Use of one-piece valved tube and variable surface area explant for glaucoma drainage surgery.

The results of glaucoma surgery on 37 eyes of 36 patients after the use of a one-piece valved silicone explant are described. With a follow-up of 6 to 24 months, intraocular pressures (IOPs) averaging 8.0 to 17.3 mmHg were recorded. The maximum number of eyes receiving antiglaucoma medicines at any of the follow-up visits was six. These results were compared with the authors' previous results with the two-piece tube and gutter explant (ACTSEB). It was found that lower IOPs were obtained with fewer complications from overdrainage in the immediate postoperative period. This difference was attributed to the valve reducing but not preventing overdrainage and less chance of "fibrosis" blocking the tube/plate interface.