Extruding Glaucoma Drainage Devices: Double layer repair using amniotic membrane plus scleral allograft

Abstract

Abstract: : Purpose:To describe a novel method of repair of extruding glaucoma drainage devices (GDD) using a donor scleral allograft in conjunction with amniotic memrane transplantation (AMT). Up to 10% of implanted GDD's erode through conjunctiva even when reinforced using donor sclera. Repair or removal is essential to prevent infection. It is usually possible to repair exposed devices but this involves a new scleral allograft to prevent re-exposure. Complete conjunctival closure over the allograft is essential to maintain its integrity but is often restricted by adjacent conjunctival scarring and the presence of the GDD bleb. Methods:Description of the clinical outcomes of a consecutive case series of 7 GDD erosions (6 Molteno implants, 1 Baerveldt 350 implant) presenting to one glaucoma specialist over a 3 year period. Each case was repaired using a double-layer technique of scleral allograft plus AMT. In two cases, repair was combined with resiting of the GDD via pars plana. Results:Successful repair was achieved in 7 cases (follow-up range: 6 months to 3 years). IOP control was maintained in 6 cases without medication and in one with additional topical medication. One GDD re-eroded and was successfully repaired by repeating the procedure in combination with pars plana resiting of the GDD. Conclusion:There are a limited number of options to avoid removal of an extruding GDD. AMT is a useful substitute to conjunctiva in this situation to cover the scleral allograft and prevent GDD re-exposure.

Keywords: 365 conjunctiva • 631 wound healing