532nm激光对兔视网膜损伤阈值研究

Retinal injury threshold of 532nm laser exposure

目的:确定532nm激光对兔视网膜的损伤阈值。方法:以家兔14只28眼为实验对象,倍频Nd:YAG激光(532nm)通过裂隙灯照射兔视网膜后极部,光斑直径为2mm,照光时间100s,功率密度为900mW/cm2-1500 mW/cm2,于照后24h观察视网膜损伤发生率,并用加权概率单位法计算损伤发生率为50%时所对应的激光剂量,即损伤阈值ED50。结果:532nm激光照射兔视网膜的ED50为119.7J/cm2,95%置信区间为:(112.6J/cm2,127.0J/cm2),斜率S为1.18。结论:当光斑直径为2mm,照光时间100s时,532nm激光致兔视网膜损伤的阈值为119.7J/cm2。

Objectives：To establish the retinal injury threshold of 532nm laser exposure to rabbit. Methods：Twenty - eight eyes of fourteen New Zealand albino rabbits exposed to a frequency - doubled Nd：YAG laser （532 nm） coupled to a slit lamp biomicrescope using a spot size of 2mm. The power density ranged from 900 to 1500 mW/cm^2 with exposure time of 100 seconds. The damage incidence rate of retina was evaluated at 24 hour after irradiation. The ED50 was calculated with pmbit analysis method. Results： The ED50 for 532nm laser exposure to the rabbit retina was 119.7J/cm^2. The 95 % confidence interval was 112.6 J/cm^2, 127.0 J/cm^2） and the pmbit slope S was 1.18. Conclusions： The retinal injury threshold of rabbits exposed to 532 nm laser is 119.7J/cm^2.