orthokeratology
If you can see objects that are in close proximity more clearly than those that are viewed from a distance, an eye health professional will most likely diagnose your condition as nearsightedness-otherwise defined as myopia. Myopic eyes are unable to correctly focus the light that enters it. Eyes that are unaffected by myopia are able to refract or bend the light correctly, throwing it back to the retina.
A myopia diagnosis does not indicate that eyes are unhealthy. Healthy eyes are often nearsighted. This occurs when an eye’s physical length is greater than its optical length, resulting in a blurring of distant objects. There is no way to prevent nearsightedness because we cannot change the physical size and shape of the eye. Male and females are equally affected and in the case of children, myopia usually gets worse with age. Once the child completes the growing process, myopia stops progressing. Though there is no way to prevent nearsightedness from occurring, special gas permeable contact lenses that gently reshape the cornea can be used to help correct myopia. This process is called Orthokeratology. Orthokeratology may be more effective in correcting myopia than wearing eyeglasses and is a non-invasive alternative to permanent, non-reversible, corrective surgery.
How orthokeratology works
Orthokeratology is the process of using special gas permeable lenses to temporarily correct/reduce myopia by reshaping the cornea. An eye health professional may refer to this process as corneal reshaping (CR) as corneal refractive therapy or vision shaping. The first step a doctor will take is to measure the refractive error of the eye. This determines the patient’s degree of nearsightedness. A tool, the corneal topographer, is used to map out the shape of the front surface of the eye. The resulting digital map will assist the doctor in defining the parameters and exact shape and size of the RGP lens that will effectively and gently change the surface of the cornea, and improve the patient’s vision.
Patients wear the corrective gas permeable lenses for at least eight hours, generally at night while they sleep. Orthokeratology can reduce or eliminate the regular use of eyeglasses or contact lenses during the day. Nearsightedness will be eliminated for longer periods of time with continued night use of the rigid gas permeable corrective lenses, much in the same way that a retainer helps to keep teeth straight. The patient may be instructed by their eye health professional to keep a specific schedule that will improve vision over time so that optimum vision is achieved. The most common scenario that patient’s may expect is nighttime wear; but a doctor will make the choice concerning length and times of wear, which is dependent upon the patient’s eyes and subsequent diagnosis.
Orthokeratology is a possible alternative for those individuals who have been identified as nearsighted with -4.00 diopters (refractive power) or less. Your eye care provider can advise you if you are a good candidate for orthokeratology.
Who is a good candidate for orthokeratology?
Orthokeratology can be an option for almost anyone who wants to improve vision clarity.
Children
Children between eight and twelve years of age are excellent candidates for wearing the lenses. It is at this age that many parents discover their children’s sight challenges. Often a child is unable to see the white board at the front of his classroom, or to adequately focus on the ball when playing sports. Because nearsightedness progresses with age, and the fact that kids have a lot of growing to do, gas permeable lenses can be of great benefit. Athletes for instance, have difficulty wearing cumbersome glasses. Choosing to wear RGP’s at night will correct vision, sometimes for days at a time, allowing children to avoid wearing glasses during sports practices and sporting events.
Adults
Gas permeable contact lenses may also be suitable for adults who are dissatisfied with the clarity of their vision. Adults, who are averse to invasive laser surgery, to remove tissue from the eyes in an attempt to correct vision, may choose orthokeratology.