Reopening filtration fistulas with the argon laser.

I used argon laser photocoagulation to reopen filtration fistulas in four cases in which the fistula had become occluded internally by a pigmented membrane. In each case the fistula had remained patent for an extended period before occlusion (range, several months to 25 years). The argon laser offers several advantages over conventional surgical methods of reopening the fistula. The patients need not be hospitalized and require no sedation or anesthesia, the risk of damaging the lens is minimized, and the treatment can be safely repeated. This technique was not successful when the fistula was occluded by nonpigmented tissue.