EyeWorld Asia-Pacific September 2013 Issue

45 EWAP CAtArACt/IOL September 2013 of vision here. Since May 2011 he has been using the ReSTOR +2.50 multifocal (Alcon, Fort Worth, Texas, USA/Hünenberg, Switzerland) in patients’ dominant eye, aiming for plano. “It gives excellent distance quality with little or no photic phenomena, glare or haloes,” he said. In the nondominant eye he uses the ReSTOR +3.0. “This does give some reduction in contrast and patients are aware of photic phenomena, but because it is the nondominant eye and because the dominant eye has excellent quality, they seem to adapt very well.” Patients also pick up some intermediate vision in the 50- to 60-centimeter range because of the transition between the +3.0 multifocal and the +2.5. While some patients do still need to wear +1.50 reading glasses in poor light, this seems to be a good overall compromise, he thinks. New multifocal lenses While such innovative approaches can help some to approximate a full range of vision, many practitioners are pinning their hopes on new lenses. One new multifocal IOL gaining ground outside of the U.S. is the Lentis Mplus (Oculentis, Berlin). David G. Kent, MD , Christchurch, New Zealand, uses this segmented, visually forgiving multifocal lens for many of his patients. “With the lens in the recommended position, the distance segment of the lens is (located) superiorly and the reading and intermediate segment is inferiorly,” Dr. Kent said. The Lentis is based on the concept of rotational asymmetry with a distinct sector for near and Myoung Joon KIM, MD Associate Professor, University of Ulsan College of Medicine, Asan Medical Center 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138- 736, Korea Tel. no. +82-2-3010-3975 Fax no. +82-2-470-6440 mjmjkim@gmail.com P resbyopia eventually affects everyone, and its solution has been increasingly important. There are two types of presbyopia-correcting IOLs: accommodative and multifocal IOLs. The term “accommodative” implies mimicking of natural accommodation in response to ciliary muscle contraction. Axial movement is a well-known mechanism of accommodative IOLs. Currently available accommodative IOLs adopt this concept and the clinical outcome of near vision has been less than expected, although they provided good distance vision comparable to monofocal IOLs. It seems that some breakthrough technologies are needed in the development of accommodative IOLs. Inmy practice, I recommendmultifocal IOLs as a presbyopia solution in cataract patients if they have good optical quality in cornea and tear film. Currently, more options are available in selection of multifocal IOLs: platform, add power, diffractive vs. refractive, pupil dependence, blue light-filtering, design of add zone (concentric zones vs. sector), and two vs. three foci. Whatever the designs are, multiple images are on retina at the same time in eyes with multifocal IOLs. When one is in focus, the other(s) is(are) out of focus. Interestingly, blur pattern is asymmetric in lenses with radially asymmetric optic such as Mplus. One of the most important factors affecting patients’ satisfaction might be neural adaptation to blur pattern. Most diffractive multifocal IOLs are bifocal and provide relatively lower intermediate vision. In contrast to bifocal IOLs, trifocal IOLs enhance vision in the intermediate range. With a variety of multifocal IOLs based on different design concepts, it becomes essential to understand the through-focus characteristics of the lenses. I would suggest surgeons take a careful look at defocus curves when selecting multifocal IOLs. New mechanisms in accommodative IOLs are changes in shape or refractive power of the optic. The FluidVision lens is filled with silicone oil, which allows changes in the anterior curvature of the optic with ciliary body movement. Sapphire AutoFocal IOLs are operated electrically, not by ciliary body contraction. It is programmable and uses a rechargeable battery. It detects miosis during accommodative efforts and controls the liquid crystal status which determines the refractive power of the lens. The battery can be charged with a special device that is wearable or equipped in the pillow during night time. The default setting is for distance correction so that it can still act as a monofocal IOL even if though there is a failure in the system. I suppose software would become more important than hardware in this system, because accommodative habit would be different from person to person. Customized algorithm or personal training may be needed. Optical and material engineering have led innovations in presbyopia-correcting IOLs. Electronic engineering has just come into this field. Everything you can imagine is becoming real. Editors’ note: Prof. Kim has no financial interests related to his comments. Views from Asia-Pacific the rest dedicated for distance. This is unlike typical diffractive or refractive multifocal lenses, made with concentric circles, which scatter the light over the entire lens. The Lentis allows for more transmission of light because it is not using a diffraction grating, Dr. Kent explained. Dr. Kent reported that his results with the Lentis Mplus have been outstanding, with 100% of his patients able to read well without glasses. The few night vision disturbances that do occur are different than the typical haloes experienced with other multifocal lenses. “Most people with the lens describe it as a street light or car headlight having light rays radiating downward like fingers or whiskers,” Dr. Kent said. As a rule, patients tend to find this far less disturbing than typical night vision problems, he thinks. “But there are definitely reports of patients who have clear problems with the lens, which require either removal of the lens or in some cases can be solved by rotating the lens up the opposite way,” Dr. Kent said. This reverses the situation, putting less of the reading segment in the pupil area and enabling patients to block some of that area if they close the eye a bit. A customized toric version of the lens is also available. Dr. Kent’s experience has been so positive with the Lentis that he finds that he is using fewer diffractive multifocal IOLs. Marc E. Wei, MBBS, FRANZCO, in private practice, Laser Sight, Brisbane, Australia, also finds that the Lentis works well. “I’ve been getting J2 reading with those lenses with continued on page 47