What is Ortho-K?
If you are nearsighted when you look at distant objects the light entering your eye focuses in front of the retina resulting in blurry vision. This condition called myopia can be corrected by wearing glasses or contact lenses through laser surgery or now with a procedure called Orthokeratology.
Orthokeratology often referred to simply as Ortho-K is a reversible non-surgical process that uses a specialty contact lens to gently reshape the cornea of your eye while you sleep. Highly oxygen permeable contact lenses are used to reduce or correct mild to moderate amounts of myopia (nearsightedness) and mild astigmatism. In some ways it is similar to the use of dental braces by an orthodontist to straighten and realign teeth in a specific position. The only difference is that the cornea (front surface of the eye) is highly elastic and fluid and will always return to its original shape. For this reason the lenses are worn nightly or alternate nights once the ideal corneal shape has been achieved to maintain good vision throughout the day. The benefit of the cornea being so elastic is that upon discontinuation of wear the cornea will flex back to its original shape.
Why Have Ortho-K Done?
- The main purpose of Ortho-K is to be free of both contact lenses and spectacles during the day.
- It is ideal for individuals involved in sports or for those individuals who work in dusty and dirty environments where other types of vision correction may be inhibiting.
- Rigid gas permeable lenses have been fitted to reduce the myopic increase seen in teenagers and shown to stabilize or retard the progression of myopia (nearsightedness).
- Some long-term contact lens wearers develop sensitivity to their traditional lenses which results in reduced wearing time or awareness. Ortho-K can solve these problems.
If you are interested in Ortho-K lenses you should discuss this option with your eyecare practitioner. The first step in determining if you are a candidate for Ortho-K lenses is a comprehensive eye exam. An instrument called a corneal topographer takes digital images of the surface curvature and shape of the eye. This gives your practitioner a chance to both assess the general condition and health of the eyes as well as determine the likelihood of success.
A pair of trial lenses are then prescribed for overnight wear. The following morning the lenses will be removed and another assessment and topographic map made. If the fit needs to be modified the measurements of the trial lenses will be utilized to design a second set of lenses. Once your practitioner has established the correct fit that can reduce your myopia to the best achievable point a custom pair of Ortho-K lenses will be ordered. The lenses will be worn nightly for one week and then assessed once again. The follow-up visits are essential in maintaining the health of the eye and the effectiveness of the lenses.
In the past Ortho-K used hard and rigid gas permeable lenses. However dramatic technological advances have resulted in new manufacturing methods that use highly oxygen permeable lens materials and more sophisticated lens designs. These new lenses are called ‘reverse geometry lenses’ and they are designed to gently re-shape the cornea. Most of the vision changes occur rapidly in the first few days. It may take a few months for maximal results and stability.
What are the advantages of Ortho-K lenses?
Ortho-K lenses are an excellent alternative for those who are uncomfortable with the risks associated with laser eye surgery or for those who do not want to wear eyeglasses or contact lenses during the day. The procedure is reversible non-invasive and can be modified.
Am I a candidate for Ortho-K lenses?
There is no age restriction to wear Ortho-K lenses as they can benefit children and adults alike. Ortho-K lenses are an excellent treatment option for nearsighted children whose prescription changes rapidly as they may prevent increases in myopia and retard progressive changes. However they are solely designed for people with mild to moderate amounts of myopia or astigmatism.
People who are not good candidates for Ortho-K lenses include those who:
- Have an eye disease or abnormality affecting the cornea conjunctiva or eyelid
- Suffer from dry eye
- Experience allergic ocular reactions that might be exacerbated by contact lenses
- Have severe cases of myopia or astigmatism
- Have an abnormally shaped cornea
How much does Ortho-K cost?
The cost involved in Ortho-K is higher than the cost of standard contact lenses as they must be custom designed to fit your eye and the duration of treatment and number of lenses required depends on the patient. Individual eyecare practitioners determine the fees for Ortho-K lenses although the cost is generally half the cost of laser surgery.