Premium intraocular lenses

Article Outline

• Explaining premium IOLs
• Advantages and disadvantages of each type of premium IOL
• Identifying candidates for premium IOLs
• Summary
• References

Premium intraocular lenses (IOLs) are the big news in surgical refractive correction today, according to Paul Karpecki, O.D., chair of the American Optometric Association (AOA) Contact Lens and Cornea Section's Refractive Surgery Project Team. Premium IOLs were developed a decade ago to help replace some of the accommodative ability lost by cataract patients with the removal of their crystalline lenses. They have since proven “very successful” from a clinical standpoint, Dr. Karpecki says. However, they have not achieved the market acceptance that manufacturers initially anticipated, he acknowledges. The IOLs may offer older adults the highly attractive prospect of freedom from bifocals, but patient dissatisfaction with visual side effects—notably, nighttime glare in the early versions of the technology—has limited enthusiasm for the devices among both patients and practitioners.

However, IOL design advancements over the last 5 years are providing improved vision correction (which has always been good, Dr. Karpecki notes) along with marked reductions in unwanted visual distortions. Those improved outcomes—along with new faster and safer forms of lens removal surgery—have spurred renewed interest in premium IOLs for cataract patients. It has also spawned the burgeoning field of clear lens exchange (CLE): the use of premium IOLs as a vision correction measure for noncataractous presbyopes. However, “the main problem is that 90% of patients have still never heard of premium IOLs,” Dr. Karpecki says. He suggests optometrists take a more active role in counseling patients on premium IOLs.

For a variety of reasons, patients are best served when they are advised on IOLs by their optometrists before being referred to an ophthalmologist for possible surgery, Dr. Karpecki contends. As primary eye care providers, who are familiar with their patients and their needs, optometrists often are in a good position to determine whether a patient would be a good candidate for premium IOLs. Patient disposition and expectations, as well as visual demands, are proving to be critical determinants in premium IOL outcomes, Dr. Karpecki notes. Public awareness of premium IOLs is relatively low, Dr. Karpecki adds. Few patients are prepared to quickly determine whether they would like to have premium IOLs implanted, let alone what type of lens would best suit them.

Optometrists should take the time to counsel patients on how premium IOLs work as well as the pros and cons of IOL correction, Dr. Karpecki said. The optometrist must then be able to discuss the various types of premium IOLs available and how those IOLs might be used to meet the patient's visual needs. The patient can then discuss IOL options with the ophthalmologist and make informed decisions, Dr. Karpecki notes. “Traditionally, ophthalmologists have made all the decisions regarding IOL surgery. But today, a range of new IOLs can be used to correct more vision problems than ever. A surgeon has more factors to consider when choosing the IOLs that will best suit the patient. Patients, of necessity, are becoming more involved in the process. That means prospective IOL patients need to be counseled by their optometrists before being referred to the surgeon,” Dr. Karpecki said.

Dr. Karpecki recommends optometrists take time to discuss premium IOLs with area ophthalmologists to whom patients may be referred. “Develop a basis for understanding IOL correction. Find out how the ophthalmologists in your area provide IOL correction for various types of patients. This will allow optometrists to familiarize patients with IOL correction, allow them time to consider such correction, and prepare them to respond when the ophthalmologist asks if they would like premium IOLs,” Dr. Karpecki said.

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Explaining premium IOLs 

Dr. Karpecki suggests optometrists may wish to provide a fairly thorough briefing, beginning by explaining that there are 2 types of premium IOLs available in the United States:

There are 2 types of multifocal lenses available: the diffractive multifocal IOL (AcrySof® ReStor®, Alcon Laboratories, Fort Worth, Texas) and the refractive multifocal IOL (Tecnis® and ReZoom™, Abbott Medical Optics, Abbott Park, Illinois). Bausch & Lomb's Crystalens® (Rochester, New York) is the only accommodating lens now available in the United States.

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Advantages and disadvantages of each type of premium IOL 

The most notable advantage of any premium IOL, including multifocals, is that they help restore some of the accommodative ability lost with the removal or aging of the natural lens. In contrast to traditional monofocal lenses that focus light to only 1 point, a multifocal lens has more than 1 point of focus. Most commonly, multifocal IOLs will be bifocal, although trifocal IOLs are also available.

Glare and haloes around lighting at night are generally considered to be the most common problems associated with multifocal IOLs. About 25% of patients with multifocal IOLs (both diffractive and refractive) experience some level of glare or haloes. Those visual distortions can interfere with the patient's ability to drive comfortably at night. However, most patients find they get used to this phenomenon with time, and the glare and haloes effectively become less obvious. Glare and haloes are considered to be an inherent characteristic of multifocal lenses. However, approximately 7% to 8% of monofocal IOL patients also notice glare and haloes. And sometimes glare and haloes can be reduced by correcting residual refractive error or by treating dry eye or ocular surface diseases that may be present.

