210nm固体激光屈光性角膜切削术的实验研究

Experimental study on solid state laser (210nm) photo-refractive keratectomy

目的 评价 2 10 nm固体激光屈光性角膜切削术对兔眼角膜组织的生物效应和皮质类固醇对角膜愈合的影响。方法 10只新西兰白兔双眼行 2 10 nm固体激光屈光性角膜切削术 ,预期矫正 - 5 .0 D,切削深度为 75 μm。根据左、右眼分为 2组 ,术后右眼滴拂炎眼液(1g· L- 1醋酸氟美松龙 ) ,左眼滴托百士眼液 (3g· L- 1妥布霉素 )。分别于术前、术后 4d、2周、1个月、3个月进行裂隙灯显微镜、光镜、透射和扫描电镜检查及超声角膜测厚。结果 兔角膜上皮在术后 4d内愈合 ,上皮愈合后激光切削区上皮下角膜实质浅层内出现轻度蜘蛛网状混浊 ,术后 3个月时中央区角膜仍有轻度混浊 (1级 ) ,厚度较术前平均减少0 .0 6 4m m。光镜检查见术后 2周、1个月切削区的角膜上皮细胞增生、增厚并上皮下成纤维细胞及胶原纤维增生 ,术后 3个月时角膜上皮细胞恢复正常 ,上皮下浅层基质内少量胶原纤维增生 ,基质排列趋于规则。激光切削区各时期的角膜内皮层和后部基质层均无异常。点滴拂炎眼和点滴托百士眼在光镜、扫描电镜及透射电镜下的表现两者无明显差异。结论 2 10 nm固体激光消融兔眼角膜后的组织愈合过程与 193nm准分子激光术后的角膜愈合过程相似。术后

Objective To evaluate the biological effects of rabbit corneas and the effect of steroids on wound healing after 210nm solid state laser photo-refractive keratectomy in rabbits. Methods Photo-refractive keratectomy was performed on each eye of 10 rabbits using 210nm solid state laser. The target ablation was-5D with an estimated ablation depth of 75μm. All eyes were divided into right eye group given Flarex eye drops and left eye group given Tobramycin eye drops. The eyes were observed through slit-lamp examination, ultrasonic pachymetry, light microscopic examination, transmission and scanning electron microscopic examinations preoperatively,on the 4th day,in the 2nd week ,1st month and 3rd month post-operatively. Results All corneas re-epithelialized within 4 days after photoablation. Sub-epithelial haze was clinically visible in all eyes and it was grade 1 in the 3rd month postoperatively. Mean corneal thickness reduced 0.064mm. Fibroblasts, collagen and epithelial cell proliferation were shown in the ablation area in the 2nd week and the 1st month, which were improved in the 3rd month. The endothelium and posterior stroma were not affected at any stage. There was no difference in eyes whether using steroids or not under light microscopic examination, transmission and scanning electron microscopic examinations. Conclusion Wound healing after 210nm solid state laser keratectomy in rabbits is similar to that after excimer laser keratectomy. There is no difference whether steroids is used or not within 3 months postoperatively.