EyeNet Magazine



   
 
Feature
Minimize Surprise After Refractive Surgery
By Lori Baker Schena, Contributing Writer
 
 

A seemingly perfect refractive correction may not always lead to perfect visual results. That’s why good communication before surgery is important— it can help prepare patients for possible surprises.

The proliferation and success of cataract and refractive surgical techniques, typified over the last decade by high patient satisfaction and low complication rates, may have resulted in an unwanted side effect: complacency. This poses a potentially dangerous mind-set for refractive surgeons, who could be setting themselves up for unrealistic expectations from increasingly educated and demanding patients.

Jonathan M. Davidorf, MD, assistant clinical professor of ophthalmology, University of California, Los Angeles, recalls a woman who had undergone cataract surgery by another surgeon. While her eyesight was perfect, she vehemently complained about the cosmetic annoyance of the IOL reflection in photographs. She showed Dr. Davidorf a photo that vividly illustrated the reflection.

“This patient was actually belligerent,” he noted. “She had no dysphotopsias or other visual complaints, but was bothered by the appearance of the IOL. I found myself defending the other surgeon and discouraged her from undergoing an IOL exchange.”

While this story may be extreme, Dr. Davidorf added, “It does point to the importance of managing patient expectations and understanding a patient’s priorities. While we, as surgeons, may believe that all the patient wants is good vision, there may be other issues, which is why good communication during the consultation is so important prior to surgery.”

Refractive Surgery Is Surgery, After All

Ernest W. Kornmehl, MD, clinical instructor of ophthalmology, Harvard University, and associate clinical professor in ophthalmology, Tufts University, noted that one of the key messages that must be understood by patients, particularly those who undergo elective laser surgery to correct refractive errors, is that laser surgery is surgery, and should not be undertaken lightly. From the patient’s standpoint, this means finding a competent surgeon experienced in techniques that can meet the patient’s refractive needs. From the surgeon’s perspective, this means taking the time to determine and manage expectations in a thoughtful and realistic manner.

“Patients who end up as ‘refractive surprises’ probably had unrealistic expectations to begin with,” Dr. Kornmehl pointed out. “Many of these patients who pay cash have done their homework and are expecting perfection. This is why it is the surgeon’s job not only to evaluate the patient’s suitability for laser correction based on the clinical exam, but also to discuss the patient’s objectives prior to the procedure. For example, I always tell my patients that they will eventually need glasses for reading and that there is a possibility they may need glasses for driving at night if they opt for monovision. They must completely understand that eventuality and be willing to accept it. Otherwise, you might have a refractive surprise on your hands.”

In one ear, and . . .

Both Dr. Kornmehl and Helen K. Wu, MD, who is director of the refractive surgery service at the New England Eye Center in Boston and associate professor of ophthalmology at Tufts University, warn of the tendency for patients to indulge in “selective hearing.” Dr. Kornmehl recalled one monovision patient who was disappointed after laser correction because she needed glasses to drive at night, a contingency she had been asked to consider. “Fortunately, the patient’s husband remembered our presurgical discussion about this very possibility, and was able to remind his wife of our conversation,” Dr. Kornmehl said. “This is why I encourage patients to bring a family member or friend to serve as a second set of ears during the preoperative consultation.”

Dr. Wu said not only do patients sometimes have selective hearing, but they also apply the experience of their friends or family to their own situations, even when it may be inappropriate. Thus, no matter what their surgeon tells them or what papers they sign or videos they watch, they do not believe that the risks of less-than-perfect outcomes apply to them. For this reason, Dr. Wu strongly suggests documenting all conversations that take place prior to surgery. She also warns not to guarantee or promise perfect vision to a patient, and to inform patients if they have special risk factors that may increase their chances for postoperative problems such as dry eye.

Three Scenarios

Daniel S. Durrie, MD, associate clinical professor of ophthalmology and director of refractive surgery services, University of Kansas, Kansas City, echoed the observation that the success of refractive laser surgery has led to the notion that patients can expect a “one-day miracle,” a perception shared by both patients and physicians. When something goes even slightly amiss, there can be a refractive surprise. Dr. Durrie explained that refractive surprises actually can be separated into three scenarios, and each requires a specific strategy.

1. When everyone’s scratching their head. The first scenario is the outcome that is a “surprise to everyone” and constitutes about 0.5 percent of the refractive patient population. At the time of surgery, everything, including the flap, looks right on target. Yet at the one-month visit, the patient’s refractive error is way off; the patient should be plano, yet he or she is either –2 D or +2 D. What should be done?

“First,” said Dr. Durrie, “I always like to put myself in the patient’s mind and try to determine what he or she is thinking. There is a tendency for patients to immediately question themselves, ‘Did I not look at the light correctly during the laser correction?’ or ‘Did I use my eye drops right?’ As the surgeon, it is extremely important to reassure the patient that he or she did not do anything wrong. So the first step when confronting this situation is to acknowledge that the refractive error is off. Then let them know they did everything right. This will help regain the patient’s confidence in you so that you can go forward with the case.”

