EyeWorld Asia-Pacific December 2011 Issue

December 2011 21 EW FEATURE Hiroko Bissen-Miyajima, MD, PhD Professor and Department Chair of Ophthalmology, Tokyo Dental College Suidobashi Hospital 2-9-18 Misaki-cho, Chiyoda-ku, Tokyo 101-0061 Japan Tel. no. +81-3-5275-1912 Fax no. +81-3-5275-1912 bissen@tdc.ac.jp T o gain uncorrected near vision without losing the quality of distance vision is our dream. The most challenging and demanding cases are the near- emmetropic presbyopes. Their uncorrected distance and near visual acuities have been excellent for many years and their lives become increasingly difficult when they cannot read properly. This article describes solutions with both intraocular lens (IOL) and corneal laser procedures. The technique of removing the crystalline lens has become very safe and the final issue is the function of the IOL. Is it worthwhile to exchange the natural clear crystalline lens with an IOL? We all know the ideal presbyopia-correcting IOL is an accommodative type which does not decrease the contrast sensitivity. However, the amount of accommodation achieved by current accommodative IOLs has not reached the level we wish. Thus, the diffractive multifocal IOL is indicated for the patient who really wishes for sufficient near vision despite the drawbacks of slightly decreased quality of distance vision. Monovision is used in both IOL and laser correction. This technique is often chosen by the ophthalmologist if he or she wishes some type of correction for presbyopia. The weak point of monovision is similar to the accommodative IOL. The difference of the refraction between the two eyes is up to 2 diopters, which is not sufficient for reading small print. If near-emmetropic presbyopes wish for good quality distance vision and acceptable near vision, treating one eye with corneal laser surgery will be the choice of treatment. With the introduction of femtosecond laser technology, the technique of lens removal including anterior capsule has become much more precise and safe. Also, we are expecting the new application to treat presbyopia by softening the lens itself. Compared with correcting myopia, hyperopia and astigmatisms, presbyopia correction is a challenge; however, we are on our way to finding the ideal solution for everybody. Editors’ note: Prof. Bissen-Miyajima is a consultant for Hoya (Tokyo, Japan), and Abbott Medical Optics (Santa Ana, Calif., USA). John CHANG, MD Director, Guy Hugh Chan Refractive Surgery Centre Hong Kong Sanatorium and Hospital 8/F Li Shu Pui Block Phase II, Hong Kong Sanatorium and Hospital, 2 Village Road, Happy Valley, Hong Kong Tel. no. +852-28358885 Fax no. +852-28358887 johnchang@hksh.com P resbyopia is now the Holy Grail of Ophthalmology; the accommodating IOLs presently available give too little accommodation for them to be considered for presbyopic lens exchange (PRELEX). I have had some good success with hyperopes and myopes (especially the high myopes) using the Tecnis Multifocal IOL (MFIOL, Abbott Medical Optics, Santa Ana, Calif., USA). But for the emmetropes who are used to good distance vision it is a very difficult matter. They must be told that their distance vision will be worse; halo and glare can be a problem and they can only see near and far and most likely they will need glasses for computer use; although, we have found that when bilaterally implanted over 60 to 70 percent do not need glasses at all distances including intermediate, i.e., computer use. Other lenses such as the Lentis Mplus (Oculentis, Berlin, Germany) give much less halo and glare and seem very promising. The FineVision trifocal lens (Physiol, Liege, Belgium) also provides intermediate vision, but there have not been enough studies to confirm its effectiveness. PresbyLASIK remains my surgery of choice, especially in the early presbyopes, in whom I perform hyperopic LASIK in the non-dominant eye to make that eye myopic. On initial consultation a +1.5 and then +2.0 lens is placed over either eye. It is surprising that many patients do not feel the myopia induced in the non- dominant eye. Low amounts of hyperopic LASIK (e.g., +2.0 D) do not regress much. This is particularly successful in large cities such as Hong Kong and New York, where a lot of people do not drive. If they do drive, they are told that most likely they will need glasses for night driving. Etching a multifocal pattern on the cornea and then placing a flap over it seems to diminish its effect. Although Supracor (TPV) has shown to be promising for the hyperopes, there has not been enough data for the emmetropes. The cornea inlay, particularly the Kamra, is very clever. It not only gives near but also good intermediate vision. The newer 5-micron inlay has not shown any flap necrosis. However, because of the possible hyperopic shift, patients must undergo LASIK to make them mildly myopic (-0.75 D). That means a flap creation, LASIK and then placement of the implant. That seems a lot of surgeries for an emmetrope. The other inlays are not available in Asia yet. The present technologies available all involve some compromises, but not being able to read anything close is extremely annoying and inconvenient. Patients must be told in detail what compromises they will experience. If they are clear about the risks and compromises, they are generally very grateful patients. Editors’ note: Dr. Chang is a consultant for Abbott Medical Optics and receives travel support from Technolas Perfect Vision. Views from Asia-Pacific Upcoming technologies Several companies are actively working on new accommodative lenses, and some have promising early results. “What we have now is better than what we had 8-10 years ago, but there’s always something better being developed,” Dr. Weiss said. “I constantly tell patients if they wait for the next best technology, they’ll never have the surgery.” The Synchrony dual-optic lens (Visiogen, Irvine, Calif., USA) “intrigues me because it’s its own encapsulated system that might transfer ciliary forces better,” Dr. Harton said. Lens refilling technologies are also promising, he said. “With those, you don’t take away the anterior capsule. Instead, a synthetic polymer is injected that has the potential to restore continued on page 22