Glaucoma drainage devices: a review of the past, present, and future

Abstract

Glaucoma drainage devices are more frequently being used for glaucoma filtering surgeries, even those at low risk for failure with trabeculectomy. There are 4 major devices available: the Molteno, Baerveldt, Krupin, and Ahmed. The Molteno and Baerveldt are non-valved implants, while the Krupin and Ahmed are valved. The success rates of the different valves are about equal at approximately 70% with a mean intraocular pressure (IOP) lowering of at least 50% from the pre-operative IOP. Unfortunately, the failure rate is about 10% per year, leading to only 50% functional drainage devices at 5 years. Therefore, research on the biomaterials, shape, and technique of drainage implant surgery is being done in hopes of increasing long term success rates.