Optimization of an Image-Guided Laser-Induced Choroidal Neovascularization Model in Mice

Abstract

The mouse model of laser-induced choroidal neovascularization (CNV) has been used in studies of the exudative form of age-related macular degeneration using both the conventional slit lamp and a new image-guided laser system. A standardized protocol is needed for consistent results using this model, which has been lacking. We optimized details of laser-induced CNV using the image-guided laser photocoagulation system. Four lesions with similar size were consistently applied per eye at approximately double the disc diameter away from the optic nerve, using different laser power levels, and mice of various ages and genders. After 7 days, the mice were sacrificed and retinal pigment epithelium/choroid/sclera was flat-mounted, stained with Isolectin B4, and imaged. Quantification of the area of the laser-induced lesions was performed using an established and constant threshold. Exclusion criteria are described that were necessary for reliable data analysis of the laser-induced CNV lesions. The CNV lesion area was proportional to the laser power levels. Mice at 12-16 weeks of age developed more severe CNV than those at 6-8 weeks of age, and the gender difference was only significant in mice at 12-16 weeks of age, but not in those at 6-8 weeks of age. Dietary intake of omega-3 long-chain polyunsaturated fatty acid reduced laser-induced CNV in mice. Taken together, laser-induced CNV lesions can be easily and consistently applied using the image-guided laser platform. Mice at 6-8 weeks of age are ideal for the laser-induced CNV model.

Retinal energy demands control vascular supply of the retina in development and disease: The role of neuronal lipid and glucose metabolism

“…The biological impact of altering lipid intake is thought to be primarily through modification of membrane microdomain composition and specific receptors. Dietary ω3 to ω6 fatty acids may, therefore, impact retinal function and retinal neovascularization (Connor et al, 2007; Fu et al, 2015; Gong et al, 2015, 2016a, 2016b, 2017; Hård et al, 2013; Rezende et al, 2014; Sapieha et al, 2011, 2012; Shao et al, 2014; Stahl et al, 2010). There is no evidence these essential fatty acids are used for fuel, and without adequate synthetic machinery, it would be surprising if they were not used primarily in other capacities.…”

“…Mice deficient for Vldlr spontaneously develop pathological RAP-like vascular lesions invading the photoreceptor layer at P12 and reaching the RPE at P16. Figure modified, with permission, from (Connor et al, 2009; Gong et al, 2015; Joyal et al, 2016). …”

Review: adiponectin in retinopathy

“…Dietary supplementation of ω-3 LCPUFA, DHA and eicosapentaenoic acid (EPA), which are major lipid constituents of retina[41], protects against neovascularization in the animal models of retinopathy of prematurity, diabetic retinopathy and age-related macular degeneration[42–45]. In humans, ω-3 LCPUFA intake is associated with a reduced risk of retinopathy of prematurity[46] and age-related macular degeneration[47].…”

Cytochrome P450 Oxidase 2C Inhibition Adds to ω-3 Long-Chain Polyunsaturated Fatty Acids Protection Against Retinal and Choroidal Neovascularization

“…DHA is present in the retina at a higher concentration (20% of lipids) than in any other tissue, and adequate dietary intake is associated with a reduced risk of ROP, DR and AMD 13–16 . Proliferative retinopathy and neovascular AMD are respectively modeled in the mouse eye by oxygen-induced retinopathy (OIR) and laser-induced choroidal neovascularization (CNV) 17, 18 . Dietary intake of ω-3 versus ω-6 LCPUFA reduces pathological angiogenesis in retina and choroid in these models 8, 18 .…”

“…Proliferative retinopathy and neovascular AMD are respectively modeled in the mouse eye by oxygen-induced retinopathy (OIR) and laser-induced choroidal neovascularization (CNV) 17, 18 . Dietary intake of ω-3 versus ω-6 LCPUFA reduces pathological angiogenesis in retina and choroid in these models 8, 18 .…”