Premium IOLs in Practice

Success With the ReZoom Multifocal IOL

One surgeon provides his perspective with this technology.

BY FARRELL "TOBY" TYSON, M.D., F.A.C.S.

I have been implanting both the ReZoom (Advanced Medical Optics, AMO, Santa Ana, Calif.) and the ReSTOR (Alcon, Fort Worth, Texas) lenses in patients since June 2005. My practice is located in Southwest Florida, which creates an interesting environment, one that is highly competitive, but also primarily Medicare covered.

I am currently implanting premium lenses in about 30% of my cataract patients. I have found much success in implanting the refractive lens bilaterally and have become partial to this procedure. There are many items to consider before implanting a refractive lens and I will share my tips and pearls for success with bilateral implantation of refractive IOLs.

Patient Selection

Choosing the appropriate 30% of premium lens patients involves some cherry picking. So, what does my refractive IOL patient population look like? Of the first 200 patients I implanted with the ReZoom IOL, I found my average patient ranged from 70 to 75 years old. Additionally, I take my multifocal IOL patients directly from my current cataract patient population — I am not having to recruit new patients for these procedures. Rather, I am converting the patients who are already in my practice.

The majority of my multifocal patients have mild hyperopia and myopia. The patients with mild myopia have the best results in the exam lane, but also seem to be the most critical patients. Patients with moderate myopia and hyperopia are usually the happiest. In addition, I have some patients with high myopia in whom I have successfully piggybacked IOLs.

An example of a typical ReZoom implantation.

In selecting patients, I have found it is best to identify a patient with a low amount of astigmatism. I have learned to cut this off at about 1.5 D, as I know I can accurately achieve correction at this level with limbal relaxing incisions (LRIs). Patients with more astigmatism can be treated, but will have to be counseled about a multi-staged procedure. When considering bioptics to treat high levels of astigmatism, one must weight the cost, contrast and dry eye concerns against the excellent results of standard monofocal or monvision surgery.

Another factor to consider during patient selection is dry eyes, which I discovered the hard way. Initially, I was finding that many of my patients were experiencing glare or halos, with minimal refractive error. I reassessed these patients, and sure enough, Schirmer’s was about 4 or 5. So, I implanted punctal plugs and put the patients on cyclosporine ophthalmic emulsion 0.05% (Restasis, Allergan). Suddenly, a lot of that glare and halo went away. Thus, I have found that preoperative evaluation and treatment of dry eyes is necessary and re-evaluation in the postop period with patients with glare or halos is warranted. This will make your postop treatment program a lot easier.

It is critical to select the right patient and not be afraid to turn down the wrong patient.

I have found that it is best to avoid implanting the ReZoom in patients who are pessimistic — thus, in patient selection, I require a "glass half full" mentality. Another key consideration that must be determined is night-time driving needs. In Florida daylight lasts a little longer, while in the North it is a bit shorter.

Choosing the Right Lens

In my practice, about 90% of multifocal patients are best served with the ReZoom lens. I tend to look for the progressive bifocal-type patient, the one who has an active lifestyle and wants to have a range of vision. Our society is moving to that intermediate lifestyle, where using the computer or playing cards is very common. I have found success in implanting the ReZoom lens, which provides patients with this near/intermediate vision. The ReZoom lens differs from the ReSTOR lens in that it moves the near-focus point a little bit closer to distance. As a result, the near add is in a more relaxed position but also allows for improved intermediate vision.

I generally use the bilateral approach. In the past when I have chosen to do the mix-and-match technique, I was getting good results on the data, but in reality I was getting mixed and matched responses from my patients. Patients cannot help comparing one eye to the other. I have had patients with 20/20 vision at distance, J1 at near and with good intermediate vision say, "one eye is dim and the other has a halo at night." So, I have found it much easier to implant the same lens in each eye, resulting in happier patients.

