Orthokeratology (ORTHO-K)

What is Orthokeratology?

Orthokeratology is a non-surgical treatment that uses precise, specially shaped contact lenses to temporarily reshape the cornea in order to eliminate nearsightedness or myopia so that you can see better at distance without wearing eyeglasses or regular contact lenses throughout the day. Most often the doctor will prescribe specially designed rigid gas permeable (RGP) contact lenses that gradually alter the shape of the cornea and temporarily eliminate myopia.

It all began in the 1960s, when doctors realized that the hard contact lenses of the time caused a slight change in the shape of the cornea. They also noted that this flattening of the cornea reduced myopia. Patients would take their contacts off and be able to see much better for the rest of the day. By the next day, however, their vision would return to its normal state, and they needed to wear their contacts again. Over the course of the next decade, orthokeratology was developed.

Orthokeratology technology continues to improve, and the average duration of treatment is now one week, versus the twelve to eighteen months it used to take. Newer materials, similar to what rigid gas permeable lenses are made of, have led to the development of a new program called CRT, or Corneal Refractive Therapy. To learn more about this program, please scroll down.

The Orthokeratology Procedure

Orthokeratology involves first measuring the refraction of your eye, which tells the doctor the degree of nearsightedness, farsightedness, or astigmatism you have. Next it will be necessary to map the shape of the front surface of the eye using an instrument called a corneal topographer. Based on this digital map of your eye, your eye doctor will determine the ideal shape of your cornea.

Then a series of special contacts are made according to your doctor’s exact specifications for your eyes. Initially they will be worn for about eight hours daily until the cornea is reshaped, proper correction is achieved, and your vision is improved.

Sometimes your doctor will actually prescribe a wearing schedule that allows you to only wear the lenses while you sleep. After that, the lenses may only need to be worn for a few hours a day for about three days a week to keep the cornea in the shape necessary for you to see clearly. The exact wearing schedule will depend on the correction your doctor thinks you need.

Am I a Candidate for Ortho-K?

People who are best suited for Ortho-K have myopia less than -4.00 diopters and astigmatism less than -1.50 diopters. Ortho-K is safe for people of all ages, as long as their eyes are healthy. This is a great alternative for those who are too young to consider LASIK, those whose prescriptions are continuing to change, and those involved in sports that make contact lenses impractical. Ortho-k is not suitable for everyone, so it is best to consult with your eye doctor if you are interested in this procedure.

Orthokeratology Advantages

  • Non-surgical method
  • Available for most people
  • Freedom from constant corrective lens wear
  • Better vision improvement

Orthokeratology Disadvantages

  • Longer result time
  • Not a permanent solution
  • Higher startup cost than regular contacts or eyeglasses
  • Currently only for myopia

Paragon Corneal Refractive Therapy CRT

Paragon Corneal Refractive Therapy, or CRT, is similar to Ortho-K except that it uses a more specialized design. Paragon CRTs are “designed oxygen permeable therapeutic contact lenses.” The combination of advanced computerized mapping of the eye, computerized manufacturing of the contact lenses, and special oxygen-permeable material has given Paragon Visual Science the first FDA-approved nighttime Corneal Refractive Therapy. These special contacts are worn at night and provide improved vision during the daytime. They correct myopia up -6.00 diopters and astigmatism up to -1.75 diopters. Most people will see vast improvement in the first few days, and 20/20 vision within about seven days. Others may take longer, depending on the degree of correction required.

Orthokeratology and CRT Cost

Ortho-K and crt are both more costly at startup than normal contact lenses and eyeglasses. After the initial correction, however, retainer contacts to preserve the shape of the cornea generally cost around $100 to $200 per pair. The total cost will range from $900 to $1,800 with two sets of lenses and fittings. Insurance usually does not fully cover these procedures because they are elective, but partial coverage may be available if your insurance covers normal contact lenses. In general, CRT can cost up to four times more than standard rigid gas permeable lenses due to the complexity of the lens design and the program’s requirement that you visit your optometrist several times during treatment.

Orthokeratology Side Effects

Although orthokeratology is effective, it is only as effective as the commitment of the patient. If the lenses are worn constantly, the patient’s vision will improve, but once the lenses are removed for an extended period, the eye will return to its original shape and the patient’s vision will revert back to its refractive error state. CRT is reversible and only lasts as long as the lenses are worn. Fluctuating or blurry vision are possible side effects of Ortho-K and CRT. Still, these side effects can be prevented.

Orthokeratology and CRT are designed for people who do not desire refractive surgery and are content with occasionally wearing contact lenses. These methods carry the same risks as regular contacts, and a few more. The risks of Ortho-K are best explained by your eye doctor, and the risks of CRT are best explained by a certified paragon practitioner. You can visit the Paragon CRT site to find a practitioner near you and learn more about Corneal Refractive Therapy lenses.

Talking to Your Eye Doctor

Here are some questions to ask your eye care professional about orthokeratology and CRT:

  • Which do you recommend for me, Ortho-K or CRT? Why?
  • How many times will I need to schedule visits during treatment?
  • Are Ortho-K or CRT the best treatment options for my vision problem?
  • How much will treatment cost?
  • What are the risks involved with this treatment?
  • Am I a good candidate for orthokeratology?
  • Are you able to perform the treatment I need or will I need a specialist?
  • What do you like and dislike about orthokeratology?
References:
  • J. Anshel, MD “Smart Medicine for Your Eyes” (SquareOne Publishers, 2011) 355-356
  • American Optometric Association, Ortho-K http://www.aoa.org/x4746.xml
  • American Medical Association “Family Medical Guide” 4th Edition (John Wiley & Sons, Inc. 2004) 1032
This article was last updated on 07/2014