EyeWorld India March 2016 Issue

19 March 2016 EWAP Feature S/p herpes, deep and excavated corneal scar corrected with VISX laser in PRK mode Source: Arun C. Gulani, MD Eyeing more precise treatment for irregular corneas by Vanessa Caceres EyeWorld Contributing Writer iDesign targets more accurate image capture for better outcomes P atients with irregular corneas may be a relatively small group, but their treatment during refractive surgery can be challenging. One key to better treatment is getting the best measurements possible before excimer laser use. “Any technology that helps surgeons detect or measure each level of refractive aberration will make their treatment outcome that much more superior,” said Arun C. Gulani, MD , Jacksonville, Fla. One new technical advance assisting surgeons in the treatment of irregular corneas is the iDesign Advanced WaveScan aberrometer (Abbott Medical Optics, Abbott Park, Ill.), which was approved by the U.S. Food and Drug AT A GLANCE • An improved aberrometer that can benefit refractive treatment for irregular corneas was approved by the FDA in May 2015. • Advantages of this aberrometer include more precise image capture, greater resolution, and more personalized treatment. • Many patients could benefit from use of the aberrometer during refractive surgery, but the patient must first be a candidate for excimer laser treatment. Not all patients with irregular corneas fit into this category. • The new aberrometer is used outside the U.S. in keratoconus patients but cannot be used in the U.S. for this purpose. Administration (FDA) in May 2015. The iDesign has a number of advantages that make the technology particularly useful for irregular corneas. 1–3 “The iDesign has significantly greater resolution—about 5 times— compared to the WaveScan [Abbott Medical Optics],” said Edward E. Manche, MD , professor of ophthalmology, Stanford University School of Medicine, and director of cornea and refractive surgery, Stanford Eye Laser Center, Stanford, Calif. “The increased resolution leads to improved spot quality of the Hartmann–Shack raw data with less spot crossover effect. The increased resolution allows for more precise imaging of normal as well as highly aberrated eyes and more precise measurement of higher-order aberrations.” The iDesign also has a greater dynamic range than previous technology and can measure –16 D to +12 D with up to 8 D of astigmatism, Dr. Manche said. The aberrometer captures information about the eye more accurately, said Steven C. Schallhorn, MD , San Diego. That more accurate capture ultimately leads to better refractive outcomes. Use of a stronger aberrometer does not help only with irregular corneas, Dr. Gulani said. He thinks that use of an effective excimer laser along with a trusted aberrometer will ultimately lead to better results in virgin eyes, complex eyes including irregular corneas, and eyes with complications from laser surgery. As aberrometer technology becomes more sophisticated, it gives surgeons a better plan for patient treatment. “It’s going from cookie-cutter LASIK or refractive surgery to picking the abnormality of the vision system of each patient and approaching it with a customized plan toward designing vision with their individual goals,” Dr. Gulani said. Refractive outcomes with the technology have been favorable so far, Dr. Manche said. A study published in August 2015 that involved use of the iDesign reported that a monocular uncorrected distance visual acuity of 20/16, 20/20, and 20/25 was reached in 76.6%, 94.4%, and 96.6% of eyes, respectively. 4 That study included 100 eyes of 50 consecutively treated patients. A study led by Dr. Schallhorn that included 621 eyes found that the mean manifest spherical equivalent decreased from –7.28 continued on page 20