Realistic expectations are important for patient satisfaction with multifocal IOLs

December 2000

VENICE — Patient selection is important with the Array multifocal IOL (Allergan, Irvine, U.S.A.), and the surgeon must take into account ocular health, refractive error and the patient’s personality and lifestyle, according to David F. Chang, MD, who spoke about multifocals at the Venice 2000 meeting, sponsored by Ocular Surgery News, the Italian Association of Cataract and Refractive Surgery and the International Society of Refractive Surgery.

“Exploring all of this might be time consuming, but our patients depend on us to help them determine if they are good candidates for this technology,” Dr. Chang said.

Dr. Chang has been implanting the Array SA40 Multifocal IOL since 1997. He implants the IOL in approximately 15% of his cataract population, he said, reflecting his caution in patient selection.

As a result of this careful approach, however, the majority of his patients are extremely satisfied, with an average patient satisfaction rating of 3.8 on the Javitt 0 to 4 subjective scale (4 = extremely satisfied; 0 = not at all satisfied).

“As cataract surgeons, we are used to thinking in terms of objective measures of our success,” Dr. Chang said. “With the multifocal IOL, important objective criteria would be spherical refractive error, postoperative astigmatism and uncorrected near and far acuity. However, patient satisfaction is really a subjective distinction. For example, two bilateral Array patients may have identical uncorrected Jaeger acuities, and yet have significantly different subjective opinions about their need for reading glasses. This is why patient selection is so important with the Array.”

Prerequisites for satisfaction

Dr. Chang listed four important criteria for achieving a happy multifocal patient. “First, we must perform flawless surgery, which is both astigmatically neutral and which provides optimal in-the-bag centration of the IOL. Second, the eye must be healthy, with excellent best-corrected visual acuity. Third, we must select the optimal IOL power. Finally, we need to generate realistic patient expectations through a combination of education and selection. This certainly increases the demands on the cataract surgeon, compared with when patients expect to wear bifocals after surgery,” Dr. Chang said.

“With the latter patient, if we inadvertently induce 1 D to 2 D of anisometropia, 1 D to 2 D of against-the-rule astigmatism, or if we miss the spherical target by + 1 D, the correction ends up in the glasses. The patient will likely be unaware of 0.5 mm or 1 mm of optic decentration. And barring late complications, the patient will be just as happy with an anterior chamber IOL in the event of posterior capsule rupture. Unfortunately, all of these scenarios compromise the uncorrected visual function of the Array patient,” he continued. “The aim of seeing well without glasses is compromised.”

Dr. Chang added, “The ideal patient is one who is strongly motivated to see without glasses, will be able to adapt to the nighttime images and has reasonable expectations that can be met. These expectations will be shaped by the patient’s personality, their level of uncorrected acuity preoperatively and preoperative education. We tend to disqualify individuals whom we feel will be difficult to satisfy for any of these reasons.”

Preoperative factors to consider

In attempting to identify Array candidates, Dr. Chang considers five factors that help him to predict patients most likely to be satisfied.

First, he assesses lifestyle issues, such as the patient’s occupation and reading needs. “If the patient drives infrequently at night, adaptation to haloes becomes much less of an issue,” he said. Second, he looks at the patient’s preoperative refractive error, because this is what patients will use as a basis for comparison postoperatively. “For example, uncorrected J4 vision will seem miraculous to someone who was +3 preoperatively, but will seem disappointing to someone who was formerly –3 and never wore glasses to read in the past.”

Third, the frequency of spectacle use preoperatively may provide important clues about the patient’s motivation to avoid glasses. “We’ve all been impressed by people who, despite having significant refractive errors, don’t wear their glasses very often, if at all,” he pointed out. “These people are apparently willing to tolerate the blur rather than bother with spectacles. On the other hand, a nearly emmetropic patient who wears bifocals daylong to hide facial wrinkles, or because he or she is too blurred without that –0.50 sphere, would seemingly have little to gain from the Array in exchange for the potential drawbacks.”

Dr. Chang added, “We know from refractive surgery that individuals differ greatly in the value they place on their ability to see without glasses. For some patients, the motivation was so strong that even the tremendous glare and fluctuating vision that accompanied a 16-incision radial keratotomy was an acceptable trade-off. Such motivated patients would more quickly accept and adapt to nighttime halos as well.”

Ability to tolerate nighttime images

Fourth, Dr. Chang considers the cataract density. “Whether it be a floater, halos, monovision or progressive bifocals, individuals vary greatly in their ability to adapt to imperfections in their vision. The degree of cataract and visual complaint may be telling in this regard,” he said. “A patient with advanced brunescent lenses, 20/200 acuity, and yet relatively understated complaints is telling you he’s not a very ‘picky’ person. This is in contrast with the 20/40 patient with minor lens opacities who, despite being reassured 3 months ago, is back again feeling utterly disabled by his or her deteriorating vision. Obviously, this person may have more trouble adapting to halos.”

Finally, assessing pupil size can help to predict the potential for dissatisfaction. Dr. Chang explained that patients with smaller pupils (that is, less than 2.5 mm in room light) are more likely to require reading glasses, but will have little problems with halos. “For these people I spend more time downsizing the expectation of reading without glasses,” he said. Patients with larger pupils (that is, greater than 4 mm in room light) will enjoy the best uncorrected near acuity, but will experience the most obvious halos. “These patients need much more reassurance pre- and postoperatively about the adaptation that is expected to occur over time.”

Getting started

“Surgeons just getting started with the Array should select the most ideal candidates who will be the easiest to satisfy,” Dr. Chang said. “A hyperopic patient with a 3-mm pupil who dislikes spectacles, rarely drives at night and has a dense cataract would be such a person. In contrast, a myope with a 4.5-mm pupil, who wears bifocals full time and who is overwhelmed by painful glare with nighttime driving attributable to a fairly minimal cataract would be a riskier candidate.”

Dr. Chang said the decision to implant the Array is like other non-medical decisions that surgeons help patients to make every week — decisions about refractive surgery, cosmetic surgery, monovision contacts or progressive add spectacles.

“In each case the potential drawbacks should be weighed against the anticipated benefits that are largely subjective and individual. It would be inappropriate to push these options on every patient,” he said, “but it would be just as wrong to deny these options to all patients because of the potential for dissatisfaction. I believe we owe it to our cataract patients to acquire the skills and experience needed to offer the Array, and to spend the necessary time educating them and evaluating their suitability,” Dr. Chang said.

For Your Information:

• David F. Chang, MD, is a clinical professor of ophthalmology at the University of California at San Francisco, and is in private practice in Los Altos, CA, U.S.A. He can be reached at fax: +(1) 650-948-0563; e-mail: dceye@earthlink.net. Dr. Chang is a paid consultant for Allergan.
• Allergan Inc. can be reached at 2525 Dupont Drive, Irvine, CA 92612 U.S.A.; +(1) 714-246-2201; fax: +(1) 714-246-4297.