Abstract
Purpose :
The development of effective therapies for non-advanced age-related macular degeneration (AMD) has been hindered by a lack of sensitive, reversible endpoints to be used in clinical trials. Our group has previously reported (1) on the Ora Variable Contrast Flicker (Ora-VCF™) test which has successfully identified differential contrast sensitivity (CS) thresholds for non-advanced AMD patients as compared to matched controls. The present study reports follow-up results from the third longitudinal visit for a cohort of non-advanced AMD patients originally tested in 2017.
Methods :
Nine non-advanced AMD patients with visual acuity of 20/25 (at the entry point) and 16 age matched controls were included in this follow-up visit. On a single study visit, all participants completed a battery of visual function assessments, including Ora-VCF™ tests. During the Ora-VCF™ test, patients viewed flickering targets presented via a customized software. Stimuli were presented at three temporal frequencies (low, mid, and high) and two background luminance levels (low- and high-mesopic) as previously reported (1).
Results :
Patients with non-advanced AMD had significantly higher contrast thresholds for the intermediate flicker rate (between 10-20 Hz) at both background luminance levels (both p < 0.03), as well as a trend for the high flicker rate (> 20 Hz) when presented on the low luminance background (p = 0.0714), as compared to matched controls. These results are consistent with patterns observed during prior visits across the duration of the longitudinal study.
Conclusions :
The Ora-VCF™ test indicates that, compared to matched healthy subjects, non-advanced AMD patients with good BCVA have higher contrast sensitivity thresholds for flickering images presented at mid- and high-flicker rates – particularly when presented in the low-mesopic luminance range. The general pattern of differentiation between non-advanced AMD patients and matched controls on this test has remained relatively consistent over a 3-year longitudinal period. This suggests a repeatable test over time that can effectively serve as a reliable, reversible functional endpoint for future clinical trials for therapies aimed at treating non-advanced AMD. It also suggests relative stability in visual function for patients with non-advanced AMD over a period of 3 years.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.