Eyeworld

EW FEATURE 84 World Cornea Congress highlights September 2015 AT A GLANCE • A collagen substitute offers promise for use as a patch graft or temporary keratoprosthesis for wounded warriors and others. The future includes use as a permanent cornea transplant substitute. • Use of a scleral contact lens can promote epithelial healing. • New understanding of neuropathic pain can lead to treatment. by Maxine Lipner EyeWorld Senior Contributing Writer in the process of applying for an FDA human trial for an artificial cornea device. Using scleral contact lenses Injuries are of course not limited to soldiers. One healing approach now being tried on those with compro- mised ocular surfaces is the use of a scleral contact lens dubbed PROSE (prosthetic replacement of the ocu- lar surface ecosystem, Boston Foun- dation for Sight, Needham, Mass.). The lens includes saline solution and creates a liquid bandage over the cornea, explained Anisa I. Gire, OD, instructor of medicine, Johns Hopkins University, Baltimore. "We use it a lot in patients where the cor- nea has been damaged, like if they have an epithelial defect that hasn't healed for a long time," she said. "We have patients where the defect could be there for a month and we put the lens on overnight." Some- times this goes away in a couple of days. In addition to bathing the cornea, the lens can serve as pro- tection from any sort of blinking interaction. "This acts like a barrier between the eyelid, the eyelashes, and the cornea," she said. Dr. Gire finds this can bene- fit patients with dry eyes from a wide variety of conditions—those with graft-versus-host disease, Stevens-Johnson syndrome, rheuma- toid patients, as well as those with Dr. Thomas, who has deployed as an ophthalmologist, recom- mends having products such as glycerin-preserved corneas, amniotic membrane, and fibrin sealants, as well as other types of glue. Collagen substitute One item that she would have liked to have had was a collagen substi- tute. This is something she later began working on with several uni- versities. "We were looking at bio- synthetic substitutes to use as patch grafts for deployment purposes," she said. The idea was to figure out if there was something that could be glued onto the eye to temporarily close it, while others fought to save the patient's life. "While deployed, I learned the importance of stabilization of the eye during polytrauma," Dr. Thomas said. Spurring efforts on biosynthetic collagen was a state-wide encounter with a patient referred to as John Doe, who suffered a bilateral blast injury. The Navy surgeon in Afghan- istan at the time did an amazing job closing both of his globes, and he was returned to WRNMMC, where he was under the care of Dr. Thomas. While it had been determined that John Doe had no light perception, Dr. Thomas and others believed he had better visual potential. After a retina specialist successfully flattened his retinal detachments, John Doe had a per- manent keratoprosthesis at another center and regained 20/200 vision. He can now navigate around his house on his own and returned to his job. The problem with kerato- prostheses is that they form ret- roprosthetic membranes, among other complications, Dr. Thomas explained. The other eye now has light perception. Doctors continue to tackle what to do about patients like John Doe. "The risk of rejection in the first 6 to 12 months after injury is almost 100%," Dr. Thomas said. The hope for wounded patients like John Doe was to develop a biosynthetic cor- nea, which would not be rejected, had no infectious potential, and did not require expensive eye banking. Her artificial cornea team built on the work of May Griffith, PhD, and Per Fagerholm, MD, who were working with collagen substitutes. Under a grant from the U.S. Army Medical Research & Materiel Com- mand, the military has experiment- ed with collagen substitutes that were first from the tobacco plant, then yeast cells, and now a mesh- work of proprietary substance. The hope is to get this FDA approved. Dr. Thomas said that the biosyn- thetic material is clearer than the human cornea, and she thinks that it does not bring with it the risk of rejection. Investigators are currently Corneal tissue engineering, physiology, and wound healing Monthly Pulse World Cornea Congress highlights T his Monthly Pulse survey was based on "Highlights from World Cornea Congress VII." We asked, "If you saw a patient with corneal stromal opacities interested in laser refractive surgery, what would you most likely do?" The majority of respondents to the survey said, "Advise to avoid any laser refractive surgery." If a 65-year-old female patient with a history of herpes zoster ophthalmicus asks whether she should get the Shingles vaccine, what would you recommend? More than half of the respondents to this survey would advise her to get the vac- cine. In a 40-year-old female patient who complains of eye pain and light sensitivity after LASIK but has a completely normal eye exam, a large majority of respondents to the survey would recommend dry eye and blepharitis treatments. Finally, we presented this scenario: A 28-year-old male patient with keratoconus has become contact lens intolerant. Which treatment would you most likely recommend for him? The majority of respondents said corneal collagen crosslinking; intrastromal ring segment with corneal collagen crosslinking was the second most popular answer. Advances in healing dynamics I njuries are an unfortunate part of war, and the eye is no exception. Eye injuries in the last decade of conflicts are more common than they were in previous wars, according to Navy Commander Karin E. Thomas, MD, corneal specialist, Walter Reed National Military Medical Center (WRNMMC), and assistant professor, Uniformed Services University of the Health Sciences, Bethesda, Md. The military countered by developing and enforcing the use of stringent eye protection, which has signifi- cantly lowered the number of eye injuries in the U.S. military popula- tion. If you saw a patient with corneal stromal opacities interested in laser refractive surgery, what would you most likely do? Advise to avoid any laser refractive surgery Recommend LASIK Recommend PRK Recommend genetic testing

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