EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
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EW REFRACTIVE SURGERY 28 December 2014 by Maxine Lipner EyeWorld Senior Contributing Writer This is something even a colleague of his who frequently recommends multifocal lenses for patients keeps in mind, he said. Before suggesting a multifocal lens, this practitioner asks patients how often they use their windshield wipers on a clear day. Those who do this frequently do not receive the multifocal lenses. "Truly that says it all," Dr. Greenbaum said. Another advantage is that the usual method of measuring the eye for monovision requires no added expense, he said. "We are doing the same contact biometry that we're used to doing," he said. Meanwhile, multifocal lenses have a separate billing code for additional measure- ments at greater cost to Medicare, and patients must fork out more for the lenses. "For multifocal lenses, the taxpayers are paying a little extra, and patients are laying out $5,000 extra for a technique that may not be as good as one for which they don't have to pay anything extra," he said. With monovision lenses, Dr. Greenbaum said, there have been no reports of patients having tolerance issues with glare and halos or loss of contrast sensitivity. He finds that there is also an excitement after the monovision procedure that engen- ders good will. "Every time I put in a monovision correction, the 'wow' effect of the patient being the only one at the senior center seeing so well generates referrals," he said. "That to me is more important than the $5,000." dominant or the non-dominant eye in question. He asked the patient to keep both eyes open and to hold one arm extended to make an OK sign with the pointer and thumb fingers, while also spotting a distant object. Then he had the patient close one eye at a time to determine which could still see the object. "We were all lucky that in this case it was the non-dominant eye that was –2.75," Dr. Greenbaum said. He urged the patient to wait and see how he felt after he had the cataract removed in the other eye before considering lens replacement. "Sure enough, once I gave him good uncorrected vision in his dominant eye, he wasn't complaining about his non-dominant eye, and he had a bonus in that he didn't need reading glasses anymore," Dr. Greenbaum said, adding that this success gave him the confidence to try monovi- sion on other patients. "That was in the early 90s, and to this day I haven't seen anyone who asked for monovision who wasn't mostly or completely satisfied with it," he said. Other advantages The technique has several bene- fits, he said. "One big advantage is that the vision through monofocal lenses is the best vision," he said. "Multifocal lenses are by definition a compromise." There is a reduction of contrast that unfortunately comes with the benefit of having a multifocal correction, Dr. Greenbaum explained. in just a 25% elimination of spec- tacles with this combination, Dr. Greenbaum said. However, his own published results from 2002, which were not included in this new paper, showed a 91% rate of spectacle indepen- dence with monovision, he said. "That was superior to their results," he said. While his own results ulti- mately appeared in a letter to the editor in Ophthalmology in July 2014, their superiority was not acknowl- edged, Dr. Greenbaum said. "That gave me the idea that what's called monovision by people who don't do it is not really monovision," he said. Instead the comparison is being made to more of a mini-monovision with less disparity between the eyes. Full correction embraced The hesitancy for many to opt for full monovision is the erroneous be- lief that patients will not tolerate the disparity between –2.75 correction and Plano in the other, he thinks. Dr. Greenbaum's own experience taught him otherwise. "I was very lucky early in my career when I had a patient referred to me by an administrator at Manhattan Eye and Ear," he said. The patient was unhappy because his eye remained nearsighted, with a –2.75 D correction. "The patient was ready to sue the surgeon and the hospital, and [he] was sent to me to see what I could do," Dr. Greenbaum said. Using a simple sighting tech- nique, Dr. Greenbaum proceeded to determine whether it was the Opening eyes to the procedure A cataract patient comes in asking to be spectacle in- dependent. While many practitioners immediately reach for multifocal lens- es, there is another highly effective, much less costly option, according to Scott Greenbaum, MD, Greenbaum Eye Associates, and clinical assistant professor of ophthalmology, New York University Medical Center, New York. The answer is monovision, he is convinced. The full monovision option, in which the dominant eye is com- pletely corrected for distance and the near eye for reading at –2.75 D, is something Dr. Greenbaum has chosen for much of his career. In fact, in a paper conducted by the Moorfields IOL Study Group com- paring multifocal lenses to mono- vision, Dr. Greenbaum was credited with being the first to publish on this technique back in 2002. In the Moorfield's paper, published in the December 2013 issue of Ophthalmology, investiga- tors found that the rate of spectacle independence with multifocal lenses was 71% in a group of 200 patients, Dr. Greenbaum said. "That included 6 patients who were brought back to the OR to have one or both of their lenses removed," he said. Meanwhile in their monovision group, they aimed for –1.25 D in the near eye, resulting Making sure monovision gets more than a wink To determine the dominant eye, the patient should make a circle with the pointer finger and thumb and extend the arm. After spotting a distant object through the circle, each eye should be closed one at a time to determine which one the object can still be viewed through. Source: Scott Greenbaum, MD