Morphometrical Evaluation of Choriocapillaris using Widefield Swept-Source OCT Angiography in Early and Intermediate AMD

Abstract

Purpose : To evaluate the vascular metrics of the choriocapillaris (CC) using widefield Swept-Source OCTA (WF SS-OCTA) in subjects with early and intermediate age-related macular degeneration (AMD) compared to controls.

Methods : Prospectively designed, cross-sectional observational study on AMD Biomarkers at Massachusetts Eye and Ear. Patients with early and intermediate AMD, as well as a control group, aged 50 years or older, were included. All patients were imaged with SS-OCTA (Plex® Elite 9000, Carl Zeiss Meditec Inc., Dublin, CA) with Angio 6x6mm and 12x12mm centered on the fovea. Images were viewed and exported using the built-in software of the device. Then, a semi-automated method (MATLAB) was used to calculate indices of microvascular density and morphology of the CC in both obtained scans. Microvascular density was quantified by using vessel density (VD) and skeletonized vessel density (SD), while vessel morphology was quantified as vessel diameter index (VDI) and fractal dimension (FD). All statistical analyses were performed using SPSS (V25). P values < .05 were considered statistically significant.

Results : We included 77 eyes of 41 subjects; 33.8% controls (n=26), 33.8% (n=26) early AMD, and 32.4% (n=25) with intermediate AMD (mean age: 69.8 ± 7.9). No significant differences were found in VD, SD, VDI and FD between AMD patients compared with controls and among early and intermediate AMD.

Conclusions : In this study, no significant differences were found in the CC, as assessed by WF SS-OCTA, among eyes with AMD compared with controls. Further studies with extended longitudinal follow-up as well as analysis with additional AMD sub-phenotypes may identify more significant differences in CC.

This is a 2020 Imaging in the Eye Conference abstract.