Indications and technique for reopening closed filtering blebs using the Nd:YAG laser--a review and case series

We reviewed the results of Nd:YAG laser treatment used with gonioscopy to reopen the internal sclerostomy in 10 consecutive patients with failing filtering blebs in whom the sclerostomy had become occluded internally with a membrane or iris after filtering surgery. Sixteen to 50 applications of 6- to 6.9-millijoules Nd:YAG laser irradiation were directed to the internal sclerostomy site. In 6 of the 10 patients, filtration was successfully reestablished, initially reducing the mean intraocular pressure (IOP) from 26.5 mm Hg (range, 20 to 40 mm Hg) to 8.6 mm Hg (range, 5 to 16 mm Hg), with an average IOP of 13.5 mm Hg at 7 months after the laser treatment. Nine of the patients were on significantly fewer glaucoma medications. We conclude that the YAG laser can be successfully used to reopen the fistula by the internal approach in carefully-selected patients who previously have had well-established filtering blebs. Identification of these suitable candidates involves careful gonioscopy.