The following information is intended to aid in your decision to have LASIK surgery or not. It is important to note that this is not the only way to correct your vision. Contact lenses, glasses, and other refractive surgeries are available such as RK (Radial Keratotomy), PRK and ALK (Automated lamellar keratectomy). LASIK is a different form of surgical correction from the previous.
Often if appropriate, patients will opt to have both eyes corrected with LASIK. Discuss this decision with your doctor. Additionally, read this Brochure carefully, and discuss any questions with your doctor to make the best decision appropriate for your case. Some occupations such as military pilots cannot have their vision standards met by having RK, ALK, PRK or LASIK. You should investigate this with the appropriate sources prior to consenting to have surgery.
What are Nearsightedness, Farsightedness and Astigmatism?
- Basic LASIK
- What to expect after the procedure?
- Cautions and Precautions
- The Procedure
- Risks and Other Considerations
Why more surgeons & patients choose LASIK as their primary choice for surgical vision correction?
- Are you a good candidate for LASIK?
- Questions to ask your doctor before deciding to have LASIK performed
- Important information to know from your doctor
What are Nearsightedness, Farsightedness and Astigmatism?
The eye works like a camera. The refractive surfaces of the eye, the cornea and the lens, focus (refract) light onto the retina (the film in the camera) that makes sense of the picture and send the signal to the brain. The cornea does about two thirds of the refracting work in the eye.
If the cornea focuses light in front of the retina, the brain will perceive a blurry image. This is what happens in myopia or nearsightedness. Myopia often starts at a young age and continues to increase until stabilizing in the twenties.
Hyperopia or farsightedness results when the light is focused behind the retina.
Astigmatism also blurs the image on the retina but it does so by creating two focalpoints instead of just one as in simple myopia. The shape of the cornea often creates this type of astigmatic image. The astigmatic patient often will see certain objects better than others depending on how much and where the astigmatism is located.
To correct these refractive errors, glasses and contacts act to compensate by altering light rays entering the eye in the opposite way the refractive error alters them thus correcting the error. PRK corrects the error itself by flattening the cornea to lessen the power of the cornea, in myopia, thereby focusing the image onto the retina or by flattening certain orientations of the cornea to create a single focal point on the retina in astigmatic patients.
LASIK utilizes a two-step method for vision correction. The first is the creation of a flap of corneal tissue. This protective layer helps in the quick recovery associated with this procedure.
The flap is created either by using an instrument called a microkeratome, which utilizes a very thin blade, or by a laser called IntraLase. The microkeratome instrument is automated to increase the level of precision of the flap. However, it is associated with many risks. We, at The Eye Center, have abandoned the use of the microkeratome. This technology was good when it was the only thing available. But by today’s standards, it is not acceptable for us to use a metal blade to create a flap, when the precision of the IntraLase is available.
The IntraLase uses a very precise laser to create a very precise flap of exact shape and thickness. Once created, the flap is lifted and the Excimer laser is utilized. (click here for more information on Intralase)
LASIK uses the Excimer laser to correct myopia, astigmatism, or Hyperopia by reshaping the surface of the cornea. The laser removes small layers of the cornea in an automated program designed to flatten, or make the cornea steeper by the amount needed to correct the refractive error of the patient. It works with the use of a cool beam of ultraviolet light controlled by the doctor. This light does not enter the eye so that other structures (iris, lens, and retina) remain unaffected.
At The Eye Center, most of our patients have obtained 20/30 vision or better, or within two lines of their best corrected vision. These results apply to our patient population only and are not meant to be a standard for treatment. Various studies have been published with better and worse results. It is important to note that while their vision without correction (i.e., glasses) improved, some patients still needed a prescription (i.e., glasses or contacts) after LASIK. Additionally, LASIK does not stop the need for reading glasses, as we get older. In fact, if a myope who utilized his myopia for reading has that myopia corrected with LASIK, he or she may then need reading glasses after the procedure.
When your doctor checks your refractive error, the unit of measure of the power of the lenses used is diopters.
What to expect after the procedure
Similar to any surgery, LASIK has inherent risks that should be discussed with your doctor prior to having the surgery. If the results are not acceptable, you may need to have additional treatment in the same eye.
During the first postoperative week, you may notice pain or discomfort lasting up to 3 days. Blurred vision and tearing may be noted as well while the cornea heals. Patients often notice light sensitivity during this time.
