Alcon Laboratories (Fort Worth, Texas) received FDA approval to market an expanded range of high-cylinder power correction intraocular lens (IOL) implants. The Acrysof IQ Toric IOL has been on the markt for several years and is designed to treat astigmatism at the time of cataract surgery. The initial lens was available in powers to treat from 1 Diopter to 2.5 Diopters of corneal cylinder (astigmatism). The expanded range now can treat up to 4 Diopters of corneal astigmatism.
The cornea of an astigmatic eye is curved unevenly (shaped more like a football than a basketball). Images focus in front of and beyond the retina, causing both close and distant objects to appear blurry. Cylindrical lenses, which have power in only one direction are used in conjunction with spherical lenses to correct for astigmatism. Most patients have small amounts of astigmatism. Larger amounts of astigmatism can cause significant distortion of the image and are often corrected with glasses or special contact lenses.
A cataract is the termed used to describe clouding of the natural lens in the eye. During cataract surgery, the cataract (and hence the lens of the eye) is removed and an artificial lens implant is placed. Traditional lens implants are spherical and do not have astigmatism correction built into them. A patient who has astigmatism and who receives a traditional spherical lens implant would still require glasses for clear vision after surgery. By placing the astigmatism correction on the lens implant, the need for distance glasses is eliminated. Most patients with Toric lens implants only require reading glasses after surgery.
Some of my happiest patients are ones who have received Acrysoft IQ Toric IOL implants. The expansion of the product line into higher cylinder powers means these lenses will be available to patients who have an even greater benefit from an astigmatism-correcting IOL.