Efficiency of Photodynamic Therapy and Avastin in Treatment of Corneal Neovascularization in Rabbit's Eye

Document Type : Original Article

Authors

1 Physics Dpt., faculty of science (boys), Al azhar University

2 Department of Vision Science, Biophysics and Laser Science Unit, Research Institute of Ophthalmology

3 Ophthalmic Unit, National Institute for Laser Enhanced Science, Cairo University

4 Ophthalmology Department, Fayoum University

Abstract

The aim of the present work is to evaluate the effect of photodynamic therapy (PDT) by using argon laser with rose bengal (Herbs) as a photosensitizer when compared to the Avastin for treatment of corneal neovascularization (CNV) in rabbits. Thirty-Nine New Zealand male rabbits aged 2.5 months and weighing 2.5-3 kg are selected from the animal house of research institute of ophthalmology, Giza, Egypt. Three rabbits are used as control, and 36 rabbits are subjected to corneal neovascularization (CNV) induced by 3 silk sutures at mid-stromal depth approximately 1 mm from the limbus. After four days, sutures are removed and slit lamp examinations are performed to determine the area of CNV. Rabbits with CNV are divided into 3 groups: (1) The first group left without any treatment(n=12); (2) The second group (n=12 rabbits) were generally anesthetized and rose bengal(C20H4Cl4I4O5) with a dose of 50 mg/Kg was administered by slow intravenous injection in the marginal ear vein. After 15 minutes, rabbit’s eyes were exposed to argon laser(Quantel-Medical, Vitra, France) in a pulsed mode at 532 nm, spot size of 50 μm, pulse duration of 0.2 ms and a power of 150-200 mW/cm 2.; (3) The third group are treated with subconjunctival injection of 25 mg Avastin (n=12). The rabbits are followed up for 4 weeks and 3 rabbits are selected and sacrificed weekly from each group. The corneas are isolated for determination of protein content, SDS-poly acrylamide gel electrophoresis, total antioxidant capacity (TAC) and total oxidative capacity (TOC). Final results show that avastin is almost as effective as photodynamic therapy.

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