Abstract
Purpose :
Several studies have reported that AMD patients have abnormal dark adaptation, contrast sensitivity, and/or low luminance visual acuity. The purpose of this study was to determine which test is the most sensitive at discriminating between age-matched normal and early to intermediate AMD patients with good acuity.
Methods :
Thirty-five subjects were enrolled in this study (20 AMD age 76.4 ± 9.60 and 15 normal controls age 73.4 ± 6.53; p = 0.28). The subjects had a complete eye exam (refraction, VA, fields, OCT, fundus photos). The logMAR visual acuities for the test eye were not significantly different between the groups (AMD = 0.04 ± 0.103; Control = 0.02 ± 0.108; p = 0.57). The AMD patients were graded using the simplified AREDS scale (average = 2.75 ± 1.02). The MacuLogix AdaptDx was used to measure dark adaptation. A Beethoven system was used to measure spatial and temporal contrast sensitivity employing a descending method of limits combined with a 2 AFC technique. The stimulus was either a stationary or 15 Hz counterphasing sine wave grating viewed at 200 cm on a ViewPixx monitor (100 cd/m2). Eight spatial frequencies (0.75 – 18.50 cpd) were tested. The contrast sensitivity functions were fit with a double exponential function. Contrast sensitivity and visual acuity were determined with and without a 2 log unit neutral density filter. The subjects wore their optimal correction for the testing.
Results :
The dark adaptation rod intercept times were significantly different (p < 0.001) between the AMD and normal control subjects. There was no significant difference between the AMD and control subjects for spatial contrast sensitivity, temporal contrast sensitivity, visual acuity, low luminance visual acuity, visual fields, or macular pigment density (all p values > 0.05).
Conclusions :
Of the tests investigated, dark adaptation rod intercept times were the most significantly different between the AMD and normal control subjects. AMD patients with good acuity and age matched control patients do not have a significant difference in contrast sensitivity (spatial or temporal) or low luminance visual acuity.
This is a 2020 ARVO Annual Meeting abstract.