Internal and transconjunctival neodymium:YAG laser revision of late failing filters.

Abstract

Seven cases of hypofunctioning trabeculectomies or full-thickness filters were treated using the Q-switched neodymium:YAG (Nd:YAG) laser delivered either transconjunctivally, gonioscopically, or by a combination approach. In four eyes, internal laser revision was attempted initially. Internal revision was successful in one case, where the sclerostomy had become occluded by a fibrous membrane. The Nd:YAG laser was then focused transconjunctivally onto the episcleral fibrous tissue within the bleb in the three eyes treated unsuccessfully by the internal approach and used as a primary treatment in three additional cases. Transconjunctival laser treatment was successful in producing an immediate and substantial decrease in intraocular pressure (IOP) (mean IOP reduction of 12 mmHg at 2 hours posttreatment) in all cases. In six of seven cases, there was a persistent reduction of intraocular pressure with an average of 5.7 months of follow-up. Transconjunctival Nd:YAG laser revision of hypofunctioning filters may be effective in restoring filtration in selected cases.