准分子激光原位角膜磨镶术后角膜基质床厚度安全值分析

目的　探讨准分子激光原位角膜磨镶术 (LASIK)后残留角膜基质床厚度的安全值及术后角膜后表面曲率的稳定时间。方法　于 2 0 0 0年接受LASIK的患者中随机抽取 117例 (2 2 7只眼 ) ,对其术前及术后 1个月、3个月、6个月、1年、2年的OrbscanⅡ角膜后表面曲率检测结果进行比较分析。结果　LASIK术后早期角膜后表面中央均有不同程度向前膨隆 ,角膜基质床越薄者 (<30 0 μm)前膨趋势越明显 ,角膜基质床越厚者 1年内角膜后表面曲率稳定或回复越明显。所有病例的角膜后表面曲率在术后 2年与 1年的比较中差异均无显著意义 (P >0 0 5 )。结论　LASIK术后早期角膜后表面前膨增加 ,术中残留角膜基质床厚度 >30 0 μm更安全。术后 1年角膜状态稳定 ,无前膨增加趋势。 (中华眼科杂志 ,2 0 0 4 ,4 0 :74 1 74 4 )

An analysis about the safe range of thickness of the residual corneal stroma bed after LASIK

OBJECTIVE: To ascertain the safe range of thickness of the residual corneal stroma bed and the length of stable time after LASIK operation. METHODS: Two hundred and twenty seven eyes were randomly selected from cases treated with LASIK in 2000. The posterior curvature of cornea was measured by Obscan II preoperatively and 1, 2, 3, 6 months, 1 year and 2 year postoperatively. These data were compared and analyzed. RESULTS: Ectasia of central corneal posterior surface was detected at different degrees in all cases at the early postoperative period after LASIK. Ectasia was more prominent in eyes with thinner corneal stroma bed (< 300 microm). In eyes with thicker corneal stroma, ectasia remained stable or reverting obviously during the first year. The posterior curvature of cornea had no significant difference between 1 year and 2 year after operation in all cases. CONCLUSIONS: Ectasia of corneal posterior surface presents in the early postoperative period after LASIK. It is safer to reserve more than 300 microm of the corneal stroma bed. The posterior curvature of cornea of all cases remains stable after one year postoperatively.