[Laser-induced occlusion of corneal blood vessels with variable emission and absorption]

Laser light has repeatedly been proposed for the occlusion of corneal neovascularizations. Priority has to be given to minimize laser energy in order to limit side effects such as corneal burns. We investigate the influence of variable emission wavelength using a dye laser or dye-enhanced absorption with intravenous sodium fluorescein. Laser energy can be reduced using intravenous dyes at vessel diameters less than 50 microns. Permanent occlusion is achieved in 43% instead of 28% without dye-enhanced absorption. Vessels measuring greater than 50 microns in diameter can be occluded best at lowest laser energy levels when 575 nm laser light is used, which approximates the absorption maximum of hemoglobin.