Effect of refractive surgery on corneal properties and visual acuity

Refractive surgery is considered as one of the methods of refractive defects’ correction. Cornea refractive surgery techniques can cause correction of refractive defects through making some changes in the corneal’s curvature, thickness and shape factor. Therefore; the aim of this study was to investigate the effect of refractive surgery on corneal base thickness and curvature as well as visual acuity. In this cross sectional study, 38 patients within the age range of 18 to 48 years old, who went to the Zahedan Alzahra Hospital for refractive surgery, were randomly selected. Refreactive defect was determined by retinoscopy method using cycloplegic drug for each patient. In the subsequent referrals of patients, which were a day, week, month, three months and 6 months after the surgery, the visual acuity of each patient was measured again. By collection of data in SPSS 15.5 software, they were analyzed using paired T-test, Pearson correlation and repeated ANOVA statistical tests. A significant difference was observed between the mean of visual acuity at different times after surgery. Likewise, a significant difference was observed between the thickness and refractive power of corneal at five points under study before surgery and 6 months after the surgery. In myopia, myopic astigmatism and hyperopy groups, there was no significant difference between corneal thicknesses at five studied points. However, there was a significant difference between the corneal powers in the given five spots. Mean visual acuity improves after surgery over time and visual acuity with the presurgery correction is higher compared with that of postsurgery.