A computer-controlled, fully programmable intraocular lens (IOL) may soon give cataract surgery patients better vision than any time in their lives. One of the persistent problems in cataract surgery is properly calculating the strength of lens to be used for optimal results. Even experienced ophthalmologists find this to be challenging, and subtle, unknown factors can lead to uncertainty in the final results. In about 1-2% of cataract surgeries, the results are so bad that the patients seek reoperation, and most often this is to have a different lens implanted. Many other patients live with less-than-optimal vision, or have secondary refractive procedures (such as LASIK) to improve the results.
The electronic IOL, known as ELENZA, may eliminate that problem, as well as possible problems that may result from future changes in vision. The new IOL is fully programmable, so it can be adjusted not just immediately after cataract surgery, but at a later date in response to eye injury, glaucoma, or other visual changes. The lens is also self-accommodating, so it does not depend on potentially weakening cilia muscles, and it may even be able to surpass the accommodating ability of the eye’s natural lenses. Theoretically, the lens could be used to give its recipients telescopic vision and super visual clarity at all distances.
You may remember the LED contact lens that was announced last year. In talking about that concept, I discussed the possibility of IOLs that replace the natural lens with an LED-array. Essentially, that would involve replacing the transparent lens with an opaque camera-transmitter array, like having a tiny video camera on one side and a tiny TV on the other.
This new electronic lens is different–it still functions like a lens, only it uses liquid crystal as the refractive medium. The arrangement of liquid crystal can be controlled by small electromagnetic fields, which in this case is used to change the refractive index and therefore the focusing power of the lens. The concept has already been applied to prescription glasses, allowing the wearer to change the focus of the glasses, eliminating the need for bifocals.
One problem with electronic lenses is that they need a power source. In the case of ELENZA, developers project the power will be provided by a microscopic rechargeable lithium-ion battery. Although similar to the batteries used on cochlear implants, they will be even smaller. These batteries will need to be recharged every 3-4 days, though developers estimate their lifespan at 50 years. Chargers, they say, can be placed in pillows or in face masks worn while sleeping.
One advantage of the liquid crystal lenses over the LED display is what happens if your batteries fail. In the liquid crystal lens, it simply reverts to a monofocal lens that gives you good distance vision, suitable for driving a car and most other outdoor tasks. The LCD display, on the other hand, would simply go dark, leaving you blind.
It remains to be seen, though, whether these new implantable lenses could be synced with a computer to give you an implanted display.
The developers of ELENZA hope to begin in vivo studies in the near future, possibly as early as 2013, and hopefully FDA approval as early as 2018.
There are still a number of good IOL options for people seeking cataracts today. To learn more about your IOL options, please contact a local ophthalmologist for a consultation today.