微脉冲半导体激光对兔眼视网膜损伤的形态学观察

An experimental study on micropulse diode laser lesions in rabbit retina

目的:研究微脉冲半导体激光对兔眼视网膜损伤的生物学效应。方法:有色兔8只16眼,每眼上、下方视网膜随机分别行810nm半导体激光连续波阈值光凝及微脉冲阈下光凝,于光凝后即刻观察光斑反应和眼底荧光造影后荧光素渗漏情况,并在光镜和电镜下观察其对视网膜和脉络膜造成的组织学改变。结果:微脉冲激光阈下光凝后光斑不可见,亦无荧光素渗漏,视网膜损伤不明显;阈值光凝后可见光斑反应并有荧光素渗漏,视网膜损伤明显,外核层细胞数量减少,内、外核层均出现少量核固缩和胞质空泡化,视网膜色素上皮细胞增生,Bruch膜完整无损。结论:微脉冲激光光凝视网膜不会损伤视网膜,但确定阈能量时要从低能量起,且选择周边视网膜。

AIM： To study the biologic effects of micropulse diode laser on retinal lesions of rabbit eyes. METHODS： The continuous-wave of micropulse diode laser was used to produce threshold retinal lesions or subthreshold retinal lesions at inferior or upper retina of every eye randomly in four pigmented rabbits （8 eyes） .The light spot reaction and fluorescence leakage were observed shortly after photocoagulation and fundus fluorescein angiography. The histopathological alterations of retina and choroid were also observed under light microscope and transmission electron microscope. RESULTS： The laser spots of subthreshold retinal lesions and leakage of fluorescein were undetectable. The retinal lesions were not observed, while the conditions of threshold retinal lesions were adverse. The retinal lesions were obvious and it showed reduction of outer nuclear layer cells. Condensed nuclei and cytoplasmic vacuolization were seen in both the inner and outer nuclear layer. The hyperplasia of retinal pigment epithelial（RPE） cells was seen and no change was seen at Bruch membrane. CONCLUSION： The micropulse diode laser technique did not destroy the retinal structure of the rabbits, and we confirm the threshold energies from onset of lower energies. Moreover, we shoud select acroteric zones of retina.