STAGED USE OF IOLS

Need a Solid Plan for Fitting Patients With Premium IOLs?

Consider this successful staged implantation approach.

By David R. Hardten, M.D., F.A.C.S.

► If you've been strategizing about how to add premium IOLs to your arsenal, you've probably realized this is "not your grandfather's" cataract practice. You're contending with new office flow dynamics, an expanding list of lens technologies and the most demanding patient population in history. The fact that you're already strategizing means you realize how valuable premium IOLs can be for your practice and patients, especially cataract patients, who desire reduced dependence on eyeglasses.

A major key to success in this area is selecting the IOL most likely to fulfill each patient's individual vision needs. To accomplish this in my practice, I've adopted a staged implantation approach that you may find useful.

Implant First Eye, Then Assess

My starting point for each patient who wants to be less dependent on eyeglasses is the ReZoom multifocal IOL (Advanced Medical Optics). In my experience, this lens, a zonal refractive design, is most likely to be a success for the majority of patients. I implant a ReZoom in the first treated eye, usually the dominant eye, or in some cases, the eye with the highest refractive error or the worst best-corrected visual acuity.

About 1 to 2 weeks after the procedure, I assess uncorrected near and distance vision and the manifest refraction. But more importantly, I have patients describe their experience with the surgery and lens. We talk about what they can see and what they can't see. We talk about what they like about their vision in this eye and whether there's anything they don't like. This information is what guides the second stage of the process, which is deciding which lens to implant in the second eye.

Choose IOL for Second Eye

In all but 5% to 10% of my premium IOL cataract and refractive lens exchange cases, patients get the results they want with bilateral implantation of the same lens. Therefore, if patients are satisfied with the vision the ReZoom provides in their first operated eye, I implant a ReZoom in the second eye as well.

At times, however, a patient expresses a concern about the vision in the first operated eye. When this happens, we are typically dealing with one of two issues: either the patient would like more improvement in near vision or the patient isn't happy with night vision. These reactions are no surprise. To provide a range of vision, all of the available multifocal designs split the light that enters the eye. Some patients are more sensitive than others to the resulting effect on near or night vision. But each IOL design manages light differently, so we have several tools to address our patients' needs.

When patients say they would like more improvement in near vision after we operate on the first eye, we can proceed in one of two ways for the second eye:

■ Implant a ReZoom lens and aim for 0.50D-0.75D of residual myopia

■ Implant an AcrySof ReSTOR Aspheric multifocal IOL (Alcon).

Both of these options help with near vision, the ReStor by virtue of its diffractive near endpoint. Choosing a ReZoom and residual myopia for this patient's second eye may induce some halos without correction at distance, but with mild correction the visual aberration pattern would be the same in both eyes. Choosing an aspheric multifocal IOL, like the ReStor Aspheric, for this patient's second eye would be less likely to induce glare or halo at distance without correction due to the distance endpoint. But the glare pattern would be different in each eye, which some patients prefer to avoid. Ultimately, the choice depends on the patient's preference.

When patients say they aren't happy with their night vision after we operate on the first eye, we can proceed in one of three ways for the second eye:

■ Implant a ReZoom lens and aim for slight hyperopia (~0.25D)

■ Implant an aspheric monofocal IOL (typically the Tecnis IOL, Advanced Medical Optics)

■ Implant a Crystalens presbyopic IOL (Bausch & Lomb).

All three of these options would reduce glare or halos. Because the aspheric monofocal designs don't split the light, we would expect them to induce fewer nighttime vision disturbances. The crystalens typically has less nighttime vision disturbance than the ReStor or ReZoom lenses. All three options also mean a trade-off for near vision. And, as in our first scenario, the choice depends on patient preference. He or she must weigh near vision without correction against accepting some visual aberrations at night.

As I mentioned at the outset, my starting point for the staged implantation approach is almost always the ReZoom IOL. In select cases, however, my preoperative discussions with patients make it clear that bilateral implantation of a different lens design is the best way to go.

