Abstract
Abstract: :
Purpose: To determine the effects of episcleral implantation of a slow release pellet containing VEGF. Methods: Hydroxylethylmethacrylate (hydron) pellets containing VEGF for sustained release were implanted into the episclera of Long Evans or Spraque–Dawley rats. Contralateral eyes were implanted with pellets containing buffer and served as controls. The induction of CNV was evaluated at four days, one and two weeks post implantation, using fluorescein angiography, India ink perfusion flat mounts, serial sections, light microscopy and immunohistochemistry. Results: Fluorescein angiography showed an increased permeability and leakage of affected vessels located beneath the pellet implant. Using India ink perfusion of albino rats and flat mount preparations of choroid, neovascularization was seen at the quadrant where the pellet was implanted. Retinal detachment with subretinal hemorrhage was also observed. Histology showed points of compromised Bruch’s membrane with choroidal vascular in–growth. Conclusion: This model provides a relatively easy approach to produce an acute CNV using VEGF delivered episclerally, thereby avoiding the complications of an intraocular invasion procedures. Systemic and oral antiangiogenic agents can potentially be tested using this model.
Keywords: choroid: neovascularization • age–related macular degeneration • neovascularization