Using rigid lenses, orthokeratology (also known as ortho-k) is a therapeutic method for reducing the progression of myopia(nearsightedness) in children.
In the past as a childs myopia would get worse they would just update their eyeglasses prescription. However it is now known that the higher a child's myopia is, the higher their incidence of serious eye diseases. Learn more about myopia management.
Children with high myopia (-6 or worse) will increase their risk of:
Orthokeratology involves wearing special hard contact lenses overnight that gently reshape your cornea, the front part of your eye, to reduce your refractive error. Similarly to how braces and retainers shape your teeth, these hard contact lenses will shape your eyes. These lenses are able to retain and mold the front part of your eyes so that when you wake up in the morning, you can enjoy clear vision throughout the day without the need for contact lenses or glasses.
The cornea actually takes about one to two weeks to achieve the shape that is necessary to be able to see clearly throughout the day. You may be able to see clearly for the first four to five hours after wearing these contact lenses the first time. After that you will be able to see clearly throughout the day. However, it is important to wear these lenses every night to prevent the cornea from returning to its original shape. Reverse geometry method is used to achieve this. There is fluid under the epithelium of the cornea, the front part of the eye. It gently squeezes that fluid from the center to the edge, resulting in the cornea having a plateau shape, so that the light entering the eye can focus on the back part of the eye and you can see clearly.
In addition to correcting your vision and helping you see clearly throughout the day without the need to wear glasses or contacts, these contact lenses are also used to slow down the progression of myopia. These lenses slow down the progression of myopia through peripheral defocus theory. This means that the contact lens reshapes the cornea to a more plateau-shaped surface overnight. Light enters the eye, focusing essentially on the retina, allowing you to see clearly, but peripherally the light is focused in front of the retina. Now there's less of a biochemical feedback signal to the brain telling the eye to keep increasing in length, which is one way to slow down myopia progression. By trying to slow down the rate of progression of a patient's eyeball, myopia and nearsightedness can be slowed down, and that's exactly what these orthoK lenses do; they slow down axial length elongation.
Research shows that orthokeratology can slow down myopia progression in children. It is essential to follow all proper procedures for wearing and maintaining contact lenses, because there is a slight risk factor for infection. While in general orthok is suitable for children, it does require a certain level of maturity to ensure proper hygiene and care, therefore they may not be suitable for young or immature children.
OrthoK lenses have been used to slow the progression of myopia and as a surgery free alternative to refractive eye surgery (such as LASIK). Because there are many different brands, you may have encountered these lenses under a different name. These include: