EyeWorld Asia-Pacific September 2013 Issue

47 EWAP CATARACT/IOL September 2013 20/20 distance vision as well,” Dr. Wei said. The clarity of the distance vision is good, he finds. “They don’t get so much of the waxy, blurry vision for distance,” he said. A small portion of people experience flaring from lights, however. As a result, he does not recommend the Lentis for those who may be required to drive at night. Dr. Wei has also begun using the AT LISA tri 839MP (Carl Zeiss Meditec, Dublin, Calif.), a trifocal lens that promises to better fill in intermediate vision. This Dr. Wei described as a diffractive lens with a number of rings on the surface, with a unique light distribution. “The lens splits the light 20% at intermediate distance around 80 centimeters and 30% for near, which is at 40 centimeters,” he said. The remaining 50% is designated for distance. So far, Dr. Wei has found the lens to be very effective. “I was quite surprised how well it did the job,” he said. “With previous diffractive lenses, patients did experience haloes. This particular lens I thought might do the same thing, but it seems like it’s not as disturbing for the patient.” Initial haloes lasted for about one month and were not enough to stop patients from driving at night. In terms of range of vision, the lens has also delivered, Dr. Wei said. “The surprising thing is that they all can see 20/20 or better and quite soon after the operation,” Dr. Wei said. He finds that patients can read the equivalent of J1 or J2 at both 40 and 80 centimeters. Dr. Wei currently uses the AT LISA tri 839MP for every patient who passes the monovision contact lens trial. Innovative accommodative prototypes Some new accommodative lenses are currently ramping up for use. The FluidVision Lens (PowerVision, Belmont, Calif., USA), true to its name, relies on liquid to make accommodative changes. “Through the movement of the fluid internal to the lens, by virtue of the natural human physiologic contraction and relaxation of the ciliary muscle, the lens changes shape very much like our pliable crystalline lens does before the onset of presbyopia,” Dr. Nichamin said. He said the implant is acrylic, filled with refractive index- matched, ophthalmic-grade silicone oil. Together these two components behave as a homogenous single optical entity, Dr. Nichamin explained. “As the ciliary body contracts and relaxes, the forces are conveyed through the zonules and the capsule to the implant and the fluid in the haptics is pushed into the optic causing the anterior curvature of the optic to increase,” he said. “As the ciliary body relaxes, the zonules are put on stretch and fluid goes back out in the haptic.” In 2010 a non-foldable prototype of the lens was implanted in 14 sighted eyes in South Africa. “We saw on average a mean of 5 D of accommodative amplitude, and we hadn’t seen anything heretofore like that,” Dr. Nichamin said. Just recently, in April 2013 a foldable version of the lens was implanted in four eyes in South Africa. “We don’t have accommodative data to report yet, but the implantations were successful and we’re very optimistic that we’re going to continue to see excellent results with this platform,” Dr. Nichamin said. If all goes well, a clinical study will be launched at seven sites with the foldable lens in hopes of attaining CE mark approval and from there the FDA trials will begin, Dr. Nichamin said. Meanwhile, Dr. Donnenfeld is eyeing another accommodative lens in prototype, the electroactive Sapphire AutoFocal IOL (Elenza, Roanoke, Va., USA), to potentially best offer patients the full range of vision. He described the Sapphire AutoFocal IOL as an electromechanical lens with a minuscule battery inside that stimulates the optic to change shape when it senses accommodation. “If the light stays constant but the pupils get smaller, that means that the patient is accommodating,” Dr. Donnenfeld said. “That induces the liquid crystals inside the lens with electromechanical impulses to change the refractive aspect of the lens to provide 3 D of reading.” The lens has reached the point where it is ready for animal study and Dr. Donnenfeld is enthusiastic about its potential. “The exciting part about this lens is that it doesn’t rely on the muscles in the eye functioning, and capsular bag contraction or hardening will not have any effect on this lens,” Dr. Donnenfeld said. “It does allow for real 3 D of accommodation, but the technology is a work in progress and has to go through clinical testing before we have any real information to pass on.” Overall, Dr. Donnenfeld is optimistic that significant ground has been gained, after much delay. He pointed out that 10 years ago practitioners were sure that true accommodative lenses would be available soon. “Ten years later we’re still waiting for those accommodating lenses to come,” he said. “We’re getting close, but for the time being for patients who want to have true reading, I think that the multifocal lenses offer the best range of vision, while accommodating lenses offer the least visual side effects.” However, accommodative lenses will ultimately be the answer, he concluded. EWAP Editors’ note: Drs. Kent and Wei have no financial interests related to this article. Dr. Donnenfeld has financial interests with Alcon, Abbott Medical Optics (Santa Ana, Calif., USA), Bausch + Lomb, and Elenza. Dr. Lawless has financial interests with Alcon. Dr. Nichamin has financial interests with Bausch + Lomb and PowerVision. Contact information Donnenfeld: 516-446-3525, ericdonnenfeld@gmail.com Kent: 64-3-3513518, David@lasik.co.nz Lawless: 61-29-4249999, michael.law- less@visioneyeinstitute.com.au Nichamin: 814-849-8344, Nichamin@laureleye.com Wei: 1800-00-3937, drmarcwei@yahoo.com.au Eyeing - from page 45