Abstract
Purpose :
Foveal involvement of GA is an important inclusion/exclusion criterion in clinical trials. Foveal involvement is best evaluated using multimodal assessment with fundus autofluorescence (FAF) and optical coherence tomography (OCT) images. The purpose of this study was to compare FAF only vs. multimodal approach in foveal involvement of GA using different definitions of GA on OCT. Association between foveal involvement and visual acuity (VA) was also evaluated.
Methods :
Participants with GA enrolled in the Age-Related Eye Disease Study 2 (AREDS2) from the University of Wisconsin were included. Subfoveal involvement of GA was evaluated from FAF only and independently from multimodal FAF/OCT. OCT evaluation used cRORA criteria for detecting GA with two approaches: 1) presence of subfoveal cRORA with a disrupted (speckled) RPE and 2) presence of subfoveal cRORA with an attenuated (bare) RPE. Either of the cRORA associated RPE changes were required to involve the center point of OCT along with hypo-autofluorescence at center point on FAF. The three assessments of GA were compared with each other and with logMAR VA.
Results :
Of the 47 eyes with GA, subfoveal involvement based on FAF only was in 26 (55%) and based on multimodal FAF/OCT in 18 (38%). Of these, multimodal disrupted RPE in 6 (13%) and multimodal attenuated in 12 (26%). Notably, 8 eyes were graded as subfoveal using FAF only that were called foveal sparing by the multimodal approach. Intergrader agreement on multimodal disrupted approach was 69% (κ=0.22) and attenuated approach was 84% (κ=0.50). Mean logMAR VA was 0.64 (20/80, SD=0.44) for subfoveal GA on FAF only, 0.75 (20/100, SD=0.44) for attenuated RPE, 0.66 (20/80, SD=0.50) for disrupted RPE, and 0.26 (20/35, SD=0.29) for foveal sparing on multimodal assessment. There was a significant difference in logMAR VA between subfoveal GA and foveal sparing (p<0.001), but no significant difference between cRORA disrupted vs. cRORA attenuated approaches (p=0.50).
Conclusions :
Subfoveal GA is best identified using a multimodal approach with FAF and OCT and has good reproducibility. Using a stringent criterion of center point involvement, there appears to be an association between foveal involvement and VA.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.