Orthokeratology is a treatment where a nearsighted patient inserts custom designed lenses in their eyes just before going to sleep. These individually designed lenses gently mold the front surface of the cornea to correct the patient’s vision. The lenses are removed in the morning and glasses or contacts are no longer necessary.
Ortho-K lenses are frequently a good option for nearsighted individuals who are too young for LASIK surgery or for some other reason are not good candidates for vision correction surgery. The treatment can be discontinued at any time without permanent change to the eye, people of any age can try the procedure, as long as their eyes are healthy. Ortho-K is great for people who participate in sports, recreational activities or who work in dirty environments that can make contact lens wear difficult.
Nearsightedness for most patients progresses until 20 to 25 years of age. If Ortho-K is started before this time, peer-reviewed clinical research indicates that the treatment may slow this progression. Patients with increased nearsightedness may be at more risks of eye diseases.
Myopia and glaucoma.
Myopia (even mild and moderate myopia) has been associated with an increased prevalence of glaucoma. In the same Australian study glaucoma was found in 4.2 percent of eyes with mild myopia and 4.4 percent of eyes with moderate-to-high myopia, compared with 1.5 percent of eyes without myopia.
The study authors concluded there is a strong relationship between myopia and glaucoma, and that nearsighted participants in the study had a two to three times greater risk of glaucoma than participants with no myopia.
Also, in a Chinese study, glaucoma was significantly associated with the severity of myopia. Among adults age 40 or older, those with high myopia had more than twice the odds of having glaucoma as study participants with moderate myopia, and more than three times the odds of having the disease compared with individuals with mild myopia.
Compared with participants who either had no myopia or were farsighted, those with high myopia had a 4.2 to 7.6 times greater odds of having glaucoma.
Myopia and retinal detachment.
In a study published in American Journal of Epidemiology, researchers found myopia was a clear risk factor for retinal detachment.
Results showed eyes with mild myopia had a four-fold increased risk of retinal detachment compared with non-myopic eyes. Among eyes with moderate and high myopia, the risk increased 10-fold.
The study authors also concluded that almost 55 percent of retinal detachments not caused by trauma are attributable to myopia.
In the Korean study mentioned above, among participants with high myopia due to elongated eye shape (axial myopia), the incidence of retinal detachment after cataract surgery was 1.72 percent, compared with 0.28 percent among participants with normal eye shape.
In a study conducted in the UK of the incidence of retinal detachment after cataract surgery, 2.4 percent of highly myopic eyes developed a detached retina within seven years following cataract extraction, compared with an incidence of 0.5 to 1 percent among eyes of any refractive error that underwent cataract surgery.
Myopia control in children through refractive therapy gas permeable contact lenses: is it for real? Koffler BH, Sears JJ. American Journal of Ophthalmology. December 2013.
Myopia Control with Orthokeratology Contact Lenses in Spain: Refractive and Biometric Changes. Jacinto Santodomingo-Rubido, César Villa-Collar, Bernard Gilmartin and Ramón Gutiérrez-Ortega. Investigative Ophthalmology and Visual Science. July 2012.
Retardation of Myopia in Orthokeratology (ROMIO) Study: A 2-Year Randomized Clinical Trial. Pauline Cho and Sin-Wan Cheung. Investigative Ophthalmology and Visual Science. October 2012.
Ortho-K has been around since the 1960’s. Ortho-K has historically been very popular in Asian countries, where myopia was much more prevalent. Recent advancements in computerized instrumentation and lens design has yielded dramatically improved results.
Myopia has become much more prevalent in the United States within the past twenty years. Nearsightedness has increased by 66 percent since 1970-1971 according to a National Eye Institute study that compared rates of myopia in the United States with a survey conducted between 1994 and 2004. The rate of myopia rose from 25 percent of participants to 41.6 percent.
The clinical research which confirms the link between Ortho-K and delayed progression of myopia has only been published in the last couple of years.