Abstract
Purpose :
To determine if choroidal hyper-transmission defects (hyperTDs) with a greatest linear dimension (GLD) ≥ 250µm detected on en face swept source OCT (SS-OCT) images could serve as a risk factor for progression to geographic atrophy (GA) in eyes with intermediate AMD (iAMD).
Methods :
This is a retrospective review of a prospective observational case series that included eyes with iAMD imaged with SS-OCT imaging (PLEX Elite 9000, Carl Zeiss Medics, Dublin, CA) at the Bascom Palmer Eye Institute. All subjects underwent 6X6mm scans and en face images were prepared using a slab positioned 64 to 400µm beneath Bruch’s membrane. Two graders independently evaluated all en face images for the presence of hyperTDs. Based on a previous study that defined persistent hyperTDs as having a GLD ≥ 250µm, all hyperTDs ≥ 250µm were identified and tracked. Progression of these eyes to GA, nonexudative macular neovascularization (MNV), and exudative MNV were recorded and graded.
Results :
A total of 182 eyes from 134 patients were included with a median follow up of 28 months (range 6-55). At baseline, 29 eyes had at least one hyperTD ≥ 250µm and all hyperTDs were found to be persistent. In those eyes without a hyperTD ≥ 250µm at baseline, 33 developed hyperTDs ≥ 250µm during follow-up and only one was found to be non-persistent. At the last available visit, 17 eyes progressed to GA, 14 eyes progressed to exudative MNV, and 4 eyes had nonexudative MNV. All foci of GA detected on B-scans were previously detected as hyperTDs ≥ 250µm. A Kaplan-Meier analysis showed that the cumulative risk of developing GA reached 52% following the appearance of hyperTDs ≥ 250µm. In a time-dependent Cox-survival regression sensitivity analysis, the increased risk of forming GA after detecting a hyperTD ≥ 250µm was 45 times greater compared with eyes without a hyperTD ≥ 250µm (hazard ratio=45, 95%CI 6-337; p<0.001).
Conclusions :
Choroidal hyperTDs detected on en face SS-OCT images with a GLD ≥ 250µm were found to be persistent and associated with the development of GA. The detection of these lesions may serve as a useful biomarker for assessing eyes at risk for progression from iAMD to late AMD.
This is a 2021 ARVO Annual Meeting abstract.