T. Saidi, R. Ben Chaouacha-Chekir and D. Hicks
Psammomys obesus is an animal model of type 2 diabetes, which develops diabetic retinopathy as a result of chronic hyperglycemia after a high caloric diet. Distinctive features of induced diabetes in P. obesus are vascular structural abnormalities, elevated ratios of pro- to anti-angiogenic growth factors in the vitreous, blood-retinal barrier breakdown, neural and glial changes. Although many existing diabetic animal models develop ocular complications, retinal lesions frequently observed in diabetic patients such as preretinal neovascularization, retinal detachment and neovascular stages are only rarely observed in these models. Nevertheless, existing animal models are useful because preventing progressive capillary obliteration from occurring in the retina is likely to be a more beneficial therapeutic goal than merely inhibiting neovascularization in an already damaged and ischemic retina. This review
highlights recent observations regarding the histological changes seen in blood–retinal barrier breakdown, the alterations of macroglial and neuronal pattern in diabetes, and how these changes lead to vision loss. Although, the P. obesus will be a useful model in studies of the pathogenesis and treatment of diabetic retinopathy.