【摘要】 目的 :评价实验性家兔不同屈光度 PRK术后角膜创面愈合的过程及皮质类固醇对愈合的影响。方法 :应用 SVS APEX PL U S型准分子激光治疗系统对 6只家兔双眼进行 PRK术 ,设定右眼 - 4.0 0 D,左眼- 8.0 0 D。随机分为 FL M点眼组和 CM点眼组 ,每组 3只家兔 ,FL M点眼组双眼滴皮质类固醇激素眼液 ( 0 .1% fluorometholone,FL M,美国 ) ;CM点眼组双眼滴 0 .2 5 %氯霉素眼液。分别于术后 3天、30天、10 0天两组随机选取 1只家兔 ,猝死摘除双眼球 ,取其角膜。每只角膜分为两半 ,一半角膜电镜下观察其超微结构 ;另一半 OCT包埋后冰冻切片 ,用于免疫组化研究 ,检测 型胶原 ( - C)和连接蛋白 ( FN) ,免疫组化切片后剩余部分 ,石蜡包埋 ,行 HE染色 ,光镜下组织学观察。结果 :术后 10 0天 ,除 1只家兔角膜 haze为 1级外 ,余家兔角膜 haze为 0级。术后 10 0天 ,角膜上皮细胞基本恢复正常。上皮细胞界限分明 ,上皮明亮细胞较多 ,但微绒毛、微皱褶相对减少。CM组 - C和 FN的表达较 FL M组明显 ;左眼 ( - 8.0 0 D) - C和 FN的表达较右眼 ( - 4.0 0 D)明显。结论 :PRK术后 10 0天角膜组织结构基本正常 ,但仍有组织薄弱处和特殊性改变。角膜基质层切削深度可能是影响 PRK术后 haze发生的一个因素。 PRK术后家兔角膜上?更多还原

【Abstract】 Objective:To evaluate the corneal healing of unequal dioptric response using histopathological, immunohistochemical and ultrastructural techniques after PRK with SVS APEX PLUS excimer laser. The effects of corticosteroid on healing were also studied.Methods:PRK was performed on both eyes of 6 white rabbits (12 eyes). PRK was performed on the right eye of the rabbit to attempt a correction of -4.00 diopters, and PRK was performed on the left eye of the rabbit to attempt a correction of -8.00 diopters. The subjects were randomly divided into two groups: the FLM group (3 rabbits, 6 eyes) and the CM group (3 rabbits, 6 eyes). Corticosteroid was given to the eyes of the FLM group, but not the CM group. The eyes were re-examined at 10 days, 30 days and 100 days. The eyes of one rabbit from each group were randomly selected and enucleated. Half of each cornea was prepared for electron microscope study (SEM and TEM); the other half was embedded in an OCT compound for immunohistochemical study to examine ⅢC and FN.Results:All eyes reepithelialized within 3 days after PRK. Subepithelial corneal haze was observed at 15 days but was not dominant at 30 or 60 days. At 100 days postoperatively, 11 eyes with corneal haze had grade 0 or 0.5. Only one eye (the left eye from the CM group) showed a denser haze (grade 1) at 100 days. At 3 days post-operatively one or two layers of corneal epithelial cells covered the ablation zone. At 30 days after PRK, the epithelial cells showed hyperplastic changes. The cells were larger and increased to 7 or 8 layers of cells from the normal 5 or 6 layers. At 100 days after PRK, the epithelium was clear and brighter. Microplicae and microvilli were less evident than before. There was significantly more expression of Ⅲ-C and FN in the CM group than in the FLM group.Conclusion:We found that despite recovery of a continuous and smooth epithelial layer and nearnormal corneal tissues 100 days after PRK, abnormalities of both epithelium and superficial stroma could be detected in the area of ablation. The ablation depth in the stroma can influence the appearance of corneal haze after PRK. The microplicae and microvilli of rabbit corneal epithelium was reduced after PRK, which may be one of the reasons for the sensation of dry eye in some patients.更多还原