Postoperative manipulation of the Krupin valve

Five patients were noted to have elevated intraocular pressure following implantation of the Krupin glaucoma tube-to-plate device. In each, conjunctiva was draped flat over the plate. A muscle hook was used to manipulate conjunctiva over the tube-plate junction at the site of the valve, producing immediate increased flow through the tube, reduction of intraocular pressure, and bleb formation. In all five cases, intraocular pressure has been controlled at longest follow-up. One cause of elevated intraocular pressure following implantation of the Krupin tube-to-plate device is excessive resistance at the valve site, which can be relieved by manipulation with a muscle hook.