[Tachyphylaxis in timolol therapy for chronic glaucoma (author's transl)].

Forty-three patients with open-angle glaucoma were treated locally with 0.5% Timolol. The drop in intraocular pressure on the day following commencement of Timolol therapy was remarkable. However, 14 patients, ten of whom had responded insufficiently to other glaucoma drugs, developed tachyphylaxis either two or three days after being put on Timolol therapy; in some cases tachyphylaxis was observed in follow-up examinations two months later. Intraocular pressure in these eyes was in some cases even higher than it had been prior to treatment with Timolol.