Prevalence of hypertensive phase and outcomes in patients with Ahmed valve implantation at one year of follow-up and evaluation of associated risk factors

PURPOSE: To evaluate the prevalence of hypertensive phase (HP) and failure in patients who underwent Ahmed Glaucoma Valve (AGV) implantation and identify the possible risk factors for both HP and failure. METHODS: A cross-sectional, observational study was conducted. Medical records of patients who underwent AGV implantation and had at least 1 year of follow-up were reviewed. HP was defined as an intraocular pressure (IOP) greater than 21 mmHg between the first week and the third postoperative month not attributable to other causes. Success was defined as an IOP between 6 and 21 mmHg, with preservation of light perception and no additional glaucoma surgeries. Statistical analysis was conducted to identify possible risk factors. RESULTS: A total of 193 eyes of 177 patients were included. HP was present in 58%; a higher preoperative IOP and younger age were associated with HP. Pseudophakic or aphakic eyes had a lower HP rate. Failure was present in 29%; neovascular glaucoma, worse basal best corrected visual acuity (BCVA), higher baseline IOP, and postoperative complications were linked to a higher likelihood of failure. No difference in the HP rate between the failure and success groups was found. CONCLUSION: A higher baseline IOP and younger age are associated with HP development; pseudophakia and aphakia might be protective factors. Factors for AGV failure are a worse BCVA, neovascular glaucoma, postoperative complications, and a higher baseline IOP. At 1 year, a higher number of medications were needed to achieve IOP control in the HP group.