Contrast sensitivity in age-related macular degeneration
R. C. Kleiner, C. Enger, M. F. Alexander and S. L. Fine
Retinal Vascular Center, Wilmer Institute, Johns Hopkins Medical Institutions, Baltimore, MD 21205.
Low-contrast charts were used to investigate the possibility that patients
with drusen have visual deficits not detected by standard Snellen charts.
We compared performance on Regan letter charts between 52 eyes with drusen
and Snellen acuity of 20/20 and 27 control eyes. The drusen group read
fewer letters than the control group on all of the charts tested. This
difference increased as the contrast of the charts decreased. The loss of
performance on all of the Regan charts correlated with drusen severity.
Twenty-one eyes with drusen and normal Snellen acuity also were tested with
a Ginsburg contrast sensitivity chart and compared with age-matched normal
controls. The results showed a loss of contrast sensitivity at high spatial
frequencies and a loss of peak contrast sensitivity with increasing drusen
severity. These results suggest that in patients with drusen, low-contrast
charts may be useful for measuring visual loss not detected by standard
Snellen charts.
