Büchi E R, Lam T T, Suvaizdis I, Tso M O
University Eye Hospital, Basel, Switzerland.
Retina. 1994;14(4):370-8. doi: 10.1097/00006982-199414040-00015.
The morphologic changes of the retina, choroid, and respective vasculatures in an experimental model of diffuse photothrombosis and photodynamic injury were studied.
After intravenous injection of rose bengal (40 mg/kg), eyes of 21 albino rats were exposed to a light intensity of 15-17,000 ft-cd for 2 to 15 minutes. Survival times ranged from 15 minutes to 6 days. The specimens were studied by light and electron microscopy.
Photothrombosis of retinal and choroidal vessels was variable in extension and duration. Vascular lesions included vacuolation and sloughing off of endothelium, and necrosis and apoptosis of pericytes and smooth muscle cells. Retinal and choroidal injuries exhibited considerable regional and structural differences, such as predominance in the outer versus inner retina, or focal versus diffuse injury.
Damage produced by this model was irregular in extent and character, due to several hard-to-control parameters. It was presumably due not only to ischemia but also to free radical chain reactions initiated by photodynamic action. This model may not be suitable for rapid quantitative assessment of ischemic retinal injury, but it provides opportunities for the investigation of pathophysiologic mechanisms.
研究了弥漫性光血栓形成和光动力损伤实验模型中视网膜、脉络膜及其各自脉管系统的形态学变化。
静脉注射孟加拉玫瑰红（40毫克/千克）后，对21只白化大鼠的眼睛进行15 - 17,000英尺烛光的光照，持续2至15分钟。存活时间为15分钟至6天。通过光镜和电镜对标本进行研究。
视网膜和脉络膜血管的光血栓形成在范围和持续时间上各不相同。血管病变包括内皮细胞空泡化和脱落，以及周细胞和平滑肌细胞的坏死和凋亡。视网膜和脉络膜损伤表现出相当大的区域和结构差异，例如外层视网膜与内层视网膜的优势，或局灶性与弥漫性损伤。
由于几个难以控制的参数，该模型产生的损伤在程度和特征上是不规则的。这可能不仅是由于缺血，还由于光动力作用引发的自由基链反应。该模型可能不适用于快速定量评估缺血性视网膜损伤，但它为研究病理生理机制提供了机会。
