兔经结膜无缝线玻璃体切除术后巩膜切口愈合的实验研究

The experimental research of rabbit's sclerotomy sites healing undergoing transconjunctival sutureless vitrectomy

目的探讨兔经结膜无缝线玻璃体切除术后巩膜切口愈合的病理机制,并比较术中不同操作方法对巩膜切口愈合的影响。设计实验研究。研究对象新西兰白兔。方法32只新西兰白兔随机分为施行核心玻璃体切除联合气体眼内填充(A组)、核心玻璃体切除(B组)、次全玻璃体切除联合气体眼内填充(C组)和次全玻璃体切除(D组)。在术前、术后1d、3d、5d、7d和14d采用Tonopen眼压计记录眼压。术后1d、5d和9d使用超声生物显微镜观察巩膜切口愈合情况,术后3d、5d和9d切口组织学切片观察巩膜切口愈合过程。主要指标眼压、巩膜切口内外径值。结果术后1d,核心玻璃体切除联合气体眼内填充组的眼压显著高于其他3组(P<0.001)。术后5d起,4组眼压无差异。超声生物显微镜显示,兔巩膜切口愈合期为9天。术后1d,50.8%(17/ 31)兔眼玻璃体嵌顿于切口内口,31.3%兔眼结膜下出现气团(5/16),64.5%(20/31)结膜下出现液腔。术后1d A和B组切口内径明显小于C和D组(P<0.001)。4组切口外径无差异。术后1d的切口内外径均明显小于术时直径。巩膜切口组织学切片显示,巩膜切口愈合过程为肉芽肿样反应。结论兔经结膜无缝线玻璃体切除手术后巩膜切口愈合的病理机制是伴有巩膜组织弹性回缩的肉芽肿样反应。采用核心玻璃体切除联合气体眼内填充的操作方式术后切口渗漏最少。

Objective To investigate the healing mechanism of the rabbit＇s sclerotomy sites undergoing the transconjunctival sutureless vitrectomy （TSV）, and to compare the wound healing effect of the different surgery procedures. Design Experimental study. Participants New Zealand white rabbits. Methods Thirty-two New Zealand white rabbits were divided into four groups： the core vitrectomy and fluid-air exchange （Group A）, the core vitrectomy （Group B）, the non-core vitrectomy and fluid-air exchange （Group C） and the non-core vitrectomy （Group D）. Intraocular pressure（lOP） was measured on the day preoperatively and the day 1, 3, 5, 7 , 14 postoperatively with Tonopen tonometers. Sclerotomy sites were investigated with the ultrasound biomicroscope （UBM） on the day 1, 5 and 9 postoperatively, and the internal and the external diameter of the wound was estimated on the day 1 postoperatively. The pathological sections of the sclerotomy sites on the day 3, 5 and 9 postoperatively were observed under the light microscope. Main Outcome Measures lOP, the internal and external diameter of the wound. Results The lOP of Group A was obviously higher than the other groups on the day 1 postoperatively （P〈0.001）. From day 5 postoperatively and on, no difference of the lOP was found among 4 groups. The UBM showed the healing course of the sclerotomy sites lasted nine days. On the day 1 postoperatively, the vitreous incarceration existed in some cases （17/31,50：8%）, the fluid cavity （20/31,64.5%） and the air cavity （5/16,31.3%） under the conjunctiva also could be found. The internal diameter of the wound in Group A and Group B was less than Group C and Group D on the day 1 postoperatively （P〈 0.001）. There was no difference in the external diameter. The internal and external diameter of the wound on the day 1 postoperatively was less than the diameter on the surgery day. The histopathological study showed the healing course was the granulation reaction. Conclusions The healing mechanism of the rabbit＇s sclerotomy sites undergoing the TSV was the granulation reaction accompanied with the elastic recovery of the sclera. The wound leakage was the least in the rabbit with core vitrectomy and fluid-air exchange.