MULTIFOCAL IOLS

Addressing Multifocal IOL Challenges

Learn how you can better prepare patients for surgery and set appropriate expectations.

By Dr. Steven J. Dell, MD

► In my practice, we strive for perfection with every cataract surgery we perform, but we've learned that the importance of getting every detail just right is amplified when we implant multifocal IOLs.

In part, this is because patients pay for the lenses and thus have higher expectations. But a demand for perfection also stems from the multifocal technology itself, which is more sensitive to refractive errors, ocular surface disease and retinal issues than standard technology. Postoperative findings that suggest something is slightly off track occur no more often with multifocal IOLs than they do with monofocal IOLs, but can create more significant visual issues for multifocal patients. Despite the challenges associated with multifocal IOLs, however, there are steps you can take preoperatively to improve patient outcomes and satisfaction.

Improve Health Prior to Surgery

The most important thing you can do prior to surgery is strive to get your patients' ocular surface health in tip-top shape. We spend a great deal of time treating patients for symptomatic and asymptomatic dry eye. Experience has taught us that many patients who have dry eye aren't even aware of it. Many have a kind of forme fruste dry eye syndrome that goes unnoticed but is evident because of findings, such as superficial punctate keratitis (SPK) on the cornea or a greatly reduced tear break-up time.

Good keratometry is important in selecting the proper power for a lens implant, and keratometry is highly influenced by the condition of the surface of the cornea. We must ensure that the tear film isn't compromised or we risk less accurate lens calculations.

Sensitive multifocal technology requires us to be even more aggressive in treating dry eye with patients receiving premium IOLs than we might be with those receiving standard lenses. We place a large percentage of patients on artificial tears prior to surgery, and we're quick to recommend topical steroids, oral omega-3 fatty acids and topical cyclosporine. We also place punctual plugs in patients with dry eye with very little hesitation. We address these tasks about 2 weeks prior to surgery.

It's important to ensure that other conditions, such as blepharitis, are also treated prior to surgery. When we encounter blepharitis, we attempt to treat it with proper hygiene, but in many cases, topical azithromycin is required as well.

Select, Communicate Wisely

Patient selection is crucial and it's also important to communicate effectively with patients prior to surgery in order to improve postsurgical outcomes. We meet a large number of patients for the first time during preoperative consultations, so I've developed a questionnaire that can be used to collect important clues about a patient's personality while also communicating information to the patient. The questionnaire works well to achieve three important objectives. First, it gives us a quick sense of what patients are hoping to achieve with regard to their vision. Second, the very process of answering certain questions, and making choices, helps to temper some patient expectations. And third, the questions are designed to help us predict how flexible or adaptable a patient is likely to be during the postoperative period. We are especially concerned when a patient gives contradictory answers, identifies himself as a perfectionist — or worse — refuses to fill out the form. These situations indicate that further preoperative counseling is needed.

Monitoring Side Effects

Although it's impossible to divide the postoperative period into distinct stages during which only certain events occur, there are events that tend to occur with greater frequency shortly after surgery and those that are more common as the postoperative period lengthens.

The most common concerns shortly after surgery, and often on the day of surgery, are intraocular pressure spikes and wound leaks. During the first week or so after surgery, we must be vigilant for signs of infection, edema of the cornea, and cystoid macular edema (CME). The first week after surgery is the best time to ensure that the lens is well centered, keeping in mind that multifocal IOLs are much more sensitive to the results of decentration than monofocal IOLs. In extreme cases, a surgeon encountering decentration may return to surgery to recenter the lens. One other option in this situation is an excellent technique developed by Eric Donnenfeld, MD, — a form of pupilloplasty performed with an argon laser in which the pupil is shifted in the direction of the decentered IOL, in lieu of shifting the IOL toward the pupil. I have used this technique and it has worked well for me.

What to Watch For

The first postsurgical week is also the time to make sure there's no retained nuclear or cortical material; although this is an uncommon complication, if it occurs, it should be recognized and addressed during this time frame. During the first postop week, we begin to check for residual refractive error; readings taken at the first postop day are likely to provide information that is less valuable.

