Intraocular lens delivers of visual quality, acuity

Boston-In the interest of providing both good-quality vision in addition to a full range of functional visual acuity for patients interested in a presbyopic IOL, the latest aspheric version of an accommodating IOL (Crystalens AO, Bausch + Lomb) may be considered a better option relative to its multifocal competitors, according to information presented by John F. Doane, MD, at the annual meeting of the American Society of Cataract and Refractive Surgery.

The data showed that when compared against various multifocal IOLs, the accommodating IOL delivered superior optical performance, as measured by image quality and modulation transfer function (MTF), better distance and intermediate uncorrected visual acuity (UCVA) outcomes, and comparable functional near UCVA.

"Image quality is extremely important for patient satisfaction," said Dr. Doane, a refractive and corneal surgeon, Discover Vision Centers, Leawood, KS, and clinical assistant professor of ophthalmology, Kansas University Medical Center, Kansas City, KS. "While multifocal IOLs can provide a full range of functional vision effectively, one cannot ignore the fact that splitting of light by a multifocal optic introduces trade-offs, including visual side effects and reduced quality of vision.

"While we can explain these consequences to patients and hope they understand the risks, in the absence of any technique for preoperatively assessing patient tolerability, whether patients notice these adverse phenomena, can tolerate the side effects, or will neuroadapt relatively quickly are unknowns," he said. "Certainly, there is individual variation with respect to these issues, and surgeons must be aware that there are some patients who can take years to adjust or never neuroadapt."

In one laboratory study, distance imaging quality associated with the accommodating IOL and two diffractive multifocal IOLs (AcrySof ReSTOR +3.0 D, Alcon Laboratories and Tecnis, Abbott Medical Optics [AMO]) was simulated objectively using a commercially available optical design program. At a 3-mm pupil size, the accommodating lens delivered superior distance image quality compared with both of the diffractive multifocal IOLs.

Consistent with these findings, computation of MTFs for six different marketed presbyopic IOLs [Crystalens AO, Crystalens 5-0, Crystalens HD (all Bausch + Lomb); AcrySof ReSTOR +4.0 D, AcrySof IQ ReSTOR +3.0 D (Alcon Laboratories); and ReZoom multifocal IOL (AMO)] showed that with a 3-mm aperture, the Crystalens AO curve was closest to ideal.