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Achieve Optimal Results With the ReSTOR Multifocal IOL

Proper patient selection is key to success.

BY DAVID B. CHAFFIN, M.D.

The wide range of IOL technology available to the cataract surgeon today provides opportunities for unprecedented patient satisfaction and practice success. To take full advantage of these opportunities, the surgeon must select the most appropriate IOL for each patient and know how to maximize its performance.

Having the AcrySof ReSTOR IOL (Alcon, Fort Worth, Texas) as an option has simplified lens selection in my practice because it is potentially suitable for more than 90% of my cataract patients who are seeking to achieve a range of vision. Postoperative distance and near vision are excellent, and with proper biometry and astigmatic correction, intermediate vision is very good. In my experience, even patients who read and use the computer, such as accountants and attorneys, have been highly satisfied with the ReSTOR IOL.

The lens is built on a familiar platform, making it user-friendly. In my experience unwanted side effects, such as glare and halos, are minimal. I have not had to explant lenses in any of my ReSTOR IOL cases. Its apodized refractive design utilizes the entire central 3.6 mm for near and distance vision, which means pupil size and centration are less critical than with some presbyopia-correcting IOL technologies.

While it is not difficult to obtain good results with the lens, attention to detail in surgical strategy and proper patient education are necessary for predictability and maximization of its potential. In this article, I share my advice for succeeding with the ReSTOR IOL.

Patient Selection

I offer the ReSTOR IOL to all cataract patients who have bilateral visually significant cataracts, normal visual potential, and a desire to have a range of vision with reduced dependence on glasses or contact lenses. Good candidates who are interested in this option run the gamut from younger to older across the entire economic spectrum.

I avoid implanting the ReSTOR in anyone in which a 20/20 visual acuity (VA) result is not expected due to factors such as amblyopia, macular pathology, uncorrectable astigmatism, ocular surface disease or dry eye that I am unable to resolve. Also, I avoid using the ReSTOR in patients with unreasonable expectations (more on setting expectations later).

Bilateral Implantation

I recommend using the ReSTOR IOL bilaterally. The best near vision is achieved once the second lens is implanted. In my practice, we avoid implanting the ReSTOR IOL unless the patient also agrees to a ReSTOR in the second eye. I recommend allowing only a short interval, 1 to 2 weeks, between procedures because a patient’s vision, especially at near, is not at its full potential until the second eye is implanted. This delay in good near vision can be distressing for some patients. For patients with only one cataract, we explain the benefits of two ReSTOR lenses and many elect to undergo a refractive lens exchange in the second eye. If a patient does not desire RLE for the second eye, I prefer to use a monofocal IOL.

That said, unilateral ReSTOR lens implantation is not out of the question. If unilateral ReSTOR is contemplated, the patient must clearly understand that they may not be able to achieve complete glasses independence, especially at near. In my experience, unilateral ReSTOR works best when the contralateral eye contributes to near vision, i.e., if it is myopic or not presbyopic rather than hyperopic.

Care should be taken when considering implanting different presbyopia-correcting lenses in the same patient. The night vision profile of each type of these lenses can be different, and some patients are bothered by the difference between eyes.

Target Refractions

With ReSTOR, it is important to break with the traditional IOL philosophy that some residual myopia is beneficial. When too much myopia is present after surgery, the near vision focal point is too close. Therefore, I target each lens for plano. Postop refractions close to plano, coupled with minimal astigmatism, provide the best combination of distance, near and intermediate vision.

I perform limbal-relaxing incisions (LRIs) for patients with 0.75 D or more of astigmatism. Best results with ReSTOR are obtained when postop cylinder is 0.5 D or less. Critically evaluate your method of determining how much cylinder to treat. Treat only corneal astigmatism because you will be removing the crystalline lens and therefore any lens-induced component of astigmatism. When creating the LRI treatment plan, I compare keratometry (K) values generated by topography with manual K values and refraction. If all three do not match closely, I do not perform the LRI at the time of surgery. Instead, I perform LRI, PRK or LASIK at a later time.

