7 things you didn't know about ortho-K
Orthokeratology, or ortho-K, is the process of fitting special contact lenses to reshape the cornea. Ortho-K uses gas-permeable contact lenses designed to be worn overnight rather than during the day.
While the patient sleeps, the lenses gently and gradually reshape the surface of the eye. When the patient wakes up and takes out the contact lenses, he or she should be able to see clearly throughout the day without wearing glasses or other contact lenses.
Ortho-K is used to treat and sometimes even eliminate conditions such as myopia, hyperopia and astigmatism. It is appropriate for all ages. In fact, today, this treatment is one of the most effective methods of slowing down progressive myopia in children.
Here are seven things you may not know about ortho-K.
1. Myopia has become considerably more prevalent over the past 30 years. Statistically, roughly 1.5 billion people around the globe struggle with myopia — more than a quarter of the world’s total population. Even worse, experts say this number could increase by an additional 1 billion people by as soon as 2020. These figures indicate myopia is a serious global health concern.
For more than 20 years, ortho-K has been one of the most effective forms of myopia management. As myopia becomes more common, this form of treatment is going to become more critical for patients in all parts of the world.
2. Ortho-K is not as new as you think. Ortho-K is often discussed as a recent or even brand-new innovation in optometry. The technique has its roots in scientific discoveries from the 1940s. It was in that era that eye doctors began to understand glass contact lenses could subtly reshape the eye.
Further innovations followed in the 1960s and the 1980s, but it wasn’t until the 1990s that the procedure really began to pick up steam. Several leaps forward in technology in the 1990s improved the feasibility of ortho-K, from computerized corneal topography software for mapping the surface of the eye to improvements in oxygen-permeable contact lenses, enabling the overnight results ortho-K delivers now.
3. The effect of ortho-K lenses can last for more than a day. Typically, the vision-clearing effects of ortho-K contact lenses last up to 2 full days. During this period, the patient will be mostly or entirely free of the issues that previously plagued their vision. Keep in mind the ortho-K effect is temporary, especially in the early stages of treatment. For best results, patients are encouraged to wear their lenses while sleeping every night. Ortho-K lenses can also be worn during the day, but because they are reshaping the cornea, they are less comfortable for daytime wear than other types of contacts.
4. Corneal reshaping while wearing ortho-K lenses results from hydraulic factors. Some patients assume corneal reshaping will be painful, in part because they think ortho-K lenses accomplish their mission by essentially “squishing” or “squeezing” the eye. The reshaping is actually made possible by hydraulic forces.
The lens forms a vault of tears or fluid over the eye, which varies in thickness. The variations in thickness cause some parts of the cornea to become dehydrated and, therefore, thinner, and other parts take in more fluid, becoming thicker. Through this process, the shape of the eye mimics the shape of the lens, effectively correcting curvature problems on a temporary basis.
5. Ortho-K fittings cannot occur in a single visit. Ortho-K fittings typically take multiple visits to get right. It is likely that multiple sets of temporary lenses and several months will be required to get a perfect fit. Ultimately, this process of getting the right tailored fit is worth the time and will yield better results for vision correction.
6. Kids are especially good candidates for ortho-K. Almost anyone with myopia, hyperopia or astigmatism is a good candidate for ortho-K treatment. However, kids or young adults are especially good candidates because they usually aren’t good candidates for LASIK or refractive surgery. Kids who want or need to be glasses-free — athletes, especially — can get terrific results from wearing ortho-K lenses every night.
7. Ortho-K is not covered by insurance. Ortho-K is considered an “elective procedure,” which means it isn’t covered by most vision insurance policies. For most patients in need of a vision solution, the cost of fitting ortho-K lenses is a small price to pay for all-day clear sight.
For more information:
Elise Kramer, OD, who is residency-trained, practices at Miami Contact Lens Institute and specializes in ocular health and disease, ocular surface disease, and regular and specialty contact lens fitting. Over the last few years she has created a unique scleral lens practice.