Abstract
Purpose :
To explore the impact of baseline factors and lesion growth rate on best-corrected visual acuity (BCVA) in geographic atrophy (GA) to understand the clinical relevance of baseline factors and lesion growth rate in GA.
Methods :
This was a retrospective analysis on the study eye of patients with bilateral GA enrolled in the lampalizumab trials (NCT02247479, NCT02247531, NCT02479386). The GA lesion area (mm2) was measured on fundus autofluorescence (FAF) images captured on Spectralis (Heidelberg Engineering, Heidelberg, Germany) at all visits. The GA lesion growth rate (mm2/year) was derived from a linear model fitted using all available FAF measurements for each patient. Time-to-event analysis was performed on the outcomes of 5-, 10-, and 15-letter BCVA loss. Cox regression model adjusted for baseline factors (BCVA, GA area, lesion location, and focality) was performed on the outcomes. Next, continuous variables were divided into quartiles, and Kaplan–Meier (KM) curves were provided for each baseline factor and for GA lesion growth rate.
Results :
From Cox regression, ~50% of patients had 5-letter loss by 12 months and ~75% by 24 months. Further, ~50% of patients had 10-letter loss and ~25% had 15-letter loss by 24 months. KM curves showed that baseline BCVA, GA area, and lesion location (subfoveal vs extrafoveal) did not impact (P > 0.05) the rate of BCVA loss. The time to BCVA loss of 5, 10, and 15 letters was shorter in unifocal compared with multifocal lesions (P = 0.02). KM curves generated after classification by GA growth rate quartiles showed that a 5-letter BCVA loss occurred in a higher proportion of study eyes in the 2 higher quartiles compared with the lower quartiles (P < 0.05). Similarly, for 10- and 15-letter BCVA loss, clear separation was seen in the KM curves between the lower 2 and higher 2 quartiles (P < 0.0001).
Conclusions :
More than three-quarters of eyes with GA will have lost 5 letters of BCVA within 2 years. Baseline factors, except lesion focality, did not impact time to BCVA loss. GA lesion growth rate analysis showed that a more rapid rate of BCVA loss is seen with a higher growth rate as compared with a lower growth rate.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.