Ahmed glaucoma valve implant for refractory glaucoma in children: A systematic review and meta-analysis

The aim of this study was to evaluate the efficacy and safety of the Ahmed glaucoma valve in pediatric patients with refractory glaucoma.

A comprehensive literature search was conducted across multiple major databases, including PubMed, Embase, the Cochrane Library of Systematic Reviews, Science Direct, China's National Knowledge Infrastructure, and the Wanfang database. We retrieved studies published before December 2022 that met the inclusion criteria, including clinical controlled trials (randomized controlled trials) and clinical noncontrolled trials (non-randomized controlled trials) on the use of Ahmed glaucoma valve in pediatric patients with refractory glaucoma. We performed a meta-analysis and systematic review. The efficacy measures included intraocular pressure, number of anti-glaucoma medications, visual acuity, and success rate. The safety measures were complications. Statistical analysis was performed using RevMan 5.0 software.

We identified 46 eligible studies: Compared with geographic location and study type, the Ahmed glaucoma valve showed a decrease in postoperative intraocular pressure and number of anti-glaucoma medications compared to preoperative levels in children with refractory glaucoma (P < 0.001). Compared with etiological, the Ahmed glaucoma valve showed a decrease in intraocular pressure after surgery compared to preoperative levels in children with refractory glaucoma (SMD: 14.57, 95% CI: 14.05-15.08, P < 0.00 1), and a decrease in postoperative number of anti-glaucoma medications compared to preoperative number of anti-glaucoma medications (SMD: 1.45, 95% CI: 1.37-1.54, P < 0.001). Compared with trabeculectomy revision surgery, there was no significant difference in the complete success rate between the two groups (SMD: 0.86, 95% CI: 0.52-1.39; P = 0.37).Overall, the postoperative intraocular pressure at the time of Ahmed glaucoma valve implantation was lower than that at the time of trabeculectomy revision surgery (SMD: 1.01, 95% CI: 0.71-1.31, I²= 99%, P < 0.001). Subgroup analyses based on whether mitomycin C was use d or not. There was a statistically significant difference in intraocular pressure between Ahmed's glaucoma valve surgery and preoperative (SMD: 14.13, 95% CI: 13.47-14.80, P = 0.007). Comparison of cumulative complete success rates of Ahmed S2, S3, and Ahmed FP7, FP8 in Ahmed glaucoma valve surgery (SMD: 0.74, 95% CI: 0.38-1.45, I²= 85%, P = 0.38). There is no statistical difference between the two groups. Choroidal effusion and anterior chamber hemorrhage are the two most common adverse events after Ahmed's glaucoma valve surgery.

The Ahmed glaucoma valve implantation has some effectiveness in reducing intraocular pressure in children with refractory glaucoma, but there are still many complications. Valve model may not be the key factor affecting the postoperative effectiveness and adverse reactions of refractory glaucoma in children.