Reconstruction of a nonfunctional trabeculectomy bleb using an amniotic membrane-wrapped silicone sponge to treat refractory glaucoma

Background This study was conducted to verify the usefulness of nonfunctional trabeculectomy bleb reconstruction using a silicone sponge wrapped with amniotic membrane. Its purpose was to allow aqueous humor to flow from the flap to the posterior orbital space. Methods Seven consecutive patients who had undergone two or more surgeries in one eye for refractory glaucoma followed by our operation were included in this study. Conjunctival adhesion to the sclera was detached with a limbus-based conjunctival incision, followed by reopening the former trabeculectomy flap. A 1.5 × 12 mm silicone sponge used for retinal detachment surgery was wrapped three to four times with amniotic membrane, placed longitudinally on the sclera, and fixed with 10–0 nylon sutures. The anterior end of the amniotic membrane was fixed underneath the scleral flap with sutures, and the conjunctival wound was closed. We periodically checked the intraocular pressure (IOP) and for complications. Follow-up periods ranged from 15 to 30 months (average 19.4 months). Surgical success was defined as a final IOP of ≤ 21 mmHg with or without additional treatment. We defined failure as an IOP of > 21 mmHg on the second of two consecutive visits after the first 4 weeks, or the need for additional glaucoma surgery. Results Surgery was successful in five of the seven eyes, although bleb needling was performed in two eyes and amniotic membrane patch covering for early aqueous leakage was needed in one eye. In four of the five successful eyes, IOP was well controlled for longer than the period between the previous and present surgeries. One of the unsuccessful eyes, with neovascular glaucoma, had high IOP with hyphema followed by phthisis of the eyeball. The other, with aqueous leakage via the conjunctival wound, required trabeculectomy in a different area. There were no other complications. Conclusions Reconstruction of the nonfunctional trabeculectomy bleb using a silicone sponge wrapped with amniotic membrane can be a useful strategy for treating refractory glaucoma.