Treatment Outcomes in the Ahmed Baerveldt Comparison Study after 1 Year of Follow-up

Abstract

Purpose To determine the relative efficacy and complications of the Ahmed FP7 Glaucoma Valve (AGV) and the Baerveldt 101–350 Glaucoma Implant (BGI) in refractory glaucoma. Design Multicenter randomized controlled clinical trial. Participants 276 patients, including 143 in the AGV group and 133 in the BGI group. Methods Patients aged 18–85 years with refractory glaucoma with intraocular pressure (IOP) greater than or equal to 18 mm Hg in whom an aqueous shunt was planned were randomized to undergo implantation of either an AGV or a BGI. Main Outcome Measures Primary outcome was failure, defined as IOP > 21 mm Hg or not reduced by 20%, IOP ≤ 5 mm Hg, reoperation for glaucoma or removal of implant, or loss of light perception vision. Secondary outcomes included mean IOP, visual acuity, use of supplemental medical therapy, and complications. Results Preoperative IOP (mean ± standard deviation, SD) was 31.2 ± 11.2 in the AGV group and 31.8 ± 12.5 in the BGI group (p = 0.71). At 1 year, IOP was 15.4 ± 5.5 mm Hg in the AGV group and 13.2 ± 6.8 mm Hg in the BGI group (p = 0.007). The number of glaucoma medications (mean ± SD) was 1.8 ± 1.3 in the AGV group and 1.5 ± 1.4 in the BGI group (p = 0.071). The cumulative probability of failure was 16.4% (standard error, SE = 3.1%) in the AGV group and 14.0% (SE = 3.1%) in the BGI group at 1 year (p = 0.52). More patients experienced early postoperative complications in the BGI group (n = 77, 58%) compared to the AGV group (n = 61, 43%, p = 0.016). Serious postoperative complications associated with reoperation and/or vision loss of ≥ 2 Snellen lines occurred in 29 patients (20%) in the AGV group and 45 patients (34%) in the BGI group (p = 0.014). Conclusions Although the average IOP after one year was slightly higher in patients who received an AGV, there were fewer early and serious postoperative complications associated with the use of the AGV than the BGI.

A Review of the Ahmed Glaucoma Valve Implant and Comparison with Other Surgical Operations

“…The existing evidence seems to suggest that AGV might have a more favorable safety profile when compared to nonvalved GDIs [20,51,52,54,55,60,61,64]. On the other hand, non-valved GDIs seem to achieve lower pressures than the AGV [54,55,[57][58][59][62][63][64]. AGV is a useful surgical choice and represents a reasonable compromise between efficacy and potential surgery-related complications.…”

“…In the AGV group, IOP was reduced from 31.2 ± 11.2 mmHg at baseline to 15.4 ± 5.5 and 14.3 ± 4.7 mmHg at 1-year and 3-year follow-up, respectively [57,58]. In the Baerveldt group, IOP was reduced from 31.8 ± 12.5 mmHg at baseline to 13.2 ± 6.8 and 13.1 ± 4.5 mmHg at 1-year and 3-year follow-up, respectively [57,58]. At 5 years, after censoring for patients who underwent additional surgery or loss of light perception, IOP was reduced from 29.6 ± 10.1 at baseline to 14.7 ± 4.4 mmHg in the AGV group and from 28.3 ± 9.3 at baseline to 12.7 ± 4.5 mmHg in the Baerveldt group [59].…”

“…Forty-two percent of patients had previously undergone trabeculectomy, while 20% of patients had no incisional surgery at enrollment. Results of the study were reported at 1, 3 and 5 years [57][58][59]. In the AGV group, IOP was reduced from 31.2 ± 11.2 mmHg at baseline to 15.4 ± 5.5 and 14.3 ± 4.7 mmHg at 1-year and 3-year follow-up, respectively [57,58].…”

“…Results of the study were reported at 1, 3 and 5 years [57][58][59]. In the AGV group, IOP was reduced from 31.2 ± 11.2 mmHg at baseline to 15.4 ± 5.5 and 14.3 ± 4.7 mmHg at 1-year and 3-year follow-up, respectively [57,58]. In the Baerveldt group, IOP was reduced from 31.8 ± 12.5 mmHg at baseline to 13.2 ± 6.8 and 13.1 ± 4.5 mmHg at 1-year and 3-year follow-up, respectively [57,58].…”

Intraoperative testing of opening and closing pressure predicts risk of low intraocular pressure after Ahmed glaucoma valve implantation

“…2,3 In vitro studies have shown a high variability of the opening and closing pressures needed to activate or deactivate the AGV, which may explain cases of hypotony after AGV implantation. 4 The present study aimed to assess whether intraoperative measurement of the opening and closing pressure can be used to identify individual valves with an increased risk of over-or underfiltration.…”