Eyeworld

71 EW FEATURE September 2017 • Update on crosslinking because these patients may not be progressing any longer. He stressed that while some of these concerns may make him less likely to perform crosslinking on a patient, none are an absolute contraindication. Impact of crosslinking on corneal transplantation Dr. Garg hopes there will no longer be a need for transplants for kerato- conus in the next 10–20 years. Dr. Raizman said he sees less need for transplants. "I think we're going to be doing far fewer corneal transplants for keratoconus because we're going to be preventing the progression to that stage," he said. Additionally, he added that when penetrating keratoplasty (PK) is done for keratoconus, it's not unusual for the host cornea to continue to steep- en over time, altering the refractive error of the eye. Dr. Berdahl thinks that cross- linking will decrease the need for deep anterior lamellar keratoplasty (DALK) and full thickness corneal transplants in the future. "If we can eliminate full thickness corneal transplants, that would be ideal," he said, noting that it's unlikely that the need for these transplants will be completely eliminated because they may still be required for corneal scars and traumatic damage. "The only concern I have is I think full thickness corneal transplantation is at risk of becoming a lost art," Dr. Berdahl said, adding that these cases are some of the most complicated. He is doing less than half the full thickness corneal transplants he was 5 years ago, which means that there are fewer cases for fellows to learn from. EW Editors' note: Dr. Raizman and Dr. Berdahl have financial interests with Avedro (Waltham, Massachusetts). Dr. Garg has no financial interests related to his comments. Contact information Berdahl: john.berdahl@vancethompsonvision.com Garg: gargs@uci.edu Raizman: mbraizman@eyeboston.com Dr. Berdahl has some experience in combining crosslinking with oth- er procedures. "We have found a re- surgence of using Intacs in our prac- tice 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 crosslinking later. Dr. Berdahl added that he is looking forward to the option for custom topo-guided ablation 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 currently sticking with on-label indications. Ideal patients, he said, are young, with progressive keratoconus, no scarring, and good vision in contact lenses or glasses. Dr. Garg added that it's important that patients be able to follow instructions and stay still during the procedure. He agreed that patient selection could expand as more surgeons in the U.S. gain experience with crosslinking. "I think there are many exciting applications for this tech- nology," he said. "I hope that it will gain an indication for keratitis." Contraindicated conditions and patient types "At this point we have not been able to do any patients who require IV sedation/general anesthesia," Dr. Garg said. "Certainly this is a group that will greatly benefit from the procedure. I'm hoping that as the procedure becomes shorter/more ef- ficient, we will be able to treat these patients in the operating room with adequate anesthesia support." There have been a few reported cases of endothelial decompensa- tion with irreversible corneal edema when treating patients whose cor- neas are too thin, Dr. Raizman said, noting that he has treated patients with corneas as thin as 350 microns. In those cases, he was able to swell the cornea prior to UV light treat- ment, but patients with thin corneas should be warned in advance that their corneas may not swell enough for treatment, he said. Dr. Berdahl said that crosslink- ing is a safe procedure, and risks are low. The risk of infection after removing the epithelium is the main concern, he said, noting that he doesn't see any strong contra- indications. If the patient has a history of herpetic eye disease, it's a little riskier. Additionally, a patient with a very thin cornea could pose a challenge. Dr. Berdahl said if a patient is older, the benefits may not outweigh the risks of the procedure Patient undergoing epithelium-off corneal collagen crosslinking Source: Sumit "Sam" Garg, MD

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