The Evolution of Glaucoma Drainage Implants.

The modern glaucoma drainage implant era was initiated with implantation of a plate posterior to the limbus connected to the anterior chamber by a long silicone tube. Non-restrictive (Molteno and Baerveldt implants) and flow-restrictive (Ahmed Glaucoma Valve) implants were developed. With increased clinical experience, variables influencing success and failure of glaucoma drainage implant surgery were better understood.