Probably the most unique approach to the problem of presbyopia-correcting IOLs is the mechanism used in the NuLens®. This lens tries to mimic the natural process that occurs in some water birds such as penguins. These birds’ eyes have a rigid iris and a soft lens. To increase the power of the lens these birds have a muscle that pushes the soft lens up against the iris resuling in a protrusion of the lens through the iris. This central bulging results in a greater power of the lens.
One way to picture how this works is with a peanut butter sandwich. If you are generous with your peanut butter and press the two slices of bread together the peanut butter will ooze out the sides of the bread. Now instead, imagine that you have created a central hole in the middle of the top slice of bread (the iris).If you push on the bottom slice of bread the peanut butter (the lens) will bulge forward through the central hole. This is essentially how the lens of a water bird works.
The NuLens® is essentially a very small peanut butter sandwich with the peanut butter replaced by a silicon gel and the bread replaced by a rigid clear material. Initial studies in monkeys have been very promising. However, it will be awhile before this is approved for use in humans.
The recession will be over long before the FDA gives its blessing so it is not going to be an option for you if you need cataract surgery in the next couple of years. Nevertheless, the technology is exciting and many baby boomers will have quite a few awesome choices when it is time for them to have cataract surgery.
© 2009 David Richardson, MD