LASIK F.A.Q.

Frequently Asked Questions
How does the Custom Wavefront Lasik, PRK or Laser Vision Correction surgery equipment and technology work in Denver or Boulder Colorado?

1. SHOULD I CHOOSE LASIK OR PRK?
LASIK and PRK both give excellent results. Both use an Excimer Laser to reshape your cornea. In PRK, the correction is placed on the surface of the cornea; in LASIK, a thin flap of corneal tissue is lifted and the correction placed on the underlying corneal bed and the overlying corneal flap then repositioned. 70% of my Laser Vision Correction patients select LASIK, primarily because LASIK has minimal discomfort and the visual improvement is evident within hours. However, if the thought of the flap in LASIK makes you uncomfortable, I would strongly encourage you to consider PRK! PRK is slightly safer and minimally more predictable than LASIK, because no flap is being made. The risk associated with the flap is small, but in 1-2% of LASIK patients, flap complications occur. The vast majority of the flap complications are not visually threatening and are easily treatable without resultant vision loss. LASIK patients have minimal discomfort lasting for a few hours; PRK patients experience mild to moderate discomfort lasting for 48-72 hours post-op; the vision takes longer to clear up after PRK than LASIK. 98% of LASIK patients can see clearly within 24 hours; PRK patients are very blurry for 2-3 days post-op, usually can see about 20/40 3-5 days post-op (well enough to pass a drivers license vision test), and slowly improve over the following weeks to months. By six months, both LASIK and PRK have the same visual results. PRK has a lower retreatment rate (1-2% vs 2-5% for LASIK) and may have somewhat less glare and dryness than LASIK. You will not experience any discomfort during the actual PRK procedure. During the actual LASIK procedure, you will experience mild pressure on your eye for 15-30 seconds. Once again, both LASIK and PRK give excellent long term results. In summary, PRK is slightly safer than LASIK but is more uncomfortable post-operatively and takes longer for the vision to stabilize. Custom Wavefront is available with both PRK and LASIK.

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2. CAN LASER VISION CORRECTION HELP ALL VISION PROBLEMS?
There are 4 types of refractive problems:

1. Myopia (nearsightedness) occurs when the cornea is too steep relative to the length of the eyeball. As light enters the eye, the visual image focuses in front of the retina, resulting in a blurred or distorted view. Without correction, nearsighted people have blurry distance vision but can see well at near. The FDA approved the use of the Excimer Laser for Myopia in November, 1995. Laser Vision Correction works extremely well for nearsightedness. In myopia, the Excimer Laser flattens the central cornea, focusing the image on the retina.

2. Astigmatism (asymmetrical cornea) occurs when your eye is shaped like a football, unlike a normal eye, that has a round shape similar to a basketball. Uncorrected Astigmatism causes blurred vision both at near and far. In April 1997, the FDA approved Excimer Laser correction of Astigmatism. The Excimer Laser works extremely well for treating Astigmatism.

3. Hyperopia (Farsightedness) occurs when the cornea is too flat relative to the length of the eyeball. Hyperopia requires people to exert focusing power to see at near and far. The normal eye only has to exert focusing power to see at near. When farsighted people are young and have ample focusing power, they usually see well both at near and far. However, with aging, people lose focusing power; farsighted people will begin to notice difficulty seeing at near and as they continue to age, will also note difficulty focusing at distance, as well. In November, 1998 the FDA approved the Excimer Laser for the correction of Hyperopia. The Excimer Laser works well for correcting Farsightedness. In farsightedness, the Excimer Laser steepens the central cornea, focusing the image on the retina.

4. Presbyopia is an age-related condition that causes people from the mid-forties and older to need reading glasses or bifocal lenses to read. Presbyopia is a result of loss of elasticity in the lens of the eye. Presbyopia cannot currently be corrected with the Excimer Laser. The Excimer Laser can, however, used to create a condition called Monovision, where one eye is corrected for near vision and the other is corrected for distance vision. I know monovision may sound somewhat ridiculous, but monovision actually works very well and allows most patients over the age of 45 to function without glasses correction for both reading and distance vision.

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3. WHAT ARE THE ODDS OF ELIMINATING MY NEED FOR GLASSES OR CONTACTS AFTER LASER VISION CORRECTION?
In the thousands of cases of Laser Vision Correction I have performed, 90% of patients have 20/25 or better vision without correction, and 97% of patients will see well enough to pass a driver's test (20/40) without correction. Less than 3% of my patients are wearing correction for distance after Laser Vision Correction.

