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Choosing a laser eye surgery procedure

by Jérôme Daoust

Revised 2012/11/5


1.      Surface VS Flap surgery


Surface VS Flap surgery

- Top of Page -


·         This diagram show the family of laser surgeries:

·         Popular procedures:

o   Surface surgery: PRK (PhotoRefractive Keratectomy). Not to be confused with RK (Radial Keratotomy, a procedure consisting of making numerous radial incisions which extend from the pupil to the periphery of the cornea in a pattern like the spokes of a wheel).

o   Flap surgery: Intralase Lasik.

·         Compared to keeping your eye glasses:

o   It is possible to achieve better vision with a laser surgery because unlike glasses which only correct for general near/far distance and astigmatism (dues to fabrication process limitation of lenses) it does not offer a true correction for the irregularities (aberrations) of your cornea. One should understand that correcting your vision with a simple prescription for diopters and astigmatism is a simplification of your case. Laser eye surgery can truly correct the unique shape of your corneas.

o   Less chromatic error. When you do not look through the middle of your glass lenses, you can see the edges of objects get rainbow colors. After laser surgery this problem no longer exists because you eyes are aligned with what you are looking at, even if it is not straight ahead of your face.

·         Comparison of the popular procedures:


PRK, a surface surgery

Intralase Lasik, a flap surgery


Jeroen van der Pol (source): In my experience (I'm an Ophthalmologist and performed more than 1000 laser surgeries) Lasek and PRK are very safe. Comparable to wearing contact lenses. Complication rate should be under 1% for this type of treatment. Serious complications like Rolan Yang's unfortunate experience are rare in Lasek and PRK.

3 to 5%. Along with a higher risk than PRK, treatment is more difficult because the problem is usually located under the flap.

Also, risks are re-applied if there is a need for a later enhancement / correction.


Moderate pain for first 48 hours. Scratchy feeling gone when temporary contacts removed on the 4th day.

Almost none.

Recovery time

Vision recovers over 1 to 3 months. During recovery you keep worrying that your not-so-good vision may be as-good-as-it-gets.

1 day or so. Protective lenses have to be worn at night for the first week.

Correction quality

The corrected surface only has a thin epithelium layer of the eye to cover it (re-grown after surgery). So there is a high level of control over the correction.


The corrected surface lies under a 90-100 mm flap. Although this flap is flexible, it averages the correction over the surface to some extent. There is a risk of striae (folds) as the flaps tries to adjust to the corrected surface (think of laying a rug over a non-flat surface).

Jeroen van der Pol (source): The flap doesn't fit well to the bottom surface after laser treatment of higher refractive errors (about -4 and higher). This causes wrinkles in flaps and detracts from good vision. This is probably the reason that vision is in my experience (but only very slightly) better with Lasek/PRK than with LASIK.

See also: Dr Nepple's opinion.

Dry eyes

Jeroen van der Pol (source): You are less likely to get dry eyes after Lasek/PRK although the first year is usually dryer than before.

Jeroen van der Pol (source): Lasek/PRK doesn't give nearly as many dry eye problems as LASIK. When the cut is deeper, nerves will be cut more "centrally" and they will take longer to regenerate or regenerate incompletely. These nerves are necessary for corneal sensation and have a crucial role in the establishment of a good tear function and tissue health.

Cornea strength

Jeroen van der Pol (source): The structural integrity of the eye is simply better preserved with Lasek/PRK.

Jeroen van der Pol (source): The total "depth" of treatment into the cornea is always greater in LASIK because of the flap that is cut prior to the (same) laser treatment.

See also: Dr Nepple's opinion.

Risk of dislodging a flap

No such risk. This is why people involved in contact sports choose this procedure

Jeroen van der Pol (source): I know of several dislodged LASIK-flaps after trauma from personal experience. A tennis ball springs to mind and a tree branch in another. Vision never fully recovered.

Epithelium growth under the flap

No such risk.

2 to 3% of the time, the corneal epithelium may be present in the interface. The corneal epithelium consist of 4 or 5 cell layers that normally cover the surface of the cornea and protect it. For example, if the corneal flap has a loose edge, say the first day post-op, the epithelium may choose to grow under the flap in that particular area and cause problems with vision and stability of the corneal flap.



Professional pilots are not allowed to undergo LASIK but they can get their license with PRK.

People who enjoy contact sports should not consider Lasik.

·         More info on problems related to Lasik:

o   Top 10 reasons not to get Lasik.

o   Known complications.

o   Links:

§  Lasik Complications: It has the purpose of warning people about LASIK complications prior to surgery.

