Orthokeratology, commonly called ortho-k, is a method used to correct myopia (nearsightedness) or astigmatism by wearing rigid gas permeable contact lenses overnight so that no corrective lenses are needed during daytime hours.
Gas permeable (GP) lenses specialized for ortho-k are inserted at bedtime and worn as you sleep. Throughout the night, the lenses reshape your cornea gently so that your vision becomes clear on the following morning. The correction is temporary, and ideally, no eyeglasses or contact lenses will be needed on the next day or two. In order to maintain sharp visual acuity on a daily basis, you need to wear the ortho-k reshaping lenses every night.
At present, three brands of orthokeratology contact lenses are approved for use by the FDA. Euclid Emerald, usually prescribed for myopia control, Paragon Vision Sciences, who produces “Corneal Refractive Therapy” (CRT), and Bausch and Lomb, who manufactures “Vision Shaping Treatment” (VST).
Candidates for Ortho-K
Ortho-k is very suitable for nearsighted people who are not appropriate candidates for vision correction surgery, such as children. Individuals of all ages with healthy eyes can try ortho-k, namely because it can be discontinued at any point without permanent effects to the eyes.
Vision Results from Ortho-k
Success rates for ortho-k are generally higher for more mild vision prescriptions. The ideal goal is to provide 20/20 vision without any need for eyeglasses or contacts during the day.
According to FDA trials conducted on both CRT and VST lenses, more than 65% of ortho-k patients achieved 20/20 visual acuity. Consult with your eye doctor to find out if your vision prescription is within range for successful ortho-k treatment.
Note that although improvement in vision is generally reported within a day or two of wearing ortho-k overnight, the full effects may not be experienced until the lenses are worn for a few weeks. During this transition period, your vision will probably not be as crisp as it was with regular contacts or eyeglasses, and glare or halos around lights may be visible. Until ortho-k works fully, a temporary pair of eyeglasses may be required for specific actions.
How Does Ortho-k Feel?
Although some people have trouble wearing regular gas permeable contact lenses during the day, ortho-k GP lenses are worn while sleeping – so discomfort and awareness of the lenses in your eyes is generally not an issue.
Is Ortho-k expensive?
Professional fitting for ortho-k requires a series of visits to your eye doctor. A number of pairs of contact lenses are also generally needed. GP lenses that are special for ortho-k are more costly than standard contacts. In sum, the fees for ortho-k add up to a higher total than regular contact lenses.