CORRELATION OF OUTER RETINAL TUBULATIONS AND CHORIOCAPILLARIS FLOW SIGNAL DEFICITS SURROUNDING GEOGRAPHIC ATROPHY.

Abstract

To evaluate and compare paralesional and perilesional choriocapillaris vascular impairment in eyes with geographic atrophy with and without outer retinal tubulations (ORT). Using swept-source optical coherence tomography angiography, 6 × 6 mm scans of eyes with geographic atrophy with and without ORT were acquired. Choriocapillaris en-face flow and structural images were binarized, before flow signal deficit (FD) analysis in the paraatrophy zone (a 500-µm-wide band adjacent to the geographic atrophy) and the periatrophy zone (a 500-µm-wide band adjacent to the latter). Twenty-four eyes of 19 patients with ORT and 18 eyes of 15 patients without ORT were analyzed. With and without ORT, mean percental area of FD (%FD) was greater in para- than in periatrophy zone. The difference of %FD between para- and periatrophy zone (deltaFD) was lower in eyes with ORT (mean 1.8477%, 95% confidence interval 0.8607-2.8346) than without ORT (mean 4.0018%, 95% confidence interval 2.8622-5.1414). In eyes with geographic atrophy caused by non-neovascular age-related macular degeneration, smaller reductions in FDs were found between the para- and periatrophy zone in eyes with ORT. In both cohorts, the paraatrophy zone had more FD than the periatrophy zone.