The next step is to review the surgical records to rule out any problem with the procedure itself, such as using the wrong prescription or a flipped axis. “I get the surgery chart and do this right in front of the patient,” said Dr. Durrie. “Interestingly enough, a lot of surgeons don’t do that right off the bat. But it is important to review the surgical records to clarify if anything did go wrong.” Once the surgeon can ascertain that there were no problems with either the surgical technique or patient, “then we probably can surmise that the patient didn’t heal the way we expected. There is a bell-shaped curve with refractive surgery patients, with some overresponding and some underresponding. That patient just fell on the outside of the bell-shaped curve.”

If this is the case, then the surgeon can tell the patient he or she is one of the 3 percent of patients who require an enhancement. He suggests that the surgeon confirm the error by repeating the measurement at least a month later. “This approach reassures the patient that the doctor wants to get the surgery right,” Dr. Durrie pointed out, equating it to a carpenter who measures a piece of board three times and only cuts it once. During the waiting period, Dr. Durrie may prescribe glasses so the patient can function. He will also go the extra mile for these refractive surprise patients, giving them after-hours or Saturday appointments to keep the patient happy.

2. The doctor was prepared, but the patient wasn’t. In the second case, the surgeon expects the patient to experience some post-op vision problems, but the patient is surprised.

For example, the –2 D or –3 D myopes who had great reading vision all their lives are now looking for perfect distance vision through refractive surgery. But following the surgery, problems arise with reading a cell phone or a menu. These patients are happy with their distance vision but failed to comprehend that their near vision would be less than perfect. In these situations, the patient has been educated about possible presbyopia and actually signs the consent noting that they will need reading glasses, but somehow the patient either ignored the information presented or used “selective hearing” during the consultation.

“The surgeon must take responsibility to ensure a full discussion of presbyopia is conducted prior to surgery,” Dr. Durrie said. “Following surgery, we fortunately can give them near vision—either LASIK with monovision or CK over LASIK. But it is critical not to suggest a surgical solution right away, and the worst thing you can do is to give the patient a lecture. “

Instead, you need to get the patient in and apologize for the fact that you didn’t get the message across. Again, this will eventually restore confidence and then you can do something to get the reading vision.”

3. The unexpected complication. The third scenario is the rare surgical complication that surprises the doctor. This would include a bad flap or a suction ring that does not hold onto the eye—something that would not allow the surgeon to complete the laser surgery. “It is vital for surgeons to remember that if something goes awry during the surgery, they should not finish it just for their ego,” Dr. Durrie warned.

“So if the patient has an incomplete flap, buttonhole or decentered flap, place it back down and stop the surgery. We have consulted on this type of case where the surgeon did the right thing, did not continue the surgery, and we were able to do PRK a few months later with the patient achieving 20/20 vision. It is important to be really up-front with the patient on these issues.”

Dr. Durrie added, “the more honest you are with your patients, the better off you will be. It is so important to establish strong relationships with your patients and then be honest.”

The Intraocular Lens Surprise:
Not a Pretty Sight

Over the years in her practice, Dr. Wu has become adept at handling and managing refractive surprise. But nothing could quite prepare her for the reaction from patients with multifocal IOLs who experienced an “IOL surprise.” She recalled, “I have had some patients who had less-than-expected outcomes after refractive surgery. But I was truly surprised by the vehemence of those individuals who experienced problems following refractive cataract surgery and implantation of multifocal or accommodating IOLs. I think when we are dealing with implantable lenses, the stakes are higher for patients, and thus any ‘surprise’ can cause an intense reaction. This is why additional chair time is required to ensure that these patients understand their individual situation and the measures that may be required to remedy the problem.”

Dr. Wu noted that special care must be taken when working with multifocal or accommodative IOLs. For example, a careful refraction is extremely important after refractive lens surgery; a small amount of astigmatism or hyperopia, for example, may appear as a “film” or a “blur” to the patient, causing the surgeon to perform an unnecessary YAG capsulotomy. In addition, patients who receive multifocal or accommodating IOLs appear to be more sensitive to mild amounts of posterior capsular opacification and the incidence of YAG capsulotomy may be higher in these groups of patients than in those after standard cataract surgery. “All patients should be counseled about the potential need for YAG capsulotomy afterward,” Dr. Wu said. “A certain small percentage of patients will not tolerate multifocal IOLs, and all patients who receive these lenses should be counseled about potential night driving problems and the possibility of explantation of the lens due to intractable night vision problems. Patients who drive at night often may opt for a monofocal or accommodating IOL to minimize this possibility.”

When residuals are not a good thing. Finally, in the case of residual refractive error after cataract extraction, a lens exchange or an appropriate refractive procedure should be performed, Dr. Wu pointed out. “In the case of low hyperopia after refractive lens surgery, conductive keratoplasty is effective and well-tolerated by patients,” she said. “LASIK or PRK may be required in patients with myopia and astigmatism who are not functioning well with regard to distance vision. This possibility should have been discussed in advance of the cataract surgery.”

The patient should also be informed about the fact that 10 or 15 percent of IOL patients may need a refractive fine-tuning procedure. If a cataract surgeon does not have access to refractive surgery modalities, he or she should establish a relationship with a refractive surgeon so that if there are any “IOL surprises,” they can be addressed.

