Photothrombosis of corneal neovascularization by intravenous rose bengal and argon laser irradiation
A. J. Huang, B. D. Watson, E. Hernandez and S. C. Tseng
Department of Ophthalmology, Bascom Palmer Eye Institute, Miami, FL 33101.
Management of corneal neovascularization by photocoagulation has been
limited and rarely successful. We evaluated the efficacy and safety of the
novel technique of photothrombosis to occlude corneal neovascularization.
Sixteen rabbit corneas with previous ocular surface wounds that had healed
with 360 degrees extensive neovascularization (persistent for 20 months)
were used. After an intravenous injection of rose bengal solution (40 mg/kg
of body weight [BW]), each vessel on the upper half of the cornea was
occluded with a photochemically induced thrombus within ten shots of argon
laser irradiation (514.5 nm, 130 mW, 63 microns, 0.2 s); those on the lower
half were used as an internal control. Throughout the four-month study
period, the treated vessels remained occluded, as evidenced by corneal
fluorescein angiography. Corneal clarity was improved after treatment. A
single injection of rose bengal at a dose of 8 mg/kg of BW or higher was
sufficient for successful photothrombotic occlusion of corneal vessels
within one hour of experimentation. Transient elevations of serum urea
nitrogen, aspartate aminotransferase, alanine aminotransferase, alkaline
phosphatase, and total bilirubin levels and decrease of serum phosphorus
level were noted on the first day after injection with 40 mg/kg of BW of
rose bengal solution.
