Abstract
In the course of a broader study investigating functional vision in low-vision subjects, we compared the chromatic and achromatic contrast sensitivities of 12 subjects with age-related macular degeneration (AMD; mean age: 75 years) with those of two control groups. One group comprised age-matched individuals with a mean age of 77 years, while the other had a mean age of 46 years. Contrast sensitivities were measured as a function of spatial frequency of sinusoidal gratings. Sensitivity to achromatic luminance contrast was severely reduced in the AMD subjects compared to both control groups, particularly for the higher and medium spatial frequencies. It was reduced to an average value of less than 10% of the age-matched normal group at 4 c/deg. At low spatial frequencies, achromatic contrast sensitivity was less affected. At 0.4 c/deg, for example, the AMD subjects showed on the average 30% of normal achromatic sensitivity, whereas sensitivity to isoluminant red-green and yellow-blue cone contrast was only about 10% of that of the age-matched normal value. This represents a significantly greater impairment of chromatic than of achromatic discrimination at low spatial frequencies in AMD.