Two approvals expand multifocal IOL options

April 15, 2005

FDA approvals occurring within a few days of each other have brought ophthalmologists two new multifocal IOLs to select fromfor patients seeking lessened spectacle dependency after cataract surgery.

On March 23, the AcrySof ReSTOR apodized diffractive IOL (Alcon Laboratories Inc.) was approved for implantation in cataract patients with and without presbyopia. On March 28, the ReZoom multifocal refractive IOL (Advanced Medical Optics, AMO) received approval for capsular bag implantation after cataract surgery in adult patients.

Commercial availability for both lenses is anticipated in May.

Richard J. Mackool, MD, was a principal investigator in the ReSTOR trial.

He observed that result compares very favorably against outcomes associated with the crystalens accommodating IOL (eyeonics) and the Array multifocal IOL (AMO), for which reported rates of complete spectacle independence were 26% and 40%, respectively.

"The ReSTOR IOL is truly a revolutionary implant," Dr. Mackool said.

Four hundred sixty-five patients received bilateral ReSTOR implantation during the FDA trial. Of these, Dr. Mackool implanted 43 lenses. The average patient age was about 65 years.

In that study, the vast majority of patients (84%) who underwent bilateral implantation with the ReSTOR IOL had a distance visual acuity of 20/25 or better and a near visual acuity of 20/32, or J2, or better without correction compared with 23% of patients who received conventional or monofocal correction.

Those outcomes translated into exceptionally happy patients who had qualitatively improved vision compared with preoperatively.

"The majority of these patients do not have 20/25 or 20/30+ vision but have 20/20 and 20/16 crystal-clear vision, and they can read the most minute print, such as that on a tube of toothpaste, without reading glasses," Dr. Mackool emphasized.

He said the unprecedented success of the implant can be attributed to the novel structure of the optic.

"What is unique about this lens is that it combines two different types of optical systems: diffractive and refractive optics," Dr. Mackool said. "It is ingenious because the refractive optics are in the outer half of the lens, which allows good night vision when the pupil enlarges. The diffractive ring elements, which are equally divided between distance and near vision, are in the central 3.6 mm of the lens.

"The step-off between each of the diffractive rings is precisely graduated on the order of as little as 1 or 2 µm from the center to the periphery. This minute step-off is what greatly reduces the incidence of halos and glare after implantation."

In the FDA study, there was a very low rate of severe halos at night; this is in contrast to the incidence of halos in patients receiving the Array lens, nearly all of whom have this problem," Dr. Mackool explained.