Anatomic and histopathologic findings following a failed ahmed glaucoma valve device.

Ahmed glaucoma valve implant (AGV) is one of the more commonly used implants in difficult glaucomas. The histology of a functioning bleb following AGV implantation and its anatomic relationship to the optic nerve when placed in the superionasal quadrant has been described. We report the histology of a failed bleb and the anatomic relationship between the optic nerve and the AGV end-plate when placed 9 mm from the limbus in a patient with neovascular glaucoma.