Impending extrusion of Ex-PRESS shunt treated by shunt-position adjustment: a case report

Background: To report a case of impending extrusion of Ex-PRESS shunt treated by shunt-position adjustment.

Case presentation: A 56-year-old Asian woman presented with impending extrusion and malposition of Ex-PRESS shunt in her left eye. The bleb of the left eye was shallow and diffuse. In the past, the patient was treated by Ex-PRESS shunt implantation under the scleral flap in both eyes. There had been no Ex-PRESS shunt-related complication in her right eye, and she reported no history of left-eye trauma. Based on these findings, we hypothesized that the source of the left-eye problem was a loosely fixed Ex-PRESS shunt spur. It was thought, furthermore, that this inadequate scleral resistance during the Ex-PRESS shunt implantation was due to the low scleral rigidity resulting from high myopia and insufficient maintenance of the anterior chamber. We proceeded to make an incision in the area adjacent to the Ex-PRESS shunt using a super sharp blade. The shunt was then pushed into the anterior chamber with forceps, and the spur was fixed firmly. Pushing the shunt to the anterior chamber was found to have been sufficient to fix it firmly. In fact, when the sclera was palpated with a sponge, aqueous outflow was observed with no shunt displacement. Postoperative intraocular pressure (IOP) was managed well, and the bleb had formed with diffuse, prominent shapes. The Ex-PRESS shunt was well sustained with good positioning.

Conclusions: When an Ex-PRESS shunt operation is performed on a patient who shows a tendency for low scleral rigidity, shunt implantation should be accomplished carefully and with force adequate for firm spur fixation.