Effects of age and the retinal zone stimulated on differential luminance sensitivity in vehicle drivers over 65 years.

Abstract

PURPOSE: To evaluate central visual field (30º) differential luminance sensitivity (DLS) in drivers over the age of 65 years and compare responses according to the zone of the retina stimulated and age. METHODS: DLS was determined under photopic conditions (85 cd/m2) in 62 subjects (right eye) using a Humphrey model HFA-II 730 campimeter (Zeiss) to perform the STACTPAC technique with Goldamnnis stimulus III. Test were conducted with habitual correction for near vision. RESULTS: The mean age of our population sample was 72.5 +- 5.4 year (85% men/15% women). Mean visual acuity was 0.82+-0.14. The mean spherical power of the lenses was +0.93 +- 1.87D and cylindrical power -0.87+-1.63D. Mean added power was 2.42+-0.59D. Mean DLS was 27.01+-2.52dB. Values by retinal zone were 30.32 +-2.35 dB (foveal) 28.77 +-2.50dB (parafoveal), and 26.14 +-2.76 dB (peripheral). When the simple was stratified by age (older or younger than 70 years), significant differences in DLS were obteined for the four quadrants and the different retinal zones. CONCLUSION: Mean DLS values for the drivers differed significantly among the foveal, parafoveal and peripheral zones of the retina, with measurements made at the fovea being significantly higher. In drivers above 65 years, age showed a negative effect on DLS in all the retinal zones examined.