Polypropylene vs silicone Ahmed valve with adjunctive mitomycin C in paediatric age group: a prospective controlled study

Abstract

Purpose To compare the results of silicone and polypropylene Ahmed glaucoma valves (AGV) implanted during the first 10 years of life. Methods A prospective study was performed on 50 eyes of 33 patients with paediatric glaucoma. Eyes were matched to either polypropylene or silicone AGV. In eyes with bilateral glaucoma, one eye was implanted with polypropylene and the other eye was implanted with silicone AGV. Results Fifty eyes of 33 children were reviewed. Twenty five eyes received a polypropylene valve, and 25 eyes received a silicone valve. Eyes implanted with silicone valves achieved a significantly lower intraocular pressure (IOP) compared with the polypropylene group at 6 months, 1 year, and 2 years postoperatively. The average survival time was significantly longer (P ¼ 0.001 by the log-rank test) for the silicone group than for the polypropylene group and the cumulative probability of survival by the log-rank test at the end of the second year was 80% (SE: 8.0, 95% confidence interval (CI): 64-96%) in the silicone group and 56% (SE: 9.8, 95% CI: 40-90%) in the polypropylene group. The difference in the number of postoperative interventions and complications between both groups was statistically insignificant. Conclusion Silicone AGVs can achieve better IOP control, and longer survival with less antiglaucoma drops compared with polypropylene valves in children younger than 10 years.

Valved Glaucoma Drainage Devices in Pediatric Glaucoma

“…In contrast, previous studies in adult eyes comparing silicone and polypropylene GDDs suggested similar, if not better, success rates with silicone GDDs. [14][15][16][17] To our knowledge, comparisons between AGVs in pediatric patients are limited to 2 studies, which showed better survival with silicone valves. 16,17 Although silicone GDDs were implanted at an earlier age than polypropylene GDDs, age was not a risk factor in the silicone GDD subgroup.…”

Vitrectomy combined with posterior-segment Ahmed valve implant: A case series study

“…The Ahmed valve and other GDDs have also been proved valid and effective options in the management of pediatric glaucoma, both with AC and posterior segment placement of the tube 44, 45, 46, 47, 48, 49, 50, 51, 52. We are aware that data extrapolation from our two cases of PC8 model implantation is not possible.…”

A Modified Tube Ligation Method during Ahmed Valve Implant Surgery

“…Apart from the differences in the ligation methods, the slightly higher incidence of hypotony in our study may be related to differences in the material properties of the AGV (S2 model in previous studies and FP7 here) because the silicone plate tended to have more postoperative hypotony (statistically insignificant). [15][16][17] However, it seems that partial ligation methods can reduce hypotony-related complications. In this and previous reports using partial ligation in AGV surgery, hypotony-related complications did not require surgical interventions.…”