Color matches in diseased eyes with good acuity: detection of deficits in cone optical density and in chromatic discrimination.

Reduced foveal cone optical density in diseased eyes with normal acuity can affect color matches. Using field diameters of 1 degree, 2 degrees, 4 degrees, and 8 degrees, we measured mean color-match midpoints and match widths in patients who had good acuity and who exhibited three categories of eye disease: hereditary macular degeneration (n = 12), retinitis pigmentosa (n = 19), and glaucoma (n = 18). Results were compared with those for normal observers of comparable ages. Mean color-match midpoints were abnormal only for the population with hereditary macular degeneration, indicating a reduction in cone optical density in the central 4 degrees. Mean color-match widths were enlarged for both hereditary macular degeneration and retinitis pigmentosa, a result consistent with a reduction in the number of foveal cones.