The cornea during the healing process can become cloudy affecting the vision. This is rare with this procedure. This effect while usually cleared over time may last in some over 2-3 years. In fact, some patients experience difficulty past the one-year mark. Further details are described later in this discussion.
- You should not have the procedure if:
- You have severe collagen vascular such as lupus, autoimmune or immunodeficiency disease such as AIDS.
- You are pregnant or a nursing mom.
- You have signs or have been diagnosed with keratoconus.
- You are taking any of the following medications:
Accutane (isotreinoin) or Cordarone (amiodarone hydrochloride).
Cautions and Precautions
You should thoroughly discuss, with your doctor, the potential complications if you have been experiencing myopic or astigmatic refractive changes, or if you are diabetic or have severe allergies, or if you have a positive history for Herpes simplex or H. zoster in the eye. LASIK is a more technically difficult procedure and has higher intraopertive risks.
Concerning the VISIX Excimer Laser System, the effectiveness and safety have not been established in the following patients:
Eyes with corneal diseases or abnormalities such as infections or scars, etc.Eyes with a prior surgical history or injury to the surgically involved area.Progressive myopia or astigmatism.Corneal vascularization within one mm. of the area where the laser will be applied.Ages less than 18 years for mild myopia; and ages less than 21 for high myopia, hyperopia and astigmatism.Patients over 2 years postoperatively.Patients who are taking sumatripin (Imitrex) for migraine.
Patients that have higher scarring tendencies
It should also be of noted that to date there has been a relatively smaller number of patients with myopia between 10 and 12 diopters (10.5%) in the appropriate trials, and therefore there may not have been a large enough statistical population to judge the effectiveness or the complication rates with the same certainty as in lower amounts of myopia.
Additionally, the effects of LASIK on vision under poor light have not been determined. The patient may find it more difficult to function in such lighting circumstances (i.e., snow, fog, or glare from bright lights at night.) In younger patients under 30, glare in low light levels may be more of a problem since pupils tend to be larger.
Before the procedure, the patient needs to have an exam to assure that the eye is healthy and suitable for LASIK. This includes a complete health and eye history, and comprehensive examination of the eyes including a computerized mapping of the cornea. If you wear contacts, it is imperative that wear is discontinued 1-2 weeks prior to the preoperative evaluation, if wearing soft contact lenses or 2-4 weeks if wearing rigid gas permeable (hard) lenses. Without this precaution poor surgical results can occur. Additionally, it is very important to tell the doctor of any medications or allergies that you may have. The doctor will discuss eating and drinking before surgery and arranging transportation after the procedure. You may start to drive after the surgery only after getting permission from your doctor.
During the day of surgery, you will be given numbing drops and positioned under the operating microscope at the laser. You will be informed of any sights and sounds and smells you will experience during the surgery. The unoperated eye will be temporarily patched. The surgeon will create the flap. Once the surgical area is exposed and prepared, it is very important that you try to focus exactly where the doctor tells you. Your surgical results are highly dependent on looking at the directed fixation target. Overall, the procedure takes less then 10 minutes. After LASIK is complete, drops and a shield or patch will be placed on the eye.
Although initially numb as the drops wear off you may experience some moderate to severe pain over the next few days. Under no circumstances are you to rub your eyes. The doctor can give medication for the pain if needed. After the procedure, you may have some foreign body sensation in the eyes as well as some light sensitivity. Sunglasses help with this normal finding. The vision will stabilize over the next few weeks and you may experience some improvement or worsening of the effect as the healing process continues. Any hazing to the cornea often resolves over time not affecting vision, but may persist for 1 to 2 years after the procedure.
It is critical, to help the healing process, that you comply with all instructions given especially regarding taking any drops or medications. It is also extremely important to comply with all follow up appointments.
Risks and other considerations
No surgical procedure is completely free of risk. It is not possible to list every complication that can occur, and there may be adverse reactions, which are unknown at this time. Since glasses or contact are currently available and, in general, safely correct myopia and/or astigmatism, you need to consider thoroughly if the risks of having the LASIK procedure outweigh possible benefits.
If the desired correction is not achieved, glasses may still be necessary for good vision. In some cases, significant under-corrections can be retreated.
In some patients, the effect of surgery is gradually lost over several months. Such regression is more common in patients who are very nearsighted (>-6.00 diopters). In some, but not all cases, significant regression can be retreated.
