EyeWorld Asia-Pacific June 2018 issue

26 EWAP FEATURE June 2018 Views from Asia-Pacific Kimiya SHIMIZU, MD Director General Department of Eye Center, Sanno Hospital 8-10-16 Akasaka, Minato-ku, Tokyo, 107-0052, Japan Tel. no. +81-(3)6863-0700 kimiyas@iuhw.ac.jp T here are two major issues with current cataract surgery that also plays a role as refractive surgery. The first issue is regarding expected high corrective accuracy after surgery. The method for achieving it is an adjustable IOL. Adjustable IOLs are also effective for “refractive surprise” that can follow cataract surgery performed after keratorefractive surgery as well as for adjustments of postoperative refractivity in pseudophakic monovision using a monofocal IOL. The second issue is regarding presbyopia correction. In the1980s, I used diffractive IOLs from 3M Company, but discontinued to use them due to low patient satisfaction because of some problems such as their rigid IOLs and remaining corneal astigmatism. Recent multifocal IOLs are optically improved, but symptoms that are difficult to adapt to are yet to be eliminated and I feel that they basically remain the same as the previous ones (e.g., waxy vision). Therefore, I do not use multifocal IOLs except for some special cases but would recommend the monovision method. However, for patients with large near-exphoria angles, I also try a method of using a multifocal IOL only in the non-dominant eye and a monofocal IOL in the dominant eye (i.e., hybrid monovision). “ Recent multifocal IOLs are optically improved, but symptoms that are difficult to adapt to are yet to be eliminated and I feel that they basically remain the same as the previous ones.... Therefore, I do not use multifocal IOLs except for some special cases but would recomment the monovision method. ” - Kimiya Shimizu, MD Currently, the market is shifting from multifocal IOLs to EDOF IOLs; however, these are low add power lenses and near vision may not be sufficient. In a study using high-speed OCT that we developed, we confirmed that what could add some physical force to IOLs is the iris and ciliary muscle. This means that the most ideal lens to correct presbyopia is accommodative IOLs that utilize the actions of iris and ciliary muscles and their fluid-changing shape. In addition, fixation of IOL needs to be changed from in-the-bag fixation, which is currently the mainstream, to out-of- the-bag fixation. In my personal opinion, out-of-the-bag fixation is not necessarily bad, and on the contrary, it may even solve various issues of IOLs, such as posterior capsule opacification and dysphotopsia. Editors’ note: Dr. Shimizu is a consultant for STAAR Surgical AG (Nidau, Switzerland) and Kowa (Düsseldorf, Germany). Robert Edward ANG, MD Senior Consultant, Asian Eye Institute 8th Floor Phinma Plaza Rockewell Center, Makati City, Philippines 1200 Tel. no. +6328982020 Fax no. +6328973582 angbobby@hotmail.com T here are several mechanisms to treat presbyopia but all current technology still involve trade-offs or shortfalls. Multifocality has so far been the most widely accepted because it offers the highest chance of spectacle independence. The advent of trifocals has expanded the range of vision to cover distance, intermediate, and near, addressing the vision needs of most patients. Complaints on poor contrast and photic phenomena, while still present, have dramatically decreased compared to bifocals. Extended depth of focus (EDOF) is an emerging contender in presbyopia management. Mechanisms involve echellete technology, small aperture, and aberration control. While EDOF IOLs offer the advantages of better contrast and fewer photic phenomena to address the complaints from multifocal IOLs, they fall short of full range of vision and are not able to provide as much spectacle independence as multifocals, unless some adjustments or sacrifice is made by resorting to mild monovision. The first accommodating IOL fell short of expectations because of two factors. First, accommodative amplitude was limited to 1.0 to 1.5 D, not enough for true spectacle independence unless mild monovision was employed. Second, the hinged haptic technology which helped translate forces of accommodation were hampered by capsule contraction causing tilt and loss of accommodation. I learned that performing a central round YAG capsulotomy early on as the capsule was beginning to fibrose ensured long-lasting accommodation and stability. The quest for the perfect presbyopia-correcting IOL continues. Everyone feels that accommodating IOLs are the way to go. But from the Crystalens experience, I believe the challenge will continue to be controlling the fibrosis of the posterior capsule which will work against the mechanism of accommodation. Another factor is the huge size of these fluid-filled lenses. If implantation becomes challenging, and explantation in case something goes wrong becomes very difficult, then uptake of these lenses will suffer, just like the previous dual-optic accommodating IOL that was approved and later pulled out of the market. An interesting concept is the adjustable IOL. I have yet to see actual photos, videos, and results of these IOLs. I would be interested to know how the change in lens would affect quality of the optics. This innovation would have to commit to a mechanism of presbyopia correction, whether multifocal or EDOF, which will be subject to the pitfalls of either of these technologies. As we wait for innovations to evolve, we continue addressing the needs of our patients with current technology. I am very happy with my trifocal and EDOF experience. But it is crucial to consistently achieve the desired refractive outcome (be it emmetropia or mild monovision) to bring out the best performance of these lenses. Which technology to use is best left to the discussions with the patient and judgment of the surgeon. The key to a successful presbyopia practice is not only harnessing the right technology for the right patient but more so managing the expectations of each patient. Editors’ note: Dr. Ang is a consultant for Acufocus (Santa Ana, California), Alcon (Fort Worth, Texas), Bausch and Lomb, Physiol (Liege, Belgium), Johnson & Johnson Vision (Santa Ana, California). A range of futuristic – from page 25