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

ABSTRACT

PURPOSE: To evaluate the effect of a glare source on visual function in patients after photorefractive keratectomy and radial keratotomy. METHODS: Thirteen patients (22 eyes) who underwent photorefractive keratectomy and 20 patients (40 eyes) who underwent radial keratotomy were evaluated in this cross-sectional study. LogMAR visual acuity and contrast sensitivity were measured. Pupils were measured with the Rosenbaum card. A halogen/tungsten glare source approximated the luminance of headlights of an oncoming car at 100 feet. RESULTS: In the photorefractive keratectomy and radial keratotomy groups, pupils were significantly smaller (P<.01) and the pupillary clearance of the ablation zone in photorefractive keratectomy and the clear zone in radial keratotomy were significantly larger under the glare condition (P<.01). In the photorefractive keratectomy group, visual acuity and contrast sensitivity under the glare condition were significantly higher than in the no-glare condition (P = .02). In the radial keratotomy group, contrast sensitivity under the glare condition was significantly higher than under the no-glare condition (P = .001 to .003). CONCLUSIONS: After photorefractive keratectomy or radial keratotomy, the traditional glare source constricted the pupil and partially masked the optical aberrations, which resulted in an improvement in visual function. A "pupil-sparing" aberration test is needed for evaluation of visual function after refractive surgery.