准分子激光治疗性角膜切削术治疗角膜浅层病变的实验和临床研究

Experimental and clinical studies on photo-therapeutic keratectomy for superficial corneal diseases

目的 观察准分子激光治疗性角膜切削术 (photo therapeutickeratectomy ,PTK)后兔角膜组织的修复情况 ,探讨PTK的临床疗效、适应证和治疗参数。方法 (1 )实验组采用 8 1 7%硫酸烧灼法制作兔角膜浅层瘢痕模型 ,2周后行PTK ;于术后不同时间进行角膜活体共焦显微镜、神经染色、光镜和透射电镜检查 ,并与对照组进行比较。 (2 )根据临床治疗组 2 6例 (30只眼 )角膜浅层病变患者的病变种类 ,分别行去除上皮和非去除上皮PTK。观察术后不同时间患者的视力、屈光状态和角膜曲率变化情况 ,以及角膜雾状混浊 (haze)的程度。随访时间 6个月。结果 (1 )实验组兔角膜切削区PTK术后早期多形核中性粒细胞和巨噬细胞浸润 ,浅基质成纤维细胞增生活跃 ,新生胶原纤维排列紊乱、疏松 ;术后 6个月趋于正常 ,组织修复稳定。 (2 )临床治疗组PTK术后 6个月最佳矫正视力与术前比较 ,2 1只眼提高 ,5只眼不变 ,4只眼下降 ;其中PTK治疗角膜营养不良和角膜带状变性的效果最佳 ;术后 6个月haze 0级 2 3只眼 ,0 5级 5只眼 ,1级 2只眼 ;平均远视移动度数 +1 52D。结论 兔角膜PTK术后 6个月组织修复趋于稳定 ;临床PTK治疗角膜浅层病变患者 ,方法简便、安全、有效 ,其中以治疗角膜营养不良和角膜带状变性的效果最佳。采用PTK治疗的?

Objective To study the histologic changes in rabbit corneas after photo therapeutic keratectomy (PTK), define the indications and treatment parameters and evaluate efficacy of PTK Methods (1) The model of superficial corneal scar in rabbit was made by burn with 8 17% sulfuric acid, and then treated with PTK in two weeks The corneas were examined with confocal microscope in vivo, nerve staining, light and transmission electron microscope during period after PTK to study the histopathologic changes (2) Thirty eyes with superficial corneal diseases including 12 eyes with corneal dystrophy, 2 eyes with band degeneration, 10 eyes with scar after infection and trauma and 6 eyes with Dimmer nummular keratitis were treated with PTK The method of treatment was varied with different diseases Follow up was more than six months To investigate the change of haze, visual acuity, refraction and keratometric power during period after PTK, chi square tests were used Results (1) Experimental group: in the ablative zone at early time after PTK, there were infiltration of polymorphonuclear leukocytes accompanied by macrophages, proliferation of fibroblast and loose nascent collagen in disorder in the anterior stroma The wound healing process was stable at six months after PTK (2) Clinical group: compared with the preoperative visual acuity, the best corrected visual acuity was improved in 21 eyes (70 0%), unchanged in 5 eyes (16 7%) and decreased in 4 eyes (13 3%) at six months after PTK, and the results were better for corneal dystrophy and band degeneration Haze grade 0 5 was in five eyes, grade I in two eyes and grade 0 the rest The mean hyperopic shift was +1 52 D Conclusions The wound healing process in rabbit cornea stabilizes at six months after PTK PTK is a simple, safe, effective treatment for superficial corneal diseases The indications for PTK are corneal pathology in the anterior one third of the cornea, especially corneal dystrophy and band degeneration