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Education and experience needed to perform PRK and refractive procedures
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--- John W. Potter.
As the development director for TLC The Laser Center, based in Toronto, John W. Potter, OD, knows as much about optometric involvement with photorefractive keratectomy (PRK) as anyone in the world. He recently visited Canada and spoke with optometrists who have been comanaging PRK for as long as 5 years. Dr. Potter is in private practice in Dallas and is a charter member of the Primary Care Optometry News Editorial Advisory Board.
PRIMARY CARE OPTOMETRY NEWS: Food and Drug Administration approval of the Summit excimer laser for PRK in the United States was a long-awaited event. Has it lived up to its expectations?
John W. Potter, OD: No, it has not. Everyone began to feel as if once this was approved, the world would stop turning, and everybody would line up to have PRK. The older practitioners—the old contact lens wizards and the old cataract gurus—have seen a lot of change, and none of them overreacted because they've accumulated a fair amount of wisdom about change in eye care over their careers. They're probably a lot more accurate than we younger folks who tend to think that every new development is the greatest thing or the worst thing that ever happened.
I see this as a 2- or 3-year evolutionary process, reaching some reasonable maturity by about 5 years. It's not easy to bring this technology into the marketplace and change the world. It's much more complex than that, because we're talking about an elective cosmetic procedure; it's not something that people have to have.
PCON: What have you been doing since the approval? Has anything changed for you?
Potter: Yes, it has. As a company [TLC The Laser Center], we are a lot busier because everybody wants to know what they should do. The doctor, be he or she an optometrist or an ophthalmologist, is talking about this with everybody, if it's the local hospital or the manufacturer or the laser management companies, so it has increased the activity in laser vision correction.
PCON: What percentage of myopes does the Summit approval cover?
Potter: Not nearly as many as you would think. There are two ways to look at this. There aren't really that many spherical myopes. There are even fewer in the –3D range, the most common contact lens prescription, because these people may be doing quite well with eyeglasses or with contact lenses and are not as likely to desire refractive surgery. They also are candidates for the other incisional procedures, either radial keratotomy or automated lamellar keratoplasty, so we don't have something that's going to move patients from spectacle correction and contact lens correction to laser correction.
PCON: Under the Summit protocol, if you want to get results equivalent to those in the clinical study, do you have to remove the epithelium?
Potter: Yes. That, in some respects, made the study complicated, because that's where PRK got the reputation for causing so much pain: nonsteroidal anti-inflammatory drugs (NSAIDs) were not used in the trial. The clinicians made strong arguments as to why the use of - NSAIDs made perfect sense, and any reasonable surgeon will want to use them. It makes a big difference to the patient, and I don't think it has any significant effect on wound healing.
PCON: How do you feel about laser in situ keratomileusis (LASIK)?
Potter: I feel very strongly about it. It offers some very clear and distinct advantages for the higher myopes, the ideal candidates for laser correction.
PCON: Can you comment about off-label use of LASIK in the United States?
Potter: It's a very complicated issue, because we're talking about not only federal regulation, but the interpretation of federal regulation. Then you also introduce issues of professional liability and corporate liability. The issue is black boxes (custom lasers), and the temptation is for clinicians to get involved in that kind of technology. I can't imagine that the regulators will just let it happen.
It doesn't sound quite right to me, but I think more and more surgeons will do it, especially those who already have a position in refractive surgery and who believe that the longer the FDA delays, the more apt their competitors are to come into the market equal to them. So some black boxes probably will be used just to maintain a competitive advantage in the marketplace as much as they will be used to do procedures.
It is possible to perform off-label LASIK with a Summit laser. But I would caution clinicians in trying to take a technology and expanding its use beyond its approval by rigging the nomograms or the protocol or by operating twice on the same eye. I don't think that's good sense. If the FDA has approved the machine for specific uses, that's what it should be used for. Optometrists who refer to surgeons who perform off-label LASIK heighten their own legal exposure.
PCON: Tell us about the Canadian market.
Potter: I recently interviewed about 100 optometrists in British Columbia, about a third of the optometrists in that province. Without FDA regulation, it took about 2 years for this market to begin to develop. A major reason is resistance on the part of optometrists and ophthalmologists to embrace this as a viable alternative to contact lenses and spectacles, regardless of approval.