Diffractive multifocal IOLs generally provide excellent reading vision, very good distance vision, and good intermediate vision. However, patients who frequently use computers may need to sit close to the monitor, adjust the font size of displayed text, or use intermediate vision eyeglasses.

Refractive multifocal IOLs, on the other hand, provide excellent distance and intermediate vision with good near vision. However, near vision may not be sufficient to read very small print such as telephone book listings or instructions on medicine labels. Patients who read frequently or read in poor lighting may experience eye fatigue. A pair of near vision spectacles may be required.

The main advantage of accommodating IOLs is their ability to more closely approximate the focusing ability of the natural lens. They provide excellent vision at all distances—although some believe they typically do not provide the same quality of vision at closer ranges as the best multifocal IOLs. (Clinical trials of accommodating IOLs conducted for the U.S. Food and Drug Administration found 100% of patients could see at intermediate distances [24 to 30 inches] without glasses, 98.4% could see well enough to read the newspaper and the phone book without glasses, and visual acuity was restored to 20/40 or better in 88% of patients [compared with 35.9% of patients who received normal IOLs])¹, ² Accommodating IOLs have proven effective in reducing haloes, glare, and other visual aberrations because light comes from—and is focused on—a single focal point. They project no unwanted retinal images and produce no loss of contrast sensitivity or central system adaptation.

The main concern with accommodating IOLs is the lack of long-term, large-scale studies on their use. Complications are rare but can include capsular bag contraction and posterior capsule opacification that will require a yttrium aluminum garnet capsulotomy. Accommodating IOLs are more difficult to implant than standard IOLs and recovery time may be longer. Typically distance vision begins to stabilize at about 1 week and near vision after 2 weeks. Patients should understand that accommodative abilities will not be restored to perfect or even near-perfect function. The degree of improvement will not be the same for all patients and some will still need eyeglasses.

Many ophthalmologists now recommend a “mix and match” approach to offer patients the best features of both major types of premium IOLs. A multifocal IOL is implanted in one eye to provide good near vision for reading, while an accommodating IOL is used in the other eye for good midrange distance vision. With this approach, distance vision is not compromised while near vision is optimized. However, some patients may have trouble adjusting to the use of a different type of IOL in each eye, Dr. Karpecki said.

Patients should also be aware they have the option of toric IOLs for the correction of astigmatism. Toric IOLs can correct up to 3.00 D of astigmatism. These are also considered premium IOLs, and patients are responsible for paying what Medicare does not cover. Other significant IOL advancements include aspheric monofocal IOLs that have been shown to improve the quality of vision, especially in mesopic or dim illumination situations.

Postoperative care for premium IOLs is similar to that required for monofocal IOLs. However, some practitioners recommend patients who receive accommodating lenses perform ophthalmologic exercises such as puzzles and word games as a part of a daily regimen to tone up ciliary muscles and ensure the maximum benefit from the lenses. In such cases, the exercises are done consistently for 3 to 6 months, and the patient's performance is monitored by the patient's eye care practitioner, Dr. Karpecki notes.

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• Figure 1 

  ReZoom™ multifocal lens technology. Abbott Medical Optics' ReZoom™ multifocal lens utilizes Balanced View Optics™ technology to provide multiple focal points, allowing patients to see well at a variety of distances. The ReZoom™ multifocal lens has 5 uniquely proportioned visual zones designed to provide clear vision for different light and focal distances.

Patients should understand that premium IOLs are more expensive than conventional IOLs and can represent a substantial out-of-pocket cost. Because they are considered a “premium” vision correction measure (helpful in reducing dependence on eyewear but not necessary to restore functional vision), Medicare and most other public and private insurance plans do not cover the cost of premium IOLs. If a cataract patient opts for a premium IOL, Medicare will provide its standard reimbursement for a monofocal IOL, cataract surgery, and facility fees, and the patient must pay the difference to get the corrective lens. Clear lens extraction solely for the purpose of correcting presbyopia is considered a nonessential procedure and not covered by Medicare at all. Most other public and private insurance plans have similar policies. Patient costs for premium IOLs therefore can top $2,000 per eye.

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Identifying candidates for premium IOLs 

In addition to educating patients on the availability of premium IOLs, optometrists should be able to help patients understand whether they are appropriate candidates for the lenses, Dr. Karpecki emphasizes. Often, the suitability of a candidate depends as much on patient needs, expectations, and temperament as on the physical characteristics of the patient's eyes.