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4. WHAT IS THE INTRALASE LASER?
First of all, I think the IntraLase is wonderful and, although it does add extra expense to the LASIK procedure, the improved safety and visual results with the IntraLase is money well spent.

What is the IntraLase. This is a little tricky, so pay attention. In LASIK a thin flap of tissue is lifted off the top of the cornea. The underlying cornea is then reshaped with the Excimer Laser and the corneal flap repositioned. Two technologies are presently available for making the corneal flap. One, the older technology, is the Microkeratome, a mechanical device that uses a metal blade to create the LASIK flap. The other, newer technology for lifting the flap is the Intralase Laser. (The Intralase is a separate laser from the Visx Star S4 Excimer Laser. Once again, we use the Excimer Laser to reshape the cornea in LASIK and PRK. We use the Intralase to create the corneal flap in LASIK). The mechanical Microkeratome works extremely well and has been used safely and successfully in millions of Lasik procedures for over ten years. However, the Intralase is better technology because of increased safety and better visual results. The IntraLase uses billions of little bubbles, instead of a metal blade, to create the LASIK flap. Patients tend to see better (7% better to be exact) after LASIK with the Intralase than with the Microkeratome. But even more importantly, the Intralase is safer than the Microkeratome. The Microkeratome is very safe but the Intralase is safer, having a lower incidence of flap complications. And when the rare complications do occur with the Microkeratome or the Intralase, complications with the Microkeratome tend to be much more difficult to manage than complications with the Intralase. There is an additional fee for the Intralase.

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5. WHAT DOES 20/20 OR 20/40 VISION MEAN?
The 20/20 nomenclature is an old system devised by Hermann Snellen, a Dutch Ophthalmologist, in 1862. 20/20 means the viewer can see at 20 feet what a "normal" person would see at 20 feet. 20/40 means the viewer sees at 20 feet what the "normal" person can see at 40 feet, i.e. the viewer can't see quite as well as "normal". This system is somewhat misleading. 20/40 vision is not twice as bad as 20/20 vision. In fact, most people with 20/40 or better vision can, and usually do, function without wearing correction. 20/40 vision or better is required to pass a drivers test in Colorado. After LASIK, 97% of patients have 20/40 or better vision and over 80% have 20/25 or better vision. In the "real world" the difference between 20/20 and 20/25 vision is negligible. Interestingly, Snellen used test subjects to determine what people with "perfect" vision could see, and called that level of vision "20/20". It turns out that his test subjects were slightly nearsighted and, therefore, people with perfect vision actually see better than 20/20. The "perfect" human eye can see slightly better than 20/10!

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6. WHOM SHOULD I CONTACT WITH MORE QUESTIONS?
Please feel free to contact my office to have any questions answered, or to schedule a free, Laser Vision consultation. The phone number is 303.393.0347 and the toll free phone number is 877.393.0347.

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7. WHO IS A CANDIDATE FOR LASER VISION CORRECTION?
Laser Vision Correction is well suited for active people who find glasses and contacts to be a nuisance and those who simply don't want to be so dependent on corrective lenses. If you wear glasses or contacts and are over 18 years old, you are probably a good candidate. Your lens prescription should be stable at distance for at least one year and you should be free of medical problems related to your eyes, primarily cataracts. You should also make sure you have realistic expectations about Laser Vision Correction. Although Laser Vision Correction has the potential to greatly reduce or eliminate dependence on corrective lenses, there can be no assurance that you will obtain perfectly corrected vision. The vast majority of patients can function without glasses or contacts after Laser Vision Correction, although, occasionally, Laser Vision Correction patients may wear a mild glasses correction to fine-tune their distance vision. People who are most satisfied with the results of Laser Vision Correction clearly understand the potential risks and side effects and have realistic expectations of what their vision will be like after surgery.

