EyeWorld India March 2017 Issue

53 EWAP DEVICES March 2017 Views from Asia-Pacific ZHAO Yun-e, MD Vice Director of Eye Hospital, Director of Cataract and Refractive Surgery Department Eye Hospital (Hangzhou), School of Ophthalmology & Optometry, Wenzhou Medical University Jianggan area, Fenggi East Road 618#, Hangzhou, Zhejiang, China Tel. no. +86-571-86795918 Fax no. +86-571-86795926 1599054793@qq.com T raditional multifocal lenses, whether of diffractive or refractive design, are actually bifocal, providing patients far and near vision after undergoing cataract surgery. Although we have implanted multifocal lenses in numerous patients over 10 years, it is not uncommon having patients complaining of bad intermediate vision. They complain of difficulty of reading the words on a computer and drawing pictures; occasionally, patients have even complained that they couldn’t see rice clearly when having a meal. So we developed the mix-match technique of +2 D and +3 D multifocal lenses and the mini- monovision technique to improve intermediate vision. It works, but it is not enough. The new diffractive trifocal lens (AT LISA, Carl Zeiss Meditec, Jena, Germany) became available in the Chinese market last year. It provides distance, intermediate, and near foci for patients undergoing cataract surgery. When targeting emmetropia or minimal myopia (–0.25 ~ –0.5 D) for myopic patients, patients achieve good visual outcomes at all distances. Our experience has shown high levels of patient satisfaction and spectacle independence. Most of them have uncorrected VA 6/6 to 6/5 at distance, 6/8 to 6/5 at intermediate and near. With respect to patient selection, I would recommend surgeons apply similar caution as with the multifocal lens for trifocal patients. The AT LISA has a range of 0 D to 30 D, so it may be implanted in extremely myopic patients. It’s crucial to rule out moderate to severe and progressive macular disorders, especially for myopic patients, diabetic retionpathy patients, and macular degeneration patients. For severe cataract patients, if we are not able to check the fundus preoperatively, we can check the macula during surgery. For eyes with predictive corneal astigmatism >1 D (corneal astigmatism before surgery plus surgically induced astigmatism), toric trifocal lenses would be the better choice. It is also important to check for dry eye. Treating dry eye is necessary for these premium IOLs because moderate to severe dry eye may affect visual function, especially in those eyes with multifocal or trifocal lenses. We also treat meibomian gland dysfunction with warm therapy and massage and artificial lubricants, and sometimes lacrimal plugs are useful. Dysphotopsias such as halos are disturbing phenomena, especially for patients with picky personalities. Well-informed patients know that they will be bothered for the first month, but will experience improvement due to selective adaption up to 6 months after surgery. Editors’ note: Dr. Zhao declared no relevant financial interests. light diffraction “is effectively utilized in trifocal lenses to provide intermediate vision, thus beside gaining an additional focus at the intermediate zone, there is less loss of defocused light and less side effects such as glare and reduced contrast sensitivity,” said Ehud Assia, MD , director, Department of Ophthalmology, and medical director, Meir Medical Center, Tel Aviv, Israel. “As more manufacturers are entering this field, the intermediate vision is definitely the most important feature of these lenses. The loss of light is reduced more and more by using it in different orders. Still, there are some issues with contrast sensitivity and halos, but a lot less than with bifocal or multifocal IOLs. Well-informed patients know that they will be bothered for the first month, but this improves due to brain adaption up to 6 months after surgery,” Dr. Mertens said. Comparing trifocal lenses Patients seem to prefer trifocal lenses more so than multifocal, these physicians said, and trifocals compare favorably to other enhanced vision lenses as well. For instance, extended depth of focus lenses “are a completely different aspect for refractive cataract surgery, as they offer optimal distance acuity and contrast sensitivity and some improved intermediate VA,” Dr. Kanellopoulos said. “Trifocal lenses may offer complete independence from spectacles at both distance and intermediate. Our 5-year experience in Europe is very positive. I can see making these lenses a mainstay surgical treatment globally and in the U.S.” Trifocals outperform accommodative, extended depth of focus, multifocal IOLs in general visual performance and regarding dysphotopsia, Dr. Cummings said. The lenses produce fewer higher order aberrations such as halo, Dr. Mertens added. Dr. Assia recently reviewed clinical results using PhysIOL trifocal IOLs and found that “90% had 6/9 uncorrected distance VA or better, 85% had 6/9 uncorrected intermediate VA, and 95% had uncorrected near VA of J2 or better,” he said. Toric trifocals showed similar results in astigmatic patients, Dr. Assia said. In comparison, in patients implanted with the Tecnis Symfony extended depth of focus lenses (Abbott Medical Optics, Abbott Park, Illinois), uncorrected distance VA was 6/9 in 84% of patients, uncorrected intermediate VA was 6/9 in 86%, “but uncorrected near VA of J2 and better was recorded in 44% only,” he said. The better visual outcomes and similar side effects are propelling patient preference, Dr. Assia said. Dr. Kanellopoulos said he’d continued on page 54