白内障手术不同方向角膜切口对术后泪膜稳定性及角膜神经损伤修复的影响

目的：分析白内障超声乳化术不同方向的透明角膜切口对年龄相关性白内障（ARC）及糖尿病性白内障（DC）患者泪膜稳定性及角膜神经损伤修复的影响。方法：前瞻性研究。收集2021年9—12月常州市第三人民医院眼科行超声乳化吸除联合人工晶状体（IOL）植入术的白内障患者67例（80眼），其中ARC患者35例（40眼），DC患者32例（40眼）。ARC患者按随机数字表法分为2组：Ⅰ组18例（20 眼）行上方透明角膜切口；Ⅱ组17例（20眼）行颞侧透明角膜切口。DC患者按随机数字表法分为2 组：Ⅲ组16例（20眼）行上方透明角膜切口；Ⅳ组16例（20眼）行颞侧透明角膜切口。术前，术后1 周、1个月及3个月时行泪膜破裂时间（BUT）、泪河高度（TMH）、泪液分泌试验Ⅰ（SⅠT）检查；术后1周、1个月及3个月时行眼前节光学相干断层成像扫描（AS-OCT）检查；术后1个月及3个月时行角膜共焦显微镜（CCM）检查。各组术后BUT、TMH、SⅠT与术前比较采用t检验；角膜神经纤维主干密度（CNFD）、角膜神经纤维分支密度（CNBD）组间比较采用单因素方差分析。角膜神经纤维长度（CNFL）、角膜神经纤维宽度（CNFW）组间比较采用非参数Mann-Whitney检验。结果：术后l周、1个月，4组患者BUT、TMH、SⅠT与术前相比差异均有统计学意义（均P<0.05）。术后1周，Ⅰ组与Ⅲ组相比、Ⅱ组与Ⅳ组相比，BUT、TMH、SⅠT值均较大，差异均有统计学意义（均P<0.05）；术后1 个月时，差异无统计学意义（P>0.05）。术后1个月，所有患者完整的长神经纤维均很少；术后3个月，4组均可见完整长神经纤维且可见神经纤维束连接。与术后1个月相比，术后3个月4组患者CNFL、CNFD、CNBD均升高（均P<0.05）。术后1个月Ⅳ组与Ⅲ组相比，CNFL、CNFD、CNBD均较低（均P<0.05）；术后1、3个月，Ⅰ组与Ⅲ组相比、Ⅱ组与Ⅳ组相比，CNFL、CNFD、CNBD均较高，差异均有统计学意义（均P<0.05）。结论：行白内障手术时，DC患者上方角膜切口对神经的损伤较颞侧切口轻。DC患者眼表泪膜损伤及角膜神经损伤比ARC患者修复慢。

Effects of Corneal Incision in Different Directions on Tear Film Stability and Corneal Nerve Repair after Cataract Surgery

Objective: To investigate the effects of transparent corneal incision in different directions on tear film stability and corneal nerve injury repair in patients with age-related cataract (ARC) and diabetic cataract (DC). Method: In this prospective clinical study, 67 patients (80 eyes) of cataract underwent phacoemulsification combined with intraocular lens (IOL) implantation from September 2021 to December 2021 in the Third People's Hospital of Changzhou. Thirty-five patients (40 eyes) of ARC were randomly divided into groups Ⅰ , Ⅱ ; 18 patients (20 eyes) of ARC in group Ⅰ were treated with upper transparent corneal incision; 17 patients (20 eyes) in group Ⅱ were treated with temporal transparent corneal incision. Thirty-two patients (40 eyes) of DC were randomly divided into groups Ⅲ , Ⅳ ; 16 patients (Twenty eyes) of DC in group Ⅲ were treated with upper transparent corneal incision; 16 patients (20 eyes) of DC in group Ⅳ were treated with temporal transparent corneal incision. Tear film break-up time (BUT), tear meniscus height (TMH) and Schirmer I test (S Ⅰ T) were examined before operation, 1 week, 1 month and 3 months after operation; anterior segment optical coherence tomography (AS-OCT) was performed at 1 week, 1 month and 3 months after operation; corneal confocal microscopy (CCM) was performed at 1 and 3 months after operation. The t-test was used to test BUT, TMH and S Ⅰ T in each group after and before operation. One-way ANOVA was used to compare differences between age, corneal nerve fiber density (CNFD) and corneal nerve branch density (CNBD) of each group. Nonparametric Mann-Whitney test was used to compare corneal nerve fiber length (CNFL) and cornenl nerve fiber width (CNFW). Results: There were significant differences in BUT, TMH and S Ⅰ T at 1 week and 1 month after operation compare with before operation (P<0.05); The values of BUT, TMH and S Ⅰ T in group I were higher than those in group III, group II than those in group IV one week after operation (P<0.05), but the difference disappeared 1 month after operation. One month after operation, there were few integral long nerve fibers in all patients. Three months after operation, integral long nerve fibers and nerve fiber branch connection were seen in all four groups. Compared with 1 month after operation, CNFL, CNFD and CNBD increased in the four groups at 3 months after operation (P<0.05). One month after operation, CNFL, CNFD and CNBD in group IV were lower than those in group III (P<0.05). One month and three months after operation, the value of CNFL, CNFD and CNBD in group I were higher than those in group III, group II was higher than those in group IV, and the difference was significant (P<0.05). Conclusion: During cataract surgery, the corneal nerve injury of the upper corneal incision in DC patients was lighter than those of the temporal incision. The repair of tear film injury and corneal nerve injury in DC patients was slower than those in ARC patients.