My stats; right -11.0, left -11.5, Corneal thickness 550, 7mm pupils. My doctor (Dr. Spivack in Denver, CO) indicated I am 'on the edge' based on using a VISX S2 laser. He stated their minimum 'safe' remaining corneal thickness was 250. When I do the math, using the VISX figures of 12-16 microns/diopter (depending on using a standard or expanded treatment zone), it seems I am over... help me figure this out?

With a 7.0 mm optical zone and significant myopia, you need to have atleast the 6.5mm optical zone plus the transition zone to try to reduce your risk of serious night time problems. However, you will still have more risk of serious night time problems compared to a person of similar myopia and 6.0mm pupils or a person with half your level of myopia and similar size pupils.
As for the amount of cornea to have LASIK - generally is works out to about 16 microns per diopter. But your doctor may have a nomogram such that when treating 11 diopters, he just plugs in 10.2 diopters. As well, the laser does some calculations and ends up reducing the amount of treatment (this is because the refraction is done at the spectacle (eyeglass) plane while the laser treats at the corneal plane.
Your best bet is to have Dr. Spivak's secretary plug in your numbers in the laser and see the exact amount of tissue removal, and then you can determine whether there is enough cornea to have LASIK. But your goal should be to have in the range of 275-300 microns left, as you are at risk for needing an enhancement (the greater the myopia, the higher the chance for regression).

I hope this helps

Please feel free to ask further questions.

Bill Trattler, MD
Miami, FL

Thanks for the quick, honest reply Dr. Trattler!
Would one of the other lasers more effective in my situation (rather than the VISX)?

If I were to 'lower' my expectations for LASIK to a result of a significantly reduced degree of myopia, rather than vision without glasses/contacts, would I still be able to wear contacts after the surgery?

At your scrip and with your pupil size, you are at much greater risk for night time visual problems, which includes glare, haloes and starbursts. Examples of compromised vision may be viewed at surgicaleyes.com. High scrips such as yours also have concomitantly high enhancement rates. High scrips have a greater incidence of complications, such as a retinal detachment. Statistically speaking, when stratified from bulk patient data, high scrips have a much lower probability of achieving 20/20, 20/30 or even 20/40 vision, even after an enhancement, regardless of the laser. These risk curves are not linear.

The majority of LASIK success stories are those with low scrips and/or those with low scrips and smaller pupils. You are neither. Do your life a favor and embark on some focused, primary research. Then make your decision.

Advances in contact lens technology make them a highly viable, cheaper and completely reversible form of vision correction. You would have enough money left over for a great Hawaiian vacation, viewed through virgin eyes with well-fitted and visually-crisp contact lenses.

If you have specific questions, feel free to email me at .

John,

Please be careful and know that lasik is a very dangerous and unnecessary gamble with your eyesight.

My prescription was very similar to yours.

My prescription was -10 in both eyes with moderate astigmatism (I do not have the actual numbers). My pupil size was measured at 5.5. I was told I was a perfect candidate and that the procedure was ‘safe and effective’ and that I would ‘love the results’.

I was treated with the Visx S2 with a 6.5 mm zone but the doctor admits that it may actually be less than 6.5. It seems like an astigmatic correction reduces the optical to an egg shaped one that can be as small as 4 mm across the short side.

My vision now is right eye, +2.0, 20/40 to 20/50 with one moderate ghost at about 4:00, about 1.5 diopters of astigmatism, cannot be corrected better than 20/40 with glasses and left eye, +0.5, 20/30 with two ghosts at about 5:00 (very strong) and 7:00 (less strong), about 1 diopter of astigmatism, cannot be corrected better than 20/25 with glasses.

The doctor tried correcting me with soft lenses but they did not get rid of the extra images. I have been to different doctors for rgp lenses and they correct me to about 20/25. They are very uncomfortable and I cannot wear them for more than a few hours. My vision also changes with each blink. When I take them out my vision is even worse for a few hours.

The problems identified from my lasik are central islands in both eyes which are causing my double and triple vision. I also have severe dry eyes and did not have them before lasik. I also have starbursts day and night and at night my vision gets very blurry. During the day windows have big halos around them and I can no longer tell who is coming towards me if their face is not well lighted. I cannot drive at night and the stop lights fill the sky with the color of their halos. I cannot see the neighbors on their porch at night when before lasik I could easily see them. Watching tv is impossible because it is so frustrating. Streetlights and headlights have starbursts that go in all directions. I have put brighter bulbs in all my lamps and hate the indoors almost as much as I hate the night time. The doctors say that an enhancement will not fix my problems. The doctors have been telling me for over a year since my laisk in August 2000 that wavefront will be able to fix me ‘in about six months’ but each time I see the doctors they say it will be another six months. I read all the news on the internet and it looks like there never will be anyway to fix my problem except for a corneal graft or transplant and doing them on both eyes will cost over $20,000! My doctor just laughed when I asked him about it. And there are no guarantees with the transplant that I will ever see as well as I did with my soft lenses.

Before my lasik the doctors assured me that the worst thing that could happen was not to get to 20/20 and having to wear a light pair of glasses. I didn’t know what ‘irregular astigmatism’ was. Yes the consent form mentioned it but the doctors said not to worry about it. No one knows what it is until they wind up with it.

