EyeWorld Asia-Pacific December 2017 Issue

Patient selection for crosslinking by Ellen Stodola EyeWorld Senior Staff Writer AT A GLANCE • Many surgeons agree crosslinking is particularly effective for younger patients because of the ability to halt progressive keratoconus early on. • Thin corneas may pose a challenge in crosslinking. Though not an absolute contraindication, these patients should be aware that the procedure may not be ideal for their condition. • Crosslinking could potentially have an impact on corneal transplantation in the future by decreasing the need for transplants because of the ability to prevent progression of keratoconus. December 2017 34 EWAP SECONDARY FEATURE Experts discuss ideal patients and factors to consider with crosslinking W ith crosslink- ing approved in the U.S. for more than a year now, more physicians are using the procedure for their patients. Sumit “Sam” Garg, MD , Gavin Herbert Eye Institute, Irvine, California, John Berdahl, MD , Vance Thompson Vision, Sioux Falls, South Dakota, and Michael Raizman, MD , Ophthalmic Consultants of Boston, discussed patient selection, ideal patients, contraindications, and other crosslinking considerations. Lessons learned from early phases of FDA approval The U.S. Food & Drug Adminis- tration (FDA) has approved the crosslinking procedure for pa- tients age 14 and older, Dr. Raiz- man said. In the clinical trials, he treated patients as young as 12 who did extremely well with the procedure. “I would recommend treating patients with progressive keratoconus even under age 14,” he said, adding that there proba- bly weren’t enough patients under age 14 for the FDA to feel com- fortable approving it for younger patients, but the worldwide experience on younger patients is excellent. “They tolerate the pro- cedure quite well,” he said. “Because the patients with progressive keratoconus at a very young age are most likely to advance to the point of needing keratoplasty, I would recommend finding a way to accomplish crosslinking as soon as possible once progression has been docu- mented,” he said. Dr. Raizman said he reserves crosslinking for progressive kera- toconus, but he added that there are some situations where kerato- conus is severe and you wouldn’t want to wait to document pro- gression. He added that crosslink- ing can be combined with PRK for certain corneas with relatively small refractive errors and Intacs (Addition Technology, Lombard, Illinois). “I have not achieved much benefit in crosslinking older patients whose keratoconus has been stable for many years,” he said. The protocol that was approved in the U.S. has been studied for years, and there’s a large database that physicians can access and use to make reasonable assumptions based on European data, Dr. Raizman said. Dr. Berdahl said that the crosslinking labeling is for progressive keratoconus, but he thinks that most young patients who have keratoconus are pro- gressive by nature. “As I’ve gotten more experience with crosslink- ing, I’m more inclined to do it right away on patients who have keratoconus,” he said. These young patients likely didn’t have an abnormal cornea when they were born, and now they have an abnormal cornea, so by definition they’re progressing. Dr. Berdahl compared keratoconus treatment to treating glaucoma. “When you do an evaluation for glaucoma, you don’t [wait until they] get worse before initiating treatment because you can’t get that vision back,” and he feels the same way about keratoconus. “You don’t want the cornea to become more misshapen.” “As physicians, our calling is to do what’s right for the patient,” Dr. Berdahl said. “The question I ask myself is what I would want for myself or my child.” He will have a straightforward discus- sion with patients about risks and benefits and come to a mutual decision. “I think this is best for a young patient who has mild keratoconus,” he said, because you’re able to freeze the cornea in position and shape before it be- comes more misshapen, and you can avoid decades of challenges, as well as a cornea transplant. Dr. Berdahl has some experi- ence in combining crosslinking with other procedures. “We have found a resurgence of using Intacs in our practice to try to normalize the shape before we freeze it in place,” he said. It can be done at the same time, but he tends to do Intacs first followed by crosslink- ing later. Dr. Berdahl added that he is looking forward to the op- tion for custom topo-guided abla- tion to normalize the shape of a cornea that’s been stiffened after crosslinking to help get a patient back to good vision corrected by glasses or contacts lenses instead of needing a specialty lens. Dr. Garg said that he is cur- rently sticking with on-label indi- cations. Ideal patients, he said, are young, with progressive keratoco- nus, no scarring, and good vision in contact lenses or glasses. Dr. Garg added that it’s im- portant that patients be able to