| 摘要 |
A technique and device for relieving intraocular pressure within the eye with a reduced risk of inflammation that may be caused by the retrograde flow of fluid and inflammatory debris back into the eye after a glaucoma surgical procedure has been performed. A unidirectional drainage device is implanted to drain fluids away from the eye. The device allows fluid flow away from the eye with a minimal pressure gradient (5 mm Hg. or less), and includes means to prevent retrograde flow. At the time of implantation, the drainage passageway is initially restricted or closed by a flow restrictor at a point downstream from the minimal pressure gradient unidirectional valve. Between the unidirectional valve and flow restrictor is a drainage trap in which debris is receivable without restricting the operativeness of the unidirectional valve. After sufficient scarring and fibrosis has occurred to prevent excessive drainage that might cause hypotony, the flow restrictor is removed to allow the free flow of fluid away from the eye, with inflammatory debris being prevented from reentering the eye. In a second embodiment, the flow restrictor is located at the distal end of the receptor tube of the device within the eye, and acts to prevent the influx of fluids into the device from the eye during the initial period after implantation. Upon removal of the flow restrictor, the free flow of fluids away from the eye is allowed while retrograde flow back into the eye is prevented by the unidirectional valve. |