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8. WHAT IS THE DIFFERENCE BETWEEN THE DIFFERENT EXCIMER LASERS? WHICH EXCIMER LASER DO YOU USE?
All Excimer Lasers are identical in one respect only; they all use an argon/fluoride gas laser source which delivers energy to the cornea at 193 mm wavelength. However, each Excimer uses a different "delivery system", i.e. spot size and firing frequency to apply the Laser energy to the corneal tissue. For nearsightedness, Laser delivery systems can be divided into two groups based upon the "spot size" of the laser beam; the large spot-size lasers, called "broad beam" lasers (VISX and Summit Lasers) and small spot-size lasers, called "flying spot" lasers (Nidek, Technolas and Autonomous-LADAR Lasers). The VISX Star S4 actually uses a combination of "broad beam" and "flying spot" delivery. The broad beam lasers deliver a large, homogeneous, uniform energy pulse to the cornea. This results in very smooth tissue removal. The flying spot lasers apply energy in very small "dots" and create a tissue removal pattern similar to pixels in a digital image. The flying spot tissue removal is "grainier" than the "broad beam" laser pattern but has the advantage of being able to apply energy to very small areas with pinpoint accuracy. This is useful in Custom Wavefront treatments. The VISX Star S4 is the only Excimer Laser available that uses both a "broad beam" and "flying spot" technology on each patient. This offers the advantage of both laser systems. The VISX Excimer Laser has had three significant upgrades in the last 18 months and is, in my opinion, the "state-of-the-art" Excimer Laser. The VISX Star S4 Excimer now has an "auto-tracker", insuring that the Excimer Laser stays centered on your cornea even if you have difficulty holding your eye still. I have used the Technolas Excimer Laser, a "flying spot" Laser, but found it to be slow and it removes too much corneal tissue. The long treatment time results in increased dehydration of the cornea, and inconsistent Laser outcomes. Also the Technolas removes up to 50% more corneal tissue than the VISX for any given power and diameter optical zone. The extreme amount of tissue removed by the Technolas can structurally compromise the cornea and is a major reason most Laser Surgeons have stopped using the Technolas. The Autonomous (LADAR) Excimer Laser takes almost twice as long as the VISX for treating nearsighted patients, and this is somewhat of a problem. Also, the Autonomous is a more expensive laser to operate, costing about $250 more per eye.

At this time, I only use the VISX Star S4 with CustomVue (Wavefront) Technology. I consider this to be the most advanced, state-of-the-art Excimer laser available.

The NIDEK Excimer Laser is the Laser-of-choice of "cut-rate" Laser Centers. They use the NIDEK because it is a less expensive Laser than the VISX. I am not aware of any Laser Centers, other than the "cut-rate" Laser Centers, that use the NIDEK Excimer Laser in the Denver area. The only advantage for the NIDEK is that it is less expensive to operate.

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9. WHAT ARE THE LONG TERM RESULTS? WILL MY EYES DETERIORATE IN THE FUTURE?
Since 1987, millions of Excimer Laser procedures have been performed worldwide. Laser Vision Correction appears to be very stable, and recurrence of refractive error after six months is uncommon. There does not appear to be any increased risk of macular degeneration, cataracts, retinal detachments or any other eye problem related to LASIK treatment. The one long term risk that has been identified with Laser Vision Correction is "ectasia". In approximately 1 in 2000 Laser Vision Correction patients, the cornea will develop weakening and instability, ie ectasia, after Laser Vision Correction. Ectasia results in progressive blurry vision that may not be correctable with glasses, contacts or Laser retreatment. With adequate pre-operative screening, we can identify, and not operate on, patients that are at risk of developing ectasia. However, ectasia has rarely been reported in patients after Laser Vision Correction that have no known risk factors. Ectasia does occur in the general population, ie people that have never had Laser Vision Correction, in approximately 1 in 2000 people so not all cases of post-op ectasia may be due to the Laser Vision Correction

The "K" in LASIK stands for "keratomeleusis", which is the "flap cutting" step in LASIK. Keratomeleusis, without Lasering, has been performed since 1959, primarily in South American, as a treatment for extremely high nearsightedness. So we, in fact, have over 40 years experience with the most "invasive" step in the LASIK procedure, the cutting of the flap. From this 40+ years of experience we have learned how deep we can safely treat the cornea without causing long-term damage to the cornea. Arguably, we have more "long term" information on the "flap cutting" in LASIK than we do with soft contact lenses, which have "only" been available for about 35 years.

