Although LASIK eye surgery can treat severe degrees of myopia (nearsightedness), moderate amounts of hyperopia (farsightedness), and astigmatism, it is not right for everyone.
While the goal of LASIK surgery is to get rid of glasses or contact lenses, undergoing LASIK surgery cannot guarantee 20/20 vision. Fortunately, post-op, most cases are successful in improving visual acuity (or sharpness).
You have to fulfill certain eligibility criteria in order to be fit for Lasik surgery. There are certain contraindications that can make you unfit for this surgery.
Nevertheless, if the eye surgeon says you are not a good Lasik candidate today, you may still be a potential candidate in the future. The technology for laser eye surgery is constantly improving and this enables people ineligible today to become eligible later.
There are certain parameters, which govern who can undergo Lasik. They tell the eye surgeon whether you are suitable and fit for Lasik surgery or not. The eye surgeon will perform a general and detailed eye examination before he declares you fit for surgery.
Contraindications for Lasik can be divided into three categories:
- Local eye contraindications
- General health contraindications
- Other contraindications
1) Local eye disorders, which are contraindications for Lasik and make you ineligible
- Blepharitis. this is inflammation of the eyelids with crusting of the eyelashes, which increase the risk of infection after surgery.
- A thin cornea. A sufficiently thick cornea is necessary for Lasik surgery so that when the corneal flap is created and the laser applied, there is sufficient corneal tissue remaining to maintain the curvature and rigidity of the cornea. The eye surgeon determines whether the thickness of the cornea is sufficient for Lasik surgery, by measuring it with an instrument called the pachymeter.
- Size of the Pupil. Too large pupils diminish the benefits of Lasik surgery.
- Keratoconus. This is a pathological condition of the cornea, where due to decreased corneal strength, the cornea progressively goes on thinning and bulges out into a conical shape causing distorted vision. Keratoconus is an absolute contraindication for Lasik.
- Changing eye prescription. If your prescription for eyeglasses is changing frequently and becomes stronger, then you are not the right candidate. You must have a stable eye prescription, without significant change for at least one year.
- Lasik prescription requirements. Your corrected vision at the time of the Lasik operation must be within the following limits:
- Myopia or short-sightedness should be less than 8 dioptres.
- Hyperopia or long-sightedness should be less than +6 dioptres.
- Astigmatism should be less than 4 dioptres.
- Eye conditions like cataracts, glaucoma, strabismus, ocular herpes, retinal detachment due to eye surgery are absolute contraindications. Any eye infections must be treated before you become eligible for Lasik operation.
- Dry eyes. History of dry eyes does become a contraindication as this condition may worsen after Lasik. However, the use of artificial tears may help.
2) General health contraindications for Lasik
- Auto-Immune diseases. Persons with a compromised immune system and suffering from lupus, multiple sclerosis, rheumatoid arthritis, HIV, and fibromyalgia are not eligible to undergo Lasik. This is because such persons do not heal in the required manner.
- Uncontrolled and unstable diabetes is another strong contraindication for Lasik eye surgery. Diabetes also can cause diabetic retinopathy and changes in vision.
3) Other contraindications for Lasik surgery
- Age. LASIK is FDA-approved for all persons aged 18 and older. Since adult vision is usually at its best between the ages of 19 to 40 years, anyone within this range is a potential candidate. Doing a Lasik on a person below the age of 18 years is contraindicated because the growth of the eye stabilizes after the age of 18 years and till then the eye is still changing. Old age is not a contraindication by itself if other contraindicating factors are not present. However, although there is no upper age limit for LASIK surgery, people above 40 years may suffer from presbyopia, which prevents them from seeing close objects.
- Pregnancy. If you are pregnant or planning to become pregnant immediately, you should avoid undergoing Lasik. This is because changes in eye refraction occur during pregnancy.
- Nursing mothers should not opt for Lasik till 6 months after pregnancy.
- Certain medications. If you are taking certain systemic drugs that alter vision, you are ineligible for Lasik. These drugs include and not limited to cyclosporine and tacrolimus, minocycline, hydroxychloroquine, ethambutol, topiramate, tamsulosin, amiodarone, anticholinergics, erectile dysfunction drugs, blood pressure medications and more.
- Certain sports. Trauma to an eye operated for Lasik can result in permanent dislocation of the corneal flap. Therefore, people who engage in sports where such trauma is likely, become an automatic contraindication. Such sports include martial arts, boxing, or wrestling.