§ (website down on 2012/11/5) Active patient bulletin board and informative research forums. The site does not endorse refractive surgery because there is abundant evidence in current medical literature that corneal refractive surgery compromises the ocular health and visual quality of the eye. The site states that refractive surgery is a violation of the physicians’ Hippocratic oath to “first, do no harm”.

§ Most popular LASIK patient site on the internet. Exposes the LASIK industry for covering up complications and deceptive advertising. Legal resources for victims of LASIK medical malpractice. Medical research of LASIK complications and risks. News articles about LASIK complications. Images of damaged eyes.

§ A comprehensive review of the medical literature of LASIK. Examines medical studies which reveal the risks and long-term complications of LASIK. The report concludes that LASIK in an inherently harmful procedure and should be abandoned.

§ Created by author and psychologist Roger D. Davis, PhD, this site features photorealistic images of the visual aberrations induced by LASIK and other refractive surgeries, including starbursting, halos, glare, ghosting, blurry vision, and night driving scenes. Also contain numerous animations, as well as simulators that allow patients to approximate and communicate their vision to friends, family, and physicians. If you want help simulating your vision for others, start here.

§ Dedicated to those whose lives have been damaged or destroyed by refractive surgery, this site contains true stories written by the victims themselves. When complications occur, your life splits in two. There is the person you were before LASIK, and the person you are now...the person whose dry eyes hurt all the time, the person who sees multiple images of everything, who can't drive at night, who can't fulfill his or her responsibilities as a parent, or his or her potential as a human being, the person who suffers from PTSD, depression, and various states of dread about the future. You realize that maybe human nature isn't fundamentally good, or at least that doctors aren't what you thought they were.

§ Created by dissatisfied patient. Warns about bad doctors that harm patients. Cautions prospective patients about lasik marketing scams that sell fake certifications and entice patients into having surgery by downplaying complications. Publishes stories of patients with bad outcomes. Links to YouTube videos about LASIK horror stories.

§ Created by patient activist Brent Hanson, this site states, "Are you planning to have laser eye surgery at TLC? Are you impressed with TLC's success stories? Do you believe that TLC will honor their "Lifetime Commitment" to you?... If you answered yes to any of these four questions, then please read about my experiences with eye surgery at TLC. Your decision to have eye surgery may result in permanently damaging results that are devastating to you. You may also discover that TLC will not back up their "Lifetime Commitment Program" if they damage your vision. I am going to share my personal story with you so that you can get a more realistic view of what your experience could be like. This story is unpleasant for me to tell, but you deserve to know that TLC personnel are fully capable of damaging your vision, deceiving you, abandoning you as a patient, harassing you, and threatening you with lawsuits for speaking out.".

§ Created by patient activist Dominic Morgan, this site chronicles Dominic's legal struggle with his surgeon and with the FDA. The site states, "Most Lasik websites are advertisements for having Lasik eye surgery. This website is to educate you to the dangers of having Lasik when you are not a proper candidate. Before you consider Lasik, you must be sure it can be done safely, and that you are a proper candidate. I went to a doctor who advertised that anyone who was nearsighted, farsighted, or had astigmatism could be done safely...that's almost everybody! I trusted these doctors, and now I'm legally blind. My name is Dom Morgan, and I tell my story because it may be useful to anyone considering Lasik.".

§  FDA's Lasik Page: Generally informative but falls short of adequately warning prospective patients. From the site, "Some patients lose vision. Some patients lose lines of vision on the vision chart that cannot be corrected with glasses, contact lenses, or surgery as a result of treatment. Some patients develop debilitating visual symptoms. Some patients develop glare, halos, and/or double vision that can seriously affect nighttime vision. Even with good vision on the vision chart, some patients do not see as well in situations of low contrast, such as at night or in fog, after treatment as compared to before treatment.".

·         On the risk of dislodging a flap after Lasik (source):

I found from a reliable source, WebMd that it does indeed never heal. Basically there is no scar to bind the flap to the rest of the cornea. It basically floats in place.


This is a link to a website that shows the strength of the flap is significantly weaker after surgery and never heals to as strong as a normal eye. The Conclusion was: "Conversely, the LASIK flap wound margin heals by producing a 10-fold stronger, peripheral hypercellular fibrotic stromal scar that averages 28.1% as strong as normal comeal stromal, but displays marked variability."


This is why an accident can cause a person, who even had Lasik 10 years ago, to have a dislodged flap. Other people have had a flap dislodged by finger pokes or airbags.


There are a lot of people who say the flap heals, but usually are saying that in order not to scare people with the technical truth. The flap does become more secure over time, but it doesn't hold the same integrity it used to.

·         Advice: Don't have your eyes treated if the ophthalmologist who performs the treatment hasn't also examined your eyes beforehand.