Abstract
Purpose :
Lack of sensitive and reliable endpoints to identify visual dysfunction at early stages of dry age-related macular degeneration (AMD) is a major hurdle in development of novel therapeutics for this disease. This study evaluated tablet based low luminance reading test as a potential endpoint for early dry AMD.
Methods :
Twenty seven subjects with early dry AMD (mean age: 74.8±6.5 years) and thirty four normal subjects (73.9±5.3 years) were included. All subjects underwent visual acuity (VA) testing using the ETDRS chart under standard condition and using 2.0 neutral density (ND) filter. Reading tests were performed using an electronic tablet under standard high contrast high luminance (HCHL) and low luminance (LL) condition with 2.0 ND filter. In addition, all subjects underwent the MN Read test also under standard condition and with 2.0 ND. Reading speed and accuracy was calculated in words per minute (wpm) for tablet reading. Maximum reading speed (wpm) and reading acuity was calculated for MN Read test.
Results :
Using the tablet device, early AMD subjects read significantly slower than normals under standard HCHL condition (152.7±9.4 wpm in AMD vs 187.6±6.9 wpm in normals, p=0.003). This visual dysfunction was further exacerbated when tested under LL condition (100.2±10.9 wpm in AMD vs 151.2±9.2 wpm in normals, p=0.0008). There was no difference in standard ETDRS VA between the AMD subjects (0.06±0.02 logMAR) and normals (0.04±0.02 logMAR) (p=0.28). ETDRS VA with 2.0 ND also was not different between the two groups (0.28±0.03 in AMD vs 0.26±0.02 in normal, p=0.46). Similarly, there was no difference in the MN read maximum reading speed under the standard condition (215.7±8.2 wpm in AMD vs 222.1±6.8wpm in normals, p=0.55) or the LL condition (188.9±10.0 wpm in AMD vs 197.4±9.5 wpm in normals, p=0.56). MN Read reading acuity showed no significant difference between the AMD and normal groups under both conditions (p>0.05 for all comparisons).
Conclusions :
While there was no significant difference between the early AMD and normal groups using ETDRS VA, low luminance ETDRS VA or MN Read test, our low luminance tablet reading test was able to identify significant visual dysfunction in early AMD subjects when compared to age-matched normals. Our low luminance tablet-based reading tests shows promise as a potential endpoint in patients with early dry AMD.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.