There are fundamental issues in educating doctors and patients about the risks and benefits of having the procedure done. A system to care for patients must be organized. This is an open market and it's still not developed in the same way people in the United States thought it would be. The interesting cultural issue here has been the perception that eye care in Canada is different from that in the United States. But there are more similarities than differences. We should be talking to our colleagues in Canada and saying, What did you learn? What would you have done differently?
PCON: How many people are undergoing PRK in Canada?
Potter: I don't know exactly, but of the optometrists I spoke to who had treated at least 50 PRK patients, none treated more than 100. Almost all had treated at least one in the last 3 to 5 years, since they've had lasers.
PCON: Do LASIK results justify what seems to be the high opinion of it held by many surgeons?
Potter: Absolutely, for a number of reasons. The patient obtains a faster visual recovery. It's a lot more predictable in terms of outcome, because there's a lot less manipulation of the epithelium and anterior stroma interface. We still don't have a really good understanding of how this interface comes together and how healing occurs following PRK, and this is where this idea of adjusting topical anti-inflammatories to control epithelial hyperplasia becomes so paramount. It's a process that we don't know and understand very well, and we're doing it, for the most part, empirically.
PCON: Is it possible that the high opinion of LASIK may suppress acceptance of PRK?
Potter: Interesting strategy there. Some in the field say that nobody should do PRK because LASIK is so much better. That's unrealistic. As the PRK results in the Summit trial show, if your patient falls within those guidelines, you'll have a good outcome.
In our facilities we consider patients who are -6 D and above as LASIK candidates in terms of spherical equivalent. In our experience, once the patient has been offered the two procedures, PRK and LASIK, the patients more often than not will want LASIK. The reason is the faster visual recovery, less pain and less risk of infection.
PCON: Do you believe that most American optometrists have an accurate understanding of PRK and other refractive techniques?
Potter: No, they do not. Both optometrists and ophthalmologists have a lot to learn about these procedures. There are fundamental misunderstandings and a lot of disinformation about the procedures, too. Both professions have an obligation to get educated. Even if a doctor believes that the normal human cornea should not be violated for the correction of refractive error, I still think that he or she should learn as much as possible about the procedures, because that position will not prevail.
It's sad to see how the education of this process has developed. Our own company, TLC The Laser Center, has a full-time education foundation because we recognize how significant an issue education is in a developing technology.
PCON: That applies to ophthalmologists, too?
Potter: No question. In fact, it potentially is even a more serious problem in the ophthalmologic community, because these are people who can actually do the procedure. You've got a group of people who may be able to do the procedure, but may not have all of the information they need, or they may have incorrect information.
PCON: There are some fundamental questions when it comes to comanagement of the refractive surgery patient. The optometrist may wonder about the credentials of the surgeon and vice versa. How are those questions answered?
Potter: The optometrist in practice is confronted with a dilemma: Am I referring to the machine or to the doctor? If the machine is capable of producing X results, and the data show that those X results were produced by a multitude of practitioners, not just one or two doctors, then, within reason, it shouldn't make any difference who pushes the button. However, we also have to consider how the patient is treated and the fine nuances surgical experience could bring to the outcomes.
From the ophthalmologist's side, everybody recognizes that the healing of the patient is very significant, and yes, you can modify healing based upon how you manipulate medications.
I recommend performing a simple outcomes analysis. Exchange information on your patients' healing as everybody learns how to handle these patients. Despite the number of patients who have had the procedures done with Summit and VisX and Chiron machines, fundamentally, we've still got a lot more to learn about healing.
I believe that it is better in the long run for the PRK or LASIK patient to be back in the hands of the optometrist. Here, optometrists have a unique advantage over surgeons taking care of these kinds of patients because of their extensive contact lens experience and dealing with patients' questions and symptoms of their visual-related problems.
PCON: Will this communication among optometrists and ophthalmologists occur within networks or in a more official way between the two professions?
