Amniotic membrane transplantation for repair of leaking glaucoma filtering blebs.
To compare the safety and efficacy of human preserved amniotic membrane transplant with conjunctival advancement for repair of late-onset glaucoma filtering bleb leaks.
                A prospective, randomized clinical trial compared amniotic membrane transplant with conjunctival advancement in patients with leaking glaucoma filtering blebs. Intraocular pressure, number of glaucoma medications, and reoperation for glaucoma or persistent or recurrent bleb-leak were compared in the two groups. Patients were followed for a minimum of 1 year.
                Mean intraocular pressure was the same at 6 (amniotic membrane transplant, 15.4 +/- 4.4, conjunctival advancement 14.1 +/- 6.4, P = 0.6), 12 (amniotic membrane transplant, 15.0 +/- 6.3, conjunctival advancement, 13.2 +/- 6.6, P = 0.5), and 24 (amniotic membrane transplant, 17.2 +/- 7.1, conjunctival advancement, 15.0 +/- 6.3, P = 0.6) months. The mean number of glaucoma medications in use was the same in the two groups at all time intervals. After an average follow-up of 19 months, there were seven failures in the amniotic membrane transplant group (two with persistent leaks that were unresponsive to further suturing, two with late-onset leaks, and three who required repeat glaucoma surgery) and none in the conjunctival advancement group. The cumulative survival rate for amniotic membrane transplant was 81% at 6 months, 74% at 1 year, and 46% at 2 years. The cumulative survival rate was 100% for conjunctival advancement throughout follow-up.
                Amniotic membrane transplantation does not offer an effective alternative to conjunctival advancement for repair of leaking glaucoma filtering blebs.
Although a variety of treatments have been proposed for bleb leaks, there is no evidence of their comparative effectiveness.
The evidence in this review was provided by a single trial that compared two surgical procedures (conjunctival advancement and amniotic membrane transplant). The trial did show a superiority of conjunctival advancement, which was regarded as standard treatment, to amniotic membrane transplantation. There is a need for more randomised trials to validate the findings of this single trial and provide more information on the different types of interventions, especially non-surgical treatments compared to surgical procedures. We recommend that any intervention should be compared to a standard procedure, which is to date conjunctival advancement.