Q-switched Nd:YAG laser treatment for corneal neovascularization.

Q-switched Nd:YAG laser treatment to occlude newly formed corneal vessels was performed in patients with herpetic keratitis to reduce corneal opacity and the risk of graft rejection. Nine neovascularized corneas of 9 patients were treated. In 8 of the 9 patients, corneal neovascularization was markedly reduced with a resulting decrease in corneal opacity. Penetrating keratoplasty was performed in 3 patients after the treatment. Two patients in whom YAG laser treatment was effective had uneventful postoperative courses for 13 and 17 months, respectively. In one patient with ineffective YAG laser treatment, rejection occurred 3 months after keratoplasty, and systemic steroid and ciclosporin therapy was needed. Ultrastructural examination of the corneal button removed during keratoplasty from a patient with successful laser treatment showed destruction of vascular endothelial cells and occlusion of the vascular lumen.