EXCIMER-LASER FILTRATION SURGERY

PURPOSE: In order to remove precisely scleral tissue overlying Schlemm 's canal with minimal trauma as an outpatient procedure under local an esthetic, we used a VisX Twenty/Twenty excimer laser. METHODS: We perf ormed excimer laser filtration in three enucleated pig eyes, seven enu cleated human eyes, and seven eyes of patients with severe glaucoma. P recise ablation to Schlemm's canal was confirmed by scanning electron microscopy in the enucleated eyes. For the patients, a local anestheti c was used, and a custom-made holder was used to mobilize the conjunct iva and fix the eye. RESULTS: A functional sclerostomy was obtained wi th 1,780 to 5,965 pulses, using a 2 x 1-mm slit. In our mean follow-up of nine months (range, six to 12 months) the excimer laser filtration technique achieved controlled filtration in five of seven patients an d minimized conjunctival trauma. One patient subsequently underwent ca taract extraction. CONCLUSIONS: This study indicates that excimer lase r filtration is an effective technique for achieving filtration in gla ucoma. It may reduce the complications of glaucoma filtration surgery, particularly the incidence of shallow anterior chamber postoperativel y, as it leaves the trabecular meshwork intact.