Purpose: To quantify photodynamic venous occlusion-induced preretinal neovascularization with fluorescein isothiocyanate-dextran (FITC-dextran) angiography in adult Sprague-Dawley rats.
Methods: Argon green laser was used to ablate retinal veins in the experimental group (24 rats), and applied between the vessels in the control group (10 rats) after systemic injection of rose bengal. Animals were systemically infused with FITC-dextran and killed 14 days after laser treatment. Retinal flat-mounts were observed under a fluorescence microscope. The number and area of neovascular tufts were measured. Confocal microscopy and histological study were performed to rule out possible artifacts, and to confirm FITC-dextran angiography findings.
Results: Out of the entire group of 34 albino rats, no preretinal neovascularization was found in the control group (total 20 eyes, 10 rats). In the experimental group (total 48 eyes, 24 rats) 43 eyes (90%) developed well demarcated neovascular tufts revealed by FITC-dextran angiography. This well demarcated boundary of neovascular tufts was reconfirmed by confocal microscopy and histological study. There were no significant differences in the number or area of neovascular tufts between the right and left eyes.
Conclusion: FITC-dextran angiography provides a time- and labour-efficient basis for quantifying both the number and area of preretinal neovascularization induced by photodynamic venous occlusion in adult rats. This model is suitable for angiostatic study in the adult animals.