In Vivo Mapping of the Choriocapillaris in Healthy Eyes: A Widefield Swept-Source OCT Angiography Study

Purpose: To report variation of choriocapillaris flow in peripapillary, macular, and near- and mid-periphery regions in healthy participants using widefield swept-source (SS) OCT angiography (OCTA). Design: Prospective, cross-sectional study. Participants: Fifty healthy participants. Methods: Healthy young participants were imaged with the SS OCTA system (PLEX Elite 9000; Carl Zeiss Meditec, Inc, Dublin, CA). OCT angiography scans were obtained in primary and extreme gazes and a montage was created automatically. The en face choriocapillaris images then were exported to ImageJ software version 1.50 (National Institutes of Health, Bethesda, MD), and a semiautomated algorithm was used for subsequent quantitative analysis. Main Outcome Measures: Quantitative analysis of the choriocapillaris performed in 3 different regions: (1) peripapillary, (2) macular, and (3) periphery. In addition, choriocapillaris variables were investigated further in distinct fields within these 3 different regions. Results: Fifty eyes (50 participants) were included in the analysis. Mean age ± standard deviation was 25.2±5.1 years (median, 24.5 years; range, 20.0–40.0 years). The peripapillary region exhibited the greatest total signal void area (P < 0.0001 vs. the macular region; P < 0.0001 vs. the peripheral region). Within the macular region, the foveal area exhibited a greater total signal void area in comparison with both the parafoveal area (P = 0.009) and the perifoveal area (P = 0.015). In the analysis investigating the near- and mid-periphery region, the temporal sector was characterized by a lower total signal void area compared with both the superior and inferior areas (P = 0.016 and P = 0.003, respectively). Conclusions: We report quantitative mapping of the choriocapillaris in healthy individuals. Choriocapillaris perfusion seems to have a wide topographic variation.