What ever happened to Ortho-K? by Deborah Southard A not-so-new technique is making a comeback print article      send to a friend

Jessica Morales (not her real name) sometimes had trouble reading the chalkboard at the local community college where she was a student. She decided that refractive surgery wasn't the right road for her, so she visited her optometrist and learned about a procedure called orthokeratology.

Orthokeratology has been around for approximately 40 years, but has recently been making a comeback. With the emergence of LASIK and new advances in lens design, Ortho-K is being offered as an alternative to refractive surgery.

What is Ortho-K?

Orthokeratology is the use of specialized contact lenses to change the curvature of the eye in order to correct myopia. The contacts are rigid and gas permeable; soft contacts would not work. The patient is fitted with a series of lenses that gradually reshape the cornea to the desired position. When the right fit is achieved, the patient will receive a pair of "retainer" lenses that must be worn at night and taken out each morning. The improved vision is only temporary and will last approximately 24 to 48 hours.

The first order of business when you visit your optometrist is a complete eye exam and construction of a topographic map of your eye - it maps the periphery as well as the center of the cornea. "We almost always do a topography, and I'll print it out and discuss it with the patient," says Steven Klein, OD from San Diego, California. It is essential that you are a good candidate for contact lenses and that your prescription is within the acceptable range for correction with Ortho-K.

The ideal candidate is someone who has a mild degree of myopia, although there is some degree of difference among optometrists as to what level of myopia is acceptable for Ortho-K. If a patient has relatively normal shaped eyes, doesn't have an enormous amount of astigmatism, and is presently wearing contact lenses, they will most likely be able to tolerate the lenses. People who suffer from dry eye are typically not good candidates for orthokeratology.

If you and your optometrist decide that orthokeratology is the way to go, then you will be fitted with your first pair of lenses. Changes will be made periodically until the correct shape is achieved. You will then need to wear retainer lenses at night that can be taken out each morning. Your eye will retain its shape throughout the day, although you may experience some regression later at night. Small changes can be made as a person ages and as the curvature of the eye changes. The entire process can take anywhere from two weeks to six months, and will probably cost somewhere between $600 and $2000.

The acceptable age range for the procedure is also pretty broad -- anywhere from ten years of age to the older patient who relies on reading glasses. "Treatable age" generally depends on the optometrist and what they feel comfortable with. A patient's profession can also influence the decision to have Ortho-K done. "Many pilots are still very leery of refractive surgery. Ortho-K is popular among law enforcement, and many people in the military prefer it," says Ralph Baker, OD, an optometrist from Roseville, California.

Similar to other long-term contact lens wearers, orthokeratology patients run the risk of neovascularization - a condition that occurs when the cornea is starved for oxygen and blood vessels grow into it - and other corneal changes. It is important that you have realistic expectations; some patients discover that what they are hoping for doesn't translate into reality. Before making a decision, discuss your expectations with your optometrist.

Like the First but in Reverse

The newest advance in orthokeratology lenses is called reverse geometry. According to Dr. Klein, reverse geometry lenses have made enormous differences in the speed and degree of accuracy achieved. "Sometimes, I can get the desired result with two sets of lenses, as opposed to several pairs," he explains.

Before the advent of reverse geometry lenses, the optometrist would have to fit your eye with a progressively flatter lens at each appointment. As the lenses got flatter and flatter they would ride high on the eye. Eventually, there would be no more room at the top of the eye.

Reverse geometry lenses are designed so that the outer part holds the lens on the cornea. The center portion is flat. These lenses hold in place so that they don't ride up. "Not only can you do it faster, with less lenses, the results tend to be more lasting," notes Dr. Baker.

While orthokeratology is not a procedure suited to everyone, it is an alternative for people who decide against refractive surgery. And the added advantage of wearing the contacts only at night is very appealing to those that find contact lens wear inconvenient. For Jessica Morales, it's academic. "Now I don't have to bug the person sitting next to me in class and ask what it says on the board."