Initial Results of the Paul Ahmed Comparison (PAC) Study in Refractory Childhood Glaucoma

Abstract

Purpose: To compare the effectiveness and safety of the Paul glaucoma implant (PGI) to the Ahmed glaucoma valve (AGV) in managing refractory childhood glaucoma.

Design: Randomized controlled trial.

Setting: Two clinical centers.

Methods: An ongoing randomized controlled trial including patients ≤ 18 years with refractory childhood glaucoma in whom glaucoma drainage implant surgery was planned. Patients were randomized to receive either PGI or AGV. The primary outcome was the intraocular pressure (IOP) reduction. Secondary outcomes included glaucoma medication reduction, success rate, and complications rate. The success rate was defined as achieving a postoperative IOP between 6-21 mmHg without or with glaucoma medications (up to three topical glaucoma medications), without the need for additional glaucoma surgeries, and without the occurrence of vision-threatening complications or evidence of disease progression. The use of oral glaucoma medications, such as acetazolamide, was considered a failure.

Results: The current report included 44 patients (44 eyes) who completed the one-year postoperative follow-up (25 in the PGI group versus 19 in the AGV group). The mean age at the time of surgery was 96.9 ± 59.1 months (90.5 ± 60.04 months in the PGI group and 105.4 ± 58.5 months in the AGV group). Preoperatively, the mean IOP was 32.6 ± 6.1 mmHg with a mean of 3.6 ± 0.6 glaucoma medications in the PGI group, compared with 29.8 ± 6.1 mmHg (P = .1) with a mean of 3.4 ± 0.7 glaucoma medications (P = .35) in the AGV group. At one year, there were no statistically significant differences in the mean IOP (14.9 ± 4.1 mmHg in the PGI group versus 15.5 ± 3.5 in the AGV group, P = .6) and number of glaucoma medications (1.1 ± 1 in the PGI group versus 1.6 ± 1.03 in the AGV group, P = .1). The success rate of PGI was 80% versus 73.6% in the AGV (P = .2). The postoperative complications rate was comparable in both groups (three eyes in each group).

Conclusion/relevance: At one year postoperatively, the IOP reduction, reduction of glaucoma medications, success rates, and rate of complications were comparable between both groups.