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43 EW FEATURE January 2016 • Management of the irregular cornea 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 great- er dynamic range than previous technology and can measure –16 D to +12 D with up to 8 D of astigma- tism, Dr. Manche said. The aberrometer captures infor- mation about the eye more accu- rately, 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 includ- ing 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 pub- lished 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 equiv- alent decreased from –7.28 D to –0.09 D at 3 months after surgery. In the study, 82.4% of eyes achieved uncorrected distance visual acuity of 20/20 or better monocularly, and 92.5% achieved this binocularly. 5 Finding ideal patients In the big picture of ophthalmic surgery, it's rare to find a patient with a significantly irregular cornea, which is why Dr. Schallhorn thinks it's important to consider the use of technological advances like the aberrometer with all patients. That said, this doesn't mean everyone will qualify for surgery with use of the iDesign. "You have to make sure the patient is an otherwise good can- didate for laser treatment and that he or she will likely achieve visual gain," he said. There are patients with irregular corneas that can't take ablation technique combined with collagen crosslinking," Dr. Manche said. Dr. Schallhorn is looking forward to incorporating full corneal curvature into the wavefront profile. EW References 1. Gulani AC. Corneoplastique: art of vision surgery. Indian J Ophthalmol. 2014;62:3–11. 2. Gulani AC. Using excimer laser PRK—not PTK—for corneal scars: Straight to 20/20 vision. Advanced Ocular Care. 2012;Sept/Oct: 1–3. 3. Gulani AC. Corneoplastique. Video Journal of Ophthalmology. 2007;22(3). 4. Smadja D, et al. Safety and efficacy of wavefront-guided myopic laser in situ keratomileusis using a new wavefront sensor technology: First 100 cases. J Cataract Refract Surg. 2015;41:1588–1593. 5. Schallhorn SC, et al. Outcomes of wave- front-guided laser in situ keratomileusis using a new-generation Hartmann-Shack aberrom- eter in patients with high myopia. J Cataract Refract Surg. 2015;41:1810–1819. Editors' note: Dr. Manche has financial interests with Abbott Medical Optics. Dr. Schallhorn has financial interests with Optical Express and Abbott Medi- cal Optics. Dr. Gulani has no financial interests related to this article. Contact information Gulani: gulanivision@gulani.com Manche: Edward.manche@stanford.edu Schallhorn: scschallhorn@yahoo.com advantage of excimer laser treat- ment, he said. This may include very irregular corneas that still cannot be captured with the new aberrometer. In the U.S., the system is ap- proved to treat patients 18 and older with myopia and compound myopic astigmatism, Dr. Manche said. The system is approved to treat up to –5 D of astigmatism, an increase from the WaveScan, which was approved for –3 D. "I also use the platform for patients with myopia and compound myopic astigmatism who are undergoing photorefrac- tive keratectomy," Dr. Manche said. "We have begun using iDesign to perform LASIK and PRK retreat- ments. These are off-label uses of the technology." In the short-term future, sur- geons anticipate FDA approval for mixed astigmatism and hyperopia and compound hyperopic astigma- tism, Dr. Manche said. Keratoconus treatment? Although some patients with kera- toconus benefit from dual treatment with corneal crosslinking (CXL) and excimer laser treatment, this is not possible in the U.S. right now because CXL is not approved by the FDA. However, surgeons familiar with the iDesign platform are hope- ful that it can one day be used in the U.S. for this purpose. "Outside the U.S., the iDesign has been used to treat eyes with stable keratoconus using a surface EyeWorld Monthly Pulse EyeWorld Monthly Pulse is a reader survey on trends and patterns for the practicing ophthalmologist. Each month we send an online survey covering different topics so our readers can see how they compare to our survey. If you would like to join the hundreds of physicians who take a minute a month to share their views, please send us an email and we will add your name. Email carly@eyeworld.org and put EW Pulse in the subject line. Poll size: 155