Abstract
The appearance and growth of persistent choroidal hypertransmission defects (hyperTDs) detected on en face swept-source OCT (SS-OCT) images from eyes with intermediate AMD (iAMD) were studied to determine if they could serve as novel clinical trial endpoints.
Post-hoc subgroup analysis of a prospective study.
Subjects with iAMD underwent 6 × 6 mm SS-OCT angiography (SS-OCTA) imaging at their baseline and follow-up visits. The drusen volumes were obtained using a validated SS-OCT algorithm. Two graders independently evaluated all en face structural images for the presence of persistent hyperTDs. The number and area of all hyperTDs along with drusen volume were obtained from all SS-OCTA scans. Eyes were censored from further follow-up once exudative AMD developed.
A total of 171 eyes from 121 patients with iAMD were included. Sixty-eight eyes developed at least one hyperTD. Within one year after developing a hyperTD, 25% of eyes developed new hyperTDs for an average of 0.44 additional hyperTDs. Over two years, as hyperTDs appeared, enlarged, and merged, the average area growth rate was 0.220 mm/yr using the square-root transformation strategy. A clinical trial design utilizing the onset and enlargement of these hyperTDs for the study of disease progression in eyes with iAMD is proposed.
The appearance and growth of persistent choroidal hyperTDs in eyes with iAMD can be easily detected and measured using en face OCT imaging and can serve as novel clinical trial endpoints for the study of therapies that may slow disease progression from iAMD to late AMD.
