Abstract
Abstract: :
Purpose: To investigate the efficacy of photodynamic therapy (PDT) with verteporfin (Visudyne, Norvatis Ophthalmics AG, Hettingen, Swetzerland), a benzoporphyrin derivative, for treatment of corneal neovascularization (CN) in a rabbit eye model. Methods: CN was induced by placing instrastromal sutures in the cornea. One week after suturing, verteporfin was administrated intravenously and 1 hour later, laser was exposed on the right eye (treated group) at 689 nm wavelength and the left eye was used for the control group. In a separate examination, 1 week after suturing, PDT with verteporfin was performed 2 times at 1–week intervals. Corneal distribution of verteporfin was identified in two rabbits by the fluorescent microscopy. Analysis of CN was done by biomicroscopy and histological examination, including light and electron microscopies. Results: One hour after the administration, fluorescent microscopy brightly revealed vigorous fluorescence in the neovascular wall and interstitial tissue of the treated and control cornea. Following one time of PDT, mean percentages of the neovascular area in the treated and control groups were 90.3 ± 3.5% and 96.4 ± 1.9% at three days, 71.6% ± 6.2% and 88.6 ± 4.6% at one week, and 43.6 ± 15.1% and 76.8 ± 4.4% at two weeks after treatment, respectively (P<0.05). Following two times of PDT, mean percentages of the neovascular area in the treated and control groups were 86.6 ± 2.7% and 96.5 ± 2.2% at three days, 71.0% ± 6.2% and 90.6 ± 3.9% at one week, and 44.9 ± 9.3% and 77.4 ± 10.7% at two weeks after treatment, respectively (P<0.05). Histologic examination showed less sectioned neovascular arean and number of vessels in treated eyes than in control eyes without histologic changes in iris. Conclusions: PDT with verteporfin is a safe and effective procedure to regress experimental CN and can be used to inhibit angiogenesis in the cornea.
Keywords: neovascularization • cornea: basic science • photodynamic therapy