Potter: The companies tend to look at it as more of a reporting issue, but the professionals tend to look at it as how we think about what we do. The two groups, the eye care professionals and the companies, working together will find the best answer to this. What's going to make the big difference is the collective understanding of our—optometrists' and ophthalmologists'—outcomes. We can't hide our complicated patients; we can't overinflate our results. We have to be factual in how we communicate about this. Otherwise, it won't work.
Optometrists in British Columbia have gotten involved in LASIK by default. No regulatory bodies require a certain number of hours of education per year on the subject. Either patients are asking for it or a nearby surgeon asks you to see his or her post-surgery patients.
PCON: Some ophthalmologists believe that it's possible to offer PRK as a surgeon without optometrists playing a role anywhere in the patient flow. Others have said that about 70% of patients undergoing PRK will come through optometrists. Does that sound like a reasonable figure?
Potter: I don't think it's that high. Ophthalmology takes care of a significant number of refractive patients, there's no question about that. But let's factor in income, age, a number of other issues that don't have anything to do with the amount of myopia the patient has. If you do that, then optometry's role is very significant, because optometrists take care of a lot of the ideal candidates, given the other factors besides myopia. Yes, it makes a lot of sense for optometry and ophthalmology to work together.
If you do not do it that way, the only way you could be successful would be to mass market. When you mass market, your risk increases enormously. These marketing campaigns are very expensive to implement. The demands to make payments to the marketing agencies and to the advertising agencies and to the media are intense, and they're very specific time-wise. That tempts surgeons to do things a little bit less thoroughly than they would like to. If anybody wants to do this on their own without collaborating with the other eye care professionals, be they an ophthalmologist or an optometrist, it doesn't make any difference; that's fundamentally flawed thinking.
Twenty years ago you could be an isolated solo practitioner. Ten years ago you could be an isolated solo practitioner, but to a lesser extent. In 1996 and going into the next century you can no longer be an isolated practitioner, and that means that you're participating in managed care plans with your colleagues and in comanagement programs, both within and outside your profession.
PCON: It has been said that refractive surgery may become a way of American middle-class life, like orthodontia has become standard for teenagers. Because it should only be performed later in life, perhaps refractive surgery will become part of the college experience. You get your degree, you get your eye surgery.
Potter: That brings up a good point. We don't know very much about when refractive error stops changing. And we still don't have good long-term information on laser vision correction. Let's just assume that at 10 years patients acquire 0.75 D or 1 D of refractive error either to the plus or minus. If we knew that, then we might build that in on the front end in order to maintain a higher quality of vision for a longer period for more patients.
That leads to what I think is the fundamental issue: What is 20/happy? There are two sides to the coin. If you believe that this procedure is designed to get rid of eyeglasses or contacts, and that's how you've positioned yourself in the marketplace, then you'll do everything you can to keep people out of eyeglasses or contact lenses after the procedure.
On the other side of the coin, assume you've focused your whole life on best corrected visual acuity—and every optometrist in the United States has that emblazoned on their souls. If a patient comes in with 20/25 or 20/30 vision, and they're pretty happy, and you can make them see better with a -0.50 sphere and 0.75 cylinder, axis 85, you're going to prescribe that, because you know it will give the patient better vision.
What we need to find out is: If you're between 35 and 45 years old and you have a family income of X, and these are your sports, you fit into this stratified grid. Only outcomes analysis on this scale will tell us who the ideal candidates really are.
I tell optometrists all the time: Do not refer young people for this procedure. Refer people who are older, who have more stable vision, who have the money to pay for this and who may still require eye wear for the correction of presbyopia. Optometrists are very nervous about losing the eye wear side of this. I don't think that will happen, but they still fear that.
PCON: It must be hard to turn away a patient who wants it.
Potter: Absolutely. But the problem with bad refractive surgery is patients don't die from it. They're around for a very, very long time, and you have to live with that bad result for 30 or 40 years.
PCON: Can you comment on ODs performing PRK?
Potter: I believe the same percentage of optometrists and ophthalmologists would be interested in doing this procedure. Many optometrists believe they could do this procedure, and they probably would do it pretty well. There are a lot of ophthalmologists who never will do this procedure for a variety of reasons—they don't believe in it, it's not their specialty, etc. I don't know whether or not optometrists will ever do this. I don't know how much difference it would make if they did.