Reopening filtration fistulas with the neodymium-YAG laser.

We used the mode-locked neodymium-YAG laser to reopen filtration fistulas in nine eyes in which the fistula had become occluded internally by a variably pigmented membrane, vitreous, or, in one case, capsular lens material. In five eyes filtration was successfully reestablished, reducing the intraocular pressure to less than 21 mm Hg (range, 10 to 20 mm Hg). The remaining four eyes had fistulas thought to be open internally after laser treatment; however, filtration was not established because of external subconjunctival scarring of the bleb. As with needling or argon laser fistular reopening, successful filtration followed Nd-YAG laser fistular surgery only when the fistula was occluded by an identifiable membrane and when the eye already had had a well-established bleb.