Reopening filtration fistulas with transconjunctival argon laser photocoagulation

Three patients (a 15-year-old girl, a 45-year-old woman, and a 61-year-old woman) with previously successful full-thickness filtering procedures developed pigmented tissue in the fistula sites and uncontrolled intraocular pressures despite maximum tolerable medical therapy. The filtering procedures in the first and second patients spontaneously failed two and four years after surgery. The filtration bleb of the third patient, after successfully controlling intraocular pressure for six years, failed two months after cataract extraction. Argon laser therapy was applied through the conjunctiva to treat visible subconjunctival pigmented tissue within the sites of the previous surgical filtration blebs. In all three cases, there was an immediate and significant decrease in intraocular pressure associated with reestablishment of the filtration bleb (from 44 to 16 mm Hg in Case 1, from 40 to 15 mm Hg in Case 2, and from 25 to 12 mm Hg in Case 3). Long-term follow-up showed well controlled intraocular pressures without glaucoma medications (Case 1, 5 mm Hg after 18 months; Case 2, 17 mm Hg after one year; and Case 3, 9 mm Hg after five months).