Shape Memory Tube Plug for Fine-control of Intraocular Pressure by Glaucoma Devices

As a standard approach to treating glaucoma, a silicone tube device is inserted into the eye to drain water and thereby lower the intraocular pressure (IOP). However, the fixed diameter of the tube often results in too much initial water drain. Suture-sheaving of the outer tube wall also leads to random IOP drops over time. In this study, self-expansion of the inner tube diameter was achieved by inserting a shape memory tube into the silicone tube. The difference in controlling small to large IOP drops before and after tube diameter expansion was demonstrated via computational modeling, a flow pumping system, and rabbit experiments.