Patients with very high refractive error—cataractous or noncataractous—are generally considered the most appropriate candidates for refractive lens exchange procedures because they are most likely to desire, and benefit from, reduced reliance on eyewear. In general, patients older than 50 with no serious eye diseases can be considered candidates for premium intraocular lenses. Presbyopes with very high refractive error or other conditions that render them inappropriate for laser-assisted in situ keratomileusis (LASIK) would generally be the most likely to be considered appropriate for clear lens extraction. A high-level astigmatism (not easily corrected with limbal relaxing incisions or refractive surgery) and other eye problems (such as retinal disease), which would reduce the quality of vision, should be considered contraindications. Pupils must dilate adequately, as IOLs will induce glare in low-light environments if the pupils dilate too large.

The ideal premium IOL patient greatly desires reduced dependence on eyeglasses or contact lenses and is prepared to overlook some potential reduction in vision quality in exchange. Patients with active lifestyles are among the best candidates. Patients with jobs such as truck drivers, who constantly require good night vision, might be considered inappropriate for certain types of premium IOLs.

Because a significant number of patients experience visual effects such as glare after premium IOL implants, adaptive behavior must be a factor when IOLs are considered, Dr. Karpecki emphasizes. Good candidates for premium IOLs generally are easy-going. An “extreme perfectionist” is the worst candidate for premium IOLs, Dr. Karpecki said. Patients with presbyopia and hyperopia generally have the best outcomes and tend to appreciate the improvement in focusing and near vision that premium IOLs provide. Patients with high to severe levels of myopia are often so accustomed to extremely blurry vision without eyeglasses that the uncorrected vision improvement achievable with IOLs, even with some visual distortions, can be impressive and appreciated. Patients who have enjoyed emmetropia most of their lives generally require additional education on proper expectations for premium IOLs, as they are used to very good vision and tend to find any kind of visual distortion unacceptable. So too are low-to-moderate myopes for whom any vision improvements may not be significant enough to make up for the possible visual distortions. Generally, younger patients tend to adapt to visual side effects easier than older patients.

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Summary 

Premium IOLs could grow in importance over the coming years as a corrective option for both cataract patients as well as noncataractous presbyopes, Dr. Karpecki believes. The most recent technologies—including the Crystalens HD, ReStor 3.0, and Technis multifocal lenses—represent significant improvements over previous versions of the lenses. A number of promising multifocal and accommodating IOLs are in clinical trials including: Accomodative 1CU (HumanOptics, Erlangen, Germany), Smartlens™ (Medennium, Irvine, California), and a new dual optic accommodating lens, Synchrony (Visiogen, Inc., Irvine, California). That means more appropriate IOL correction options are becoming available to more patients. As a result, optometrists will be called on to play a greater role in helping patients understand their premium IOL options, Dr. Karpecki said.

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• Figure 2 

  Examples of multifocal and accommodating intraocular lenses for cataract surgery and refractive lens exchange include (top row, from left) ReStor® (Alcon) and ReZoom™ (Abbott Medical Optics) as well as (bottom row, from left) Crystalens® (Bausch & Lomb) and Tecnis® (Abbott Medical Optics).

“Optometrists should consider counseling their cataract and presbyopia patients on the availability of premium IOLs for several reasons,” Dr. Karpecki said. “First, it is simply the right thing to do for the patient. Many patients can benefit from premium IOLs. Second, if a patient is appropriate for premium IOLs, the patient should learn about the lenses from the optometrist before being referred to the ophthalmologist for surgery. Patients need to be educated on the potential benefits of these lenses when they have the time to think about them and adequately consider them. Surgery is an unnerving experience for any patient. The optometrist should take the time to help spare the patient any surprises. No patient wants to be confronted with the need to make choices regarding a subject they know little about—such as whether to opt for premium IOLs—when talking to an ophthalmologist whom they have just met,” Dr. Karpecki said

Finally, properly advising cataract and presbyopia patients on the availability of premium IOLs can help the optometrist retain those patients. By advising the patient of this relatively new vision correction option, the optometrist demonstrates knowledge of state-of-the-art eye care. The optometrist who fails to inform patients of such vision correction options is at risk of appearing “not as progressive as one could be,” Dr. Karpecki contends. “When a patient is informed of the premium IOL option by an ophthalmologist after a referral for surgery, the patient may decide the ophthalmologist is a better, more knowledgeable eye care provider than the optometrist. The patient might then decide to begin seeing the ophthalmologist for routine eye care.”

For additional information, see the AOA Web site presbyopia page (www.aoa.org/x4697.xml) or cataract page (www.aoa.org/cataract.xml).

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References 

1. United States Food and Drug Administration. Center for Devices and Radiological Health (CDRH). Crystalens Model AT-45 Accommodating IOL P030002. New Device Approval. CDRH Consumer Information. Updated January 21, 2004. Available at http://www.fda.gov/cdrh/mda/docs/p030002.html. Last accessed June 22, 2009.
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2. Crystalens Accommodating IOL. USA Eyes. Council of Refractive Surgery Quality Assurance. Available at www.usaeyes.org/lasik/faq/crystalens.htm. Last accessed June 22, 2009.
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