Evaluation of the Aspheric ReSTOR Intraocular Lens (IOL) After Routine Cataract Extraction

Cataract is prevalent throughout the world and IOLs are routinely implanted after the extraction of the cataractous lens. It is the most frequently performed surgery in the United States with an estimated 2-3 million procedures performed annually. With the aging population on the rise, as well as the increasing popularity of refractive intraocular lenses, the number of intraocular surgeries continues to rise. Over the years, the surgical technique has evolved from intracapsular extraction to modern phacoemulsification. This development has helped with the evolution of IOLs as well. The IOLs have advanced extensively: different materials and designs are available, permitting implantation through smaller, sutureless incisions. Traditional IOLs are of monofocal design providing vision at one distance, typically far. Patients implanted with traditional monofocal IOLs usually require glasses for near distance tasks such as reading. The new multifocal IOLs offer the possibility of seeing well at more than one distance, without glasses or contacts.

The AcrySof ReSTOR (Alcon Laboratories) uses apodized diffractive technology - a design that responds to how wide or small the eye's pupil might be - to provi de near, intermediate, and distance vision. Clinical studies used to support the March 2005 FDA approval showed that 80% of people who received the lens did not use glasses for any activities after their cataract surgery; 84% who received the lens in both eyes had distance vision of 20/25 or better, with near vision of 20/32 or better. Wavefront analysis is a technique currently used to measure the aberrations of the entire optical system. The term aberration derives from the Latin ab-erratio, which means going offtrack or deviating. Therefore, and aberration is the difference that exists between the ideal image of that we would expect to see when the luminous rays are refracted in the perfect optical system (Snell's law) and what is actually achieved. This technology is widely used in refractive surgery with successful outcomes. With the introduction of wavefront analysis, a new tool is available to re-design and study the performance of IOLs. Regarding IOL design, it has been used to modify the IOL to partially compensate for the average spherical aberration. The goal is to improve the ocular optical quality of pseudophakic patients. Clinical results using the aspheric monofocal IOLs confirm that this modification leads to a significant improvement, particularly in contrast sensitivity, mesopic visual quality and reduction of high order aberrations mainly spherical aberration when compare to spherical IOLs. The new aspheric ReSTOR IOL is the first single piece acrylic multifocal IOL to be available in the United States and a comparison to a regular (spherical) multifocal IOL is necessary to determine if the aspheric ReSTOR lens shows the same improvement.

The purpose of this study is to evaluate the visual outcomes and patient satisfaction after bilateral implantation of the aspheric ReSTOR multifocal intraocular lens (IOL) and compare it to a historical control group of patients implanted bilaterally with the spherical ReSTOR multifocal IOL.