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[摘 要] 目的:研究准分子激光原位角膜磨镶术(laser in situkeratomileusis,LASIK)前后角膜滞后量(corneal hysteresis,CH)和角膜阻力因子(corneal resistance factor,CRF)变化量,对其相关因素进行多元线性回归分析。方法:前瞻性研究。纳入行LASIK手术的近视眼及近视散光患者70眼(38例),术前与术后6个月各项参数分别由眼反应分析仪(ocular response analyzer,ORA)、非接触眼压仪、超声角膜测厚仪及Pentacam眼前节分析仪测量。分析LASIK手术前后△CH,△CRF与术前、手术设计等参数的相关性,并对相关参数进行多元线性回归分析。结果:手术前后CH分别为(10.05±1.36),(8.15±0.90) mmHg(1 mmHg=0.133 kPa),CRF分别为(9.91±1.38),(6.92±0.88) mmHg,差异均有统计学意义(P<0.01);△CH与△CRF分别为(1.90±1.15),(2.99±1.23) mmHg。△CH与术前CH,CRF,眼压(intraocular pressure,IOP),预计切削深度(ablative depth,AD)以及AD/CCT呈正相关;△CRF与术前CH,CRF,IOP,AD,AD/CCT,术前等值球镜(spherical equivalent,SE)以及预计
基质床厚度(residual stromal bed’s thickness,RSBT)有相关性。采用多元线性回归对LASIK手术前后△CH,△CRF与术前、手术设计等各相关参数进行分析,回归方程为:△CH=?6.182+0.658CH术前+8.421AD/CCT (R2=0.639,P<0.01),△CRF=?0.007+0.725CRF术前?0.014RSBT (R2=0.689,P<0.01)。结论:LASIK术前后CH与预计AD和角膜厚度比值密切相关,CRF变化量与预计角膜RSBT密切相关,在设计手术时应慎重考虑预计AD与预计RSBT。
Abstract Objective: To discuss the change of corneal hysteresis and corneal resistance factor before and after laser in situkeratomileusis (LASIK), and to analyze their related factors by multivariate linear regression. Methods: In this prospective study, 70 eyes (38 patients) with myopia and myopic astigmatism undergoing LASIK were included. Related factors were measured preoperatively and at 6 months postoperatively by ocular response analyzer, noncontact tonometer (NCT), ultrasonic pachymeter, and Pentacam system. The correlation was analyzed between △CH, △CRF and preoperative and operative design’s parameters, and correlative factors analyze. △CH and △CRF were analyzed by the multiple linear regression. Results: CH before and after LASIK were (10.05±1.36) and (8.15±0.90) mmHg, and CRF before andafter LASIK were (9.91±1.38) and (6.92±0.88) mmHg. There was significant difference between preoperative and postoperative CH and CRF (P<0.01). △CH and △CRF were (1.90±1.15) and (2.99±1.23) mmHg. Preoperative CH, CRF, intraocular pressure (IOP), ablative depth (AD) and AD/CCT were positive correlated with △CH. Preoperative CH, CRF, IOP, AD, AD/CCT, preoperative spherical equivalent (SE) and predicted residual stromal bed’s thickness (RSBT) were correlated with △CRF. The regression equation of △CH and △CRF and influencing factors were △CH =?6.182 + 0.658CHpreoperative + 8.421AD/CCT (R2=0.639, P<0.01), △CRF =?0.007 + 0.725CRFpreoperative ? 0.014RSBT (R2=0.689, P<0.01). Conclusion: The change of CH before and after LASIK is correlative with AD/CCT. The change of CRF before and after LASIK is correlative with predicted residual stromal bed’s thickness. Ablative depth and predicted residual stromal bed’s thickness should be considered carefully during the surgical design.