It is also important to monitor LRI outcomes and develop a personal nomogram based on results. I recommend the use of a pachymetry-adjusted nomogram for best results. If you are frequently undercorrecting, consider moving your incision a little more central. Ideally, the incision should be 1 to 2 mm central to the limbus and central to the vascular arcades. Incisions that are too peripheral are not as effective and produce less predictable results.

Biometry and IOL Calculations

Accurate biometry is another critical aspect of maximizing results with the ReSTOR lens. Because my practice is located in a dry climate and dry eyes or poor tear film can affect keratometry, I treat all patients with preservative-free artificial tears for 1 week prior to taking A-scan measurements. It is also important to instruct patients to discontinue contact-lens wear and follow them with serial topography to ensure any contact-lens—induced irregularity resolves prior to biometry.

I use the IOLMaster (Carl Zeiss Meditec, Dublin, Calif.) and its most current software, which obtains extremely accurate axial length measurements, but I also compare its automated keratometry reading with my manual K values. If the two do not match, I look for signs of dry eye, excessive tearing, or other conditions that can influence results before proceeding.

For IOL power calculations, use one of the latest generation formulas and track results to optimize your A constant.

Patient Expectations

A large part of successfully incorporating the ReSTOR lens, or any advanced IOL, into the practice is educating patients about what to expect. With the ReSTOR lens, they can expect quality vision at all distances. However, as with any technology, they have to be willing to accept some potential trade-offs. Make sure your patients understand that their near vision focal point may be closer than it was prior to surgery. Use a near card to illustrate the point where postop near vision will be best. Some patients might need to work on getting accustomed to the near focal point and may need to practice reading before they achieve the best results. This may be especially important to low myopes, who may not want a closer near point than they are accustomed to. They may prefer monofocal IOLs with a target of low myopia instead.

When discussing near vision, make sure patients grasp that it involves more than just reading. Once they understand that with monofocal IOLs they may need glasses for reading as well as tasks such as seeing their watch or dialing a cell phone, they tend to prefer the ReSTOR lens. Also inform patients that intermediate vision may not be at its best immediately after surgery, but tends to improve with time. Most of my patients report complete freedom from glasses by 6 months postop.

One of the most important things to tell patients is that they may not be entirely satisfied with their vision after the first ReSTOR implantation, but vision improves after the second implantation. When patients are aware of this, they accept the limitations they experience between surgeries and are more eager to proceed with the second one. I use an eyeglass analogy. I tell them to imagine that both of the lenses in their glasses are faulty, but we were only going to replace one at a time. Getting used to the new lenses one at a time would be much more difficult than if they got a whole new pair of glasses at once. Most patients relate to this very well.

Finally, be clear when discussing the ReSTOR lens with patients whose occupations require driving at night. Explain that they may see halos around lights or struggle with glare, which usually improves after a few months, but may not. Although most cataract patients are already used to dealing with halos and glare, they must consider them a reasonable trade-off for having vision at all distances after surgery.

Postop Fine-Tuning

As explained previously, minimization of astigmatism is crucial to achieving the best outcomes with ReSTOR. However, some patients can’t be completely corrected with LRIs. In these cases, I have performed LASIK or PRK after ReSTOR lens implantation with excellent results. Overall, just four eyes out of the more than 500 in which I’ve used the ReSTOR IOL have undergone unplanned laser vision correction for residual refractive error. Results were excellent in each case.

Other, not so obvious, factors can also affect outcomes. In cases where patients express concern about their vision postop, but the refraction is plano, recheck for any ocular surface issues, such as dry eye. Also consider that cystoid macular edema might be present. Once these issues are resolved, the expected favorable outcomes emerge in the vast majority of patients. OM

David B. Chaffin, M.D., specializes in cataract and refractive surgery at Chaffin Eye Center in Reno, Nev. Dr. Chaffin is a speaker and mentor physician for Alcon. He can be contacted at (775) 329–2300 or via e-mail at: dchaffin@chaffineye.com.