Eyeworld

64 by Michelle Dalton EyeWorld Contributing Writer Phaco and corneal comorbidities September 2014 Survey shows members vary in managing astigmatism and postop residual refraction Survey respondents show little uniformity in their techniques V isually signifi cant astigma- tism is routinely treated in the cataract population, but how to treat it varies widely among surgeons, especially for patients with under 1.0 D of astigmatism. According to the 2014 ASCRS Clinical Survey results, toric IOLs are by far the treatment of choice for patients with 1.25 D or more of astigmatism. But for patients with lesser degrees of astigmatism, treatment preferences included doing nothing (22.9%), treating with a toric IOL (5.9%), treating with on-axis incisions (42.1%), or even treating with glass- es or contact lenses (7.1%) (Table 1). Edward J. Holland, MD, pro- fessor of ophthalmology, University of Cincinnati, Ohio, and director of cornea, Cincinnati Eye Institute, said the results were somewhat surprising, especially that almost 30% of respondents felt no correc- tion or spectacles/glasses would be appropriate. "Certainly with 0.75 D of uncorrected astigmatism, the patient is going to need spectacle correc- tion for distance. I'm surprised that more respondents wouldn't want to address that much astigmatism," he said. Residual astigmatism is "the single most common rate-limiting factor in patient satisfaction in patients seeking spectacle indepen- dence following cataract surgery," said Eric D. Donnenfeld, MD, partner at Ophthalmic Consultants of Long Island, Rockville Centre, N.Y., and clinical professor of oph- thalmology at New York University Medical School, New York. "I was surprised to fi nd 30% of respondents felt 0.75 D was acceptable." If patients wear spectacles, that amount of astigmatism "would be unacceptable." Where the astigmatism lies may be one reason for the varied respons- es, Dr. Holland suggested. "If it's oblique or with-the-rule, it's harder to treat astigmatism with an on-axis incision," he said. "Most surgeons don't like to operate superiorly. But if the astigmatism is against-the-rule, an on-axis incision is easier." Dr. Holland said more surgeons are managing astigmatism today than 5 years ago, when even 0.75 D was considered insignifi cant. Treating residual astigmatism is "an evaluation of risk and reward. As our technologies improve and become safer and more effective, our willingness to treat lower and lower levels of residual astigmatism will become more likely and common- place," Dr. Donnenfeld said. "Today, the conventional wisdom is that 0.50 D of cylinder is acceptable. I would predict that this number will decrease in the coming years, and today I routinely offer treatment of 0.50 D of cylinder with a proper informed consent. About half of my patients take me up on this offer," and the remainder are content with their current level of vision, he said. Correcting residual cylinder Dr. Holland said treating residual cylinder has been a challenge for many surgeons. "There are nu- merous surgeons who do not feel like they have the tools to manage residually refractive error," so it was not a surprise that 18.4% of respon- dents manage residual cylinder with spectacles (Figure 1). "If this question was asked of refractive cataract surgeons only, I 2014 ASCRS Clinical Survey think you'd see it as 100% either laser vision correction or limbal relaxing incisions or AK," he said. Managing postoperative residual astigmatism "is even more import- ant with presbyopia-correcting IOLs for 2 reasons," Dr. Donnenfeld said. "In eyes with multifocal IOLs, astigmatism will degrade quality of vision dramatically more signifi cant- ly than in a patient with a mono- focal IOL, and patient expectations are generally higher when they have paid for a refractive solution to their glasses." He was "surprised that 18.4% of responders would offer a patient with a presbyopic IOL and 'signifi - cant astigmatism' glasses or contact lenses. I doubt that these patients would fi nd the solution acceptable." Dr. Holland agreed, saying people who have paid out-of-pocket for these premium lenses are not go- ing to be pleased that "they've paid money for spectacle freedom and then have to wear glasses." Refractive cataract surgery requires the "willingness and ability to treat residual refractive error," Dr. Donnenfeld said. "For the novice re- fractive cataract surgeon, this means the need to become skilled at exci- mer laser vision correction with PRK and/or LASIK, as well as incisional astigmatic surgery." Another option is to partner with a colleague that has the refractive surgical skill. Dr. Holland said he hopes future improvements in biometry will allow surgeons to better hit their refractive targets and reduce the need for postop correction. EW Editors' note: Drs. Donnenfeld and Holland have no fi nancial interests related to their comments. Contact information Donnenfeld: ericdonnenfeld@gmail.com Holland: eholland@holprovision.com Figure 1. If a presbyopia-correcting IOL patient has a visually signifi cant amount of residual cylinder postoperatively, how are you most likely to correct it? 0.75 D 1.25 D 2.0 D 3.0 D On-axis incision 42.1% 12.0% 0.9% 0.5% Manual LRI or AK 13.2% 17.1% 3.5% 1.1% Femtosecond laser LRI or AK 7.9% 8.3% 1.6% 1.1% Toric IOL 5.9% 53.9% 89.7% 91.6% Post laser vision correction 0.9% 1.6% 2.7% 3.6% Glasses or contact lenses 7.1% 5.3% 1.5% 1.8% No special correction needed 22.9% 1.9% 0.1% 0.2% Table 1. What is your most common procedure to manage astigmatism in a cataract patient with the following levels of cylinder? Global Trends in Ophthalmology ™ Copyright © 2014 Global Trends in Ophthalmology and the American Society of Cataract & Refractive Surgery. All rights reserved.

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