A new animal model of choroidal neovascularization

Purpose: The purpose of this study was to evaluate the ability of different methods to induce choroidal neovascularization (CNV) in the domestic pig. Methods: A total of 26 Danish landrace pigs was used. A sample of 22 eyes in 12 pigs underwent retinal photocoagulation with a xenon lamp, six eyes in four pigs underwent retinal photocoagulation with a diode laser, and mechanical rupture of Bruch's membrane (BM) was induced in 12 pigs following surgical debridement of the retinal pigment epithelium without damage to the neuroretina. Results: All 12 pigs (100%) in the group with mechanical rupture of BM developed CNV. The induced membranes were morphologically similar to CNV membranes in humans. Induced CNV was found in 13 of 22 (54%) xenon lamp-treated animals and in five of six (83%) diode laser-treated animals. The CNV in these groups was small and the morphology of the induced lesions was dominated by retinal gliosis and retinal neovascularization, probably due to a marked destruction of the neuroretina. Conclusion: Surgical debridement of the retinal pigment epithelium followed by mechanical rupture of BM is a reproducible method of producing CNV in the domestic pig, whereas photocoagulation gives rise to glially derived subretinal fibrovascular membranes and primarily retinal neovascularization.