Abstract

This study aimed to establish an experimental exudative age-related macular degeneration (AMD) model in the common marmoset (Callithrix jacchus), which is a small New World monkey. Choroidal neovascularization (CNV) was induced by laser irradiation on the left eye of each animal under anesthesia. Eight laser spots were applied around the macular area using the image-guided laser system (532 nm) attached with Micron III at 650 mW–2,000 mW power. Laser pulse duration and spot size were fixed at 100 ms and 50 µm, respectively. At 14 days after laser irradiation, fluorescein angiograms were observed. At 21 days after laser irradiation, the fluorescein angiograms were transcardially perfused to the bilateral common carotid arteries with 4% paraformaldehyde for the transverse section or with fluorescein-conjugated dextran (MW = 2,000 kDa) for the retinal pigment epithelia (RPE)-choroidal flatmount. At 14 days after laser irradiation, late hyperfluorescence and leakage within or beyond the lesion borders were observed in a laser power-dependent manner. In the RPE–choroidal flatmount, the mean size of the CNV lesions at 1,500 mW was 1.34 ± 0.49 × 10⁵ µm² (Mean ± S.D., n = 29), and the coefficient of variation for each CNV area was 36.5% (n = 29). In conclusion, we succeeded in producing an experimental exudative type of AMD model in the common marmoset. This model may be useful in elucidating the pathophysiological mechanism and screening of new candidates for exudative AMD.

Keywords: Age related macular degeneration, common marmoset, choroidal neovascularization, fluorescein angiograms, placental growth factor, vascular endothelial growth factor.