Distribution of optical coherence tomographic morphologic components within areas appearing as atrophic or scarred after two years of anti-VEGF treatment for neovascular age-related macular degeneration in the Comparison of Age-related Macular Degeneration Treatments Trials

Abstract

Purpose : Geographic atrophy (GA) and scar are more prevalent at two years in the Comparison of Age-related Macular Degeneration Treatments Trials (CATT) than at baseline and are associated with poorer visual acuity. We sought to identify the distribution of optical coherence tomography (OCT)-based retinal and subretinal components across sites of macular scar or atrophy, as determined by color photography and fluorescein angiography (CP/FA) after two years of treatment in the CATT.

Methods : Imaging sessions for 70 eyes at year 2 in CATT were selected from original CP and FA grading, selecting eyes with GA (present in 25 eyes), non-GA (44 eyes), fibrotic scar (FS, 26 eyes) or non-FS (7 eyes) as at least one macular component delineated at year 2 by CP/FA readers. Two eyes were excluded for poor image quality. OCT readers (masked to CP/FA) delineated OCT retinal and subretinal morphologic characteristics. Using custom software and graphic user interfaces data were registered so that presence of each OCT and CP/FA feature, and subretinal lesion thickness at each assigned en face pixel could be determined (Figure).

Results : Of all pixels designated as GA by CP/FA, 79.4% had increased choroidal signal on OCT (versus 31.5% for NGA, 39.8% FS, 15.1% non-FS, and 4.6% non-lesion, respectively), 82.3% had localized photoreceptor layer thinning (versus 39.5% for NGA, 47.7% FS, 20.7% non-FS and 10.6% non-lesion, respectively), and 30.6% had subretinal lesion components present (versus 46.8% for non-GA, 90.2% FS, 74.0% non-FS, and 4.4% non-lesion respectively). Mean (± standard deviation) thickness (microns) of subretinal material + RPE was 48 (± 25) for GA, 61 (± 35) non-GA, 151 (± 74) FS, 83 (± 17) non-FS, and 33 (± 6) non-lesion, respectively, which were significantly different (p<0.001).

Conclusions : In contrast to non-lesion areas, photoreceptor thinning and increased choroidal signal on OCT were found in both scar and atrophic areas after 2 years of anti-VEGF treatment. Subretinal lesion thicknesses and distribution of OCT components varied by presence of scar or atrophy.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

 

Images from an eye with geographic atrophy