Effectiveness of corneal neovascularization photothrombosis using phthalocyanine and a diode laser (675 nm)

We used chloroaluminum sulfonated phthalocyanine as a photo-sensitizer and a diode laser as a light source for induction of photothrombosis of corneal neovascularization. Corneal neovascularization was induced in 1 eye of each of 10 New Zealand white rabbits using intrastromal 6.0 silk sutures. After the intravenous injection of phthalocyanine in a dose of 4 mg per kg of body weight, photothrombosis was carried out using a diode laser emitting at 675 nm. The animals were followed up by both fluorescein angiography and slit-lamp photography for up to three months. At the end of the follow-up period the eyes were prepared for histology. After photothrombosis, thrombus formation was induced within new vessels demonstrating histological characteristics of both arterioles and venules. Most of the vessels disappeared or remained closed during the follow-up period. Recanalization of some of the thrombosed vessels occurred within the first 20 days after the operation. The combination of phthalocyanine and a 675 nm diode laser is effective for the induction of photothrombosis of corneal neovascularization.