ABSTRACT
Background There is no effective preventing way for the posterior capsular opacification(PCO) after cataract surgery.Objective The aim of this study was to investigate the preventing effect of adenovirus-mediated herpes simplex virus thymidine kinase/ganciclovir(HSV-tk/GCV) system on PCO.Methods Twelve New Zealand white rabbits were divided into BSS+BSS group,BSS+GCV group,HSV-tk+BSS group and HSV-tk+GCV group at random.Phacoemulsification was performed in bilateral eyes of rabbits,and 0.1ml of BSS or adenovirus vector with HSV-tk gene were injected into lens capsular bag during the operation based on the grouping.In 12 hours after operation,0.1ml BSS was injected into the anterior chamber daily for 3 times in BSS+BSS group and HSV-tk+BSS group,and 0.1ml GCV was used in the same way in BSS+GCV group and HSV-tk+GCV group.The situations of the anterior segment and the posterior capsule were examined under the slit lamp postoperatively.All the wet weight of capsular bags was assessed using electronic balance.The capsular membrane was histopathologically examined in the 4th week after injection.PCO was graded according to the method of Couderc.Results Mild corneal edema and aqueous humor opacity were observed in all the eyes within 3 days and returned to normal level gradually within 2 weeks postoperatively.PCO scores were higher in BSS+BSS group,BSS+GCV group,HSV-tk+BSS group than the HSV-tk+GCV group,showing the significant differences between them(H=2.647,P=0.008;H=2.939,P=0.003;H=2.884,P=0.004).No obvious difference was seen in PCO score among BSS+BSS group,BSS+GCV group,HSV-tk+BSS group(P＞0.05).The wet weight of the capsular bags in HSV-tk+GCV group was reduced in comparison with BSS+BSS group,BSS+GCV group,HSV-tk+BSS group with the statistically significant difference between them(q=9.93,q=10.15,q=10.07,P＜0.05).Histopathological examination revealed that mild proliferation of lens epithelial cells(LECs) at the capsular equator and migration toward the posterior capsule to form a thin soemmering ring in the periphery of the capsular bags and thin fibromembrane at the center of the capsular bags without cells or cortices in HSV-tk+GCV group.However,in BSS+BSS group,BSS+GCV group and HSV-tk+BSS group,the proliferation and migration of LECs were more obvious to form a dense soemmering ring in the periphery of the capsular bags and thick fibromembrane in the center of capsular bags.Conclusion Adenovirus-mediated HSV-tk/GCV system can effectively prevent PCO.