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EW NEWS & OPINION 18 February 2016 3 with a spike to IOP of 27, which quickly resolved. That eye, like this one, ended up 20/20 with IOP of 13 on no topical medication. I have now seen 2 other cases of recurrent microhyphema early in the postoperative course due to reflux of blood through the stent that appears to be associated with sleeping on that side. Although this has not been reported yet in association with iStent placement, a similar phenomenon seen after Trabectome (NeoMedix, Tustin, Calif.) surgery has been. Ahuja 1 reported 12 cases of delayed onset symptomatic hyphema after Trabectome surgery and noted that, "The most common charac- teristic was maintaining a sleep position on the surgical side." Since this case I have been care- ful to ask patients to avoid sleeping on the side with the stent and if possible to discontinue aspirin and sleep with the head slightly elevat- ed. When these hyphemas do occur, I am confident that they will resolve and can be managed medically. EW Reference 1. Ahuja Y, et al. Delayed-onset symptomatic hyphema after ab interno trabeculotomy sur- gery. Am J Ophthalmol. 2012 Sep;154(3):476– 480.e2. Contact information Brown: reaymary@comcast.net Liang: Eva.Liang@c4slv.com McKee: mckeeonline@mac.com Myers: jmyers@willseye.org Safran: safran12@comcast.net CHF that leads to jugular venous distention upon lying down? Does she frequently engage in a heavy Valsalva maneuver (constipation, weight lifting, etc.)? Perhaps she spends time on an inverted back stretcher device? In this case I would certainly prefer to manage the patient's condition medically (as has been already described by your other colleagues) while avoiding any activity that may increase jugular venous distention. If the situation worsens or cannot be controlled medically, either argon laser near the stent or removal of the device could be considered." What was done When I came in on Saturday to see this patient I was initially in favor of removing the stent because I had a crying patient in front of me, with significantly elevated IOP and blurred vision, and it appeared that it was being caused by the stent. I knew I had a window of opportu- nity to fix this and after that I was going away on a trip. I was going to bring her to the OR on Monday, which happens to be my regular surgery day, and remove the stent. This is what both the patient and I were initially most in favor of doing. However, after discussing the case with colleagues who reassured me, I decided to first try a medical approach, with a trip to the OR as a backup plan. After examining the surgical video and the patient, I had come to the conclusion that the stent was in Schlemm's canal and that the blood was most likely due to reflux through the stent. It turns out that she sleeps on that side at night and was waking up every morning with the hyphema. I asked her to sleep with her head—and particularly this side—elevated. She was also on aspirin, which I had her discon- tinue. I switched her from bimato- prost to brimonidine/timolol as it seemed to me that when I added the bimatoprost her bleeding became worse and her IOP increased. I saw her the next day and her IOP had come down significantly to the low 20s, with significant clearing of the blood in the anterior chamber, which improved my view of the stent on gonioscopy. Her vision had returned to 20/20. When I checked her Monday morning, her IOP had dropped into the teens so the back- up plan to take her to surgery was scrubbed. Figure 2 shows the way her stent looked at that time. The rest of her postoperative course was uneventful, and she was ultimately able to discontinue all topical medications. IOP in this eye has remained at an average of 13 for 1 year. In retrospect, I think that the problem in this case was due to nocturnal reflux of blood through the stent exacerbated by sleeping on that side. I examined her eye very carefully, and the blood did appear to be coming from the lumen of the stent itself, but this was difficult to be sure of because the bleeding had stopped each time by the time I saw her. There was no evidence of iris contact with the stent or any abnor- mal vessels in the angle found to be bleeding. I'm not sure what role the bimatoprost played here, but things seemed to worsen when I started that and improve when I discontin- ued it. So when I did her second eye a month later, I had her off the aspi- rin, sleeping with her head elevated, and did not use bimatoprost. She did extremely well with 1 small mi- crohyphema on awakening on day and anti-viral medication. I would expect more corneal edema and inflammation if this were the case. "The second possibility is that there was an unusually large reflux of blood at the time of iStent place- ment. This could have lead to a clot in the angle that is now dissolving and causing suspended RBCs and el- evated IOP. In this case the situation should self-resolve shortly and can be managed medically until then. In the video of the iStent placement there was no visible blood reflux, so this scenario is unlikely. It certainly appears that the stent was placed properly across trabecular meshwork and into Schlemm's canal. Improp- er placement of an iStent into the ciliary body can lead to bleeding, iritis, and elevated IOP, but I do not believe that to be the case here. "The third probability is that there has been delayed reflux from the iStent, causing high IOP. This is a reasonable theory since the gonio- scopic pictures show a fair amount of blood in Schlemm's canal. While it is common to see RBCs in the anterior chamber immediately after the iStent placement and even for 1–2 days after surgery, I have not personally seen a layering hyphema with elevated IOP after an iStent placement. I have seen 2 cases of a new microhyphema on day 3 or 4, but this only caused a little blurred vision without elevated IOP. The cause of 1 microhyphema was a Valsalva maneuver during a bowel movement, and the other was of indeterminate cause. Presuming that the problem here is reflux of RBCs via the iStent, the cause of elevated venous back pressure would be of interest. Does this patient have an occult diagnosis of a low-flow C-C fistula? Is there a varix or hemangio- ma in the orbit? Does she have early iStumped continued from page 17 Watch a video of this surgery on EyeWorld Clinical rePlay now! clinical.ewreplay.org EyeWorld Blog Focusing on Refractive • Advances in technology • Refractive advice • Surgical techniques • Ask a question • Post a comment • Recommend a topic Visit: Blog.EyeWorld.org

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