Abstract
Purpose :
It is important to identify sensitive visual function endpoints that can capture visual deficits during early stages of dry age-related macular degeneration (AMD) for development of novel therapeutics for non-advanced AMD. In this study, we report longitudinal follow-up data on subjects whose baseline results on assessing various visual function tests were previously published.
Methods :
Subjects with non-advanced AMD N=23 (grade 1 to 4 on AREDS simplified scale) and normal controls N=34 (AREDS grade 0) with best visual acuity (VA) 20/25 or better during their baseline visit were followed up longitudinally one year later. Several visual function tests were re-evaluated including common tests such as standard ETDRS VA, ETDRS VA (2.0 neutral density (ND)), Pelli-Robson contrast sensitivity (CS) and novel tests including the variable contrast flicker (VCF) test and low luminance tablet reading, both developed at Ora. For Ora-VCFTM test the minimum contrast needed to detect the stimulus was recorded as the threshold. For tablet reading, reading speed was recorded in words per minute (wpm). Differences between the groups were compared. Change from baseline visit was calculated.
Results :
Longitudinal follow-up data was available for 53/57 subjects from baseline visit. Consistent with results from the baseline visit, at the follow-up visit the Ora-VCFTM test found significant differences between non-advanced AMD (mean 0.59±0.25) and normal controls (0.37±0.15) (p=0.0002). At the follow-up visit, the Ora-VCFTM threshold changed by 0.048 in AMD group and 0.068 in normal group (p=0.79). Reading speed using low luminance tablet was not significantly different during the follow-up visit (126.2±33.5 wpm in AMD and 134.6±42.6 in normals, p=0.45). No difference between the groups were found using the commonly used VA tests in the follow-up visit. The mean ETDRS LogMAR VA was 0.07±0.12 in AMD group and 0.06±0.09 in normal group (p=0.80).The mean 2.0ND VA was 0.28 ±0.14 in AMD and 0.27±0.13 in normal group (p=0.81).The mean Pelli-Robson CS was 1.58 ±0.20 in AMD and 1.74±0.23 in normal group (p=0.009).
Conclusions :
The Ora-VCFTM contrast sensitivity test using a flickering target, was consistently able to identify visual dysfunction in non-advanced AMD. Ora-VCFTM test could serve as an endpoint for early and intermediate AMD therapeutic trials.
This is a 2021 ARVO Annual Meeting abstract.