Multifocal lenses a welcome option

March 15, 2010

Now we can offer cataract patients something of added value-spectacle independence.

Key Points

If I were facing cataract surgery, I would like to know about all of my options. I view my role as educating patients on all of the options and benefits with cataract surgery, making a recommendation based on my best judgment, and then allowing them to make the decision that is best for them.

I do not generally recommend multifocal IOLs if there is compromise to the vision due to glaucoma, age-related macular degeneration, or other pathology, or if there is risk of IOL decentration after surgery (e.g., some traumatic cataracts). One patient of mine was wearing trifocal lenses and hoping to return to bifocals after surgery. After I performed cataract surgery with bilateral multifocal implantation (Tecnis Multifocal, Abbott Medical Optics), he does not need glasses at all.

In the FDA-monitored clinical investigation of this multifocal IOL, 292 subjects received the lens in both eyes. Their results were compared with a control arm of 118 patients who received monofocal IOLs. Only 5% of the control subjects stated postoperatively that they never wear glasses. Of those who received the multifocal IOL in both eyes, 88% reported never wearing glasses 4 to 6 months after surgery.1 With the multifocal IOL, 94.9% never needed glasses for distance activities such as driving, while 93.8% never needed glasses for near activities such as reading (for the control subjects, 83.1% did not wear glasses for driving, while only 5.1% did not need glasses for reading).

At 1 year (n = 112), 96.4% of subjects who received bilateral multifocal IOLs reported being able to function comfortably without glasses for distance and near activities, while 93.8% said they could function comfortably at intermediate range without glasses. Comparable studies of the ReSTOR 3- and 4-D add IOLs (Alcon Laboratories) demonstrated that 76% of subjects with either lens implanted in both eyes never wore glasses.2

Realistic expectations

One of the best sources for physicians and patients is the FDA Web site ( http://www.fda.gov/), where the results of all Investigational Device Exemption studies are available. Here, one can find what percentage of patients never needed glasses for activities such as driving and reading and which patients had results of 20/25 and J3 or better.

By its intrinsic optical properties, multifocality diminishes image quality to some extent. Diffractive IOLs (such as the Tecnis Multifocal and the ReSTOR) rely on constructive and destructive interference of light waves to create two distinct focal points. In the process, some light never reaches the retinal photoreceptors (about 20% is lost to destructive interference) and the blurred image of the near focal point may produce halos around distant lights at night.

I encourage all surgeons to become familiar with the outcomes, especially with the percentages of visual disturbances or unwanted optical side effects. With the Tecnis multifocal IOL at 4 to 6 months, 24% of subjects notice halos and 9% describe them as severe. By 1 year, only 5.2% of subjects (n = 116) with the Tecnis multifocal implanted experienced moderate and 6.2% severe halos. That means that I need to prepare patients who may experience bothersome halos with information on neural adaptation. The brain can teach itself to reduce or eliminate noxious stimuli, making it possible to remove unwanted visual side effects.

If we are realistic when offering this lens and fully explain the benefits and drawbacks, we will not have a lot of patients who are surprised or unhappy with any optical side effects. One patient reported, for example, "One of the side effects of these lenses is halos, and I have experienced them, but you kind of just retrain the brain to say that it's not that big a deal."

The possibility of spectacle independence is an amazing option for patients. With the correct education before surgery, patients report back to others, "Don't be afraid to get the surgery . . . the results will amaze you."

This and other patient reports are available on my practice's Web site ( http://www.finemd.com/) and in a recent DVD released by the American Academy of Ophthalmology, "Challenging Cases in Cataract Surgery" (edited by Bonnie Henderson, MD, and Natalie Afshari, MD).

Listening to what patients say provides the confidence and enthusiasm for new technology that surgeons need to achieve success with presbyopia-correcting IOLs.

References

1. Summary of Safety and Effectiveness Data (SSED), Tecnis Multifocal Intraocular Lens. http://www.fda.gov/cdrh/pdf8/P080010b.pdf

2. Physician Labeling, Alcon Laboratories Inc. AcrySof IQ ReSTOR Multifocal IOL.

Mark Packer, MD, FACS is co-editor of Cataract Corner. He is associate clinical professor of ophthalmology at Oregon Health & Science University, Portland, and is in private practice in Eugene with Drs. Fine, Hoffman, and Packer. He is a consultant to Abbott Medical Optics.