Safety and efficacy of undersurface ablation of the flap for regression after LASIK / 国际眼科杂志(Guoji Yanke Zazhi)

ABSTRACT

AIM: To investigate the safety and efficacy of undersurface ablation of the flap ( UAF ) for laser in situ keratomileusis ( LASIK ) retreatment in eyes with regression. METHODS: Twelve patients ( 22 eyes ) with regression after LASIK were performed undersurface ablation of the flap. The mean of preoperative refractive error was -2. 27±0-88D, the astigmatism was -0. 44±0. 30D, the central corneal thickness was 424. 9±8. 2μm. The follow-up time was 1a, including visual acuity, refractive error, the elevation of posterior cornea, WavScan. The data was analyzed with Student's t test andχ2test. RESULTS:During the operation, the measured stromal thickness was 275. 4±9. 3μm, the flap thickness 144. 7±7-5μm, the depth of ablation 28. 1±9. 3μm. The mean postoperative uncorrected visual acuity (UCVA) was 4. 99±0. 04, best corrected visual acuity ( BCVA) 5. 03±0. 04, at 1a follow up. There was no patient with postoperative BCVA decreasing, compared to preoperation. Mean spherical refraction decreased to-0. 22±0. 19 D at 1a follow up (t=10. 232, P CONCLUSION:UAF, as one of a choice, is an effective and safe procedure for the treatment of regression after LASIK, based on the reasonable surgery design.