9 criteria for a good LASIK candidate
A successful LASIK procedure is determined largely by whether you meet certain patient criteria and if laser eye surgery is right for you.
LASIK and PRK outcomes are almost always favourable; however, not everyone is a good candidate for vision correction surgery.
The following laser eye surgery checklist is a good start to help you determine if LASIK or PRK is right for you.
1. Your eyes must be healthy
If you have any condition that can affect how your eyes respond to surgery or heal afterwards, you must wait until that condition is resolved. Examples are severe dry eye syndrome, conjunctivitis, infections and any type of eye injury.
If you have persistent dry eyes, where you do not produce enough tears to keep your eyes lubricated and healthy, LASIK surgery may aggravate this condition. Common symptoms of dry eyes include burning or stinging, a gritty sensation in the eye, reduced tolerance to wind, intermittent blurry vision, and even excessive tears in some cases. If you have some of these symptoms, be sure to discuss them with your ophthalmologist prior to surgery.
Your optometrist can determine if you have dry eyes during your preoperative examination and usually can successfully treat the condition so you can then proceed with laser eye surgery. Possible treatments include artificial tears, punctal plugs, medicated eye drops, flaxseed or fish oil supplements, or a combination of these approaches.
2. Your cornea must have sufficient thickness
Most refractive procedures improve visual acuity by reshaping the front surface of the eye (cornea). Performing laser eye surgery on a cornea that is too thin or has a surface that is extremely irregular and misshapen (for example, if you suffer from keratoconus) could compromise results and impair your vision.
If you've been told in the past that you couldn't have LASIK because your corneas are too thin, recent advances may mean you're now an acceptable candidate for laser vision correction. For example, using a femtosecond laser instead of a microkeratome may enable your surgeon to make a thinner corneal flap and thereby preserve more underlying corneal tissue for laser treatment.
3. Your pupils must not be too large
If your pupils are naturally large, you could be at increased risk of side effects such as halos, glares and starbursts in low light, especially when driving at night.
4. Your prescription must be within certain limits
Results of LASIK surgery for the treatment of very high refractive errors are less predictable and may not be worth the cost and potential risks.
In addition, very high amounts of myopia, for example, could require removal of too much corneal tissue and put you at increased risk of vision complications.
5. You must be old enough
Certain procedures require you to be 18 years old; others, 21. Patients younger than these ages can be treated as an exception at the discretion of the LASIK surgeon with permission from the patient's parent(s) or guardian.
Generally there is no upper age limit to laser eye surgery. However, it is important to note that once you hit your 40s, you may still need glasses to correct near vision due to a normal, age-related condition called presbyopia.
Keep in mind that women are more at risk for dry eyes after menopause, and men have a greater risk for dry eyes later in life as well. As noted above, a dry eye condition should be treated before LASIK surgery.
6. Your vision must be stable
Teenagers and many young adults often experience changes in their contact lens prescription and glasses prescription from year to year. It's important for refractive errors to be stable for at least 12 months before undergoing LASIK or other refractive surgery.
Usually it is near-sightedness that gradually becomes worse, but there may be other changes as well.
Younger people are not good candidates until their eyes have "settled down" into one prescription. Your optometrist can tell you whether your prescription is stable.
7. You must be in good health
Contraindications to laser eye surgery may include certain uncontrolled degenerative conditions or uncontrolled autoimmune diseases such as Sjogren's syndrome, rheumatoid arthritis, type 1 diabetes and AIDS. People with HIV who have good immune cell counts may be candidates for LASIK.
Basically, if your body has any trouble with healing, you will have a higher risk of an unsatisfactory LASIK surgery outcome.
Opinions vary among LASIK surgeons regarding which diseases are automatic disqualifiers and which ones might pose acceptable risks in certain cases.
Also, certain medications can increase risks associated with laser eye surgery. For example, immunosuppressants may interfere with post-operative healing, and some medications may increase the chance and/or severity of dry eye syndrome.
8. If you are pregnant, you should delay surgery
Surgery should not be performed until your hormones and vision have returned to normal after pregnancy. This could take a few months.
Pregnant women often have dry eyes, which is another reason you may need to postpone LASIK until a few months after pregnancy. Also, some medications that would normally be used before or after surgery to promote healing (such as antibiotics and steroids) may be risky for your baby, whether unborn or nursing.
9. You must have realistic expectations
While the vast majority of LASIK surgery results are excellent, you should be fully aware of the possible side effects, risks and potential LASIK complications before you choose to undergo the procedure.
It's important to tell your surgeon all pertinent information relating to your health and medical history to ensure you achieve the best possible results.
Page published in March 2020
Page updated in September 2020