Refractive IOLs find niche in cataract patient population

Cape Coral, FL-New-generation refractive IOLs that provide a range of vision are valuable additions for a standard cataract practice, said Farrell C. Tyson II, MD.

Refractive multifocal lens

The ReZoom lens is a second-generation acrylic refractive multifocal IOL with Balanced View Optics Technology. Like the Array, the ReZoom optic is a five-ring system with alternating zones for distance and near vision. However, the location and sizes of the zones have been modified in its Balanced View Optics Technology. As a result, the optimized multifocal surface of the ReZoom functions more like a three-ring system, so the IOL provides good distance, intermediate, and near vision with reduced glare and less noticeable halos in low-light conditions.

Other design modifications compared with the Array IOL include use of a hydrophobic acrylic platform with stiffer, polymethylmethacrylate (PMMA) "capsule fit" haptics that reduce decentration. In addition, the optic features the proprietary OptiEdge with a posterior square edge that helps reduce the development of posterior capsule opacification (PCO) and a rounded anterior edge that decreases dysphotopsias.

Apodized diffractive lens

The ReSTOR IOL is an apodized diffractive lens on an acrylic platform. With its design, about half of the incoming light goes to near and about half goes to distance throughout most of the pupil size range. However, when the pupil becomes large, as in a night-time situation, the ReSTOR becomes a more distant-dominant lens.

The ReZoom is primarily a distant-dominant lens when the pupil is small, but as the pupil enlarges, incoming near light rays begin to fall on the retina without compromising the amount of light coming in from distance. With a large pupil, the lens shifts back to being a distant-dominant lens.

"Vision with the ReSTOR is less pupil-size dependent and because of how the light is distributed, patients who receive this IOL also have a perception of images sometimes being dimmer," Dr. Tyson said. "A patient experiencing night glare with the ReZoom can reduce that problem by turning on the dome light in the car to decrease pupil size while people who have difficulty reading in very bright light, such as outside, can be helped by wearing sunglasses."