When a patient has visual complaints in the weeks that follow, and everything in the front of the eye looks good, optical coherence tomography (OCT) may be helpful to determine whether problems with the retina are contributing to visual issues; OCT may be required at any time after surgery. Posterior capsular opacification (PCO) can occur quite early in rare cases, and even mild PCO will degrade the near performance of a multiofocal IOL out of proportion to the distance vision. It's also essential to keep in mind that CME can occur quite late after surgery, even after a long interval of good vision.

Addressing Specific Conditions

■ Residual refractive error: Astigmatic correction is commonly performed in conjunction with multifocal lenses, because if astigmatism isn't corrected, patients won't see well either close up or at a distance. There are a variety of strategies for treating astigmatism. Some surgeons may treat 100% of patients with laser vision correction following surgery, but for relatively small-to-moderate degrees of astigmatism, it's often better to begin with limbal relaxing incisions (LRIs). Afterward, residual astigmatism, with or without residual spherical error, can be treated with laser vision correction. When refractive errors are small, and particularly when the patient has a compromised ocular surface and dry eye, I am inclined to choose surface laser treatment with the excimer laser over LASIK.

■ Dry eye: Because we know that procedures such as LRI, and cataract surgery in general, can cause dry eye or exacerbate it, it's essential to address this condition adequately prior to surgery, as previously discussed. However, despite the best preparatory efforts, some patients will have dry eye after surgery, which they experience as a fluctuation in visual clarity. In many cases, postsurgical laser vision correction must be delayed until dry eye has been appropriately treated.

■ CME: The best way to handle CME is to learn how to prevent it. We do this in my practice by pretreating patients with topical nonsteroidal medications and continuing these medications for at least 1 month after surgery. For higher risk patients, we continue therapy beyond our usual schedule, often extending treatment for 2 months or longer after surgery.

■ PCO: Despite the significant pressure that patients are likely to place on you to achieve excellent vision as soon possible after surgery, it's best to defer YAG laser capsulotomy until after the third postoperative month. Postponing the procedure until the third month will reduce the risk of CME. Once again, it's valuable to remember that PCO tends to interfere with near vision first. If we have a patient who is seeing 20/20 at a distance and who experiences a worsening of near vision several weeks after surgery, we don't hesitate to attempt to correct this situation with the YAG laser.

Understanding Neuroadaptation

When patients are in the process of adjusting to multifocal IOLs, it's often difficult to determine when true neuroadaptation is occurring and when patients are just tired of complaining. But I do believe that, as time goes by, most patients are bothered less by problems that are related to the IOL.

When we have a patient with any visual complaint, it's essential for us to clearly establish for ourselves, and for the patient, which symptoms are lens-related and which are due to problems with the eye. Once we've clearly established that particular complaints are directly related to the multifocal technology, we reassure patients that their vision will get better with time, and that it's in their best interest to wait before discussing a possible lens exchange. Among typical patient complaints, I find that halos have the greatest tendency to fade with time. However, complaints of waxy vision, in my experience, are less likely to disappear with time. Instead, we sometimes find waxy vision can be traced to decentration of the IOL or may be related to irregular astigmatism in the cornea. In some cases, waxy vision is related to issues intrinsic to the multifocal IOL. Glare, in my experience, is not a typical multifocal IOL patient complaint, unless there is PCO.

Sometimes we encourage a patient with a diffractive multifocal IOL to stick with the process of adaptating to the lens by having the patient put on a pair of –3.00 spectacles. This forces him to use his near focus for distance vision. We ask the patient to read with spectacles on, and when the patient finds this impossible, we point out that the near vision he's enjoying would be sacrificed with a standard IOL. We hear few complaints after this demonstration.

In our practice, younger patients have the most trouble adjusting to new lenses. A 55-year-old patient is going to notice things that an 85-year-old would be less likely to notice. But regardless of the patient's age, we reassure all multifocal IOL recipients that in 3 to 6 months, the vast majority of patients adjust to their new lenses.

Meeting Challenges Head On

Today's multifocal IOLs are among a number of advanced lens technologies that enable cataract surgeons to offer patients an improved range of vision and reduced dependence on spectacles. Although these lenses have the potential to meet the visual needs of many cataract patients, multifocal IOLs present some challenges. However, with appropriate management of patient expectations, careful patient selection and communication, and refined preop and postop clinical strategies, surgeons can take advantage of the enormous opportunity inherent in multifocal technology. nMD