Abstract
Purpose: :
Retinal edema associated with vein occlusion (RVO) is a leading cause of visual loss in humans, yet there is a paucity of clinically relevant animal models of such edemaWe developed a pig model of post-RVO acute retinal edema to evaluate potential pharmacological interventions.
Methods: :
RVO was induced by transvitreal cauterization of a branch retinal vein in 34 eyes of adult farm pigs. At 24h, blood-retinal barrier rupture was quantified by optical coherence tomography and post-mortem measurement of Evans Blue (EB) dye content.
Results: :
At 24h, complete occlusion of the vein was observed in 85% of eyes. In occluded eyes, fundus examination showed extensive retinal haemorrhages, blebs and folds upstream of the occlusion site. Fluorescein angiography revealed widespread capillary closure and leakage. Retinal thickness was increased (mean (±SD) 404 ± 19 µm vs. 190 ± 4 µm ; P<0.001) and EB dye content was higher in RVO eyes (9.4 ± 0.7 µl plasma x g retina wet weight-1 hr-1) as compared to sham-operated eyes (3.2 ± 0.6) and control animals (2.1 ± 0.6; P<0.001). Similar differences were found in the vitreous (2.0 ± 0.3 vs. 0.19 ± 0.04; P<0.001). In the 4 eyes followed up 3 weeks, retinal atrophy was observed.
Keywords: edema • vascular occlusion/vascular occlusive disease • imaging/image analysis: non-clinical