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Comparison of polyprolene and silicone Ahmed valve survival 2 years following implantation in the first 2 years of life
  1. Arif O Khan (aokhan{at},
  2. Faisal Al-Mobarak
  1. King Khaled Eye Specialist Hospital, Saudi Arabia
  2. King Khaled Eye Specialist Hospital, Saudi Arabia


    Aim: To compare 2-year survival rates of polyprolene and silicone Ahmed glaucoma valves (AGVs) implanted during the first 2 years of life.

    Methods: Retrospective analysis of polyprolene and silicone AGV implantation during the first 2 years of life in children with 2 years post-operative follow-up. Patients with prior aqueous drainage device implantation were excluded.

    Results: Forty-two eyes of 31 children were reviewed. Thirty-one eyes received a polyprolene AGV (6 S1, 25 S2) and 11 eyes received a silicone AGV (11 FP7). Average survival time (maintenance of intraocular pressure <= 22 mm Hg with [or without] medications and without significant complications) was significantly longer (p=0.001 by the 2-tailed t-test) for the silicone group (23.36 m, standard deviation [SD] 5.43, 95% confidence interval [CI] 20.16-24.00 m) than for the polyprolene group (19.10 m, SD 8.53, 95% CI 16.1-22.12 m). Cumulative probabilities of survival at 2 years by Kaplan-Meier analysis were 90.9% (standard error [SE] 8.7, 95% CI 70 - 100%) and 54.8% (SE 8.9, 95% CI 23 -87%), respectively (p=0.001 by the log rank test). All eyes implanted with silicone AGVs had the diagnosis of congenital glaucoma, which was independently associated with 2-year survival.

    Conclusions: Two years after surgery, silicone AGVs survived longer than polyprolene AGVs. However, all eyes that received silicone AGVs in our cohort had congenital glaucoma, which had better survival than other pediatric glaucoma diagnoses. A study of silicone AGV implantation in other pediatric glaucoma diagnoses is needed to determine whether or not silicone AGVs independently have better survival.

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