True vision may take time. Dr. Wu noted that time also is a key factor in adjusting to vision, and that may be all that is required for some patients. For example, a Crystalens accommodative intraocular lens takes a minimum of six months to work the way it was designed. “These patients must be carefully managed and educated preoperatively, and there is a good chance that even after six months they may need reading glasses for fine print,” Dr. Wu said. “As more multifocal and accommodative lenses are implanted, there is no doubt that the number of surprises will increase accordingly. This is why surgeons should be fully prepared to actively manage these patients to minimize the surprise factor.”

One More Surprise

Ronald R. Krueger, MD, medical director of refractive surgery at the Cleveland Clinic, raised another refractive surprise that particularly concerns him: custom re-treatment of a symptomatic aberrated eye. This is for patients who have undergone a previous conventional treatment and are looking for a “custom upgrade,” not to be confused with an enhancement. For example, consider a patient who has surgery for a –10 D with a conventional treatment. He achieves 20/20, but the quality of the vision appears more like 20/30 because of the resultant aberrations. This can occur simply because making the cornea flatter in the center in a high myope can create spherical aberration. Also, with traditional techniques, inadequate tracking and registration can lead to subclinical decentration and ablation nonuniformity, inducing coma and other higher-order aberrations. 

Having a bad eye day? This patient seeks a custom re-treatment to improve his vision. Yet instead of achieving a good end result after the custom re-treatment either with PRK or under the flap, he is in even worse shape with a +2 D or even up to a +5 D overcorrection. “The problem is that the patient’s eye has so many aberrations that the depth of tissue removal to correct all these far exceeds what would be expected for the small residual refractive error. As a result, the surgeon gets a refractive surprise, and ends up overcorrecting the patient,” Dr. Krueger said. He attributes this to the fact that when wavefront-driven custom ablation officially made its FDA-approved debut on October 25, 2002, it was approved for primary treatment. When custom ablation is used for re-treatment, it can behave differently due to the excessively high aberrations and thinner cornea, which can result in massive overcorrections. The surgeon needs to compensate for this.

Dr. Krueger selectively performs this custom re-treatment procedure, but when he does, he adjusts the target offset to compensate for the high aberrations and deeper-than-expected ablation depth. For example, to re-treat a –1.5 D residual myope with high spherical aberration, the wavefront measurements may indicate 50 µm of tissue removal, but that would likely be too much. As a rule of thumb, he suggests planning for about 20 to 25 µm for each diopter of residual myopia to avoid an overcorrection, and compensating for the difference by using a positive target offset. In the case above, using the current maximum target offset of +0.75 D would be recommended, but the exact outcome is still dependent of many other factors, such as the amount of spherical aberration.

In a recent review of his custom upgrade procedures, Dr. Krueger noted that the amount of spherical aberration before the re-treatment is directly correlated to the amount of overcorrection seen postoperatively. In the future, when expanded target offsets are available, he hopes that a more specific correlation of target offset with expected ablation depth and magnitude of spherical aberration might be made to avoid refractive overcorrection. “The bottom line,” said Dr. Krueger, “is that you don’t want to go into a custom re-treatment without first discussing the risk of overcorrection with the patient. Then when you both decide to go ahead, carefully plan to use the target offset, or else you may experience a huge refractive surprise.”

Education Shapes Expectations

Of course, the real key in dealing with refractive surprises is to prevent them from occurring in the first place.

For Dr. Davidorf, this means making a commitment to carefully consult with patients and manage their expectations. “And this time should be used very carefully,” he noted. “I spend the highest percentage of my consultation time not necessarily addressing the serious, truly vision-threatening complications because the risk of these occurring in the standard case is extremely small. Yes, grave and difficult-to-treat complications can occur, but we need instead to concentrate on the more common things that will have the potential to lead to problems such as a refractive surprise.”

“Tailor your discussion to the patient’s condition and his or her needs,” Dr. Davidorf added.

“I liken it to discussing a ski trip with a rookie skier. There is a small chance he could get caught in an avalanche, but there is a better possibility that he will twist his knee on a catwalk. So that is what you focus on in terms of injury prevention. To avoid any refractive surprises, we need to remain vigilant. Refractive surgery has come a long way, but it still is not a perfect science.”

Meet the Experts

Jonathan M. Davidorf, MD

Assistant clinical professor of ophthalmology at the University of California, Los Angeles. Financial disclosure: None.

Ernest W. Kornmehl, MD

Clinical instructor of ophthalmology, Harvard University, and associate clinical professor in ophthalmology, Tufts University. Financial disclosure: None.

Ronald R. Krueger, MD

Medical director of refractive surgery at the Cleveland Clinic. Financial disclosure: He receives research and travel support from Alcon.

Daniel S. Durrie, MD

Associate clinical professor of ophthalmology and director of refractive surgery, University of Kansas, Kansas City. Financial disclosure: None.

Helen K. Wu, MD

Director of the refractive surgery service at the New England Eye Center, Boston, and associate professor of ophthalmology at Tufts University. Financial disclosure: Consultant with Becton Dickinson and on the speakers’ bureau for Alcon.

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