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Consider the follow questions and answers about LASIK technology provided by Emory physicians:
- What is LASIK?
- What can I expect from LASIK?
- Who is the “ideal candidate” for LASIK?
- Who is the “less than ideal” candidate for LASIK?
- Who is the “non-LASIK” candidate?
- What are myopia, hyperopia and astigmatism?
- How is LASIK different from previous refractive eye surgery techniques?
- Is LASIK right for everyone?
- Is LASIK Safe?
- What are the risks associated with LASIK?
- What happens before LASIK surgery?
- What happens during the LASIK procedure?
- Is LASIK painful?
- How long does the procedure take?
- How long must people wait to resume normal activities after LASIK treatment?
- Will a person’s vision remain stable long after the procedure?
What is LASIK?
LASIK is a safe and effective surgical procedure designed to reduce a person’s need for glasses or contact lenses. Called Laser-Assisted In Situ Keratomileusis, LASIK permanently changes the shape of the cornea (clear covering of the eye) using a laser referred to as an excimer laser.
LASIK is a quick, usually painless, procedure. It is performed on a delicate part of the eye, and therefore an individual undergoing the procedure should understand the risks and the benefits, the importance of a initial screening exam by a physician, and hold realistic expectations about the procedure’s outcome.
Essentially, during a LASIK procedure, the cornea is reshaped using an excimer laser. A microkeratome is used to make a flap in the cornea. A hinge is left at one end of this flap. The flap is folded back to reveal the stroma (the middle part of the cornea). At this point, the computer-controlled laser emits pulses of light that vaporize excess tissue in a painless procedure. The flap is then laid back into position.
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What can I expect from LASIK?
Laser vision correction surgery has been proven to be very successful for helping individuals reduce their dependence on glasses and contact lenses. However, the degree of improvement will vary among individuals.
You, as are all individuals seeking vision correction, are concerned with reaching a satisfactory outcome. Although Emory Vision cannot promise patients 20/20 vision, most with mild to moderate prescriptions do reach this or are close to 20/20 vision. While visual acuity is a common test for vision, it is not the only measurement used. Patients should not focus on achieving a 20/20 vision as a “perfect” vision, the realistic expectation is to reduce dependency on glasses or contact lenses.
And, with the use of customized vision assessment and correction, using technologies such as a wave-front-guided LASIK, vision may improve dramatically in both quality and quantity.
According to national statistics, the overwhelming majority of patients that have LASIK surgery are fully satisfied with the results. However, a small minority of patients overall, may experience a complication with surgery. Finding a vision correction center such as Emory Vision, with a track record of success will ensure a greater likelihood of success for you.
Each person should be fully informed about benefits, risks, and probable outcomes. LASIK surgery, as all surgical procedures, has the risk of complications.
According to the nationally respected Eye Surgery Education Council Medical Advisory Board, one co-chaired by Emory Vision’s Medical Director Doyle Stulting, MD, many millions of LASIK procedures have been conducted, and less than 1 percent of patients have experienced serious vision problems. The Board states that most complications represent delays in full recovery and resolve within a few months of surgery.
The Council also states that a LASIK patient may require an enhancement (re-treatment) to achieve the optimal outcome. This may be done about three months after the original procedure. There is the possibility that a glare or halo under dim lighting may occur, but this usually resolves after a few months following surgery.
In a small number of corrections, the eye may be undercorrected or overcorrected.
Possible side effects from LASIK may include dry eye during the healing process and discomfort immediately after the procedure.
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Who is the “ideal candidate” for LASIK?
