Evaluation of early postoperative intraocular pressure for success after ex-press surgery

Aim: The aim of this study is to identify target levels of early postoperative intraocular pressure (IOP) associated with successful trabeculectomy using an Ex-Press glaucoma shunt. Materials and methods: This was a retrospective single-facility study. We enrolled 158 glaucoma patients who underwent trabeculectomy with Ex-Press and were followed for >1 year, and investigated risk factors for the failure of Ex-Press surgery. We examined age, sex, central corneal thickness (CCT), number of preoperative glaucoma medications, simultaneous performance of cataract surgery, history of trabeculotomy, hypertension (HT), diabetes mellitus (DM), subtype of glaucoma, and early postoperative IOP (minimum, 2 weeks, 1 month, and 3 months). Results: Ex-Press surgery could significantly decrease IOP. Success rates at 1, 2, 3, and 4 years were 91.1, 86.1, 82.5, and 78.1%, respectively. Factors significantly affecting the success rate included age, the number of preoperative glaucoma medications, and early postoperative IOP. The IOP cutoff values of minimum IOP for the success of Ex-Press surgery was 5 mm Hg. Conclusions: Younger age, a high number of preoperative glaucoma medications, and high IOPs in the early postoperative period were found to be the risk factors for failure of Ex-Press surgery. Considering hypotonic complications, it is desirable to control the minimum IOP from 3-5 mm Hg within 2 weeks after surgery. According to our calculations, target IOPs at 2 weeks, 1 month, and 3 months after Ex-Press surgery should be 8 mm Hg, 10 mm Hg, and 14 mm Hg, respectively. Clinical significance: We thought that Ex-Press surgery might require lower IOP in the early postoperative period than conventional trabeculectomy.