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

Effects of Digital Ocular Massage in Patients in a Hypertensive Phase after Ahmed Glaucoma Valve Implantation

PURPOSE: To evaluate the course of the hypertensive phase (HP) after Ahmed glaucoma valve (AGV) implantation and the effects of digital ocular massage. METHODS: A total of 131 eyes of 131 patients, who underwent AGV implantation surgery, were studied retrospectively. HP was defined as an IOP (intraocular pressure) > or = 22 mm Hg within 6 months after surgery. Various clinical factors related to the occurrence of HP were analyzed. The HP group was compared to the non-HP group. Ocular massage was performed in patients showing acute elevation of IOP at a relatively early postoperative period, and the effects were compared with the non-massage group. The patients who received ocular massage were divided, based on its effects, and compared. RESULTS: HP developed in 62.6% of the patients after AGV surgery, and the success rate was significantly lower in the HP group. HP occurred more often in males and in patients with high IOP before surgery. HP developed in 82 eyes at 3.3 weeks after surgery in average. Ocular massage was performed in 30 eyes that showed acute IOP increase. The amount of IOP reduction, compared to 1 month after surgery, was greater in massage group than no massage group from 2 months to 3 years after surgery. Successful IOP control by ocular massage was observed in 14 eyes (46.7%), and the success rate was higher in these patients than the patients who showed no significant IOP reduction by ocular massage. But, the difference was not significant (p = 0.072). CONCLUSIONS: HP is related to the final outcome of surgery. Digital ocular massage can be used as an effective method to control HP and prevent further glaucomatous damage.

Ahmed Valve Implantation for Refractory Glaucoma following Pars Plana Vitrectomy

PURPOSE: To evaluate the effectiveness of Ahmed valve implantation for refractory glaucoma following pars plana vitrectomy. METHODS: Seventeen eyes of 15 patients suffering from secondary glaucoma following pars plana vitrectomy underwent Ahmed valve implantation. All the eyes were in critical condition, and intraocular pressure could not be controlled with anti-glaucoma medications. Success was characterized by an intraocular pressure less than 22 mmHg and greater than 6 mmHg, regardless of anti-glaucoma medication usage. RESULTS: The total success rate was 83.4% at 6 months and 76.4% at the final visit. The reduction in intraocular pressure and the number of medications used postoperatively were both statistically and clinically significant (p< 0.005). Postoperative complications included: transiently increased intraocular pressure, transient hyphema, early postoperative hypotony, choroidal detachment, malposition of the valve tip, and phthisis bulbus. CONCLUSIONS: Ahmed valve implantation is a safe and effective method for refractory glaucoma following vitrectomy.

The Effectiveness of Surface Area Extension with Pericardial Membrane in Ahmed Glaucoma Valve Implant Surgery

PURPOSE: To assess the effect of surface area extension with pericardial membrane on the hypertensive phase and surgical success in Ahmed glaucoma valve implant surgery. METHODS: This prospective study included 10 eyes of 8 patients who underwent Ahmed glaucoma valve implant surgery with pericardial membrane(Preclude(R)) which were designed to have surface area of 300 mm2 (Group I) and 10 eyes of 9 patients who underwent Ahmed glaucoma valve implant surgery without surface area extension (Group II). The mean follow-up was 11.5+/-5.1 months and 14.9+/-4.3 months for the group I and group II, respectively. RESULTS: Two eyes (20%) exhibited hypertensive phase in group I and 8 eyes (80%) in group II (p=0.007). The complete success rate was 90% in group I and 70% in group II (p=0.291). The mean number of preoperative antiglaucoma medication was 2.4+/-0.5 and 1.9+/-0.3 for the group I and group II, respectively, and the mean number of postoperative antiglaucoma medication was 0.1+/-0.3 and 0.4+/-0.7 for the group I and group II, respectively. CONCLUSIONS: Surface area extension with pericardial membrane (Preclude(R)) in Ahmed glaucoma valve implant surgery affords statistically significantly lower hypertensive phase rate and trends toward high complete success rate and less number of postoperative antiglaucoma medications.