[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.

随着科学技术的提高、手术方式的改进，角膜屈光手术成为治疗近视的主要方式。角膜屈光手术后角膜形态及生物力学的变化对于尽早发现术后相关并发症及术后长期稳定性具有重要意义，不同的术式及术后不同的恢复阶段角膜表面非球面参数及生物力学指标的变化存在一定差异，明确其变化的原因及机制可对临床研究提供一定的参考。

With the improvement of science and technology and the improvement of surgical methods, corneal refractive surgery has become the main way to treat myopia. The changes of corneal morphology and biomechanics after corneal refractive surgery are of great significance for early detection of postoperative complications and also affect the long-term stability after corneal refractive surgery. There are some differences in the changes of aspheric parameters and biomechanical properties in different surgical procedures and different postoperative recovery stages. Clarifying the reasons and mechanisms of these changes can provide some reference for clinical research.

目的：探究角膜塑形镜(OK镜)配戴者使用中的镜盒的葡萄球菌及假单胞菌污染状况以及其可能存在的危险因素。方法：于四川大学华西医院隐形眼镜门诊收集镜盒使用1个月及以上的O K镜复查患者，使用问卷调查其基本信息与日常配戴情况，并收集其镜盒。收集的镜盒于无菌操作台内取样后转移入葡萄球菌选择培养基与假单胞菌选择培养基，置于37 ℃恒温培养箱中培养48 h后观察微生物生长情况。结果：本研究共收集受试者52例，其中男15例，女37例，年龄(11.8±2.5)岁。在收集的镜盒中，葡萄球菌的检出率为42%(22例)，其中金黄色葡萄球菌检出率为21%(11例)；假单胞菌的检出率为12%(6例)，未发现铜绿假单胞菌，总体微生物检出率为44%(23例)。存放于客厅或书房的镜盒微生物检出率为25%(5/20)，日常存放于卧室或卫生间的镜盒(58%，18/31)。日常护理由家长完成的镜盒微生物检出率为31%(10/32)，由戴镜儿童本人完成的镜盒微生物检出率为65%(13/20)。随着镜盒使用时间的增加，镜盒内微生物的检出率的增加差异无统计学意义。结论：OK镜戴镜者日常使用的镜盒中，葡萄球菌的污染率较高，其中相当一部分是金黄色葡萄球菌。日常护理操作人员、镜盒存放位置是镜盒污染的危险因素。镜盒使用的时间可能是镜盒微生物污染的危险因素，但是需要进一步的实验验证。

Objective: To investigate microbial contamination in Ortho-K wearer’s lens cases caused by Staphylococcus and Pseudomonas and to solicit its risk factors. Methods: Lens cases used for at least 1 month were collected from Ortho-K wearers coming back for after-care in West China Hospital and an interview using preset questionnaire about their demographic information and lens wearing was performed. Lens cases were sampled in clean bench and the samples were then transferred onto Staphylococcus selective agar plate and Pseudomonas selective agar plate, which were incubated at 37 ℃ for 48 h before observed. Results: A total of 52 subjects were recruited, including 15 male and 37 female, with an average age of (11.8±2.5) years. Contamination rate of Staphylococcus was 42% (n=22), in which 21% (n=11) were detected with Staphylococcus Aureus (SA). With no Pseudomonas Aeruginosa (PA) was detected, the general rate of microbial contamination was 44% (n=23). Contamination rate of cases stored in living room was 25% (5/20), significantly lower than cases stored in bedroom (58%, 18/31). And cases that daily cleaning operated by parents (31%) (10/32) were less contaminated than that operated by children themselves (65%) (13/20). The increase of detection rate of microorganism in lens cases didn’t reach a significant statistical difference with longer use. Conclusion: The contamination rate of Staphylococcus, in which a considerable part was contributed by SA, is high in Ortho-K lens cases. Personnel of daily cleaning and location of case storage are the risk factors of lens case contamination. Length of case use could be a potential risk of microbial contamination but remains to be proved by further research.