[Selective excimer laser ablation of the trabecular meshwork. Clinical results].

PURPOSE

Examination of the efficacy of pore formation in the trabecular meshwork by excimer laser to reduce intraocular pressure in glaucoma eyes.

PATIENTS AND METHODS

In 27 consecutive eyes with chronic simple glaucoma and 8 eyes with low-tension glaucoma, 3 to 5 pores were ablated into the trabecular meshwork with an excimer laser (308 nm, 35-55 mJ/mm2), creating an open communication between the anterior chamber and Schlemm's canal. This was accomplished by the use of a 400-micron quartz fiber and a modified Trokel goniolens. All patients were candidates for trabeculectomy because visual fields continued to deteriorate in spite of maximum medication.

RESULTS

Intraocular pressure was median 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 eyes, further medication has to be continued, yet at a lower dose and lower level of intraocular pressure. In five eyes therapy failed. In three of these eyes, a trabeculectomy had to be performed. In eight eyes with 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 level was continued. No further surgery was necessary.

CONCLUSIONS

With the microsurgical method of pinpoint ablation of the trabecular meshwork 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 microendoscope. The minimal trauma to the eye of this procedure leaves all other options of surgery open.