Abstract
Purpose :
Subretinal fibrosis greatly reduces visual acuity and is associated with poor prognosis in eyes with neovascular AMD. Fibrosis is typically diagnosed by color fundus photography (CFP) and fluorescein angiography (FA). We performed multimodal imaging analysis including FA, CFP, and SD-OCT to diagnose and quantify fibrosis in eyes enrolled in Comparison of Age-Related Macular Degeneration Treatments Trials (CATT), a randomized prospective interventional study, to assess the role of SD-OCT.
Methods :
CATT eyes previously graded for subretinal fibrosis using CFP/FA (n=66) were reviewed. Corresponding Heidelberg Spectralis and Zeiss Cirrus SD-OCT images were exported into custom software (DOCTRAP) and the area of fibrosis was segmented. Fibrosis was defined as white/yellow circumscribed lesions on CFP that stained on FA, accompanied by homogeneous subretinal hyperreflective material with reflectivity matching or exceeding that of RPE in the same B-scan. Area of fibrosis was calculated as fibrosis pixel area multiplied by the lateral and axial B-scan resolutions. We compared the area of fibrosis on SD-OCT to our previously published area measurements of the same eyes obtained using only CFP/FA, with eyes excluded if the area of fibrosis extended beyond margins of SD-OCT. Agreement was assessed using intraclass correlation area (ICC).
Results :
Of the 66 eyes analyzed, 58 had subretinal fibrosis in the original CFP/FA-only analysis. Only 32 of the 58 eyes were found to have fibrosis when additionally analyzed with SD-OCT. Among the 26 eyes which showed no fibrosis on SD-OCT, 4 had geographic atrophy (GA), 17 had a pigment epithelial detachment (PED), and 5 had both GA+PED. Among these 22 eyes with PED, 19 were fibrovascular PED. Among the 8 eyes without fibrosis in the original CFP/FA-only analysis, none had definite fibrosis and three had areas of probable fibrosis on SD-OCT. Median area of fibrosis from SD-OCT was 0.41 mm2, from CFP/FA was 0.78 mm2, with an ICC of 0.02 (95% CI 0.0-0.45).
Conclusions :
Subretinal fibrosis may be over-diagnosed when using CFP and FA alone. The results underscore the importance of multimodal analysis including CFP, FA, and SD-OCT to diagnose and quantify subretinal fibrosis.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.