Solaiman Kamal A M, Fouda Sameh M, Bor'i Ashraf, Al-Nashar Haitham Y
Ophthalmology Department, Zagazig University, Zagazig, Egypt.
J Ophthalmol. 2017;2017:8725172. doi: 10.1155/2017/8725172. Epub 2017 Jan 12.
. To evaluate the safety, efficacy, and predictability of photorefractive keratectomy (PRK) on the corneal flap for correction of residual myopia following myopic laser in situ keratomileusis (LASIK). . A retrospective study on eyes retreated by PRK on the corneal flap for residual myopia after LASIK. All eyes had no enough stroma after LASIK sufficient for LASIK enhancement. Data included spherical equivalent (SE), uncorrected and best corrected visual acuity (UCVA and BCVA), central pachymetry, corneal higher order aberrations (HOAs), corneal hysteresis (CH), corneal resistance factor (CRF), and corneal haze. . The study included 64 eyes. Before PRK, the mean central pachymetry was 400.21 ± 7.8 m, the mean SE was -1.74 ± 0.51 D, and the mean UCVA and BCVA were 0.35 ± 0.18 and 0.91 ± 0.07, respectively. 12 months postoperatively, the mean central corneal thickness was 382.41 ± 2.61 m, the mean SE was -0.18 ± 0.32 D ( < 0.01), and the mean UCVA and BCVA were 0.78 ± 0.14 ( = 0.01) and 0.92 ± 0.13 ( > 0.5), respectively. The safety index was 1.01 and the efficacy index was 0.86. No significant change was observed in corneal HOAs. . Residual myopia less than 3 D after LASIK could be safely and effectively treated by PRK and mitomycin C with a high predictability. This prevents postoperative ectasia and avoids the flap related complications but has no significant effect on HOAs.
评估准分子激光角膜切削术（PRK）用于角膜瓣上矫正近视性准分子原位角膜磨镶术（LASIK）后残余近视的安全性、有效性和可预测性。
对LASIK后行角膜瓣上PRK治疗残余近视的眼睛进行回顾性研究。所有眼睛在LASIK后没有足够的基质用于LASIK增效。数据包括等效球镜度（SE）、未矫正和最佳矫正视力（UCVA和BCVA）、中央角膜厚度测量、角膜高阶像差（HOA）、角膜滞后（CH）、角膜阻力因子（CRF）和角膜 haze。
该研究纳入64只眼睛。PRK术前，平均中央角膜厚度为400.21±7.8μm，平均SE为-1.74±0.51D，平均UCVA和BCVA分别为0.35±0.18和0.91±0.07。术后12个月，平均中央角膜厚度为382.41±2.61μm，平均SE为-0.18±0.32D（P<0.01），平均UCVA和BCVA分别为0.78±0.14（P = 0.01）和0.92±0.13（P>0.5）。安全指数为1.01，有效指数为0.86。角膜HOA未观察到显著变化。
LASIK后残余近视小于3D可通过PRK联合丝裂霉素C安全有效地治疗，具有较高的可预测性。这可预防术后角膜扩张并避免与角膜瓣相关的并发症，但对HOA无显著影响。
