CLINICAL-RESULTS OF SELECTIVE EXCIMER-LAS ER ABLATION OF THE TRABECULAR MESHWORK

Purpose: Examination of the efficacy of pore formation in the trabecul ar meshwork by excimer laser to reduce intraocular pressure in glaucom a eyes. Patients and methods: In 27 consecutive eyes with chronic simp le glaucoma and 8 eyes with low-tension glaucoma, 3 to 5 pores were ab lated into the trabecular meshwork with an excimer laser (308 nm, 35-5 5 mJ/mm(2)), creating an open communication between the anterior chamb er and Schlemm's canal. This was accomplished by the use of a 400-mu m quartz fiber and a modified Trokel goniolens. All patients were candi dates for trabeculectomy because visual fields continued to deteriorat e in spite of maximum medication. Results: Intraocular pressure was me dian reduced by 7 mmHg (range 10.5 to 1.5 mmHg) in 22 of 27 eyes with chronic simple glaucoma over a median follow-up of 7 months. In 12 eye s,further medication has to be continued, yet at a lower dose and lowe r level of intraocular pressure. In five eyes therapy failed. In three of these eyes, a trabeculectomy had to be performed. In eight eyes wi th low-tension glaucoma,a median reduction of intraocular pressure of 5 mmHg (range 10 to 0.5 mmHg) was accomplished over a median follow-up of 7 months. In five of these eyes,further medication on a lower leve l was continued. No further surgery was necessary. Conclusions: With t he microsurgical method of pinpoint ablation of the trabecular meshwor k by excimer laser, intraocular pressure was reduced in 30 of 35 eyes over a median follow-up period of 7 months. These results encourage us to continue the development of this procedure, perhaps with a microen doscope. The minimal trauma to the eye of this procedure leaves all ot her options of surgery open.