Abstract Details
| Presented By: | Bishop, Corey |
| Affiliated with: | University of Utah, Bioengineering |
| Authors: | CJ Bishop, H Sant, RM Burr, S Molokhia, BK Ambati |
| From: | University of Utah |
Title
Abstract
Introduction: Treatment of age macular degeneration requires monthly intravitreal injections, which are costly and have serious risks. The objective of this study was to develop a novel intraocular implant for drug delivery. The capsule drug ring is inserted at the time of cataract surgery. The device is a refillable reservoir, and capable of delivering multiple drugs in a sustained manner. The capsule drug ring consists of a shell, semi-permeable membrane for controlled drug elution, and two silicone membrane check valves for refilling. The valves will allow access for refilling the drug-reservoir at 6-months/1-year intervals with a 27 gauge non-coring needle. The valve is a 1 mm in diameter polyimide tube filled with a Versa-lasered silicone plug which re-seals after each insertion. We report the valve rupture pressure findings to date. Methods: Five volts were applied across a pressure transducer which was attached to the refilling port under a water liquid bath. A 27 gauge non-coring needle was inserted into the port. Subsequently, the pressure of the system was increased until air exuded from the port. The voltage differential was compared to ambient pressure. Results: Six ports were tested. The mean ± standard error of mean is shown below. The first mean which was below 40 mm Hg was at insertion 30. Conclusion: With each insertion, the maximum sustainable pressure decreases. The device must maintain a pressure > 40 mm Hg. If the device were refilled every 6 months/1 year then the utility for one capsule drug ring would be 15 to 30 years, which would be a dramatic improvement over short-term intraocular drug delivery devices.
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