高度近视薄角膜患者LASIK术后3a疗效观察

目的:通过研究角膜相对较薄的高度近视患者LASIK术后的远期效果,进一步探讨LASIK术中保留角膜基质床厚度与术后疗效的关系,以及可能影响术后屈光回退的因素.方法:选2001-01/2002-10在我院行LASIK手术的高度近视相对薄角膜患者21例39眼,查术后3a的视力、眼压、屈光状态、角膜曲率及中央角膜厚度,并与术前及术后早期数据进行统计学比较分析.结果:术后3a无1例出现继发圆锥角膜改变,术后视力0.8以上25眼,占64%,术后视力与术前最佳矫正视力间呈低度正相关.术后3a与早期视力无显著性差异,但屈光与角膜曲率有明显增加.术后3a屈光回退量≥1.00D30眼,占77%,屈光回退量与术前屈光度呈负相关,与患者年龄、术后角膜曲率的改变和实际角膜厚度与预留角膜厚度的差值呈正相关.结论:高度近视薄角膜患者LASIK术后的远期稳定性较低,可预测性较差,术后屈光回退可能与术前屈光、年龄、角膜厚度和曲率的改变有关.本组患者今后是否会继发圆锥角膜的改变仍需进一步观察研究.

A three-year follow-up study of high myopia with borderline corneal thickness after LASIK

AIM:To investigate the relationship of residuel corneal stromal bed thickness and the possible mechanism of regression after operation by evaluating laser in situ keratomileusis (LASIK) for high myopia with thinner corneal thickness at 3 years after surgery. METHODS:From January 2001 to October 2002,21 high myopia patients (39 eyes) with borderline corneal thickness were treated with LASIK. Visual acuity,keratometry readings and central corneal thickness were measured at 3 years after surgery. These data were compared with preoperative and early postoperative results. RESULTS:None of the 39 eyes displayed corneal ectasia 3 years after surgery. In 64% of eyes (25 of 39 eyes),uncorrected visual acuity (UCVA) of 0.8 or better was achieved. A weak positive correlation was found between preoperative best corrected visual acuity (BCVA) and postoperative UCVA. No significant difference was found in UCVA measured during earlier post-LASIK follow-up versus the 3-year post-LASIK evaluation. Refraction and keratometry readings increased when compared to the latter post-LASIK follow-up data. After surgery 77% of eyes (30 of 39) regressed more than 1.00D 3 years. A negative correlation was found between the extent of regression and the preoperative refraction. Positive correlations were found among two sets of variables:extent of regression and age,actual changes of keratometry readings and the dispersion of the actual corneal thickness and the expected corneal thickness after surgery. CONCLUSION:The long-term outcomes of highly myopic patients with borderline corneal thickness after LASIK were less stable and predictable. The regression was probably related to the preoperative refraction,age,corneal thickness and keratometry readings. We need to further investigate these patients to determine whether there are secondary corneal ectasia in the future.