Surgical Outcomes of a Human Umbilical Cord Allograft Over the Ahmed Glaucoma Valve Plate for Refractory Glaucoma

Objectives: To report the surgical outcomes of sterile dehydrated human umbilical cord allograft over the Ahmed glaucoma valve (AGV) plate for refractory glaucoma. Methods: Thirty-four eyes of 34 patients with refractory glaucoma who underwent AGV with umbilical cord allograft (AmnioPlast THICKTM; Life Cell International Private Limited, Mumbai, India) placed over the AGV plate between September 2021 and 2022 at a tertiary eye care centre were included (group1) and compared with 30 eyes of 30 patients undergoing AGV without amnioblasts (group 2). The intraocular pressure (IOP) at day one, one month, six months, and final IOP; the necessity for medications; or additional surgeries for IOP control were extracted from the hospital database. Success was defined as achieving an IOP below 22 mm Hg with or without glaucoma medications. IOP spikes after surgery were identified as a rise in pressure beyond 22 mm Hg at any point beyond six weeks post-surgery following an initial reduction of pressure exceeding 30% from the baseline pre-surgical IOP. Results: A notable reduction in intraocular pressure (37 +/- 7.9 mm Hg preoperative versus 14 +/- 3.7 mm Hg at the final follow-up and 28 +/- 3.6 mm Hg versus 18 +/- 6.7 mm Hg in group 1 and 2, respectively) was observed in all eyes, with successful outcomes observed in 23 out of 34 eyes (67%). Ten eyes experienced a pressure spike, occurring at a median time of 12 months (range: 6-18 months), predominantly beyond six months post-surgery in group 1, while group 2 had similar pressure spikes in 21 of 30 eyes at a median time of two months (range: 1-5 months). No eyes necessitated supplementary glaucoma procedures, concluding with a final IOP of 14 +/- 3.7 mm Hg at 1.9 +/- 0.8 years. Vision loss occurred in only one of the 11 eyes that failed owing to non-glaucoma-related causes in group 1. Conclusions: The human umbilical cord allograft plate over the AGV plate may help in postponing the onset of intraocular pressure spikes beyond traditionally defined timelines. This helps in reducing and delaying the hypertensive phase occurring due to fibrosis.