角膜基质透镜泪道栓治疗兔干眼的实验研究

目的　探讨角膜基质透镜泪道栓治疗兔干眼的疗效。方法　选取新西兰大白兔24只（48眼），随机分为A、B、C三组，每组各8只（16眼）。除C组正常对照的8只不予处理外，其余16只均用1 g·L^-1苯扎氯铵滴双眼，连续2周，建立中重度兔干眼模型。A组为实验组，于造模结束后予以置入基质透镜泪道栓治疗；B组为模型组，造模后不予治疗。分别在干预后0周、2周、4周、6周观察实验兔泪膜功能相关检查，包括Schirmer泪液分泌试验（S Ⅰ T）、泪膜破裂时间（break-up time，BUT）测定、角膜荧光素染色（fluorescein staining，FL）评分。根据分组于相应时间点收集其角膜及泪道组织，行HE染色观察角膜上皮情况及透射电子显微镜下观察角膜上皮细胞超微结构变化。结果　A、B两组造模结束后泪液分泌量分别为（9.88±1.54）mm、（9.66±1.64）mm，BUT分别为（3.25±0.50）s、（3.50±0.58）s，两组差异均无统计学意义（均为P＞0.05）。A组植入角膜基质透镜泪道栓治疗后2周，其泪液分泌量增加为（13.75±1.61）mm，BUT增加为（6.50±1.29）s，角膜FL评分由（4.424±1.178）分减少为（2.132±1.175）分，3种干眼指标治疗前后差异均有统计学意义（均为P＜0.05）。植入角膜基质透镜泪道栓治疗后4周，A组和C组泪液分泌量、BUT、角膜FL评分差异均无统计学意义（均为P＞0.05）。电镜观察可见A组、C组角膜上皮微绒毛呈指状突起，微绒毛数量多，排列整齐，细胞连接排列规则；而B组角膜上皮微绒毛减少、变短、排列紊乱，可见微绒毛脱落，细胞连接破坏。结论　角膜基质透镜泪道栓对兔干眼模型有一定的治疗作用，有望为临床干眼的治疗提供一种新的方法。

Corneal stromal lenticule punctal plug for the treatment of dry eye in rabbits

Objective　To investigate the effects of corneal stromal lenticule punctal plug in the treatment of dry eye rabbits.Methods　A total of 24 New Zealand white rabbits (48 eyes) were selected in this study and divided into 3 groups randomly (group A,B and C),with each group consisting of 8 rabbits (16 eyes).Except for the 8 rabbits of group C as normal controls without any treatment,the other 16 rabbits were treated with 1 g·L^-1 benzalkonium chloride eye drops for 2 consecutive weeks to establish a moderate to severe dry eye model.Group A was the experimental group,and the corneal stromal lenticule punctal plug was implanted after the modeling；Group B was the model group,and no treatment was given after modeling.The clinical manifestations of tear film function were measured before and 2 weeks,4 weeks,6 weeks after injection respectively,which included the tear volume (S Ⅰ T),tear break-up time (BUT),corneal fluorescein staining (FL).Corneal and lacrimal duct tissues were collected according to the groups at the corresponding time points,histological investigation of corneal epithelium was observed by hematoxylin and eosin staining,and ultrastructure of corneal epithelial cells was further examined by transmission electron microscopy (TEM).Results　After modeling,the tear secretion in the group A and group B was (9.88±1.54)mm per 5 min and (9.66±1.64)mm per 5 min,and the tear break up time was (3.25±0.50)s and (3.50±0.58)s,respectively.There were no statistically significant differences between the two groups (both P>0.05).In group A,2 weeks after implantation of the corneal stromal lenticule punctal plug for treatment,S Ⅰ T increased to (13.75±1.61)mm per 5 min,BUT increased to (6.50±1.29)s,and FL scores decreased from 4.424±1.178 to 2.132±1.175.The differences between the three dry eye indicators before and after treatment were statistically significant (all P<0.05).At 4 weeks after implantation,BUT,FL score and S Ⅰ T had no statistical differences in group A and group C（all P＞0.05）.TEM showed the microvilli of corneal epithelium in group A and group C was regular and fingerlike arrangement.In contrast,a cluster of disordered,shorter and fewer microvilli was observed in group B.Conclusion　Implantation of corneal stromal lenticule punctual plug has a certain effect on the treatment of dry eye syndrome in rabbits,so it is expected to provide a new method for clinical treatment of dry eye.