ROCHESTER, N.Y., Nov. 17 -- The ophthalmologist who pioneered customized Lasik surgery ("supervision") now aims to further improve patients’ eyesight and minimize the risk of side effects. Patients should benefit from several recent discoveries, Scott MacRae, MD, told an audience of eye doctors in a keynote address at the annual meeting of the American Academy of Ophthalmology last month. MacRae, professor of Ophthalmology and Visual Science at the University of Rochester Medical Center and medical director of Strong Vision refractive surgery center, discussed three recent findings by his team that boost vision quality even further: Increasing the size of the surface of the eye being treated helps prevent a visual defect known as spherical aberration. Geunyoung Yoon, PhD., a colleague of MacRae's, has untangled how the laser can affect spherical aberration, which can cause blurry vision and sometimes results in patients seeing halos around lights at night. The researchers found that increasing the area of the "treatment zone" on the eye reduces this side effect dramatically. Precise positioning of the laser during surgery is vital to prevent a defect known as coma, which causes lights to appear fuzzy and can result in a sharp and annoying glare from lights at night. In a recent study, MacRae’s team got its best results when the tracking device used to position the laser was within 200 microns -- about three times the width of a human hair -- of the most desirable spot. Better tracking devices in recent years have helped physicians position the beam precisely. Careful manipulation of the flap of the cornea that is cut during surgery is more crucial than was previously thought to achieve the best vision possible. MacRae has found that keeping the area dry during surgery helps prevent swelling that can make it difficult for a surgeon to bring the cornea back together meticulously. Since the field is still emerging, it’s crucial for patients to choose their physician carefully, said MacRae, who has helped train nearly 1000 physicians around the country about refractive surgery and is an author of the book, Wavefront Customized Visual Correction: The Quest for Supervision II. MacRae said he turns away significant business after investing hours with a patient because he discovers that many patients -- around 20 percent -- are not good candidates for refractive surgery and might have troublesome side effects. He said he and others also use extensive, seemingly repetitive screening techniques to check traits such as the thickness of a person’s cornea, which is crucial to the surgery, as well as the characteristics of a patient’s pupil. For more information, visit: www.stronghealth.com/services/strongvision