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Abstract #10820 Published in IGR 6-2
Postoperative pressure regulation in glaucoma shunt surgery: focal tube constriction is not the answer
Rietveld E; van der Veen AJJournal of Glaucoma 2004; 13: 216-20
PURPOSE: To evaluate, in a laboratory setting, the accuracy and the clinical use of focal tube constriction as a means to regulate intraocular pressure after glaucoma drainage implant surgery. MATERIALS AND METHODS: A silicone tube identical to the one used in the Baerveldt and other glaucoma drainage implants was connected to a syringe-pump delivering a continuous flow of demineralized water at a rate of 2.5 microliters per minute. Focal constriction of the tube was obtained by a ring made of a shape-memory metal alloy designed for this purpose. After complete occlusion of the tube lumen by crimping the ring with calibrated pliers, the ring was opened in a stepwise manner by heating it with an argon laser beam. In a second experiment the tube lumen was constricted by placing the tube between the jaws of a micrometer. RESULTS: In both experiments a stepwise lowering of the pressure could be obtained. The resulting pressure levels, however, lacked consistency and predictability to such an extent that clinical application is not feasible. CONCLUSION: It is not possible to regulate pressure in a reliable and predictable way merely by constricting the tube lumen of glaucoma drainage implants.
Department of Ophthalmology, VU University Medical Center, Amsterdam, The Netherlands. e.rietveld@vumc.edu.
Classification:
12.8.2 With tube implant or other drainage devices (Part of: 12 Surgical treatment > 12.8 Filtering surgery)
