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Cornea surgeons are achieving amazing results with Descemet stripping endothelial keratoplasty. “DSEK has revolutionized corneal transplantation,” said Deepinder K. Dhaliwal, MD. “It’s a fantastic procedure. Patients recover functional vision quickly. And because there are very few sutures to remove, it’s almost as if they’re having routine cataract surgery.” But they’re not. And that’s what Dr. Dhaliwal and other cornea specialists want comprehensive eye doctors to know: DSEK may be getting easier all the time, so comprehensive eye care providers will be seeing more of these patients. But those providers can’t let down their guard.
“I tell patients, ‘You’ve had a corneal transplant. That is someone else’s tissue now in your eye. Your body may realize this is foreign tissue and start rejecting it,’” said Dr. Dhaliwal, who is director of the cornea service and chief of refractive surgery at UPMC in Pittsburgh.
More Patients (and Complications)
The chance that a comprehensive ophthalmologist will be providing follow-up care for DSEK has grown exponentially since the procedure was introduced around 2005. That year, according to the Eye Bank Association of America, penetrating keratoplasty accounted for nearly all—45,821 of the total 48,298—corneal grafts performed in the United States. Endothelial keratoplasty accounted for fewer than 1,500 procedures. By 2009, only 23,269 PKs were performed, compared with 18,221 EKs.
More patients, and sooner. In addition to seeing more DSEK patients, comprehensive providers may be seeing them early in their recovery period. Recently, for example, Natalie A. Afshari, MD, had a patient who, because he’d driven four hours to Duke University’s Eye Center for DSEK, wanted to see his “own doctor” for the one-week follow-up exam. “One week is early for me,” said Dr. Afshari, who is director of Duke’s cornea and refractive surgery fellowship program in Durham, N.C. She prefers to see her patients at day one, one week and one month following surgery. But she understands the burden that travel may impose on patients and agreed to consult with the patient’s doctor by phone.
This quick handover was unthinkable when patients were getting full corneal transplants. Cornea surgeons routinely followed patients for much longer than they now do post-DSEK, said Christopher J. Rapuano, MD. “The patient and doctors weren’t as comfortable referring PK patients back to the comprehensive ophthalmologist.” But DSEK patients are sent back sooner. There are far fewer sutures, none of which are in the central part of the cornea, which minimizes the risk of infection. And there’s less induced astigmatism or refractive change.
Underestimating the seriousness. Like Dr. Dhaliwal, Dr. Rapuano believes that DSEK patients, and their doctors, tend to minimize the potential for complications. “One of the problems with DSEK is that the patients almost don’t think this is a transplant because it’s much less invasive, there’s less postoperative care and the results are so good and so fast,” said Dr. Rapuano, who is chief of the cornea service at Wills Eye Hospital in Philadelphia. “So they’re not thinking of rejections.” But DSEK, he warned, can lead to both rejection and steroid-induced glaucoma.
Fear of Rejection: It Pays to Stay on Steroids
Graft rejection can occur anytime, said Dr. Rapuano. That’s why he prefers keeping his patients on some dose of steroids for several years, often forever.
Dr. Dhaliwal agreed. “I want to make my plea for keeping patients on steroids long-term,” she said. “If they’re pseudophakic and not having any issues with pressures, they should be on one drop of steroid for the rest of their life. Just because it’s a year out, the risk of rejection isn’t zero.” Typically, her patients start on prednisolone four times daily, and by year’s end they’re on one drop a day.
Dr. Afshari often starts patients on four drops a day, and after the first couple of months she starts tapering the steroids by one drop a month, but only if the graft is fully clear. “The steroids are going to be decreased very gradually in DSEK patients, much more gradually than in patients who undergo cataract surgery, but much faster compared with a full-thickness corneal transplant.” Depending on the diagnosis that led to the endothelial grafting, there will be more or less inflammation and edema. “If I see some edema, I keep the patient on steroids longer,” Dr. Afshari said. For steroid responders, she tapers much faster.
But if steroids aren’t causing pressure rises or cataract, Dr. Rapuano leaves patients on a low to medium potency steroid, such as loteprednol etabonate, 0.5 percent, or prednisolone acetate, 0.125 percent, once a day or every other day.