Again, referring to the respected Eye Surgery Education Council Medical Advisory Board "LASIK Surgery Screening Guidelines for Patients", co-chaired by Emory’s Doyle Stulting, MD, a candidate who is ideal meets the following criteria:
- over 18 years of age with stable glasses or contact lens prescriptions for at least two years
- have sufficient corneal thickness for a physician to create a clean corneal flap of appropriate depth
- affected by common vision problems or refractive error – myopia (nearsightedness), astigmatism (blurred vision caused by an irregular shaped cornea), hyperopia (farsightedness), or a combination of these
- do not suffer from any disease, vision-related or otherwise, that may reduce the effectiveness of the surgery or the patient’s ability to heal properly and quickly
- are adequately informed about the benefits and risks of the procedure by thoroughly discuss the procedure with their physicians and understand that for most people, the goal of refractive surgery should be the reduction of dependency on glasses and contact lenses, not their complete elimination
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Who is the “less than ideal” candidate for LASIK?
According to the Council, factors exist that preclude a candidate from being ideal for LASIK surgery. In many cases, a surgeon may still be able to perform the procedure safely, given that the candidate and physician have adequately discussed the benefits and risks, and set realistic expectations for the results. Candidates in this category include those who:
- have a history of dry eyes, as they may find that the condition worsens following surgery
- are being treated with medications such as steroids or immunosuppressants, which can prevent healing, or are suffering from diseases that slow healing, such as autoimmune disorders.
- are under age 18
- have unstable vision, which usually occurs in young people, with physicians recommending that, prior to undergoing LASIK, candidates’ vision has stabilized with a consistent glasses or contact lens prescription for at least one year
- are pregnant or nursing
- have a history of ocular herpes within one year prior to having the surgery
- have refractive errors too severe for treatment with current technology — currently the FDA states appropriate candidates are those with myopia up to -12 D, astigmatism up to 6 D and hyperopia up to +6 D
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Who is the “non-LASIK” candidate?
The Board states that certain conditions and circumstances completely preclude individuals from being candidates for LASIK surgery. Non-candidates include individuals who:
- have diseases such as cataracts, advanced glaucoma, corneal diseases, corneal thinning disorders (keratoconus or pellucid marginal degeneration), or certain other pre-existing eye diseases that affect or threaten vision
- do not give informed consent, as it is absolutely necessary that candidates adequately discuss the procedure and its benefits and risks with their surgeon, and provide the appropriate consent prior to undergoing the surgery
- have unrealistic expectations, as it is critical for candidates to understand that laser eye surgery, as all surgical procedures, involves some risk and that the final outcome of surgery and the rate of healing vary from person to person and even from eye to eye in each individual
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What are myopia, hyperopia and astigmatism?
People with myopia, or nearsightedness, have more difficulty seeing distant objects as clearly as near objects. People with hyperopia, or farsightedness, have more difficulty seeing near objects as clearly as distant objects. Astigmatism is a distortion of the image on the retina caused by irregularities in the cornea or lens of the eye. Combinations of myopia and astigmatism or hyperopia and astigmatism are common.
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How is LASIK different from previous refractive eye surgery techniques?
Current FDA-approved laser vision correction methods, such as LASIK, have a higher predictability of the final result with a lower incidence of complications. Additionally, older non-laser techniques typically involved manually performed incisions rather than automated lasers for correction.
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Is LASIK right for everyone?
Only an eye care professional can determine whether or not an individual is eligible for LASIK treatment. In general, a good LASIK candidate is at least 18 years old, has healthy corneas, and has maintained a stable eye prescription for the last 12 months. Because hormonal levels can affect the shape of the eye, women who are pregnant or nursing should not undergo LASIK treatment. The procedure should also not be performed on patients who:
- Have glaucoma, cataracts or dry eyes
- With collagen vascular, autoimmune or immunodeficiency diseases
- Show signs of keratoconus (an eye disorder in which there is thinning of the cornea that results in blurred or distorted images)
- Take medications with ocular side effects (such as Accutane® or Cordarone®)
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Is LASIK Safe?
The FDA recognizes LASIK as proven, safe and effective. According to guidelines recently released by the Eye Surgery Education Council (ESEC), fewer than 1% of patients who have received LASIK to date have experienced serious, vision-threatening problems. Most LASIK complications can be treated and usually resolve within several months of surgery. There are no known cases of blindness resulting from LASIK.
