EyeWorld Asia-Pacific September 2011 Issue

September 2011 14 EW FEATURE JCRS study renews discussion on lens preference E ver since 29 Nov. 1949, when Sir Harold Ridley, MD, FRS, first successfully implanted an IOL in a patient in a London hospital, surgeons have researched, debated, and sometimes obsessed over the best surgical lens to use. Nearly 62 years later and after many advances in the surgical technique and the lenses themselves, the discussion continues—this time over multifocal versus monofocal IOL implants for presbyopia correction. While monofocal IOLs are still considered the standard, especially in distance vision, advocates for the latest in multifocal implants say that patients’ push for spectacle independence make multifocals a more attractive choice. An exciting study led by Fuxiang Zhang, MD, in the March issue of the Journal of Cataract and Refractive Surgery (JCRS) did a head-to-head comparison of the technologies, with both continuing to show great promise. JCRS study In the study, researchers set out to compare how patients with bilateral diffractive multifocal IOLs stacked up against those who were implanted with monofocal IOL monovision. Forty-three patients received either the AcrySof ReSTOR SN60D3 multifocal IOL (Alcon, Fort Worth, Texas, USA/Hünenberg, Switzerland) or the monofocal AcrySof SN60WF IOL (Alcon) as monovision. At the 3-month mark, investigators found that the multifocal IOL group did slightly better in terms of bilateral uncorrected distance and near vision, but the difference was not statistically significant. The monovision group experienced better intermediate vision, which allowed them to use computers with significantly less difficulty than their multifocal counterparts. Monovision scored higher in terms of satisfaction, fewer complaints, and less out-of-pocket costs. The pseudophakic monovision patients achieved comparable distance and near vision, but without the risk of disturbing visual symptoms sometimes associated with multifocal IOLs. Multifocal options James A. Davison, MD, Marshalltown, Iowa, USA, said multifocal and monofocal lenses represent strategies to improve spectacle-free real world vision performance, but both come with their own set of optical compromises. Dr. Davison said he prefers multifocal lenses because they are “high-performance” devices, which provide simultaneous bilateral fine stereoscopic vision. He mostly uses ReSTOR lenses and said the latest lens would have fared better in Dr. Zhang’s JCRS article. “The problem with the article is that it used the first generation ReSTOR lens,” Dr. Davison said. “The more modern generation lens would have an expectation to overcome some of the results that were mentioned in the [JCRS] article. It has an aspheric surface, which will help with contrast sensitivity.” The great debate: Monofocal vs. multifocal by Jena Passut EyeWorld Staff Writer AT A GLANCE • Experts share preferences on two types of lenses • Monofocal patients fared slightly better in the JCRS review, while multifocals did negligibly better at distance and near • Neither lens is ideal for patients with maculopathies The newer lens is better for “quality of vision, fewer halos, less glare, and improved computer distance near performance,” he said. “Achieving a plano result is our biggest challenge because of the cumulative effect of the contributions of all the various error sources,” Dr. Davison continued. “These include measurements of axial length, keratometry, anterior chamber depth, lens thickness, and formula application and computations for each individual patient, and then having to pick between IOLs that only come in 0.5 D increments.” Dwayne K. Logan, MD, Atlantis Eyecare, Calif., USA, said he prefers the Tecnis multifocal IOL (Abbott Medical Optics, AMO, Santa Ana, Calif., USA) because, in his opinion, it offers excellent distance and near vision, as well as intermediate vision comparable to other multifocal lens options. Because the diffractive rings on the Tecnis lens extend out to the periphery of the lens, patients are able to see better in dimmer light, Dr. Logan said. “With a lot of my patients, when I am recommending these premium lenses for multifocality, I’m selling the fact that patients are going to be able to see at distance and near in all levels of light,” Dr. Logan said. Although he will use other multifocal lenses when needed, Dr. Logan said it benefits his patients for him to stick with his favorite premium lens. “I have a very high conversion rate because I’ve found what I’m selling and that’s what I sell. I’m not all over the place,” he said. There are drawbacks, however, including some dysphotopsia. “I tell patients that with this lens they’re going to lose some contrast sensitivity, but the nature of the lens is such that if we have all of our parameters corrected, the vision will be relatively comparable,” he said. “They may lose one line of vision, but the brain would not know the difference if we eliminate all of the other variables.” The multifocal lens is better for patients who want to achieve total spectacle independence, Dr. Logan said. To that end, ophthalmologists should maintain a “brilliant” relationship with the patient’s primary care physician, as well as make sure that refractive errors are corrected “in order for patients to really enjoy these lenses”. The face of an ideal multifocal patient is shifting from younger, active patients to anyone who might appreciate spectacle independence, Dr. Logan said. “I used to say that they were for patients who are still working and are young, enthusiastic, and motivated, but I have patients who are 80–90 years old and they enjoy these lenses as well,” he said. “They enjoy not having to wear glasses, and it makes them more active. They’re out and about, and it’s almost like it turns back the clock a little.”