Article Date: 6/1/2009

FAQs About Refractive Surgery Procedures
REFRACTIVE SURGERY

FAQs About Refractive Surgery Procedures

An optometrist in the refractive surgery field answers questions commonly asked by contact lens experts.

By John Potter, OD, MA


Dr. Potter is vice president for patient services for TLC Vision Corporation. You can reach him at (972) 818-1239 or john.potter@tlcvision.com.

I have significant respect for the contact lens field and for Contact Lens Spectrum, but I myself have limited qualifications in the direct care of contact lens patients. In the small universe of refractive procedures, I am more qualified and have several opinions about things as they are and as they might be in the future.

What I am going to attempt to do in this article is answer the three most common questions that contact lens experts ask me about refractive procedures. My answers are my opinions only. The responses do not represent the opinion of TLC Laser Eye Centers or of any professional organization of which I am a member. And I am confident that some of you will disagree with what I have to say, and that is fine, too.

I have two habits that you may find enjoyable to read about or perhaps even relevant to your practice today. First, I love to doodle. I make drawings to help me think of things differently, and often they have really helped me. And, I often use them with patients, too.

Second, I am impatient. I don't like waiting a year or two to find out something if I can put some effort into it and find out on my own. So, I am nearly always doing a one-minute survey. I pick my topic, buy a pack of index cards, and then ask people I meet what they think. I have learned many skills and methods to make this work for me and also to require less than a minute of time for the person who has agreed to help me. In the years I have been doing these oneminute surveys, it is rather uncommon for someone to decline to participate.

You will see both of these habits of mine as you read this article.

Question 1: Can the enhancement rate following laser vision correction be lessened in the future?

From the standpoint of the physiology of the eye, the enhancement rate for refractive surgery can be reduced in the future, but it will never be zero.

Why? The answer is a math problem. Enough variation exists in the human eye's response to laser vision correction that there will always be variance in the result by either over-or under-corrections. In this regard it is better to under-correct a patient than to over-correct. So, if you had the expected variance of the human eye's response to treatment and know that under-corrections are slightly better than over-corrections from both the clinical and patient perspective, then the enhancement rate will never be zero.

If you consider enhancements from the vision standpoint, the answer is still yes. As time goes on, clinicians are becoming more astute about which patients should have — and are most likely to benefit from — enhancement procedures and which are not. That is to say, the ultimate goal of refractive procedures is to produce good and useful vision for patients, not to treat a refractive error so that no refractive error remains following treatment. Enhancements are for patients, not for refractive errors. Millions of people have a small refractive error but have never used eyeglasses, contact lenses, or undergone a refractive procedure for distance or near vision. They function well and do just fine in their everyday life. And frankly, you are in the best position to make these decisions with your patients because you know and understand vision correction as well as your patients' visual needs.

There is, however, a common problem that many optometrists and ophthalmologists have difficulty with when considering enhancement surgery for their patients. "When I cover my right eye, my left eye is not as good as my right," says your patient, followed by, "I want both eyes to be the same." From time to time practitioners will struggle with this dilemma and subsequently recommend enhancement when the risks probably outweigh the benefits. A reasonable response in this dilemma is to say, "Many people see better with one eye than they do with the other, so that is not unusual. In addition, treating a small prescription would probably carry more risk than benefit for you."

Now, the patient may say, "You just don't want to spend the time or the cost for me to have an enhancement." So here is where a one-minute survey may help you. A few years ago I asked 100 people I met over a two-or three-month period whether they thought they saw better with one eye than they did with the other. Often, the person would simply check right then because I had asked the question. It was interesting that well more than half of all the people I surveyed experienced better vision with one eye than with the other. So in responding to your patient who indicates a desire to undergo enhancement when the risk may well outweigh the benefit, you could say, "Probably half of the people you will meet today will have better vision with one eye than with the other…just ask them. You are just like everyone else; you have vision with one eye that is better than with the other."

So, to reiterate, as we learn more and the technology used continues to improve, the enhancement rate will lessen some, but it will never be zero.

Question 2: What is all this about refractive procedures being "safer" than contact lens care?

Well, this is just clan warfare at its worst. It is all innuendo and misdirection by some people who do not have the public health — or even a single patient's — interest at heart, just their clan identity. In fairness, I have been guilty of sticking my neck out for my clan, too, so I am tolerant of poor behavior in both optometry and ophthalmology.

There have been some serious issues with corneal infections in contact lens users, and these have been covered well by experts in the field and by the public media. Manufacturers of products, providers of eye and vision care services, and regulatory bodies have all responded, and steps have been taken to increase safety for patients.

However, when someone says that refractive procedures are "safer" than contact lens wear for patients, they are typically referring to a very narrow point of view suggesting from a few reports that fewer corneal infections occur following refractive surgery than occur in contact lens wearers.

I have very strong feelings about this subject, and here they are for you to consider. First, I am reasonably confident, even as someone who is not well-qualified as an expert in contact lens wear for patients, that similar studies conducted among a great number of optometrists and their contact lens patients would demonstrate a lower rate of corneal infections with lens wear than that seen in previously published reports. Yes I am sticking up for my clan, and am guilty as charged, but I also think that I am right. I think the rate of corneal infections among contact lens patients in optometric practices is less than that in hands of other eyecare professionals.

Second, I am not sure that such a statement about corneal infections would hold up today to careful review. An increase in corneal infections following refractive procedures has occurred over the past year or two, and it is being addressed by experts in the field, just as infections among contact lens wearers have been.

