EyeWorld Asia-Pacific December 2012 Issue

36 December 2012 EWAP REFRACTIVE Which unexpected snags should be high on the radar? M ention the use of the femtosecond laser in conjunction with LASIK and many immediately think of the enhanced safety compared to the use of the mechanical microkeratome. While the bulk of literature supports this, that’s not to say that the femtosecond doesn’t have its own unique set of complications that may rarely occur, according to George O. Waring IV, MD , director of refractive surgery, Storm Eye Institute, assistant professor of ophthalmology, Medical University of South Carolina, Charleston, SC, USA, and director, Magill Vision Center, Charleston, SC, USA. From suction loss to haze, practitioners may find themselves unexpectedly mired in femtosecond hitches. Considering suction breaks Spurred by a paucity of literature on the relative complications with the femtosecond laser, Dr. Waring took a closer look at what happens when there is a suction break in one of these cases. “We wanted to get a sense of if a patient had a suction break and a recut, did it affect the outcome?” he said. In this retrospective study published in the January issue of the Journal ring were reapplied, with the same sized cut.” One slight difference was the pocket setting would be turned off. If the suction break occurred during the sidecut phase then the diameter would be decreased by 0.2 mm. Attention would go to initiating the new sidecut. “There were some stromal irregularities observed after the flap lift, but these were outside of the visual axis and would be reduced after you apply the excimer laser,” Dr. Waring said. Loss of suction in the cases studied didn’t seem to appreciably affect outcomes. “We found that 97% of eyes that had suction loss were 20/20 [6/6] or better,” Dr. Waring said. “One hundred Femtosecond flaps in the ditch by Maxine Lipner Senior EyeWorld Contributing Writer percent of eyes had corrected distance acuity of 20/20 or better or were within 0.5 D of plano.” Practitioners were encouraged by the results. “It allowed us to realize that patients do fine even if you need to recut,” Dr. Waring said. One of the potential factors that may have led to suction breaks in many of these cases, he thinks, was that despite the fact that the anatomy of the largely Asian population in Tokyo is not the same as elsewhere, only one sized suction ring is available with the IntraLase (Abbott Medical Optics, Santa Ana, Calif., USA). “This Asian population tends to have flatter keratometric readings To avoid haze such as this, it is recommended that practitioners limit femtosecond flap thickness to between 100 and 120 microns. Source: Sonia H. Yoo, MD of Refractive Surgery , investigators considered all patients who had experienced a suction loss over the last 2 years at Japan’s high-volume Shinagawa LASIK Center in Tokyo. Out of 232,000 femtosecond LASIK procedures performed here from 2006-2008, investigators found that there was suction loss during flap creation in just 71 eyes. Two main techniques were used depending upon when this occurred. “If it occurred during the raster cut and [there was] a suction break, we would examine and make sure that there were no defects in the suction ring,” Dr. Waring said. “In these cases, the same cone, the same patient interface and the same suction