Please don’t have lasik. There are better options coming.

Terri

I have little knowledge of the US legal system but it appears that after 6 months you may not have the right to legal redress. Something about the statute of limitations expiring. As with all issues of this nature you should get a lawyer on the case asap.

http://www.lasikdisaster.com/new_page_10.htm

My pre-Lasik prescription was -10 right eye & -11 left eye w/ 7mm pupils. I am now 20/25 right and +1.50 left (will have an enhancement on my left eye in Feb.) I had Lasik with the Autonomous Ladarvision...my Dr. said no other laser would touch my combination of prescription & pupil size. I'll admit recovery time was slow (dry eyes, nighttime vision problems, etc.) But at 3 months post, I am thrilled. I don't have to wear any correction except to read. I'm not sure what my corneal thickness was...plenty though...something over 600 (Dr. said that was pretty rare). Be careful...but I'm so glad I went for it!

John,

As you can see from the replies to your original post, outcomes with your level of myopia and pupil size can vary greatly. Something that is important to remember is that some of the results discussed here are from surgeries in the year 2000. Some things have changed, but some have not. It will be important for you to separate what applies to you and what does not.

Although new technology exists today, it is not approved for your level of need. The Alcon LADARVision with wavefront-guided ablation was recently expanded to accommodate 8.00 diopters of myopia, but that is still quite short of your goal. The laser your doctor is considering is essentially the same base technology as the first excimer laser that was approved years ago and does not benefit from all the advances since that time. If you want the greater accuracy and higher probability of a good outcome that the new technologies provide, you will need to wait until those technologies catch up to your needs.

LASIK, LASEK, PRK, and Epi-LASIK are all limited by the thickness of the patient’s cornea. Depending upon the size of the ablation zone, the amount of tissue per diopter of correction can range from 12 microns to 20 microns. The larger the ablation zone, the greater the amount of corneal tissue removed. At a minimum, you would require about 138 microns of corneal tissue removal, but that would be with a 6.0mm optical ablation zone, which is significantly smaller than the size of your naturally dilated pupils. To keep the probability of night vision problems to a minimum, the optical ablation zone needs to be at least equal to the size of your pupils. At 7.0mm, it would require about 207 microns of tissue removal.

LASIK requires a flap of corneal tissue that is moved aside during the application of the laser energy, and then repositioned over the treated area. By applying the laser energy to the lower stromal layer of the cornea (not on the surface) the probability of corneal haze is greatly reduced. Flaps are created with a mechanical or laser microkeratome. The mechanical microkeratome is a steel blade that is attached to a small device the slides the blade across the anesthetized eye. The laser microkeratome creates tiny bubbles of separation in the corneal tissue, with enough bubbles next to each other a flap is formed. The laser microkeratome has the advantage of being more accurate and being able to create a thinner flap. I mechanical microkeratome flap is normally around 160 microns deep with a variable of around 20-50 microns. A laser created flap can be as little as 100 microns with a variable of about 10 microns.

If a laser flap was created at 100 microns thick, plus the 207 microns of tissue removal, you would have no more than 243 microns of untouched corneal tissue. This is not enough to keep the cornea stable, and more than half the thickness of the cornea is being disrupted. Both of these events can cause serious long-term problems.

If you opted for a surface ablation technique such as PRK or its cousins LASEK and Epi-LASIK, then you would not require the 100 microns of corneal flap and would have about 343 microns of tissue untouched. The problem with a surface ablation is that the cornea often becomes hazy when more than 6.00 diopters of refractive error is corrected with a surface ablation. There are techniques to reduce the probability of haze, but even the best techniques would still leave a significant risk of permanent corneal haze.

You could stick with LASIK and accept an undercorrection to go from -11.50 to about -4.00, but this really is not as much of an improvement as it sounds. If this intrigues you, try contacts that undercorrect you to -4.00 to see what it would be like.

You could go with a surface ablation technique in multiple steps, having 6.00 diopters corrected then six months later having the remaining refractive error corrected. This two-step process has the advantage of being able to accommodate your high myopia and the regression that almost always accompanies a high myopia correction, while being careful about corneal haze. The second surgery could be wavefront-guided, however you are subjecting yourself to the risk of two surgeries rather than one.

As you can see, it may be possible to maneuver through the limitations of today’s refractive surgery techniques and get you down to where you want to be, but it is clear that you are not an ideal candidate and you may be charting unknown waters in your attempt to gain the convenience of a reduced need for corrective lenses. Use all due caution.

Glenn Hagele
Council for Refractive Surgery Quality Assurance
http://www.USAEyes.org
http://www.ComplicatedEyes.org
Email: glenn dot hagele at usaeyes dot org

I am not a doctor.

"You could stick with LASIK and accept an undercorrection to go from -11.50 to about -4.00, but this really is not as much of an improvement as it sounds. If this intrigues you, try contacts that undercorrect you to -4.00 to see what it would be like."

I dont think you will be too happy with -4, I am -5 without my glasses and I see 20/500. -4 would be 20/400, maybe a little better. You wont see the big E on the snellen chart. Youd be taking the risks of lasik and *still* would need glasses full time. Forget lasik, not worth the risks, stick with contact lenses or maybe consider implantable contacts