EyeWorld Asia-Pacific September 2015 Issue

September 2015 14 EWAP FEATURE Intraoperative pearls for nailing toric IOL alignment by Lauren Lipuma EyeWorld Staff Writer AT A GLANCE • Don’t ignore the posterior corneal astigmatism. • Be consistent with surgical techniques to optimize the effective lens position. • After alignment, tap the lens to make sure it is pressed rmly against the posterior capsule. • Intraoperative aberrometry is helpful but not necessary if you’re consistent with your surgical technique. Experts share tips for hitting the axis and achieving the best refractive outcomes T oric IOLs are a great option for neutralizing astigmatism and offering patients spectacle independence after cataract surgery. Unlike other premium IOLs, toric lenses do not require the patient to have a perfect macula, so they are an attractive option for a larger group of patients. Nailing toric IOL alignment can be a challenge, with many preoperative, intraoperative, and postoperative factors affecting the final lens position and refractive outcome. But once surgeons overcome these obstacles and consistently achieve good alignment, they can offer toric IOLs to more patients than ever before. Here, three experienced surgeons discuss the most important factors that contribute to final refractive outcomes and their pearls for nailing the intraoperative alignment and preventing postop rotation. Don’t ignore the posterior cornea Accurately measuring the magnitude and axis of astigmatism preoperatively is essential for completing the toric IOL case. Ignoring the contribution of the posterior cornea to the total astigmatism can have a detrimental effect on the final refractive outcome. A study published in the January 2015 issue of the Journal of Cataract & Refractive Surgery found that surgeons tend to overcorrect with-the-rule astigmatism and undercorrect against-the-rule astigmatism when they do not factor in the posterior corneal surface. Manual keratometry only takes into account the anterior corneal surface, so mapping the topography of the anterior and posterior cornea is key. “Because of that study, I now use the total astigmatism magnitude and axis from the Galilei [Ziemer Ophthalmic Systems, Port, Switzerland] when I calculate my toric IOL powers,” said D. Rex Hamilton, MD, associate clinical professor of ophthalmology, Stein Eye Institute, and director, UCLA Laser Refractive Center, Los Angeles, the study’s principal investigator. “I feel that’s a bit more accurate.” Mark the cornea appropriately Mark Kontos, MD , in private practice, Empire Eye, Spokane, Wash., and Hayden, Idaho, marks all of his patients at 0, 90, and 180 degrees manually at the slit lamp prior to surgery and again with the Catalys femtosecond laser (Abbott Medical Optics, Abbott Park, Ill.). “I know that some people mark at the chair right before they go in, but I like to have the patient sitting at the slit lamp so I can have a good magnified view of everything,” he said. “I think it gives me the opportunity to get a finer mark.” The alignment system on the Catalys also shows whether his preoperative alignment marks line up with the marks from the laser. “By the time I go into the OR and sit down to the patient under The Verion system (Alcon) projects an overlay through the microscope, identifying the correct meridian for aligning toric IOLs. Corneal marker with level for creating toric reference marks at 3, 6, and 9 o’clock with patient sitting upright prior to surgery (ASICO, Westmont, Ill.) Source (all): D. Rex Hamilton, MD