Biomechanical properties of the cornea after laser in-situ keratomileusis in myopic patients

Abstract

Aim The aim of this study was to assess changes in corneal biomechanical properties in myopic eyes after laser in-situ keratomileusis (LASIK) with ocular response analyzer. Materials and methods Corneal biomechanics was recorded before and 1 month after LASIK was done in 76 eyes for correction of myopia. Central corneal thickness (CCT) was also measured prior and 1 month postoperatively. Preoperative biomechanical values were compared with postoperative values and both were correlated with age, sex, and CCT and tissue ablation depth. Results In all, 76 eyes of 38 patients were involved in this study. Mean preoperative corneal hysteresis (CH) and corneal resistance factor (CRF) were 9.7 ± 1.7 and 10.1 ± 1.7 mmHg respectively. Mean preoperative Goldmann correlated intraocular pressure (IOPg) and corneal compensated intraocular pressure (IOPcc) were 16.2 ± 3.8 and 17.3 ± 3.9 mmHg, respectively. There was a statistically significant reduction of these parameters postoperatively (CH = 8.0 ± 1.6, CRF = 7.4 ± 1.8, IOPg = 11.7 ± 3.1, and IOPcc = 14.4 ± 2.6) mmHg. A moderate positive significant correlation between CCT and CH, CCT and CRF was found. Conclusion Corneal biomechanics represented in CH and CRF showed statistically significant reduction following LASIK.

Keywords

• cornea
• corneal hysteresis
• corneal resistance factor
• laser in-situ keratomileusis
• myopia