Eyeworld

EW FEATURE 101 diamond blade and sets the blade based on the thickness of the tissue. "We take all of our measure- ments—the astigmatism, the loca- tion, the amount, as well as the corneal tissue—very carefully, and we labor over the exact location of these incisions," Dr. Nichamin said. Specifically, the incisions are not actually in the limbus; they're just inside of it, still in the periph- eral clear corneal, he said. The main points he teaches are careful positioning, careful place- ment, and careful measurement such that one obtains accurate depth incisions with a high-quality diamond. "If all of that is adhered to, the results of LRIs are excellent," he said. The LRI is a technique that any good surgeon can master, Dr. Holland said. One of his tips in- cludes setting the diamond blade to 550 microns. He also recommended getting one of the available nomo- grams because the length of incision and whether a surgeon uses one or two incisions is based on the age of the patient, the axis of astigmatism, and the magnitude of astigmatism. There are plenty of nomograms available that a surgeon could use to guide him or her, Dr. Holland said. According to Mark Packer, M.D., clinical associate professor of ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, his results using the ORange Aberrometer (WaveTec Vision Systems, Aliso Viejo, Calif.) to measure and enhance his relaxing incisions as needed are similar to re- sults with the toric intraocular lens up to about 2.5 D of corneal astig- matism. Beyond that, he said, it be- comes difficult to achieve the full effect a surgeon may want with a re- laxing incision. Contraindications As with many procedures, there are patients for whom performing an LRI is not advisable. These include patients with limbal peripheral corneal pathology, extreme dry eye, particularly associated with rheuma- toid disease, and those who have had radial keratotomy and astig- matic keratotomy, Dr. Nichamin said. For the later two, additional surgery becomes dangerous and in that situation, he would prefer using a toric IOL. In addition, Dr. Holland said he would not recommend LRIs in pa- tients with asymmetric astigmatism, for instance, mild inferior steepen- ing that might be seen in forme fruste keratoconus. In such a case, Dr. Holland said, "I don't think it's a choice, I'd much prefer a toric lens to an LRI." EW Editors' note: Drs. Holland and Nichamin have no financial interests related to their comments. Dr. Packer has a financial interest in WaveTec Vision Systems. Contact information Holland: 859-331-9000, eholland@holvision.com Nichamin: 814-849-8344, nichamin@laureleye.com Packer: 541-687-2110, mpacker@finemd.com March 2011 COMBINED SURGERY 088-104 Feature_EW March 2011-DL_Layout 1 2/27/11 5:39 PM Page 101

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