both iAMD (240.54±82.78 μm2, p=0.048) and control (206.46±32.14 μm2, p=0.003) eyes.
Conclusions :
Intermediate AMD eyes of patients with wet AMD in the fellow eye have an increased average CC flow void size compared to eyes without wet AMD in the fellow eye. If replicated in future studies, CC flow void size may prove to be a useful parameter for evaluating eyes with AMD.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.