飞秒激光制作准分子激光原位角膜磨镶术角膜瓣预测性的研究

Predictability of the corneal flap creation with the femtosecond laser in LASIK

目的探讨准分子激光原位角膜磨镶术（LASIK）中应用FEMTOLDV型飞秒激光仪制作角膜瓣的可预测性及影响角膜瓣厚度及横径的相关因素。方法系列病例研究。将260例近视眼按预设角膜瓣厚度分为110μm组（208只眼）和90μm组（52只眼），角膜瓣横径8．5—9．5mm。对角膜瓣实际横径与预设角膜瓣横径及角膜瓣实际厚度与预设角膜瓣厚度分别进行差异性分析，对相关影响因素进行多元逐步回归分析。结果110μm组与90μm组的角膜瓣厚度测量值分别为（104．81±3．09）、（95．12±7．65）μm，与目标值比较，差异均无统计学意义（t=-1．743，-1．892；P〉0．05）。110μm组及90μm组患者的角膜厚度分别为（550．81±32．88）、（509．13±23．25）μm，年龄分别为（24．80±5．08）、（25．20±6．11）岁，角膜中央最大K值分别为（45．01±1．55）、（45．20±1．59）D，角膜瓣横径分别为（9．04±0．19）、（8．98±0．23）mm，眼压分别为（15．73±2．44）、（14．65±1．50）mmHg（1mmHg=0．133kPa）。相关性分析显示，两组角膜瓣厚度与角膜瓣横径呈负相关（r=-0．143，-0．315；P〈0．05），与患者术前年龄（r=一0．160，0．024）、角膜厚度（r=0．054，0．074）、角膜中央最大K值（r=-0．011，-0．212）及眼压（r=-0．008，0．038）均无相关性（P〉0．05）。8．5、9．5mm负压环的角膜厚度分别为（537．14±35．81）、（541．45±39．64）μm，角膜中央最大K值分别为（45．35±1．59）、（44．25±1．41）D。相关性分析显示，角膜瓣横径与术前角膜中央最大K值呈正相关（r=0．580，0．451；P〈0．001）。结论FEMTOLDV型飞秒激光仪制作角膜瓣预测性好，角膜瓣横径是角膜瓣厚度的影响因素。

Objective To observe the predictability of corneal flap creation with the FEMTO LDV femtosecond laser and analyze preliminarily the factors correlating to the thickness and diameter of the flap. Methods It was a study of serial cases. 260 eyes of 130 consecutive patients were treated with the FEMTO LDV. The eyes were assigned to two groups according to intended flap thickness, 110 μm （208eyes） and 90μm （52 eyes）. Intended flap diameter varied from 8.5 to 9. 5 ram. Difference analysis of flap diameter and intended diameter as well as flap thickness and intended thickness were made. The data was analyzed with SPSS to sum up a multiple stepwise regression formula that could express their quantitative relationship. Results The 90 μm flap group had a average flap thickness of （95.12 ± 7.65 ） μm, while for the 110μm group the average flap thickness was （ 104. 81 ± 3.09）μm. The difference between right and left eyes was not statistically significant （ t110μm = - 1. 223, t90μm = - 1. 343, P 〉 0. 05 ）. Corneal flap thickness was inversely correlated with flap diameter （ r1l0 μm = -0. 143, r90μm = - 0. 315, P 〈 0. 05 ） , but was not related to preoperative patient age, corneal thickness, keratometric value K or intraocular pressure （r110μm =-0. 160, 0. 054, -0. 011, -0. 363; r90μm =0. 024, 0. 074, -0. 212, -0. 434, all P 〉0. 05）. Corneal flap diameter was positively correlated with preoperative corneal keratometric value K and thickness （ P 〈 0. 001, P 〈 O. 05 ）. Multiple stepwise regression analysis showed flap diameter was an influencing factor for flap thickness. Preoperative corneal keratometric value K and thickness were influencing factors for flap diameter. Conclusions The LASIK flap creation with the FEMTO LDV laser has relatively good predictability. Flap diameter is an influencing factor for flap thickness.