Evaluation of Nd:YAG Laser Membranectomy in Blocked Tubes After Glaucoma Tube-Shunt Surgery

To determine the effectiveness of Nd:YAG laser membranectomy for reopening blocked glaucoma tube shunts and maintaining the patency over time. We reviewed retrospectively the records of 13 patients (13 eyes) who, during the period January 1990 through June 1996, underwent Nd:YAG laser membranectomy in an attempt to reopen a blocked glaucoma tube shunt. Intraocular pressure and tube patency were evaluated at each follow-up visit. Nd:YAG laser membranectomy effectively opened the blocked glaucoma tube shunts in 11 (84.6%) of 13 eyes. Two tubes could not be reopened. Reblockage occurred in seven eyes (53.8%) within the first 11 weeks; four tubes (30.8%) remained patent through follow-up periods of 39, 82, 106, and 169 weeks. Postlaser complications were moderate anterior chamber reaction in four eyes (30.8%), hyphema in two eyes (15.4%), corneal edema in two eyes (15.4%), pressure spike in one eye (7.7%), and shallow anterior chamber in one eye (7.7%). Nd:YAG laser membranectomy is effective in reopening blocked glaucoma tube shunts but is associated with a relatively high rate of subsequent reblockage in the initially successful cases.