When addressing the patient who requires surgery on one eye, such as a unilateral posterior subcapsular cataract or a traumatic cataract, I have found unilateral ReZoom implantation highly successful. One of my first patients was a 45-year-old female traumatic cataract who I decided to implant with the ReZoom. She achieved 20/15 uncorrected distance vision and J1+ reading. She was easily able to adapt to having an accommodating eye along with a multifocal implant. This specific case made me a believer in this technology.

Preoperative Pearls

If you find that you are not getting good measurements with your monofocal IOLs, you will have difficulty on your results with your multifocal IOLs. One must be using either immersion A-scans or an IOLMaster (Carl Zeiss Meditec, Dublin, Calif.). The use of contact A-scans is too variable for multifocal lens implantation. I use an IOLMaster and an Accutome (Malvern, Pa.) Immersion A-scan unit with optimized third-generation IOL calculation formulas. The Haigis and Holladay II formulas are also highly effective with multifocals as they work well over a large range of axial lengths.

I generally aim for plano, or if necessary a little bit of minus. A little minus will leave room for an LRI if necessary postop. Even though an LRI will supposedly keep you spherically equivalent, you are going to have a perceived hyperopic shift. I have also found staggering lens targets reduces best uncorrected binocular vision due to reduced cerebral summation.

In my opinion, underselling and overdelivering are key to success with the ReZoom. I approach the preop discussion with, "This is not going to give you 18-year-old eyes, but this is going to give you the best chance for success." I always make the patient aware of the possibility of halos and that it may be a multi-stage procedure, because I may want to go back and touch up with an LRI. I let patients know that reading glasses will probably be needed for some tasks. In general, patients are happier postop when they know what to expect.

Postop Result

I have found that I achieve good reading results for uncorrected vision: approximately 15% are J1+ — which is a surprise — and 53% are J1, (in the ReZoom study group, 48% were J1). Approximately 82% are J2 and 98% are J3. I can tell my patients with confidence that they have a 98% chance of using both eyes to read the newspaper.

With uncorrected distance, I have compared my results binocularly vs. monocularly. One line of vision will be added by having binocular ReZoom implantations. This differs from my ReSTOR patients, who gain 1.5 lines with binocular implantation. I typically tell my patients not to be surprised if vision is not quite as expected for the first eye — it will get better when the second eye is implanted. This is another reason why I usually implant the second eye about a week out. Ninety-three percent of my patients are 20/25 or better at distance, which is similar to my monofocal patients.

When considering the role of age, I find that younger patients tend to have better distance and reading vision. These same younger patients also tend to be the most critical and demanding. I attribute this to better retina health. Once patients reach 60 or 70 years of age, the results start to flatten out, but even when a patient is 80 years of age, he is still seeing, on average, better than 20/25 at both distance and near.

I have found that a good technique is to accentuate the positives. Patients may not be sure what to expect, so they expect perfection. You need to let them see with -3 D glasses what they truly have gained up close. Treating small amounts of posterior capsular opacification (PCO) early can be very beneficial, as PCO will rapidly decrease contrast. Small amounts of cylinder should be treated, and any remaining cylinder over 0.75 D should be retreated.

Both PCO and astigmatism tend to decrease near vision rapidly and, if treated, can usually have a marked improvement in near vision. When patients are complaining of glare or halos, rechecking for dry eyes usually will solve most cases. If the glare symptoms persist, I have found that polarized sunglasses work well during the day for glare, and if they even have a little bit of glare at night, you may want to look at glasses with an anti-reflective front coat with a flash-mirror back.

In summary, implanting the ReZoom lens bilaterally has worked well in my practice. I am achieving excellent reading results with my patients, 98% are J3 or better and 53% percent are J1. To achieve good results, it is critical to select the right patient and not be afraid to turn down the wrong patient. If you cherry pick on the front end of the surgical process, you will have great results and happy patients on the back end. OM

Farrell Tyson, M.D., practices refractive cataract and glaucoma surgery in Cape Coral, Fla. He obtained his biomedical engineering degree from Johns Hopkins University and completed his ophthalmology residency at the Storm Eye Institute in Charleston, S.C. He has no financial relationship with the manufacturers of products discussed in this article. Dr. Tyson may be e-mailed at tysonfc@hotmail.com.