Purpose: AMD is one of the leading causes of vision loss globally. Since color vision impairment is often one of the first symptoms of retinal disease, earlier AMD detection may be possible using color vision screenings. This potential detection could result in earlier treatment and decreased progression of the disease before irreversible damage to sight occurs.
Methods: Patients from the Illinois Eye Institute and Chicago Eye Institute were asked to perform the King Devick Variable Color Contrast Sensitivity(VCCSC) iPad test monocularly at their best corrected near visual acuity with black, red, blue, green, and yellow letters at various contrast levels (100%,75%,50%, and 25%). Identification accuracy (out of 5 letters) was recorded as both color and contrast changed.
Results: Data was analyzed using SPSS v21. All values are presented as means±SEM. The control group (n=35) age 50-79 years (46% male, 54% female). The non-exudative (NE) AMD(n=26) age 60-82 years (67% male, 33% female). A significant decrease in vision was noted in AMD patients for black 100% (C:36.0±1.7 vs AMD:109.9±21.7,p<0.001), blue 75% (C 4.4±0.2 vs AMD:4.7±0.1,p<0.028), yellow 75%(C:3.2±0.3 vs AMD:4.1±0.3,p<0.023), and blue 50%(C:4.1±0.2 vs AMD:4.6±0.1,p<0.045) contrast letters compared to the control. Interestingly, difficulty reading all colors at 25% contrast was similar between AMD and control patients.
Conclusions: Our results show that there is greater variability in color vision and color contrast in NE-AMD patients compared to healthy patients. Specifically, blue and yellow seem to be more difficult for AMD patients. Further testing is needed to determine what threshold of color and contrast best distinguishes AMD with the potential to detect AMD at an earlier stage and initiate more effective treatment.
- The tablet-based K-D Variable Contrast Sensitivity Chart was used to measure color contrast sensitivity in patients with age-related macular degeneration (AMD).
- AMD patients demonstrated significantly worse vision under conditions of 100% black, 75% blue, 75% yellow and 50% blue letter presentations.
- There is greater variability in color vision and contrast acuity in AMD patients. This tool is useful in measuring visual function deficits and differentiating controls from AMD patients.