准分子激光原位角膜磨镶术矫正中度以上近视术后5年屈光回退分析

目的探讨准分子激光原位角膜磨镶术（laser in situ keratomilgus，LASIK）矫正中度以上近视术后屈光回退的相关因素，从而评价其疗效。方法将行LASIK手术，术后随访5年的中度以上近视患者30例（59眼）进行回顾性分析。结果术后5年55眼（93．22％）屈光回退量大于或等于1．00D。屈光回退主要发生在术后第1年；术后第2～5年中、高度近视组屈光度稳定，而超高度近视组发生了轴性再近视。屈光回退量与术中实际矫正屈光度呈正相关，与残留角膜基质床厚度呈负相关。中央角膜厚度（central corneal thickness，CCT）与角膜前表面曲率在术后第1年增加明显，且两者呈正相关。结论屈光回退最主要的因素可能是术后早期CCT增加引起角膜前表面曲率改变。虽然术后存在屈光回退，但中、高度近视组远期疗效好，而超高度近视组因本身病理因素术后的稳定性和预测性较差。

Analysis on refractive regression five years after eximer laser assisted in-situ keratomileusis for rectifying moderate or excessive myopia

Objective To investigate the correlation factors for refractive regression five years after eximer laser assisted in-situ keratomileusis （LASIK） for rectifying moderate or excessive myopia,and to evaluate its curative effect. Methods We retrospectively analyzed the clinical data of 30 moderate or excessive myopia patients （59 eyes） who underwent LASIK and were followed up for 5 years after LASIK. Results Refractive regression＇s quantity of 55 eyes （93.22%） was up to 1.00 D,and it mainly occurred in 1st year. Medium and excessive myopia were stable for 2nd to 5th year, but axial myopia occurred in the super-high myopia group. The amount of refractive regression was negatively correlated with postoperative residual corneal matrix bed thickness, and positively correlated with actual rectified diopter. The central corneal thickness （CCT） increased with the corneal surface curvature in 1st year. Conclusion Postoperative CCT increase may cause change of corneal curvature,which produces refractive regression. By comparison,the prostecdtive efficacy is satisfactory in medium and excessive myopia group;while the postoperative stability and predictability are poor in super-high myopia group due to its pathological factors.