Orthokeratology:
Reshaping the Eye with Contact Lenses

Wouldn't it be great if your nearsightedness could be corrected while you sleep? It might sound far-fetched, but it's a reality for some people. It's called orthokeratology, or ortho-k, and it is available throughout the country.

Here's how it works: When you sleep, you wear special contact lenses that gently reshape the surface of your eye, so you can see clearly even after you remove the lenses. The effect is temporary — generally enough to get you through a day or so, but you must wear the special lenses each night.

Reshaping the cornea with contact lenses to improve vision isn't new. Orthokeratology has been practiced by some eye doctors for decades. However, in the past ortho-k produced mixed results and wasn't FDA-approved for overnight wear, so the procedure had limited appeal.

Then in June 2002, the FDA granted overnight wear approval to a type of corneal reshaping called Corneal Refractive Therapy (CRT). More overnight ortho-k approvals followed.

At the same time, new manufacturing methods and lens designs were enabling orthokeratology lenses to achieve much higher success rates than experienced in the past. The performance of so-called "reverse geometry" or "return zone" designs have fueled new excitement about orthokeratology.

Myopia (nearsightedness) is caused by light coming into the eye in such a way that it doesn't focus properly on the retina. Typically, this problem is corrected by using eyeglasses or regular contact lenses to re-focus the light rays.

A similar result can be achieved by reshaping your cornea. LASIK is a surgical way to do this. Ortho-k contact lenses flatten your cornea without surgery, enabling light to focus properly on your retina, resulting in better vision. (Read more about myopia.)

Two brands have FDA approval for overnight corneal reshaping: Corneal Refractive Therapy (CRT) from Paragon Vision Sciences, and Bausch & Lomb's Vision Shaping Treatment (VST). Both are fit only by eye care professionals who have been through each company's certification procedure.

Other ortho-k lens brands without overnight approval are sometimes fit by practitioners for daytime ortho-k, or for overnight ortho-k as an "off-label" use at the doctor's discretion (see sidebar).

Orthokeratology is for people of any age who are nearsighted. The FDA has approved CRT for people with up to six diopters of myopia (-6.00 on your prescription); the VST approval is for up to five diopters. Astigmatism can also be treated: up to -1.75 with CRT, and -1.50 with VST. Many doctors believe the best candidates are people who have low amounts of myopia, about four diopters or less.

The procedures can be performed on practically anyone 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 have used ortho-k, so it's wise to pursue this with an eye care practitioner who is experienced in treating this age group.

Eye care professionals usually aim for 20/20 vision, but 20/40 vision (the legal minimum for driving in most of the United States) is typically considered acceptable. In the FDA clinical study for approval of CRT, 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.
 

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 order lenses for you, or some doctors may have an existing inventory.

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." Dr. Rah fits CRT as well as other ortho-k designs.

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.

Some people have comfort issues with daytime wear of GP contact lenses (also known as RGP or "oxygen permeable" lenses), which are used for ortho-k. With GPs, 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 since ortho-k lenses are worn during sleep, blinking and lens awareness are generally not a problem.

Fitting ortho-k lenses takes much more of a doctor's time than a regular contact lens fit. 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 on both time and lens costs.

On average, eye care practitioners will charge $800 to $1,500 for both eyes, according to the lens manufacturers, plus the cost of replacement lenses in subsequent years. This can vary based on the region of the country, urban vs. rural settings, and the type of practice. Normally, ortho-k is not completely covered by vision care insurance plans. (Read how this compares with the cost 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 be glasses- and contacts-free 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 ortho-k 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 is sometimes 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 for a period of time before surgery (possibly several months), your surgeon would have you stop wearing your lenses so your corneas can revert to their natural shape.

As with all contact lenses, there are some side effects and possible complications. Ask your eye care practitioner about the challenges you can expect.