Abstract
Purpose: :
Aging and several pathological conditions such as cataracts increase ocular scattering and thereby diminish visual function, and this can be considered a risk factor in driving, particularly at night. We examine the visual performance and optical quality in night driving for younger drivers as well as for older drivers (with and without cataract).
Methods: :
A total of 29 subjects who did not have a cataract in either eye (20 younger and 9 older drivers) and 8 older adults with cataract in one or both eyes were included in this study. In the younger age group, 20 subjects were tested with an average of 24.8±2.6 years (19-29 years), and the older group (>60 years) consisted of 9 healthy drivers and 8 drivers with cataracts, averaging 72.4±7.2 years of age. Despite the cataract, the visual acuity with the best correction was >0.5 in all eyes. Subjects were examined for distance high-contrast visual acuity (VA), contrast sensitivity, disturbance index (halos) with a Halometer test, and optical quality (Strehl ratio). Subjects also completed a subjective Driving Habits Questionnaire (DHQ), designed to provide information on their driving during the past year.
Results: :
The Strehl ratio indicates worse optical quality for older drivers, being significantly (P<0.05) lower than the Strehl ratio for young drivers. The CSF for older drivers was also significantly lower than that for the young drivers (P<0.05). The Disturbance index increased with the age of the driver. All the parameters studied showed a deterioration in visual performance and optical quality for the drivers with cataract, reflecting greater difficulty in driving, especially at night, even when having good visual acuity.
Conclusions: :
It is advisable, in addition to measuring visual acuity and contrast sensitivity, to use new tests that are quick and objective in measuring age-associated visual deterioration and performance and that can be considered a risk factor in night-time driving.
Keywords: aging: visual performance • contrast sensitivity • cataract