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Visual function one year after excimer laser photorefractive keratectomy
Z Butuner1, D B Elliott, H V Gimbel
1School of Optometry, University of Waterloo, Canada.
Background:
The purpose of this study is to investigate retrospectively the visual function of eyes 1 year after photorefractive keratectomy.
Methods:
Visual function was assessed in 34 eyes of 22 patients who had undergone excimer laser surgery (Summit Excimed UV200). The mean time after surgery was 12.3 months. Twenty eyes of 20 age-matched normal subjects served as controls. The following tests were used: high and low contrast logMAR visual acuity, Pelli-Robson contrast sensitivity, and straylightmeter scores at 3.5 degrees and 10 degrees.
Results:
There was a significant difference between scores obtained for the photorefractive keratectomy population and the control (p < .001, ANOVA). Fifty-six percent (18/32) of the excimer treated eyes fell outside the 95% confidence limits of the normal data in at least one test of visual function; 22% (7/32) fell outside in at least 3 out of 5 tests.
Conclusions:
Some eyes showed reduced visual function 1 year after excimer surgery compared to age-matched normal controls. These deficits can only be detected fully when psychophysical tests in addition to visual acuity are employed.
