Who is a Good LASIK Candidate?
Your eye surgeon will consider many factors when assessing your LASIK candidacy. It would all start with a thorough eye examination for both eye health and vision. You could potentially benefit from LASIK if you suffer from one of the three lower order aberrations, and they are:
These are aberrations in how your eyes react to light. If you are considering LASIK, you are probably tired of dealing with eyewear to correct them and would be pleased to have freedom from glasses or contact lenses.
Some Basic Candidacy Requirements
To be a good LASIK candidate, you need to be able to answer Yes to all these questions:
- Are you over 18 years of age?
- Have you had the same vision prescription for at least the past year?
- Have your eyes been free of infection (including herpes) for at least a year?
- Are your eyes free of any corneal scarring?
- Do your tears keep your eyes comfortably moist?
- If you have diabetes, is it under excellent control?
- Are you free of any autoimmune disease like rheumatoid arthritis, lupus, or multiple sclerosis?
- Are your eyes free of disease such as advanced glaucoma, Fuch’s Dystrophy, or cataracts?
There are other LASIK candidacy parameters where your eye doctor can make a judgment call and decide that in your case, as long as you understand the possible risk, you can be qualified for LASIK.
A good LASIK candidate has corneas of at least average thickness. Corneal thickness is hereditary and on average is about 540 to 560 microns (and a micron is one millionth of a meter). The usual minimum thickness required for LASIK is 410 microns.
Our eyes are filled with fluid that exerts outward pressure against the eye’s periphery. The cornea is part of that periphery and needs to have a certain minimum thickness to hold its curvature against that pressure. When a cornea is too thin, for whatever reason, it will tend to bulge forward and distort vision, a condition known as keratoconus.
At the start of a LASIK surgery, a corneal flap is created from surface tissue and folded back. Then LASIK works by removing small pieces of corneal tissue. That thins the cornea to some extent and therefore average or better thickness is necessary for safety.
If you have severe myopia, your corneas have a steep curvature. LASIK is not safe if the corneas are very steep because the corneal flap may not be cut correctly. Myopia is considered severe when it is -6 diopters or more.
Before you have any LASIK vision correction, your eyes will be diagnosed for their exact vision errors. This is best done with Wavefront technology. The corneal area to be treated is designated with microscopic precision, as are the tiny irregularities of contour. The iris and upil are directly behind the cornea. When you are in dim light, the pupil will dilate to allow more light into the eye, and it will constrict in bright light.
LASIK needs to be done over a treatment area that is as large, or larger than, the size of your dilated pupil. The reason is that if your dilated pupils will be admitting light that has passed through a non-treated corneal area, your vision will be distorted. There is a maximum area where the LASIK laser can work without risking corneal damage, and if your pupils dilate larger than that area, you would not be a good LASIK candidate.
If your diabetes is well-controlled and you have no diabetic retinopathy, you could be a good LASIK candidate. Your eye surgeon would base his or her decision on your medical history and his findings from examining your retinas.
There are other retinal problems that could disqualify you, such as Retinitis Pigmentosa, which is progressive, and retinal detachment. There would be little point in improving your vision with LASIK only to have it deteriorate from these conditions.
Each person is assessed individually and your LASIK surgeon will let you know why you are not a good LASIK candidate, if that is what he finds. There are other ways to correct your vision, such as PRK, IntraLase, LASEK, Epi-LASIK, and Conductive Keratoplasty.
To speak with a qualified LASIK surgeon in your area, please contact us today.