Halo and glare effect
Halo is an optical effect that is noticed in dim light. As the pupil enlarges, a second faded image is produced by the untreated peripheral cornea. Some patients who have undergone LASIK notice this effect while driving at night and this can interfere with night driving. Halo occurs less frequent with the larger treatment zones being used today.
Significant decentration of the zone of treatment (the laser beam not centered on the pupil) can occur when the patient does not fixate correctly during surgery. Halo and blurry vision can result.
Inconvenience between surgeries
If surgery is performed on each eye at a separate session, in the time between surgery on the first and second eye, the two eyes may not work well together because of their temporary differences in refraction (spectacle correction). If a contact lens is not tolerated on the unoperated eye, work and driving may be awkward or impossible until the second eye has had LASIK.
Presbyopia and reading glasses
Even if the operation is successful in correcting your myopia, you may require reading glasses sooner than you would otherwise. As a person grows older, the lens of the eye is less able to focus, and near vision becomes more difficult. This normal aging process is called presbyopia, a condition that can be alleviated with reading glasses or bifocal lenses. An advantage of being myopic or nearsighted is that it generally takes longer to be affected by presbyopia. Therefore, if you do not have the operation and remain myopic, you may not need reading glasses until age 50 or older. If you have the operation, you may need reading glasses in your early forties, as do most individuals with normal eyesight.
Loss of best corrected acuity
In some patients there is a very small chance that the best possible corrected vision is lost, i.e. the patient may not get back to their best visual acuity, even with glasses.
Raised eye pressure
Transient elevation of intraocular pressure occurred on 2% of patients who were on topical steroids following LASIK surgery with return to normal pressures and no ill effects following discontinuation of steroids. You may not be aware of intraocular pressure, however, this is a routine part of the follow-up care provided by eye care professionals.
These include wrinkles, dislocation or loss of the flap. This occurs rarely in patients.
As with any eye surgery, there is a remote possibility of severe infection, corneal perforation, drug reaction, or other rare complications, which could cause chronic pain, an unsightly eye, or partial or complete loss of vision.
Why more surgeons and patients are choosing LASIK as their primary choice for surgical vision correct.
- Today more and more patients are choosing LASIK as their primary choice for vision correction. Although the procedure requires greater surgical skill and is more expensive than PRK and other refractive procedures, it has many advantages.
- Wider range of correction than PRK, or RK. Some patients have greater than 12 diopters of myopia and 3 diopters of hyperopia.Faster recovery, where most of the patients are back to work within one day of the procedure.
- Lower risk of infection, since the outer protective layer of the cornea (the epithelium) is not completely removed, allowing for faster healing.Low level of discomfort, especially when compared to PRK. Greater level of predictability of the results.
Are you a good candidate for LASIK?
- You must fit into the following categories:
- Be at least 18 years old with mild myopia or 21 years if you have high myopia or astigmatism.
- Be free from eye disease or corneal abnormalities.
- Have myopia no more then 15 diopters and/or have astigmatism between 0.75 and 4.0 diopters, or have less than 3 diopters of Hyperopia.
- Have documented support that your refraction has been stable for at least one year preoperatively. (I.e., has not changed more than 0.5 diopters)Be informed of the risks and benefits of LASIK versus other management for myopia and astigmatism.
- Be willing to sign the informed consent form
Questions to ask your doctor before deciding to have LASIK
- What are my other options for correcting my refractive error?
- What will be my limitation after surgery and for how long will I be limited?
- What are the benefits of LASIK for my amount of refractive error?
- What can I expect my vision to be like after surgery?
- If LASIK does not correct my vision, what are the chances that my glasses
will be stronger or my needs for glasses increase over time?
- Can I still wear contacts after the procedure?
- Will LASIK affect the need for glasses or contacts, as I get older?
- After having LASIK, will my cornea heal differently if injured?
- Should I have LASIK in my other eye?
- How long should I wait to have LASIK on the other eye?
- What kinds of problems may I experience if I only have LASIK on one eye?
- How much does this procedure cost and is it covered under any health insurance plan?
Important information to know from your doctor:
- How many procedures do you perform per week?
- How long have you been performing refractive surgery (all types of vision correction surgery)?
- What is your enhancement rate (retreatment rate) after the initial treatment?
- Is there any update to the information in this handout?
- Is your laser FDA approved?
- Is your laser approved for nearsightedness, farsightedness and astigmatism?