Eyeworld

EW NEWS & OPINION 19 A lthough Intacs (Addition Technology, Des Plaines, Ill.) was originally Food and Drug Administration- approved for treating low amounts of myopia and subse- quently became more well-known for correcting keratoconus, new re- search suggests the device is promis- ing for patients with low amounts of myopia with abnormal topography. "The 4-year results indicate that ICRS [intrastromal corneal ring seg- ments (Intacs)] is effective and safe in the correction of low myopia in patients for whom excimer laser sur- gery is contraindicated because of abnormal topography, including forme fruste keratoconus," according to lead study author Jose Luis Guell, M.D., Instituto de Microcirugia Ocu- lar, Barcelona, Spain. The study was published in the July 2010 issue of the Journal of Cataract & Refractive Surgery. Dr. Guell acknowledged that In- tacs outcomes aren't always as great as LASIK results, but not everyone can have LASIK. "ICRS implantation has lower predictability and efficacy than reported in excimer laser series with the best results," Dr. Guell wrote. "In our experience, ICRS im- plantation is an effective alternative to correct low myopia in patients with topographic contraindications to excimer laser keratorefractive sur- gery." He also noted that Intacs has an advantage over refractive ablation surgery generally. "Removability, and thus reversibility, is a clear ad- vantage over refractive corneal surgi- cal procedures that permanently alter the cornea," Dr. Guell noted. The Intacs way Dr. Guell and colleagues analyzed 39 eyes of 21 patients with myopia less than –4.50 D and abnormal topogra- phy that partially or completely ex- cluded corneal ablation surgery. Examples of abnormal topographic signs included those suggestive of ir- regular astigmatism, insufficient residual stromal bed thickness, and others. Keratoconus suspect and forme fruste keratoconus patients were included in the study, although manifest keratoconus eyes were ex- cluded. "Two symmetrical segments were centered at 12 o'clock and im- planted through a superior (nasal– temporal) incision in 31 eyes (79.5%) or through an incision placed in the flattest meridian in 8 January 2011 by Matt Young EyeWorld Contributing Editor Using Intacs to treat myopia with abnormal topography Intacs in the eye Source: Addition Technology continued on page 20 at this over each time point," Dr. Pflugfelder said. "It can identify the earliest point that the tears break up and also follow the tear smoothness and stability over a 6- or 10-second period." In addition, because the TSAS system is more sensitive than fluo- rescein staining, Dr. Pflugfelder thinks that it may turn out to be valuable in determining whether someone is a candidate for refractive surgery. An added benefit of the test is that no drops in the eye are needed. Anyone coming in for a LASIK screening could easily be run through the test. "Let's say that the breakup is above a certain threshold, then it might be a red flag that you need to investigate it more and that the patient may need to be treated," he said. However, if it is under the threshold then practitioners could move forward confidently. "One thing about this test is that when it's normal, it's really normal," Dr. Pflugfelder said. Overall, Dr. Pflugfelder views the TSAS technology as very excit- ing. "I think that we're looking for useful new techniques. I see a lot of things that look like they have po- tential and probably don't, but this one does," he said. EW Editors' note: Dr. Plugfelder has no fi- nancial interests related to his com- ments. Contact information Pflugfelder: 713-798-4732, stevenp@bcm.tmc.edu Patrolling continued from P. 18

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