准分子激光原位角膜磨镶术二次使用角膜刀制作角膜瓣厚度分析

Analysis of flap thickness made with the reuse of the microkeratome blade in laser in situ keratomileusis

目的分析准分子激光原位角膜磨镶术(laser in situ keratomileusis,LASIK)中二次使用角膜刀制作角膜瓣的厚度。方法应用MoriaM2显微角膜刀制作角膜瓣,每位患者用同一角膜刀制作双眼角膜瓣,手术顺序为先右眼后左眼,角膜瓣厚度为手术前角膜厚度减去角膜瓣下激光切削前角膜基质厚度。按手术顺序分为首次刀片使用组(右眼组)和二次刀片使用组(左眼组),对角膜瓣厚度进行统计学分析。结果首次刀片使用组角膜瓣厚度平均(144.46±20.25)μm,二次刀片使用组角膜瓣厚度平均(131.64±20.46)μm,差异有统计学意义(P<0.01)。两组角膜瓣厚度均比角膜瓣厚度标识值(160μm)薄,差异有统计学意义(P<0.01)。结论首次使用角膜刀组(右眼组)角膜瓣厚度比二次使用角膜刀组(左眼组)厚。MoriaM2显微角膜刀所做角膜瓣比预测值薄,角膜瓣厚度在一定范围内变化。

Objective To analyze the flap thickness made with the reuse of the microkeratome blade in the laser in situ keratomileusis （LASIK）. Methods All flaps were created by using the MoriaM2 microkeratome head . The same blade was used in the fellow eyes. The right eye was treated firstly. Patients were assigned into two groups according to the blade＇s using time. Flap thickness was calculated by substracting the central stromal bed thickness from the preoperative central corneal thickness. Flap thickness was recoreded for statistical analysis. Results The mean flap thickness was （144.46 ±20.25 ） μm in OD group, （131.64 ± 20.46 ） μm in OS group, with significant difference between them （P 〈0.01 ）. In the two groups, the Moria M2 microkeratome all created a thinner flap than predicted （160 μm, P 〈 0.01 ）. Conclusions Flaps cut on the first eye were thicker than those of the second eye by using the same blade. Flap thicknesses were variable and the MoriaM2 microkeratome tend to cut thinner flaps than anticipated based on the blade used.