Abstract
Purpose :
Age-related macular degeneration (AMD) is a progressive disease that can destroy central vision in both eyes, often asymmetrically. The purpose of this retrospective, longitudinal study was to investigate the effect of disease progression on the monocular preferred retinal locus (PRL) of the better (BE) and worse (WE) eye.
Methods :
Fifty-one patients with bilateral AMD (mean age 77 ± 11 years) from our 13-year research database were included. The PRLs of the 2 eyes were recorded with the MP-1 microperimeter (Nidek Technologies Srl., Padova, Italy) during 2 visits that were an average of 458 ± 249 days apart. For each eye and visit, the following measurements were obtained: 1) scotoma size, 2) PRL distance from the former fovea; and 3) location of the PRL in polar coordinates. The change in PRL location from visit 1 to visit 2 was evaluated with the differential map analysis module.
Results :
Scotoma size increased significantly in both eyes (p < .001). For the BE, there was a significant increase in the PRL distance from the former fovea from the first to the second visit, t(50) = 2.2, p = .03. For the WE, this measure did not change; for 33% of the PRLs the center of the fixation target fell on the scotoma and for 39% of cases there was a reduction in the PRL distance from the former fovea in visit 2. The polar angle was relatively stable in both visits for the BE, but differed by a median of 20 deg (mean 50 ± 76 deg) from the first to the second visit for the WE. Multiple regression analysis revealed that the change in PRL location in the BE was predicted by the PRL distance from the former fovea in visit 1(β = -.61, p = 0.017) and in visit 2 (β = .82, p = .001), but not by the polar angle or scotoma size measured in the 2 visits. For the WE, the change in PRL location was not predicted by measurements made on that eye; rather, the best predictor was the change in the PRL location in the BE (β = .45, p = .001).
Conclusions :
For the BE, PRL distance from the former fovea increases with disease progression while maintaining a relatively stable polar angle. The change in PRL location with disease progression in the WE depends on the status of the BE rather than on changes in the WE’s own measures. These results may reflect the need for binocular correspondence of the PRLs in asymmetrically damaged eyes.
This is a 2020 ARVO Annual Meeting abstract.