Intermediate-term Result of e-PTFE Membrane Implant Surgery for Refractory Glaucomas

ABSTRACT

Recently, various tube-shunt implants have been used in treating refractory glaucomas.They have large volumed reservoir portion made of hard materials.We made a new implant with soft and freely malleable membrane[expanded polytetrafluoroethylene, e-PTFE]as a reservoir portion attached to the conventional silicone tube. Based on the encouraging result from experimental animal study, we performed a clinical trial for the membrane-tube implant.We performed Glaucoma Tube-Shunt Implant surgery using double layers of e-PTFE membrane and silicone tube with its one end fixed between the two layers.The subjects had refractory glaucomas without useful vision who visited our hospital from May 1991 to Sep.1995. There were 40 eyes of 37 patients and their mean follow-up period was 32.6 months.We could control the IOP within 6~21 mms of mercury in 26 eyes[65.0%, Success].In remaining 14 eyes, we could not control the IOP or additional surgery was needed to control the IOP or treat severe complications[35.0%, Failure].The Kaplan-Meier Survival for IOP control was 78.4% at 1 yr, 71.6%at 2 yr, and 60.3%at 3 yr.The complications were similar to those of other commercially available Glaucoma implants. This new implant is made of soft, freely malleable membrane for the reservoir portion with small volume which can be inserted with smaller incision on the conjunctiva with less complication.We have obtained comparable result from this membrane-tube implant to other implants, and it may be considered as an another substitute for the treatment of refractory glaucomas.