EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/276058
76 Physician's work looks at this new technology in treating keratoconus A lthough corneal collagen crosslinking remains a much-debated topic and is awaiting FDA approval in the United States, many countries around the world have approved and are using the t echnique. A number of physicians are exploring ways that crosslinking can be combined with other tech- niques to treat conditions like keratoconus and ectasia. Simon P. Holland, MD, Pacific Laser Eye Centre, and Department of Ophthalmology, University of British Columbia, Vancouver, B.C., Canada, is exploring options in Canada, having recently published the one-year results of refractive outcomes of topography-guided photorefractive keratectomy with simultaneous crosslinking to treat keratoconus. Dr. Holland spoke about his work with David T.C. Lin, MD, Department of Ophthalmology, University of British Columbia, at the 2013 American Academy of Ophthalmology meeting. He ex- plained that although it is a contro- versial area, the goal is to present early results from these procedures. Obviously any change in shape can cause a refractive change of the cornea, Dr. Holland said, and the combination of topography-guided PRK and crosslinking aims to com- pensate for the induced astigmatism and refractive error produced by the treatment itself of the regularization of the cornea. Looking at the results He noted that this technique may be a slightly hyperopic treatment, so many patients tend to have a my- opic result. Dr. Holland discussed his work on hundreds of eyes over the last four years, specifically speaking about the results of 165 eyes that were available for analysis at 12 months or longer follow-up. Of these eyes, about 49% had 20/40 or better uncorrected vision and about 16% were at 20/25 or better. "These were all contact lens intolerant patients," he said. In about half of these patients, BCVA improved, with about a quarter improving by two lines or better. Complications included epithe- lial healing with subsequent haze, HSV keratitis and delayed healing, and two patients required penetrat- ing keratoplasty so far, Dr. Holland said. "Most of our patients are re- maining myopic through the follow- up rather than hyperopic," he said, noting that there is some regression in results. But overall the results seem to be showing satisfactory im- provement for patients' symptoms and vision with close to half of the patients with 20/40 or better vision and almost a third of the patients gaining two lines or more, Dr. Holland said. This could be a useful option for keratoconus in the future, he said, even though it is a contro- versial area of treatment. "We need to continue with the long-term follow-up to know whether we're doing the best thing for [the patients]," he said. EW REFRACTIVE SURGERY 7 6 March 2014 by Ellen Stodola EyeWorld Staff Writer Refractive outcomes of topography- guided photorefractive keratectomy with R efractive editor's corner of the world C orneal collagen crosslinking is hopefully just around the corner f or those in the United States. Crosslinking has been extremely helpful for patients with corneal dystrophies. It has also been used to treat post LASIK ectasia, as well as visual fluctuations in patients status post radial keratotomy. How about using crosslinking combined with PRK for the treatment of irregular astig- matism with keratoconus? There has been a c oncern about removing more corneal tissue in an already thin cornea. But what if the cornea was strengthened with crosslinking? Can PRK be effective in these patients? Is there a role for crosslinking combined with PRK? Thanks to Simon P. Holland, MD, for contributing to this month's "Refractive editor's corner of the world." He shares some of the work he and his colleague David T.C. Lin, MD, have been pursuing on topography- guided PRK combined with crosslinking. Kerry Solomon, MD, refractive editor Effect of limited refractive treatment on improving both uncorrected and corrected vision with topography-guided PRK and crosslinking in keratoconus Pre- and postoperative topography with difference map in extreme keratoconus Source (all): Simon P. Holland, MD 76-87 Refractive_EW March 2014-DL_Layout 1 3/6/14 3:17 PM Page 76