If you have worn eyeglasses or contacts most of your life, the possibility of having good eyesight without them may seem remote. But today, high success rates with LASIK and PRK are inspiring more people to seriously contemplate laser eye surgery. A good way to get started is to address these two questions: Am I a good candidate for LASIK surgery, and how do I find the best surgeon?
Am I a Good Candidate for LASIK?
Whether LASIK is the best option for you will ultimately depend on the judgment of your eye surgeon, who will make that determination during a preoperative evaluation. However, good candidates for LASIK have some basic conditions in common.
A good candidate is at least eighteen years old, because the vision of people younger than eighteen years often continues to change. Myopia may continue to
increase in some patients until their mid to late twenties.
No matter what your age, to be considered a good candidate for LASIK, your vision prescription should be stable. In practical terms, your prescription is stable if your
glasses or contacts are at least a year old and you still see well with them.
Treatable Eyesight Parameters
A good candidate for LASIK has an eyeglass prescription that falls within certain parameters. If you are nearsighted, you may have myopia of up to –12.00 diopters. If
you are farsighted, your hyperopia may be up to +6.00 diopters. Your level of astigmatism may be as high as 6.00 diopters. These are normal parameters, but they can vary
from patient to patient and from doctor to doctor.
Surgically Ideal Eyes
You will not know until the preoperative examination whether your eyes meet the standards required for LASIK.
These would include:
- A cornea of the right thickness (not too thin)
- A cornea that is structurally normal (not irregularly shaped)
- Generally healthy eyes (no eye diseases or injuries that could interfere with the outcome)
Conditions That May Prevent Surgery
Any number of factors could make you a poor candidate for LASIK. Some patients fear their eyesight is too poor, yet later discover, after meeting with their eye doctor,
that it falls within treatable parameters that yield successful outcomes. So, do not assume you are a poor candidate until you have consulted with your eye doctor and he or she confirms it.
Contemplating Laser Eye Surgery
Severe Refractive Error
If your refractive error is so severe that it falls outside normal treatable parameters, you may not be a candidate for LASIK. To correct extreme nearsightedness or farsightedness
requires too much deep sculpting and corneal reshaping. Other vision correction procedures, such as the implantable contact lens (see chapter 11), may be preferable. But to be certain, get your eye doctor’s opinion.
Other Health Conditions
You may be a poor candidate for LASIK if you have any of the following conditions:
- Thin cornea. LASIK will not weaken a normal cornea, but if your cornea is unusually thin, LASIK could weaken it, causing distortion in your vision. If you have a thin cornea, PRK may be a better option for you, because it won’t weaken a thin cornea.
- Abnormally structured cornea. This condition is not treatable with LASIK.
- Pregnancy. Vision can be unstable during pregnancy, especially during the third trimester. As a result, the measured refraction may be inaccurate. On the other hand, if a woman is early in her pregnancy and her vision hasn’t changed, it may be possible in special cases to do LASIK.
- Cataract. Cataract is a clouding of the lens within the eye that causes blurry vision. If you have a cataract, LASIK can accentuate the blurring of vision caused by the cataract.
- Corneal dystrophies. These are inherited conditions in which one or more parts of the cornea lose normal clarity due to a buildup of cloudy material.
- A history of ocular herpetic keratitis. The same herpes virus that causes cold sores on the lips can cause recurring infection in the eye, resulting in scarring and blurred vision. This is not a sexually transmitted disease.
- Diabetic retinopathy. This is a potentially blinding complication of diabetes that damages the eye’s retina. Patients with diabetes who have normal corneal sensation and do not have retinopathy are usually candidates for LASIK, however.
- Severe dry eye. Patients with severe dry eye can have healing problems after LASIK. On the other hand, mild to moderate dry eye that is treated before surgery does not cause healing problems, so this condition does not automatically mean LASIK is not an option. Learn more about LipiFlow for chronic dry eye.
Although the conditions listed above are generally contraindications to LASIK, none are absolute contraindications. If you have one of these conditions, consultation with an
experienced LASIK surgeon will help you determine whether LASIK is still a possibility for you.
If you have unrealistic expectations, you may be disappointed with the outcome of laser eye surgery. As a patient, you are responsible for understanding exactly what the procedure can and cannot do. For example, you might still need eyeglasses for performing certain activities, such
Contemplating Laser Eye Surgery
“Some people aren’t good candidates for LASIK. When I recommend against the surgery, my concern is that these patients will go somewhere else and have the surgery done when they
shouldn’t.” Dr. Robert Maloney
It is best to think of LASIK as reducing your dependence on eyeglasses and contact lenses and improving your natural vision.
Issues to Discuss with Your Doctor
The following factors represent areas of controversy in terms of whether a patient is a good candidate for LASIK. Some eye doctors recommend that people with these conditions avoid LASIK surgery, while others believe that decisions need to be made on a case-by-case basis. If you have any of these conditions, discuss them with your eye surgeon.
- Unusually large pupils. One of the potential side effects of LASIK is glare or seeing halos around lights at night. If you have unusually large pupils, more light enters your eyes at night. Some doctors believe that this extra light causes more glare and halos. A number of major studies have now shown that this is not the case, that there is little if any correlation between pupil size and night vision. More and more doctors are coming to agree with us that pupil size is relatively unimportant to your candidacy for LASIK.
- Nursing mothers. Some doctors are concerned that vision may change while a mother is nursing. This is not our experience. If more than two months have passed since delivery, you are a candidate for LASIK. However, if you are nursing and do have the surgery, we recommend that you do not take any oral sedatives, like Valium, that your doctor routinely offers, because they will get into your breast milk.
- Pacemakers. Some pacemakers that are more than twenty years old can be affected by electromagnetic fields emitted by equipment like the excimer laser. Patients with older pacemakers can still have LASIK,but they may require that a technician be present to oversee the pacemaker. Newer pacemaker models are unaffected by the laser.
- Autoimmune diseases. These diseases are caused by an abnormal attack by your immune system on the natural, healthy cells of your body. Certain autoimmune diseases, such as rheumatoid arthritis, are rarely associated with corneal melting, or dissolving, in patients who have eye surgery. Autoimmune conditions can also cause severe dry eye. In general, we find that if you have an autoimmune disease but are under age sixty-five and don’t have severe eye dryness, you may be a candidate for LASIK.
- The use of certain prescription medicines. Some doctors believe that certain prescription medicines impair healing. These prescription drugs include Accutane, used to treat severe acne; amiodarone, prescribed to treat irregular heartbeat; and oral steroids, often used by individuals with severe allergies, with asthma, or with inflammatory diseases such as arthritis and lupus. Tell your eye doctor about any prescription and over-the-counter medications you are taking.