[Targetted ablation of the trabecular meshwork with excimer laser in primary open-angle glaucoma]

Abstract

The trabecular meshwork and the inner wall of Schlemm's canal constitute 75% of the outflow resistance of the aqueous. Attempts to improve the outflow facility with laser beams have not been satisfactory because they produced thermal effects with coagulation of the trabecular meshwork. With the excimer laser tissue can be removed with minimal thermal effects and necrosis. This results in minimal scar formation. With these qualities the excimer laser lends itself very well for ablation of the trabecular meshwork. It should be possible to create an open connection between the anterior chamber and Schlemm's canal. The goal of our experiments is selected ablation of the trabecular meshwork and the inner wall of Schlemm's canal in order to create pores and enhance the outflow facility. First experiments were carried out on pig and cadaver eyes, followed by eyes destined for enucleation because of malignant melanomas. Finally, we treated 6 patients with open-angle glaucoma. In 4 cases intraocular pressure was reduced by 11 mmHg over a follow-up time of 5 months. In 2 cases IOP rose by 2 mmHg in spite of medication. These preliminary results encourage us to continue with our investigation because there could be a possibility of an effective glaucoma therapy.