Most ophthalmologists are not used to managing a steroid regimen without an end in sight, Dr. Dhaliwal said. Dr. Rapuano agreed. “Many of the comprehensive ophthalmologists don’t understand. They stop the steroids. Sometimes that’s okay. Oftentimes, it’s not,” he said, explaining that most of the rejection cases he’s treated involved patients who stopped taking the steroids.
Dr. Dhaliwal added that the alert ophthalmologist can catch rejection early and can halt the rejection episode. If the patient has new keratic precipitates, topical steroid drops should be started immediately and hourly.
Dr. Rapuano noted that the appointment desk needs to be attuned to the possibility of rejection in these patients. It’s not something they’ve seen much of in the past. If a patient who has had DSEK calls complaining of new redness, new pain, new photophobia or newly decreased vision, they need to be seen within 24 hours.
Tips on Follow-Up Care
There’s no hard-and-fast rule that a patient can’t be followed closer to home by his or her regular ophthalmologist. “If the graft is well-secured, these patients are pretty stable,” Dr. Dhaliwal said. “They don’t want to go back and forth. And they don’t need to. It’s reasonable for a comprehensive ophthalmologist to follow these patients, as long as they follow them closely and do a few extra things beyond the routine eye exam.” Here are those extras:
- Use the slit lamp. Dr. Afshari advised looking by slit lamp to ensure that the graft is fully attached. DSEK grafts are vulnerable to dislocations, especially in the first week because the donor tissue is held in place with an air bubble instead of sutures. It’s like wallpaper, she said. “Are the wall and wallpaper one, or is there a little space between the wall and paper?”
Signs of rejection after DSEK look different than rejection after PK, Dr. Dhaliwal said, specifying that after DSEK, rejection typically manifests as scattered keratic precipitates instead of an endothelial rejection line, and there may be edema or conjunctival hyperemia. She noted that one study found that a third of patients who exhibited rejection after DSEK were asymptomic. 1 “That’s why it’s important to do a careful slit-lamp exam.”
- Check IOP at every visit to monitor for steroid-induced pressure spikes. In a retrospective study of 51 DSEK patients, Dr. Rapuano found that of 29 patients without glaucoma prior to surgery, 21 percent developed pressures high enough at some point to warrant antihypertensive drops. And those with glaucoma prior to surgery had a 40 to 50 percent chance of needing additional pressure management.2 “The bottom line is that these patients can and do get glaucoma after surgery. It may be temporary or long-term, but it needs to be managed.”
If patients have a response to the steroids that are given to prevent rejection, Dr. Dhaliwal switches them to loteprednol etabonate 0.5 percent (Lotemax) and adds timolol (Timoptic), if the pressure warrants it.
- Check the refraction at every visit after the first month, but do a thorough refraction when it’s time to prescribe glasses. Typically, the refraction occurs when the cornea is compact, anywhere from one to three months after surgery. Dr. Rapuano noted that a worsening of refractive error is almost a nonissue with DSEK patients.
- Check the central corneal thickness. A graft that is getting thicker over time may be failing, and a graft that gets thicker suddenly signals rejection, said Dr. Dhaliwal. Dr. Rapuano, however, finds CCT less helpful than other aspects. “I tend to pay more attention to graft clarity, edema, keratic precipitates and an anterior chamber reaction,” he said. “As the central graft becomes more compact over time after DSEK, I think these clinical slit-lamp findings are more useful.”
- Watch for detachments. If the graft is detached, it will need to be reattached by adding more air bubbles in the anterior chamber. And it may need to be recentered with a rolling instrument. The procedure may be performed using the slit lamp or in a minor operating room. Dr. Dhaliwal said that ideally the DSEK surgeon would perform the rebubble.
Both Drs. Afshari and Dhaliwal agreed that detachment is not an emergency. “We don’t want to wait a long time to fix a detached DSEK graft, but keep in mind that patients who show up detached at one month may have been detached for a week or two. Since the graft has been in aqueous fluid, it often works beautifully after reattachment,” Dr. Afshari said.
1 Jordan, C. S. et al. Br J Ophthalmol 2009;93:387–390.
2 Rapuano, C. J. Postoperative Glaucoma Progression After Descemet-Stripping Automated Endothelial Keratoplasty Surgery. Poster P275 presented at ASCRS, 2010, in Boston.