应用共聚焦显微镜评价角膜接触镜对SBK术后角膜神经再生的影响

Confocal microscopy evaluations of the effect of contact lens wearing on corneal reinnervationbefore and after SBK

目的利用活体共聚焦显微镜（IVCM）观察配戴角膜接触镜对前弹力层下激光角膜磨镶术（SBK）后角膜基底下神经纤维（CSNFs）修复的影响，探讨IVCM在评价屈光手术神经损伤修复中的价值。方法前瞻性队列研究。选择2010年5月至2011年6月在北京同仁眼科中心行SBK术患者43例（86眼），年龄18-35岁，屈光度-2．75--10．00D，部分患者术前均配戴过软性角膜接触镜。将患者分为4组：组Ⅰ，戴镜时间≤5年，共10例；组Ⅱ，戴镜时间〉5-10年，共6例；组Ⅲ，戴镜时间大于〉10年，共4例；组Ⅳ（对照组），无角膜接触镜配戴史，共23例。分别于术前，术后1、3、6个月采用IVCM观察CSNFs的密度、数量级弯曲度．并通过评分评价CSNFs再生速度。数据采用独立样本t检验、单因素方差分析和X^2检验进行统计分析。结果术前不同戴镜时间患者角膜中央CSNFs密度、数量及弯曲度比较差异无统计学意义（F=1．042、1．947、0．821，P〉0．05），但配戴时间大于10年的患者神经密度和数量较低，弯曲度较高。术后6个月角膜中央再生CSNFs密度、数量明显低于术前，弯曲度高于术前（t=6．150、-4．141、9．709，P〈0．01）。术后6个月不同戴镜时间组角膜中央再生CSNFs密度、数量及弯曲度差异无统计学意义（F=1．472、0-318、0．353，P〉0．05），但随戴镜时间延长，数量和密度下降，弯曲度增高；不同戴镜时间对SBK术后CSNFs再生速度的影响差异无统计学意义（X^2=4．273、8．806、5．364，P〉0．05），但配戴角膜接触镜大于10年患者术后3和6个月再生CSNFs进入角膜中央3mm区域的比例低于其他各组。结论配戴角膜接触镜时间对SBK术前后CSNFs无显著影响，但长时间配戴可延缓术后CSNFs的修复。IVCM可客观、定量评价SBK术后角膜神经的损伤与修复。

Objective To analyze the effect of contact lens （CL） wear on corneal reinnervation after sub-Bowman keratomileusis （SBK） corneal subbasal nerve fibers （CSNFs） by in vivo confocal microscopy （IVCM） and to evaluate the clinical applications of IVCM on corneal reinnervation. Methods It was a prospective cohort study. Forty-three patients （86 eyes） were selected from May 2010 to June 2011 in Beijing Tongren Eye Center. The age was 18-35 years old, refractive error was -2.75--10.00 D. They were divided into 4 groups： group I, time of soft CL wearing 45 years （20 eyes）; group II, 5 years〈time of soft CL wearing 〈--. lO years （12 eyes）; Group III, time of soft CL wearing 〉10 years （8 eyes）; group IV, without history of CL wearing （46 eyes）. The density, number, tortuosity and regenerated velocity of CSNFs of different group were evaluated by IVCM before and 1, 3, 6 months after SBK. Data were analyzed with independent t test, one-factor analysis of variance and chi-square test. Results There were no significant difference of density, number and tortuosity of central CSNFs among different groups preoperative （F=1.042, 1.947, 0.821, P〉0.05）, but the density and number of central CSNFs decreased and the tortuosity increased in group of CL wearing 〉10 years. The density and number of central CSNFs were significant lower,and the tortuosity was significant higher than that of pre-operation （t=6.150, -4.141, 9.709, P〈0.01）. The density, number and tortuosity of central CSNFs among different groups were not significant different （F=1.472, 0.318, 0.353, P〉O.05）, but the longer CL wearing, the lower density and number of central CSNFs and the higher tortuosity were. The velocity of CSNFs regeneration among different groups were not significant different （xZ=4.273, 8.806, 5.364, P〉0.05）, but the percentage of regenerated CSNFs deriving into the central 3 mm in group III was lower than other groups at 3 and 6 month after surgery. Conclusion The time of CL wearing has no significant effect on CSNFs reinnervation before and after SBK. But long time wearing would delay the reinnervation of CSNFs. IVCM was useful to quantitative evaluate the corneal reinnervation pre-SBK and post-SBK.