My real argument with the line of reasoning that refractive procedures are "safer" compared to contact lens wear is that the public health is not better because of this misdirection, nor are individual patients. Let me prove it with a doodle and a one-minute survey.

First, the doodle: take a piece of paper out of your printer and draw a line across the bottom of the page in landscape mode that is an arrow pointing to the right. Label the line increasing risk. Now add vertical ovals and label them with increasing risk. That is, safest on the left and less safe on the right. I will let you define what "safe" means to you and your patients.

What is the vertically oriented oval on the far right and how big is it? I bet you missed it. Take a moment and think again. The oval on the right should be pretty large, and it should be labeled "no correction." That's right, no correction. Millions of people do not have the benefit of even the most basic eye and vision care, and these people have poor vision that could easily be corrected if they had access to eye and vision care, which they don't. Does that change your perspective? It did mine, which reinforces the reason why I like doodles. They make me think in new and different ways.

So, what is second? Well, it is refractive procedures. This vertical oval is much smaller than the uncorrected vision oval, but clearly procedures on the cornea carry more risk than do contact lenses or eyeglasses — but they are clearly less risk than no correction.

Now let's add a one-minute survey to enhance this discussion somewhat more. When this idea first appeared in print that refractive procedures are "safer" than contact lens wear, I began one of my little studies. I would stop people and ask them if they knew anything about contact lenses and laser assisted in situ keratomileusis (LASIK). I chose LASIK as it is probably the most recognized refractive procedure among consumers. If respondents said they were at least aware of the two, I would ask them which was safer from their perspective. After a hundred or so one-minute surveys, the results were repeating themselves to the point that I stopped my little study. While a few patients thought that refractive procedures were just as safe as, or perhaps slightly safer, than contact lens wear, the overwhelming majority of people just knew that a procedure was permanent and more "risky" than a contact lens that could be removed from the eye at any time.

Next on our doodle comes contact lenses, which would have a vertically oriented oval that would be smaller than that for refractive procedures, but larger than the one for eyeglasses. Now, I could move things around slightly or an extreme amount by including past-radial keratotomy patients or extended wear lenses, but in general, I think this doodle works for me. Finally, on the far left would be a smaller oval for eyeglasses (Figure 1).

Figure 1. This doodle illustrates the relative risk of different refractive error correction methods.

However, as much fun as this exercise was, it entirely misses the point. It is not so much what is "safer" as what, in your professional judgment and in your patients' mind, is the greatest benefit for their eyes and vision compared to the risk to obtain the benefit. This is why we cannot generalize too much as it takes away from the doctor-patient relationship and leads to discussion and debates that have less meaning for your patients. I don't think you would tell patients to not use any correction for their eyes and vision as that would be too risky, even for the most cavalier among us.

Now, when choosing between contact lenses and refractive procedures, the answer is "it depends." Many patients find contact lenses inconvenient, which still is the most common driver for patients to move from contact lens wear to having a refractive procedure. Conversely, unexpected results from refractive surgery can be a difficult challenge for your patients and yourself. So again, "it depends." There is a balance between risk and benefit from the doodle that may help you, but that is just an exercise. What matters most is what you and your patients think is the benefit for the risk? This is basically the same decision-making that you use when considering contact lens wear for your patients versus eyeglasses, and so it goes.

Question 3: I am interested in multifocal/accommodative intraocular lenses, but I am not too sure where this is all going. What do you think?

A multifocal/accommodative intraocular lens (IOL) sounds like a great idea, and there are good lenses and improving technology in this area with each passing month. However, the human eye in this regard presents an interesting challenge. The lenses are wonderfully crafted and exquisite in design, but they are placed inside the eye, where there is enough variance in human biology that the eye may cause more unpredictability in the results than would the lenses. This is one reason why the growth of multifocal/accommodative IOLs has not been what the manufacturers had hoped it would be.

More importantly, vision issues are the key to this question. What do the patients really want? Well, they want accommodation, not distance, near, or intermediate vision. Although there are lenses that attempt to address this need, they are limited by the eye and how the biology responds to the treatment, just like all IOLs in this segment of refractive procedures. This is why you see so much difference in approach to correction and lens of choice, etc.

So what can you do today, and what should you expect from the future? Again, let's do a doodle. Take another sheet of paper from your printer and draw the numbers 1 through 10 spaced out across the middle of the page with 1 being on the far left. Then, draw a line underneath the numbers and make it an arrow pointing right. Label the line "Increasing Satisfaction." Now, there is much behavioral and social science behind what I am going to suggest that is beyond the scope of this article, but just bear with me. You and your patient are considering multifocal/accommodative IOLs as a treatment option. So the question is, "If you got little or no benefit from the IOL in terms of improvements in your near and intermediate vision, what number would you pick to represent how satisfied you would be with the result?" This is a forced choice question, and if patients pick a number less than 4, they are probably not an ideal candidate for a multifocal/accommodative IOL. If they pick a number 6 or greater, then they probably are a candidate. If they pick 5, you need to probe more. So tell patients who choose 5 that 5 is no longer a choice, and then force a choice again. Then ask why they chose the number they chose, and ask what would make the number increase or decrease for them.

Multifocal/accommodative IOLs are getting better all the time, but what you need today is a tool you can use to help your patients. I hope this exercise was helpful for you. Just remember that you don't have time to speculate on what might be best tomorrow. You need to help your patient today. CLS



Contact Lens Spectrum, Issue: June 2009