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10. WHAT IS WAVEFRONT ANALYSIS AND CUSTOM CORNEA TECHNOLOGY? HOW GOOD IS IT?
Wavefront analysis is a new way of analyzing the cornea. Wavefront technology was initially developed by astrophysicists to improve the quality of optics in telescopes. Wavefront analysis involves sending a reference light ray into a telescopic mirror system and measuring the reflecting light ray as it exits from the mirror system. Sensors can detect the location of the exit reference light ray. The difference between the position of the reflected wave and the location of where the wave should theoretically have been in a "perfect" system can be determined. Then, by adjusting the reflecting mirror surface with small servo-mechanical "suction cups" located on the backside of the mirror, aberration (distortion) can be removed from the mirror system. Wavefront analysis has significantly improved the quality of images in telescopes such as the Hubbell Telescope. Wavefront analyzers are now available for analyzing human visual systems. I am have used both the VISX CustomVue and the LadarWave Custom Cornea Wavefront systems. Both work well but I found the results to be better with the VISX CustomVue Wavefront system. Wavefront adds another level of accuracy and predictability to LASIK and increases the quality of vision after LASIK, especially at night or in dim lighting situations. Wavefront does add $500 per eye to the cost of LASIK and PRK, but I feel it is worth the extra expense. Not every patient is a candidate for Wavefront or even needs Wavefront, especially if you have small pupils (under 6 mm in dim light). Please contact my office if you have more specific questions regarding Wavefront-guided Laser Refractive Surgery.

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11. SHOULD I WAIT FOR THE LASIK TECHNOLOGY TO GET EVEN BETTER?
Anytime we deal with advanced technologies we have come to expect continuous, ongoing improvements. And you could argue why buy a new car, a new computer or undergo LASIK today when the technology will be "better" in the future. However, at least with Wavefront guided LASIK, the Laser Vision technology appears to be stabilizing. We can look 3-5 years down the FDA "pipeline" for new technologies, and there is presently nothing "revolutionary" on the horizon. I would expect in the future for the FDA to approve the use of Wavefront technology on a wider group of patients, including Farsighted patients. However, the Wavefront-guided LASIK we have today gives excellent results for 98% of patients and it appears to me that waiting for future technologic improvements will not give you access to significantly better visual outcomes.

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12. WHAT IS CK?
CK (conductive keratoplasty) is a refractive surgical procedure somewhat similar to LASIK. CK reshapes your eye by using a small needle-like probe that applies radio-wave energy to the surface of the cornea. The radio-wave energy causes the corneal tissue to slightly "shrink", thus reshaping the cornea. By applying the energy in a specific pattern and inducing a controlled "shrinking" of the corneal tissue, refractive changes can be induced. CK is an outpatient procedure that takes less than a minute to perform. The cornea is numbed with eye drops. The needle-like probe applies the energy in a circular pattern approximately three millimeters from the center of the cornea. Depending on how much correction is required, anywhere from 6 to 18 "spots" of energy are applied. There is mild to moderate discomfort after CK. The refractive change is almost immediate.

CK can only treat mild amounts of farsightedness; it cannot treat nearsightedness or astigmatism. This limits its usefulness. If you have good uncorrected distance vision, (and are over the age of 45), CK can also be used to create Monovision, allowing you to read without glasses. In monovision your non-dominant distance eye can be treated with CK, making it a reading eye. (This will blur your distance vision in the treated eye, but with both eyes open, you can see both distance and near.) CK does not give you back the focusing power you lost with age.

CK has three major drawbacks. The first drawback is that CK's effect regresses within 1-2 years, and CK is not as effective if reapplied a second time. The second drawback is that CK not only cannot treat astigmatism, but it can actually induce astigmatism, which then is difficult to correct. The third drawback is the very limited number of patients that are actually candidates for CK.

I see no advantage to CK over LASIK. In fact, I would recommend LASIK over CK. LASIK is much more precise than CK and can treat a much wider range of farsightedness, astigmatism and nearsightedness. LASIK uses an Excimer laser with 1/4 micron (1/200 of a hair) precision to reshape your eye. CK uses radio-waves to shrink the corneal tissue and does not have the precision of LASIK. LASIK can be repeated, if necessary, to enhance the visual outcome. CK cannot be enhanced. LASIK has a very stable long term effect; CK's effect regresses over 1-2 years. LASIK can treat astigmatism (just about everybody has astigmatism), CK cannot treat astigmatism. CK and LASIK cost approximately the same, take about the same amount of time to perform, regain vision at about the same rate, and are both performed with only eye drops to numb the eye. LASIK has very minimal discomfort; CK is more uncomfortable than LASIK, especially for 2-3 days after the procedure. I don't really understand why anyone would choose CK when LASIK is available.

