More than half of all Americans have a cataract or have had cataract surgery by age 80. Almost 4 million cataract surgeries are performed each year.
The mainstay of treatment has been monofocal lenses that improve distance vision. However, the FDA has just approved the first intraocular lens (IOL) to provide extended depth-of-focus, which improves sharpness of vision at near, intermediate, and far distances.
The Tecnis Symfony Extended Range of Vision IOL has been available in Europe since 2014. At the 2014 American Academy of Ophthalmology meeting, US cataract surgeon Mark Packer, MD, called the new lens “an exciting development.”
The lens is designed to correct both chromatic aberration (inability to focus due to competing wavelengths of light passing through the lens at different angles) and spherical aberration (lack of focus due to the shape of the lens). Clinical studies have demonstrated a low incidence of dysphotopsias such as halo and glare, which can impede night vision and driving. However, the FDA cautions that some patients experience visual halos, glare, or starbursts; some may experience worsening of or blurred vision, bleeding, or infection; and the device may cause reduced contrast sensitivity that worsens under poor visibility conditions.
More than 50 countries have approved the IOL has been approved, and has been widely studied with data from clinical studies involving more than 2,000 eyes, according to the manufacturer, Abbott Laboratories. FDA approval was based on a review of results from a study comparing 148 cataract patients implanted with the Tecnis Symfony Extended Range of Vision IOL and 151 patients implanted with a monofocal IOL.
Both groups of patients had comparable results for good distance vision. Of the patients in the Tecnis Symfony group, 77% had good vision (20/25) without glasses at intermediate distance, compared with 34% of those in the monofocal group. At near distances, patients with the Tecnis Symfony IOL could read 2 additional, progressively smaller lines on a standard eye chart, compared with those in the monofocal group.
In clinical trials for Tecnis IOLs, adverse events occurred at rates between 1.6% and 3.3%, including macular edema, endophthalmitis, and anterior lens tissue ongrowth. However, the events were not related to the lenses, the manufacturer says.
The FDA approval includes a version of the lens for people with astigmatism. The new lens is available in 4 toric models.