GLARE SENSITIVITY AND VISUAL-ACUITY AFTER EXCIMER-LASER PHOTOREFRACTIVE KERATECTOMY FOR MYOPIA

Background--Following excimer laser photorefractive keratectomy (PRK), an increase in glare sensitivity and a reduction in contrast sensitiv ity can occur owing to changes in the cornea (structure and topography ). In this study, an attempt was made to quantify and document objecti vely a change in those subjective perceptual factors. Methods--Snellen visual acuity and disability glare were measured with the Berkeley gl are test preoperatively as well as 1, 3, 6, 9, and 12 months postopera tively, after excimer laser photorefractive keratectomy (PRK) on 32 my opic patients (46 eyes). During the postoperative progress checks, haz e was graded and contrast sensitivity was measured with the Vistech ch art. All the data were statistically analysed by multiple regression. Results--One year after PRK, a reduction in visual acuity (VA) measure d with the low acuity contrast chart (10%) with and without glare coul d still be found, despite the fact that acuity measurements with a hig h contrast Snellen chart showed the same VA 6 months postoperatively a s well as before the treatment. The lowest VA could be measured 1 mont h postoperatively; thereafter, the acuity increased despite the increa se in haze that occurred during the first 3 months. Conclusion--Disabi lity glare and a reduction in contrast sensitivity could be observed i n most patients after PRK treatment with the Meditec laser system with its scanning slit. The future will show if new technology and a broad er flattening area of 6 to 7 mm can minimise these postoperative compl ications.