Improvement of visual function with glare testing after photorefractive keratectomy and radial keratotomy

PURPOSE: To evaluate the effect of a glare source on visual function in pat ients after photorefractive keratectomy and radial keratotomy. METHODS: Thirteen patients (22 eyes) who underwent photorefractive keratect omy and 20 patients (40 eyes) who underwent radial keratotomy were evaluate d in this cross-sectional study. LogMAR visual acuity and contrast sensitiv ity were measured. Pupils were measured with the Rosenbaum card, A halogen/ tungsten glare source approximated the luminance of headlights of an oncomi ng car at 100 feet. RESULTS: In the photorefractive keratectomy and radial keratotomy groups, p upils were significantly smaller (P < .01) and the pupillary clearance of t he ablation zone in photorefractive keratectomy and the clear zone in radia l keratotomy were significantly larger under the glare condition (P < .01). In the photorefractive keratectomy group, visual acuity and contrast sensi tivity under the glare condition were significantly higher than in the no-g lare condition (P = .02). In the radial keratotomy group, contrast sensitiv ity under the glare condition was significantly higher than under the no-gl are condition (P = .001 to .003). CONCLUSIONS: After photorefractive keratectomy or radial keratotomy, the tr aditional glare source constricted the pupil and partially masked the optic al aberrations, which resulted in an improvement in visual function. A "pup il-sparing" aberration test is needed for evaluation of visual function aft er refractive surgery. (C) 1999 by Elsevier Science Inc. All rights reserve d.