Multifocality and Asphericity: A Winning Combination

By Eric D. Donnenfeld, M.D In the realm of refractive cataract surgery, patient satisfaction reigns supreme. Without it, no procedure, no matter how technically correct, can be considered a success. While this may be daunting scenario, especially for new surgeons such as yourself, the latest innovation in intraocular lenses is on your side. Two new IOLs, one FDA-approved and one awaiting approval, merge multifocal and aspheric technology to provide better overall quality of vision than any previously available lenses. Multifocal lenses are the best way to give refractive cataract surgery and refractive lens exchange patients what they want — spectacle independence. The first-generation multifocals offer a range of vision as well as good Snellen visual acuity, depth perception and stereopsis. However, because they're spherical, they add to the positive spherical aberration of the cornea. Positive spherical aberration in the visual system can create glare and halo in lowlight or nighttime-driving conditions for some patients. It also can decrease contrast sensitivity. The new multifocal aspheric IOLs retain the benefits of multifocality, but they also address spherical aberration. Both are designed with negative spherical aberration, which means they counteract, rather than add to, the positive spherical aberration of the cornea. Awaiting FDA Approval The AcrySof ReSTOR aspheric IOL (Alcon) received FDA approval in January 2007. The newest option in this category, the Tecnis Multifocal (Advanced Medical Optics) is currently awaiting FDA approval (Figure 1). The Tecnis Multifocal has a full diffractive posterior surface and a wavefront-designed aspheric anterior surface. It will be available in both acrylic and silicone. Like the aspheric Tecnis monofocal IOL, the Tecnis Multifocal is based on research showing that the average human cornea has +0.27 microns of spherical aberration throughout life,1 and peak visual performance occurs at age 19, when the average spherical aberration is 0.0 microns.2,3 To bring spherical aberration in the visual system to zero, it adds 0.27 microns of negative spherical aberration. Figure 1. The Tecnis Multifocal, shown here implanted, has a full diffractive posterior surface and a wavefront-designed aspheric anterior surface. The FDA is reviewing data from a multicenter clinical study, involving 13 investigators and approximately 250 patients who received bilateral monofocal IOLs or bilateral Tecnis Multifocal IOLs. At one year, the Tecnis Multifocal patients had statistically significant better reading acuity and speed compared with the monofocal patients. Among the more than 100 patients who were bilaterally implanted with the Tecnis Multifocal, a high percentage reported they were able to function comfortably without eyeglasses at all distances (Figure 2). In addition, 94.6% of Tecnis Multifocal patients reported that they would choose the lens again (Figure 3). Figure 2. Study results presented to the FDA showed that a high percentage of patients, all of whom had received bilateral implantations of Tecnis Multifocal IOLs, reported that they were able to function comfortably without eyeglasses at all distances. Figure 3. In the multicenter clinical study presented to the FDA, 94.6% of patients who received bilateral implantations of the Tecnis Multifocal IOL said they would choose the lens again. Screening, Selection Simplified As part of the FDA clinical trials for the Tecnis Multifocal IOL, I've treated approximately 30 patients, and the results have been extremely gratifying. All of the patients are enjoying minimal or no dependence on eyeglasses and have excellent quality of vision with minimal complaints. The combination of multifocality and asphericity in one IOL is good news for experienced and new surgeons alike. Because these new lenses are a better option for just about every patient, the screening and selection process is simplified. And even more importantly, they go a long way toward our ability to ensure complete satisfaction for the growing number of patients who seek spectacle independence. References Holladay JT, Piers PA, Koranyi G, van der Mooren M, Norrby NE. A new intraocular lens design to reduce spherical aberration of pseudophakic eyes. J Refract Surg. 2002;18:683-691. Artal P, Alcon E, Villegas E. Spherical aberration in young subjects with high visual acuity. Poster presented at ESCRS 2006, Paper 558. Holzer MP. Data presented at the 19th Congress of German Ophthalmic Surgeons (DOC), Nuremburg, Germany, 2006. Eric D. Donnenfeld, M.D., is a clinical professor of ophthalmology at New York University Medical Center and a partner in Ophthalmic Consultants of Long Island, in Rockville Centre, N.Y. You can reach him at (516) 766-2519 or eddoph@aol.com.

One Step at a Time

The staged implantation approach has been very successful in my practice, because it affords my patients and me the opportunity to assess the performance of the first lens, and then make a more informed decision about which lens to implant in the second eye. It also allows patients to participate more in the entire process, further increasing their satisfaction with the experience.

If you plan to implement a similar strategy, be prepared to explain to patients what they can expect from each lens technology, then listen carefully to their feedback after the first implant. This will help ensure satisfaction for your premium IOL patients. nMD