氩绿激光致兔视网膜感光细胞凋亡的实验研究

目的:观察氩绿激光对兔视网膜损伤及修复的组织学改变及对兔视网膜感光细胞凋亡的影响。方法:将8只有色兔(16眼)中每只眼的上、下方视网膜随机分配为激光光凝区及空白对照区,光凝后24h、4wk通过光镜和电镜及TUNEL技术观察视网膜改变及感光细胞凋亡。结果:(1)光镜观察:光凝处视网膜损伤不明显但脉络膜小静脉充血,4wk后消退。(2)电镜观察:光凝处外节膜盘排列稀疏,神经节细胞轻微肿胀,外核层细胞异染色质增多,4wk后色素增殖,胶原增生。(3)TUNEL染色观察:光凝后24h,光凝处外颗粒层可见较多阳性细胞,内颗粒层偶见,4wk后接近正常。(4)感光细胞凋亡率:光凝后24h,感光细胞凋亡率较正常对照组增加,差异有统计学意义(P<0.01)。光凝后4wk较24h凋亡率显著降低,差异有统计学意义(P<0.01)。结论:轻度氩绿激光光凝视网膜损伤轻微。

Retinal photoreceptor apoptosis induced by the argon green laser in rabbits

AIM:To observe the histopathological changes of retinal lesions and restoration and the effects on apoptosis of retinal cells induced by argon green laser in rabbits.METHODS:Argon green laser was used to produce retinal lesions in inferior retinal or upper retinal at random in each of two eyes in eight pigmented rabbits(16 eyes).The histological changes of retinal were observed under light microscope and transmission electron microscope and the apoptosis of retinal tissue was examined by TUNEL in 24 hours and 4 weeks after photocoagulation.RESULTS:1)Observed under light microscope:the lesions were slightly at spots of argon laser and those were completely recovery in 4 weeks after photocoagula-tion.2)Observed under transmission electron micros-cope:the outer membranous discs were arranged disorder and rare at argon spots.The heterochromatin increased in outer nuclear layer.Hyperplasia of pigment and collagen were seen in 4 weeks.3)Observed by TUNEL:the results of TUNEL examination indicated that many apoptosis cells were found in outer nuclear layer and the apoptosis gradually involved the inner nuclear layer.The changes were completely recovery in 4 weeks after photocoagulation.4)Rate of apoptosis cells of photo-receptor at argon spots is higher than that of normal retinal.There was statistical difference in comparison(P<0.01).Rate of apoptosis cells of photore-ceptor in 4 weeks was lower than that in 24 hours.There was statistical difference in comparison(P<0.01).CONCLUSION:The lesions are feeble induced by argon green laser slightly photocoagulation in rabbits.