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13. DIDN'T A CLIMBER WHO HAD PREVIOUS REFRACTIVE EYE SURGERY HAVE A PROBLEM WITH HIS EYES WHILE CLIMBING MT. EVEREST?
Yes. However, the climber had Radial Keratotomy (RK) performed many years before he climbed Mt. Everest. He did not have LASIK or PRK. In RK, deep incisions are made in the cornea which flatten the cornea by structurally weakening the cornea. At very high altitudes, such as Mt. Everest, the decreased atmospheric pressure caused the cornea to pathologically flatten further. This caused the patient to experience the onset of farsightedness, making it very difficult for him to see. This would not occur with LASIK or PRK because the cornea is not structurally weakened by these procedures.

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14. WHAT IF I DON'T GIVE THE RIGHT ANSWERS WHEN YOU MEASURE MY EYES? WILL I GET A BAD RESULT?
Absolutely not!!! I realize some people get extremely nervous that they will give the "wrong" answer when I do the "which is better, 1 or 2" measurements. This measurement, which is called the "refraction", is used for calculating the amount of tissue the Excimer Laser will remove, so it is important. However, when I am doing the refraction on you I am not obediently following your responses. Before I even start your refraction, I will take computerized measurements of your eyes which will give me an extremely precise "objective" refraction. I then give you the opportunity to "fine tune" my objective measurements. All you need to do is tell me which of the two choices I give you make the letters look clearer. If neither choice is better, that is actually the end point I want; that means the refraction we have attained is precise because any subtle adjustment to your refraction is making your vision blurrier. To add even more precision, I will have my ophthalmic assistant refract you, and I will refract you myself, twice. These three "human" measurements, and the computerized "objective" refraction are then compared, and they better be extremely close, otherwise, I will keep rechecking your refraction until I get a consistent refraction result. And to add even more precision, consider Custom Wavefront. Wavefront measurements use a scanning Laser mapping of your eye; we avoid having to depend on the the refraction, and your responses.

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15. I HAD A LASER VISION CONSULTATION WITH A "LASER CENTER" AND THEY CLAIMED THAT THEY HAD ACCESS TO "SPECIAL" TECHNOLOGY AND USED "SPECIAL" TECHNIQUES THAT NOBODY ELSE USED AND THAT THEIR RESULTS WERE BETTER THAN EVERY OTHER LASIK SURGEON'S RESULTS. WHAT MAKES THEM BETTER?
Beware of any Laser Vision Center that makes unreasonable claims, including claims that they are the "best", were the "first", or that they are the "only one" to do something "special". Laser Vision Correction is not a secret, magical, mystical procedure. Laser Vision Correction is a highly predictable, reproducible procedure based on the research and shared experience of thousands of extremely smart scientific investigators and surgeons who have collectively performed over 20 million Laser Vision procedures. I attend two major Laser Vision meetings a year - The American Academy of Ophthalmology meeting every fall and the American Society of Cataract and Refractive Surgeons meeting every spring. These meetings present to all Laser Vision Surgeons the most up-to-date information on Laser Vision Correction, based on the shared research and clinical experience of the top Laser Vision Surgeons in North America, Europe and Asia. This information is widely disseminated and readily available to all Laser Surgeons, around the world. The goal is to continuously improve Laser Vision Correction results by sharing information and experience about what works, and what doesn't work, in Laser Vision Correction.

In my opinion, any Laser Vision Surgeon who claims to do something "special" is either arrogant and making exaggerated, boastful claims (remember, this is Laser Vision Surgery, not the World Wrestling Federation!), or is exposing you to unnecessary risk by using techniques that are "special" only because no other experienced Laser Vision Surgeon deems those techniques safe and/or beneficial.

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Rose Medical Plaza, 4545 East Ninth Avenue, #270, Denver, CO 80220

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The Levinson Eye Clinic, in Denver Colorado, and its laser vision correction surgeon, Dr. Richard A. Levinson, M.D., provide the latest technology in eye care and Lasik vision correction surgery for Custom Wavefront Lasik in the Denver and Boulder Metro area. Dr. Levinson and his refractive eye surgery staff use the Visx Star S4 excimer laser for Lasik or PRK refractive eye surgery with Customvue Wavefront Lasik. Contact Dr. Levinson and his Denver, Colorado laser vision correction staff for more information or to schedule a complimentary Custom Lasik vision correction consultation.

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