Abstract
Purpose :
The ability to effectively treat dry age-related macular degeneration (AMD) is significantly hampered by a lack of reliable functional endpoints for proof of concept clinical trials. The main objective of our study is to evaluate and quantify visual function metrics that can be used as predictors of AMD progression and visual acuity (VA) loss in patients with early and intermediate AMD.
Methods :
Observational, cross-sectional, prospective study of 101 patients enrolled at Duke Eye Center: 80 patients with AMD age-related eye disease study (AREDS) stage 2 (N=33) and stage 3 (N=47) and 21 age-matched, normal controls. During baseline examination, a dilated retinal examination, including best-corrected VA (BCVA), mesopic microperimety with eye tracking (MAIA), dark adaptometry (AdaptDx), low luminance VA (LLVA) (standard using a log 2.0 neutral density filter and a computerized method), and cone contrast test (CCT) (Innova Systems Inc) were performed. Low luminance deficit (LLD) on LLVA testing was defined as the difference in numbers of letters read at standard vs. low luminance. The Research Electronic Data Capture (REDCap) system was used for data entry and management. Group comparisons were performed to evaluate differences between the control group and the AREDS 2 and AREDS 3 groups using two-sided significance tests.
Results :
BCVA was similar between control and AMD groups. The functional measures that showed significant differences between the normal and the intermediate AREDS3 AMD groups were LLVA standard and computerized (0.5 cd/m2), percent reduced threshold and average threshold on microperimetry, CCT tests (red, green, and blue), and rod intercept on dark adaptation (p < 0.05). Compared to age-matched controls, patients with early AMD AREDS 2 showed increased rod intercept values (p < 0.05). The AREDS 3 group demonstrated deficits in microperimetry reduced threshhold, computerized LLD2 and dark adaptation rod intercept (p <0.05) relative to AREDS 2. There was no difference between the three groups in standard or computerized LLD.
Conclusions :
Our study demonstrates that LLVA, MAIA microperimetry, CCT and dark adaptation may be used as reliable functional measures of disease progression for eyes with early and intermediate AMD and as alternative clinical trial endpoints for future studies of dry AMD.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.