Evaluation of Ex-PRESS mini glaucoma shunt implantation in refractory postpenetrating keratoplasty glaucoma.

Purpose: To evaluate the intraocular pressure (IOP) control and graft survival after Ex-PRESS mini glaucoma shunt implantation in refractory postpenetrating keratoplasty glaucoma.
Methods: The study included postpenetrating keratoplasty glaucoma cases unresponsive to medical antiglaucomatous therapy in whom 15 Ex-PRESS mini glaucoma shunt implantation was carried out. All glaucoma shunt implantations were performed in a separate session after penetrating keratoplasty. Nine operations were performed under general anesthesia and 6 were performed under local anesthesia. Topical antibiotherapy and topical corticosteroids were used during the postoperative first month.
Results: Mean age of the study population was 37.4 years (range: 10 to 80 y). IOP decreased from 41.46 mm Hg (range: 26 to 80 mm Hg) to 12.06 mm Hg (range: 8 to 25 mm Hg) over a mean follow-up of 12.2 months (range: 8 to 19 mo) (P<0.001; Wilcoxon signed rank test). IOP was below 21 mm Hg in 14 of 15 eyes (93.3%) with or without antiglaucomatous drugs. Complete success (IOP<21 mm Hg without medication) rate was 86.6%. Average number of antiglaucomatous drug usage decreased from 3.20 (range: 2 to 4) preoperatively to 0.26 postoperatively (range: 0 to 3) (P<0.001; Wilcoxon signed rank test). In 93.3% of the cases, the decrease in IOP was 30% or above postoperatively. After Ex-PRESS implantation, clear grafts remained clear while edematous grafts became clearer due to IOP decrease. Neither biomicroscopy nor pachymetry showed worsening of preoperatively opaque grafts.
Conclusion: Ex-PRESS mini glaucoma shunt implantation may be an effective procedure for refractory postpenetrating keratoplasty glaucoma with acceptable graft failure rates in short term.