A dual optical accommodating foldable intraocular lens
Accommodative intraocular lenses have been an intriguing method of addressing presbyopia primarily because they attempt to mimic the eye’s natural method of focusing.Surgeons have also warmed to them because they appear to pose a greatly decreased risk of visual aberrations such as halos or contrast sensitivity loss, since they don’t force the brain to choose between different images as some multifocal lenses do.When wearing distance correction but looking at near, 68 percent of the patients read J6, 86 percent read J8 (equal to print in a phone book) and 95 percent read J9 (newspaper print). Dougherty thinks reading speed may be an even better measure of efficacy, however, since he says it’s a real-world use of near vision, ra-ther than “showing someone optotypes on a chart and seeing how far you can push him.” At one year, in a test of 239 Tetraflex patients and 96 controls implanted with a three-piece collamer monofocal lens, the Tetraflex patients had statistically significantly higher reading speeds at all print sizes from 20/25 to 20/80, Dr. Seventy-five percent of the Tetraflex patients either never wore readers or wore them occasionally for small print or in dim light, vs. The study also looked at the amplitude of accommodation provided by the lens.At one year, 72 percent of the patients had 1 D or more of accommodation, 52 percent had 1.5 D or more and 31 percent had 2 D or more.The Tetraflex is a hydrophilic acrylic plate lens composed of flexible hydroxyethylmethacrylate (26 percent water) with a UV blocker.
The lens’s approval application is currently under review by the Food and Drug Administration.The initial idea behind the Tetraflex was to use the IOL’s slight anterior vault to help the lens move forward with accommodative effort, giving improved near vision.However, though the lens moves somewhat, the amount of movement doesn’t seem to account for all the improvement in near focus that patients get with the lens.At intermediate distances, 20 percent saw 20/20 or better and 86 percent saw 20/40 or better.At near uncorrected, 81 percent read J6, which is the equivalent of stock quotes in the newspaper.