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Electro-active diffractive IOL may provide accommodation without movement
The novel technology may be a boon for patients with capsular and ciliary issues that thwart natural accommodation.
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 Jay S. Pepose |
An electro-active diffractive IOL promises to provide accommodation without movement, a physician said.
Jay S. Pepose, MD, PhD, described design features of a prototype electro-active accommodating IOL being developed by Elenza.
The novel implant promises to provide accommodation in eyes with various capsule-related factors that can hinder normal accommodative function, Dr. Pepose said.
“Consistent performance of accommodating intraocular lenses can be influenced by individual variations in the diameter of the capsular bag, variable capsular shrinkage and fibrosis, and systemic drug effects on ciliary muscle contraction,” he said. “A lens being developed that could accomplish accommodation or a change in dioptric power without requiring movement could obviate some of these problems.”
In 2006, Pixel Optics and investigators at the University of Arizona invented an electro-optic diffractive lens and developed spectacles with a dynamic add component that uses an electro-active lens triggered by an accelerometer in the frame. The electro-active spectacles were recently commercialized, and Elenza maintains an exclusive right to this technology for implantable applications inside the eye.
“We’re also seeing the development of implants and other ophthalmic devices using this technology,” Dr. Pepose said.
Major components
“The main component, the secret sauce, so to speak, of this lens is the electrical control of the refractive index of a nematic liquid crystal sandwiched between a circular array of transparent electrodes,” Dr. Pepose said. “One hundred percent of light energy is still transmitted but the refractive index changes.”
The lens works with high transmission, low voltage, fast response and high diffractive efficiency, with a power failure-safe feature, Dr. Pepose said.
“This lens will have a power failure distance fail-safe configuration, meaning that if we lost electrical current, it would default into the distance dioptric power,” he said.
A monofocal static IOL with an aspheric modification allows distance and intermediate vision. A smart electro-active diffractive liquid crystal lens allows near vision.
Microsensors detect physiological triggers of accommodation, such as the difference in illumination with miosis, and program that data into dual-application integrated circuits with onboard processors and algorithms that govern the power sequence, Dr. Pepose said.
“There are differences in the dynamics of pupil response to light vs. accommodation. And, of course, each one of us has individual patterns. That would be assessed and programmed into these integrated circuits. So, the difference in illumination in the periphery vs. the center would be triggered,” he said during Refractive Subspecialty Day preceding the American Academy of Ophthalmology meeting in Orlando, Fla.
The resulting accommodation would trigger an additional 3 D of power for near at the IOL plane.
The dual lithium ion batteries would be recharged periodically by an external inductive charging element and have a life expectancy of at least 50 years.
“All of the components required for the creation of this first electro-active IOL are currently available,” Dr. Pepose said. “And while subject to many challenges, this IOL may offer some advantages in providing accommodation without movement.”
The electro-active lens technology may be applied to other ophthalmic instruments and devices, such as cameras, according to Dr. Pepose.
“Just use your imagination,” he said. – by Matt Hasson
For more information:
- Jay S. Pepose, MD, PhD, can be reached at Pepose Vision Institute, 1815 Clarkson Road, Chesterfield, MO 63017; 636-728-0111; email: jpepose@peposevision.com.
- Disclosure: Dr. Pepose is a consultant for Elenza.