Aging effects for opponent mechanisms in the central visual field.
Visual field sensitivity measures were obtained for normal observers between the ages of 20 and 83 years, using test conditions in which detection has been shown to be mediated by opponent (chromatic) mechanisms (Size V target, 620 nm stimulus, 31.5 asb [10 cd/m2] white background). Average visual field sensitivity for opponent mechanisms decreased by approximately 0.6 dB per decade. This age-related sensitivity loss was smallest for the central 10 degrees visual field (0.5 dB per decade) and increased as a function of stimulus eccentricity (0.66 dB per decade for 20 to 30 degrees eccentricity), although the differences in aging effects for various eccentricities were not statistically significant. There were negligible differences in age-related sensitivity losses for opponent mechanisms in various quadrants of the visual field. These findings are generally similar to those obtained for standard automated perimetry, which uses a small white target on a white background. By comparison, short wave-length-sensitive mechanisms exhibit age-related losses that are more than twice as large, even after lenticular transmission losses are taken into account. These data provide a basis for distinguishing early disease-related losses from those related to normal aging.
Johnson
C A
CA
Department of Ophthalmology, University of California, Davis, USA.
Marshall
D
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D003118:Color Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012684:Sensory Thresholds; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*