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What are the risks associated with LASIK?
Although no one knows the exact number of complications, studies suggest that the incidence of minor difficulties such as dry eyes and nighttime glare is around 3% to 5% from combined LASIK and PRK procedures. These minor complications include:
- Halos — Some patients will notice glare, halos or starburst around objects in low-light conditions. For the vast majority, these symptoms are temporary. However, others will continue to experience them for several months or longer. During pre-operative evaluation, the refractive surgeon can determine whether or not a person is at high risk for seeing long-term halos.
- Dry eyes — There is increased dryness of the eyes typically for several months following LASIK, though some patients may experience dryness for a longer period of time. It is important to use lubricating drops frequently. If the eyes remain dry for prolonged period, there are other drops or techniques that can help. Pre-operative evaluation will help determine whether or not a person is a likely candidate for experiencing dry eyes.
- Infection — This is an extremely rare occurrence, with a 1 in 2000-3000 chance (similar to any eye surgery). Fortunately, as the LASIK technique has developed over the years and proven to be of great benefit to millions of patients nationwide, firmly established protocols now exist which minimize the risk of infection.
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What happens before LASIK surgery?
Before a surgeon will perform LASIK, preoperative tests are performed to screen for glaucoma, cataracts and other disqualifying conditions. The surgeon may also use an instrument called a corneal topographer to photograph and electronically map the eye in order to gather more information about the individual’s eyes prior to treatment.
Because contact lenses change the shape of the cornea, LASIK candidates are required to switch to eyeglasses before their baseline evaluation is taken and continue wearing only eyeglasses between 2-4 weeks before LASIK surgery. Not leaving contact lenses out long enough for the cornea to assume its natural shape before surgery can cause inaccurate measurements and poor vision after surgery.
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What happens during the LASIK procedure?
Once the surgeon has conducted all pre-operative examinations, the eye is anesthetized with numbing eyedrops, the area around the eye is cleaned, and an instrument called a lid speculum is used to hold the eyelids open. The surgeon will then use a specialized instrument, called a microkeratome, to cut a thin, circular flap — the outermost 20 percent of the thickness of the cornea — to expose the portion beneath. This part of the procedure is called keratectomy.
While the inner cornea (the stroma) exposed, the surgeon will ask the patient to fixate on a specific light source above the patient. This is to ensure that the laser beam is aligned precisely with the center of the patient’s eye. Once the eye is in the correct position, the laser treatment is performed. The computer-controlled excimer laser removes the tissue under the flap and reshapes the cornea of the eye. In less than 60 seconds, ultraviolet light and high-energy pulses from the excimer laser reshape the internal cornea with accuracy up to 0.25 microns, or 1/4000 of a millimeter.
After the pulses of laser energy vaporize the corneal tissue, the flap is put back into its original position. The surgeon will observe the eye for three to five minutes to ensure bonding. Because the cornea bonds quickly, healing is rapid, and the eye does not require stitches.
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Is LASIK painful?
The procedure is painless, however, most people experience 4-6 hours of mild irritation after their LASIK procedure.
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How long does the procedure take?
The laser treatment itself usually takes less than a minute, while the entire procedure takes around 15 minutes per eye.
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How long must people wait to resume normal activities after LASIK treatment?
In most cases, people can return to work within 1-3 days following LASIK surgery. People cannot drive until after the 24 hours post-op visit or until a doctor says it is alright to drive. Women can start wearing makeup within two to three days of treatment, however, they are advised to wear only new cosmetics in order to decrease risk of infection.
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Will a person’s vision remain stable long after the procedure?
The vision correction is permanent. However, a person’s vision may change naturally with time and LASIK does not affect visual conditions that may develop with age. Also, LASIK does not prevent presbyopia and the eventual need for reading glasses. Depending on the cause, retreatment may be a viable solution to later vision changes, and other treatment options also exist.
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