Wouldn't it be great if you could correct your nearsightedness and reduce your dependence on glasses or contact lenses — without having to undergo eye surgery?
It might sound far-fetched, but it's a reality for many people. It's called orthokeratology, or ortho-k, and it is available throughout the country.
Ortho-k is not new: It has been performed for decades by eye doctors who specialize in contact lens fitting. Interest in orthokeratology has increased in recent years due to advances in ortho-k technology and a desire among many people for a non-surgical alternative to LASIK and other refractive eye surgery to correct their nearsightedness.
How Ortho-k Works
Orthokeratology is the design and fitting of special gas permeable contacts that gently reshape the clear front surface of the eye (cornea), so you can see clearly even after you remove the lenses.
Myopia (nearsightedness) is caused by the cornea being too steep. Ortho-k, like LASIK, reshapes the cornea so light entering the eye is more accurately focused on the retina.
Unlike LASIK, however, the corneal reshaping effect of orthokeratology is temporary — generally enough to eliminate your need for glasses or contacts for a day or so. Then you have to wear the ortho-k lenses again to maintain the proper corneal shape.
Overnight Ortho-k: Corneal Reshaping While You Sleep
In June 2002, the FDA granted approval to Paragon Vision Sciences for overnight corneal reshaping called Corneal Refractive Therapy (CRT). Approval of overnight wear of corneal reshaping lenses has made ortho-k much more convenient and has led to a recent surge in its popularity. With overnight ortho-k, all corneal reshaping takes place while you sleep, and "retainer" contact lenses no longer have to be worn during the day to preserve good vision.
Currently, two brands have FDA approval for overnight corneal reshaping: Paragon CRT from Paragon Vision Sciences, and Bausch + Lomb's Vision Shaping Treatment (VST). Both are fit only by eye care practitioners who have been through each company's certification procedure.
Sometimes other extended wear gas permeable (GP) contacts are used for overnight ortho-k as an "off-label" use at the doctor's discretion (see sidebar).
Who Is a Candidate?
Orthokeratology is for people of any age who are nearsighted.
The FDA has approved Paragon CRT corneal refractive therapy lenses for the treatment of up to -6.00 diopters (D) of myopia; VST overnight ortho-k lenses are approved for up to -5.00 D.
Astigmatism also can be treated: up to -1.75 D with Paragon CRT, and up to -1.50 D with VST.
Many doctors believe the best candidates for ortho-k are people who have no more than -4.00 D of myopia and little or no astigmatism.
Non-surgical corneal reshaping with contact lenses can be performed on people of any age, as long as their eyes are healthy. Ortho-k holds particular appeal for people who participate in sports, or who work in dusty, dirty environments that can cause problems for regular contact lenses.
Because ortho-k offers similar benefits to LASIK, it's also appealing to adolescents and teens, who are not eligible for LASIK. However, there are some concerns about corneal infections in young people who are fitted with ortho-k lenses, so it's wise to discuss this with an eye care practitioner who is experienced in treating this age group.
What Results Can You Expect from Ortho-k?
Eye care practitioners usually aim for 20/20 vision after ortho-k and corneal refractive therapy, but 20/40 vision (the legal minimum for driving in most of the United States) typically is considered acceptable.
In the FDA clinical study for approval of Paragon CRT lenses, 93 percent of patients achieved 20/32 vision or better, and 67 percent achieved 20/20 or better. In the clinical study for FDA approval of one VST design, about 95 percent achieved 20/40 or better, and 73 percent achieved 20/20 or better. Both studies followed patients over at least a nine-month period.
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 might use an in-office inventory of lenses for fitting your eyes with ortho-k lenses the same day corneal topography measurements are taken, or he or she may order custom ortho-k lenses for fitting at a later date.
You may need a series of temporary lenses to see properly until you reach the desired prescription. "My goal is one pair of lenses for each patient," says Marjorie J. Rah, OD, PhD, of the New England Eye Institute. "But for the most part, I'm using two pairs of lenses."
How Long Does Ortho-k Take?
Ortho-k can reshape two to three diopters of myopia in two weeks or less, says Dr. Rah.
During the time your eyes are being reshaped, you can experience side effects. "In the beginning, you'll have glare and halos that will be reduced with time, but may never completely go away," says Dr. Rah. "As with LASIK, patients with large pupils are especially susceptible to this."
Once your eyes reach the desired prescription, you will need to wear lenses when you sleep or during part of the day to maintain your prescription. Discontinuing lens wear altogether allows your corneas to gradually regress to their original shape or close to it.
Is Ortho-k Comfortable?
Some people have comfort issues with daytime wear of gas permeable contacts (also known as GP, RGP or "oxygen permeable" lenses), which are used for ortho-k.
With GP contacts, a sensation of lens awareness can result from interaction of the eyelid with the edge of the lens during blinking. (This doesn't happen with soft lenses because they are larger and remain tucked under the eyelids.) But when ortho-k lenses are worn during sleep, blinking and lens awareness generally are not a problem.
Cost of Ortho-k
Fitting ortho-k lenses takes more of a doctor's time than fitting regular contact lenses. It requires a series of office visits and potentially multiple sets of lenses. Each eye care practitioner determines his or her fee for orthokeratology, which is based both on time and lens costs.
According to industry sources, ortho-k on average costs $800 to $1,500 for both eyes, which is roughly half the cost of LASIK. This does not include the cost of replacement lenses.
Ortho-k cost can vary based on the region of the country, urban vs. rural settings, and the type of practice. Normally, orthokeratology is not completely covered by vision care insurance plans.
Should You Have Ortho-k Instead of LASIK?
Ortho-k works best for people who don't want to wear glasses or contact lenses all day, every day — but don't mind wearing contact lenses at night, or occasionally during the day.
If your primary goal is to reduce your dependence on glasses or contacts during the day, then ortho-k might be a good alternative for you. However, if you want to eliminate the bother of contacts altogether, then corneal refractive therapy is not likely to satisfy you.
Ortho-k may be a good option if you suffer from dry eyes. It's been found that this condition sometimes is worsened by LASIK.
Unlike LASIK, ortho-k is reversible. If you try reshaping lenses and later decide you want laser eye surgery instead, you can do that. But you will have to discontinue wearing the lenses and wait a period of time before surgery (possibly several months) to allow your corneas to fully revert to their natural shape.
As with all contact lenses, there are some possible side effects and complications of wearing ortho-k lenses. Ask your eye care practitioner for details.
