Outcomes of sequential tube shunts in complicated glaucoma

Objective: To evaluate intraocular pressure (IOP) control, change in visual acuity, and complications in eyes that have undergone a second glaucoma tu be shunt procedure. Design: Retrospective, noncomparative case series. Participants: Twenty-two eyes of 22 patients that have undergone sequential tube implants for management of glaucoma, Methods: Parameters analyzed included IOP, visual acuity, and number of hyp otensive agent before each shunt procedure and at last follow-up visit. The overall IOP lowering effect attributable to each tube shunt was calculated . Any ocular complications after the second tube shunt were recorded. Succe ss was defined as an IOP between 6 and 21 mmHg and a 20% reduction in IOP f rom the second tube shunt procedure. Qualified successes met one of these t wo requirements at the last follow-up visit. Total failures did not meet an y of the above criteria, required additional surgical intervention to lower IOP, or both. Main Outcome Measures: Intraocular pressure control, visual acuity preserva tion, and complications. Results: At the last follow-up visit, the average percent reduction in IOP from both tube shunt procedures was 42 +/- 21%, The average percent IOP red uction from the second tube shunt was 33 +/- 17%. Eleven (50%) patients met the criteria for success, 8 (36.4%) patients were qualified successes, and 3 (13.6%) were failures. The median number of hypotensive agents decreased from two to one. Ten patients experienced new or worse pseudophakic bullou s keratopathy after the second tube shunt, six of whom underwent penetratin g keratoplasty. Thirteen (59%) patients maintained visual acuity within one line of their second tube shunt pre-operative Snellen visual acuity. Seven (32%) patients lost more than 2 lines, and one patient lost light percepti on, Conclusions: Although corneal morbidity is a common complication, a second tube shunt does not cause higher-than-expected rates of other complications associated with tube shunt surgery. Eyes that undergo a second tube shunt procedure can achieve pressure control, require fewer hypotensive agents, a nd may maintain stable visual acuity. (C) 2000 by the American Academy of O phthalmology.