EyeWorld Asia-Pacific September 2011 Issue

September 2011 10 EW FEATURE Tetraflex, Synchrony to be approved soon T his year may finally be the year the Crystalens (Bausch & Lomb, Rochester, NY, USA), a silicone, hinge design, accommodating IOL, has some competition. The long-awaited Tetraflex (Lenstec, St. Petersburg, Fla., USA) should garner the coveted FDA stamp of approval soon, becoming a serious market rival. “The company thought it might get FDA approval before the ASCRS Annual Meeting [in March], but it still hasn’t heard,” said Paul J. Dougherty, MD, clinical instructor of ophthalmology at the Jules Stein Eye Institute, UCLA, medical director of Dougherty Laser Vision, Los Angeles, Calif., USA, and clinical investigator for the lens. “I look forward to having access to this technology for my patients because my clinical trial patients were so happy with their results.” The Tetraflex has a 2.2-millimeter injector allowing surgeons to make a 2.5-mm or 3.0-mm incision. The lens itself is made of hydrophilic acrylic with closed loop haptics and a 5-degree anterior angulation. “This is like any other IOL implantation,” said Dr. Dougherty. “It’s an extremely easy lens to put in. When it comes out, it will be the most accurate premium lens in the US in terms of refractive outcomes. It is manufactured to a tenth of a diopter tolerance, which is better than any other premium IOL in the world. It’s going to come out in quarter-diopter steps between 15 and 25.” Dr. Dougherty acknowledged The Tetraflex Source: Paul J. Dougherty, MD Next-generation accommodating IOLs: A status update by Faith A. Hayden EyeWorld Staff Writer Hungwon TCHAH, MD Professor, Department of Ophthalmology, Asan Medical Center, University of Ulsan 388-1 Pungnab-dong Songpa-gu, Seoul, 138040 Korea Tel. no. +82-2-30103680 Fax no. +82-2-4706440 hwtchah@amc.seoul.kr A s you know, both multifocal and accommodating types of presbyopia- correcting IOLs have advantages and disadvantages. Multifocal lenses divide incoming light into two to three zones. They work because the brain learns to select the appropriate zone to “look” through to provide sight at near, intermediate or far ranges. Therefore, some advantages of seeing through just one zone in monofocal lenses are lost, such as better contrast sensitivity, less glare and halo. However, these lenses provide enough power for reading. Most of our patients are satisfied with their near visual acuity. In contrast to multifocal IOLs, accommodating IOLs maintain one focusing zone. Research indicates that these IOLs, because of their design, are less likely than multifocal IOLs to produce visual side effects for distance vision such as night vision problems, including glare and halos. At long distance, it is possible that vision may be crisper with accommodating IOLs. However, accommodating IOLs, so far, may not provide as much of a range of focus (near to far) as multifocal IOLs, and this might lead to the need for reading glasses. The long-term accommodative ability of these lenses, especially lenses with in-the-bag movement, has also been an issue. In my personal experience, the initial results seem promising at 3 to 6 months. Twelve- to 18-month data for the Humanoptics 1CU accommodating IOL, however, suggests that the accommodative amplitude may fade over time. So the surgeon should discuss with the patient to clarify which type of presbyopia-correcting IOL, if any, might work best for your particular vision needs. If accommodating IOLs provide long-term stable power for near, these IOLs may be the future because they can provide better quality of vision. That is why many venture companies are researching accommodation IOLs. The first generation of accommodating IOLs used only one mechanism of accommodation, the forward movement of the capsular bag, which may decrease over time especially in case of capsular fibrosis. Accommodating IOLs that are available or going to be available internationally use different mechanisms, such as ciliary body action (Tetraflex), dual optics (Synchrony), dual part (Nulens), fluid mechanism (Fluidvision), high negative spherical aberration (WIOL), and even electro-active switchable optics(Elenza). I expect there may be a dramatic improvement in the field of presbyopia correcting IOLs in the next 5 to 10 years. I think we are fortunate to live in this era and to witness the change. Editors’ note: Prof. Tchah has no financial interests related to his comments. Views from Asia-Pacific AT A GLANCE • Tetraflex and Synchrony will be the next near-enhancing IOLs to come to the US market • These new lenses might deliver near vision that is closer to what nature did in a young, healthy eye • The first electronic autofocus lens is currently in experimental use