Clinical experience with sulcus-implanted Baerveldt glaucoma tube shunts fully concealed behind the iris in undilated pseudophakic eyes.

PURPOSE: To describe our clinical experience with ciliary sulcus-implanted Baerveldt glaucoma tube shunts entirely concealed behind the iris in undilated pseudophakic eyes (concealed tubes, CT group), compared with similarly implanted tubes whose openings remain fully exposed in the undilated pupillary area (nonconcealed tubes, NCT group).

METHODS

A retrospective interventional nonrandomized comparative chart review. The main outcome measures were postoperative tube incarceration by the iris, and postoperative intraocular pressure (IOP) and the number of IOP-lowering medications.

RESULTS

Fifteen eyes of 15 patients were identified in the CT group and 41 eyes of 41 patients in the NCT group. In the CT and NCT groups, the postoperative follow-up period was 14.4±10.2 months (mean±SD; range, 3 to 42 mo) and 22.9±18.1 months (mean±SD; range, 3 to 72 mo; P=0.08), respectively. Only 1 case of tube incarceration by the iris has occurred in the CT group (6.7%) and none in the NCT group. This eye was treated with laser iridotomy with no recurrence. Preoperative IOPs in the CT and the NCT groups were 27.2±9.6 mm Hg (mean±SD; range, 16 to 46 mm Hg) and 25.5±10.6 mm Hg (mean±SD; range, 12 to 59 mm Hg; P=0.6), respectively. The IOPs were significantly reduced to 13.3±4.1 mm Hg (mean±SD; range, 6 to 22 mm Hg; P=0.0001) and 10.8±4.4 mm Hg (mean±SD; range, 4 to 25 mm Hg; P=0.0001), respectively, at the final visit. The difference in the final visit IOP between the groups approached significance (P=0.056). The number of preoperative IOP-lowering medications was 3.9±0.7 (mean±SD; range, 2 to 5) and 4.0±1.0 (mean±SD; range, 1 to 6), respectively. It was significantly reduced to 1.9±1.2 (mean±SD; range, 0 to 4; P=0.0001) and 1.8±1.4 (mean±SD; range, 0 to 5; P=0.0001), respectively. There was no significant difference between the groups before (P=0.6) or after surgery (P=0.8).

CONCLUSIONS

Although NCTs tend to have a lower final IOP compared with CTs, the latter are safe and effective and do not require surgical repositioning. Should a CT become occluded by the iris, an uncommon event in our study, it could be treated by laser iridotomy alone.