Ortho-K And Corneal Refractive Therapy:
Overnight Contacts To Correct Myopia
What Is Ortho-K?
Orthokeratology (ortho-k) is the fitting of specially designed gas permeable contact lenses that you wear overnight. While you are asleep, the lenses gently reshape the front surface of your eye (cornea) so you can see clearly the following day after you remove the lenses when you wake up.
Ortho-k Lenses Are Prescribed For Two Purposes:
- To correct refractive errors (primarily nearsightedness, but also astigmatism and hyperopia). In some cases, ortho-k also is used to correct presbyopia.
- To slow the progression of childhood myopia. (Read more about myopia control.)
Ortho-k lenses are also called “corneal reshaping contact lenses” or “overnight contact lenses to correct or control myopia.”
How Long Does The Ortho-K Effect Last?
You should be able to see acceptably well without glasses or contact lenses for a day or two, sometimes longer. For best results, you should wear the ortho-k lenses every night.
Which Vision Problems Can Ortho-K Correct?
Orthokeratology is most frequently used to temporarily correct myopia (nearsightedness). Generally, ortho-k can correct upwards of -6.00 diopters (D) of myopia.
Ortho-k also can correct lesser degrees of astigmatism, hyperopia and presbyopia.
Who Is A Good Candidate for Orthokeratology?
Most people with mild to moderate myopia (with or without mild astigmatism) are good candidates for ortho-k.
Because the corneal reshaping effect is temporary, little risk is involved, and you can discontinue wearing the lenses at any time — provided you are willing to start wearing glasses or contacts again when your myopia returns!
Children and young adults who want to be glasses-free but are too young for LASIK or are not good candidates for refractive surgery for other reasons (dry eyes, for example) often are good candidates for ortho-k. People who participate in contact sports or work in dusty environments that can pose problems for contact lens wear also can be good candidates.
What To Expect When You Begin Ortho-K
The eye doctor will begin by measuring the curvatures of your corneas using an instrument called a corneal topographer — a painless procedure that takes about a minute and produces a topographical map of your eye’s surface.
Your doctor will order custom ortho-k lenses for fitting at a later date.
How Long Does It Take For Maximum Ortho-K Effect?
Some people can have excellent vision after a day or two of overnight ortho-k. But for higher prescriptions it can take two weeks or longer for maximum correction.