光化学反应诱导大鼠视网膜水肿模型

A Novel Rodent Model of Retinal Edema Induced by Photochemical Reaction

目的:通过静脉注射光敏剂Erythrosin B联合激光照射诱导大鼠视网膜水肿模型,并观察该模型中大鼠视网膜及血管形态改变。方法:大鼠尾静脉注射光敏剂Erythrosin B后,使用532nm Nd:YAG激光(1.95±0.05 mw)照射大鼠视网膜8分钟。分别于建模后第1、2、3、5、7及14天进行眼底照相、眼底荧光造影(FFA)及视网膜光学相干断层扫描(OCT)检查。并在OCT图像上测量大鼠视网膜厚度(RT)。结果:眼底照相、FFA及OCT结果显示大鼠视网膜在激光照射后可立即出现血管损伤及视网膜厚度增加,但未发现视网膜血管栓塞。激光照射前RT为219±2μm,激光照射后第1天RT即增加至283±6μm,并在第2天到达顶峰(302±7μm),之后开始下降,至第5天恢复到激光照射前水平(234±9μm),到第14天时视网膜发生明显萎缩,RT较激光处理前减小(198±6μm)。结论:这一通过光化学反应诱导的视网膜水肿模型具有可靠及可重复性,可被运用于视网膜水肿的病理学及动力学研究。

Objective： To establish a rat retinal edema model, based on microvascular endothelial leakage caused by a laser-driven photochemical reaction mediated by singlet molecular oxygen. Methods： The retinas of Spragne-Dawley （SD） rats were exposed to a 532 nm continuous wave neodymium-doped yttrium aluminum garnet （Nd：YAG） laser beam （1.95~ 0.05 mW, 5 mm diameter） for 8 minutes after intravenous erythrosin B （20 mg/kg） infusion. At 1, 2, 3, 5, 7 and 14 days after irradiation, morphological changes.of the retina and vascular leakage were detected by fundus photography, fluorescein angiography （FA） and optical coherence tomography （OCT）. Results： Retinal Edema was observed by OCT immediately after induction. Retinal thickness and vascular damage increased over time. Retinal thickness reached maximum on the second day following edema induction. Subretinal fluid, vascular narrowing and vasodilatation were observed, but there was no photothrombosis. The retinal thickness prior to induction was 219＋ 2 Ixm; This thickness increased to 283 ＋ 6 p^m on the first day after induction and reached 302＋ 7 Ixm on the second day after induction. The edema lasted for 5 days, then de- creased to 234＋ 9 I^m on the fifth day after induction. On the fourteenth day after induction, the retinal thickness had decreased to 198＋ 6 ~m, which was significantly lower than that in the control retinal thickness （P〈0.05）. Conclusion： This retinal edema model induced by a photochemical reaction is reliable and repeatable. It can be used to study the patholo~.~v and dynamics of retinal edema.