半导体激光透巩膜视网膜光凝与电凝及冷凝比较的研究

A Comparative Study of Transscleral Diode Laser Retinal Photocoagulation with Cryotherapy and Diathermy

目的对比半导体激光透巩膜视网膜光凝、冷凝、电凝猕猴眼的组织学反应。 方法猕猴 2只 ,光凝功率 0 .1～ 0 .7W ,脉宽 0 .2～ 0 .8s,光斑直径 2 0 0 μm ,每个术区光斑数 2 3～ 5 8点 ;冷凝温度为 - 75℃ ,作用时间 2 -5s,探头直径 2mm ,每个术区 4个冷凝斑 ;电凝探头直径为 2mm ,电流强度 70～ 80mA ,时长 2 - 3s,每个术区 3个电凝斑。 结果组织学检查见光凝斑视网膜色素上皮细胞连续性尚完整 ,内外界颗粒层结构混乱 ,色素颗粒沉着 ,脉络膜细胞增生 ,Bruch氏膜外胶原层受损 ;冷凝视网膜细胞变性明显 ,脉络膜色素细胞肿胀 ,Bruch氏膜弹力层明显变性 ,色素细胞游离于玻璃体腔。电凝视网膜全层色素沉着 ,结构紊乱 ,巩膜板层状结构消失。 结论半导体激光透巩膜视网膜光凝损伤小 ,具有一定的临床应用前景。

Objective To study the histopathologic characterististics of transscleral diode laser retinal photocoagulation, cryotherapy and diathermy in rhesus monkeys. Methods Transscleral diode laser photocoagulation was applied using 23 to 58 spots of 0.1 ～ 0.7W power and 0.2 ～ 0.8s duration and 200μm diameter. Cryotherapy was applied using 4 spots of -75℃ and 2 ～ 5s duration. For diathermy, the parameters were 70 ～ 80mA, 2 ～ 3s duration and 3 lesions. Results The histopathologic characteristies of the lesions induced by transscleral diode laser treatment were inner and outer nuclear layer disorganization with pigment deposits, and in some parts of choroid, coagulation and choriocapillary occlusion were seen. Cryotherapy lesions showed enlarged choroidal pigment cells and pigment deposits all over the retina. In both laser and cryotherapy lesions, the sclera was spared. The sclera was severely injured in diathermy spots which demonstrated loss of lamellar structure with intense retinal coagulation necrosis. Conclusion Transscleral diode laser photocoagulation may be clinically useful for coagulation of the retinal tears.