Abstract
Purpose:
To develop a reliable, reproducible rat model of retinal vein occlusion (RVO) with a novel photosensitizer (Erythrosin B) and study the cellular responses in the retina.
Methods:
Central retinal vein occlusions (CRVO) and branch retinal vein occlusions (BRVO) were created in adlult male rats by photochemically induced ischemia. Retinal evolution was examined by Color fundus photography and fluorescein angiography at 1hr and 3hr and 1, 4, 7, 14 and 21 days after irradiation. Tissue slices were used to investigate the pathologic changes. Retinal ganglion cell survival at different times after RVO induction was quantified by nuclear density count. Retinal thickness was also observed.
Results:
In all cases (CRVO and BRVO) blood flow ceased immediately after laser irradiation and retinal edema was evident at 1h, with that retinal detachment (RD) appeared at 3h examination and developed into bullous retinal detachment (RD) within 24h. Retinal hemorrhages were not observed until 1 day. FA demonstrated reopening of the occluded veins at 7 days examination. The manifestation of CRVO group was severer than BRVO group. A remarkable reduction in the ganglion cell count and the thickness of retina was observed in CRVO group by 21 days, whereas moderate changes happened in BRVO group.
Conclusions:
Rat RVO created by photochemically induced ischemia using Erythrosin B is a reproducible and reliable animal model for mimicking the key features of human RVO.
Keywords: 688 retina •
578 laser •
572 ischemia