Individuals who suffer from a refractive error (whether it is nearsightedness, farsightedness, astigmatism, or childhood myopia) usually turn to the use of eyeglasses or contact lenses to correct their vision. LASIK or PRK are also considered by some to reduce their dependence on eyewear.
However, refractive surgery is not for everyone. Children, for example, are too young to be good candidates for refractive surgery. Likewise, certain eye conditions such as severe dry eye syndrome may prevent individuals from being a candidate for LASIK.
Fortunately, there’s another viable method for those seeking to permanently achieve corrected vision without surgery.
Orthokeratology (Ortho-K) is a non-surgical optical correction procedure used to treat vision problems.
The Ortho-K procedure uses specially designed therapeutic contact lenses to gently reshape the cornea to improve vision. This application is typically worn overnight. Because the procedure works to change the curvature of the eye, the patient achieves clear functional vision during the day.
A brief history of orthokeratology
The idea of improving visual acuity through specially designed contact lenses is not new.
The process was pioneered by George Jessen in the 1960s. Back then, the procedure was known as “Orthofocus.” When it was first practiced, the technique experienced a minor setback as many members of the scientific community felt that altering the curvature of the eye was not safe.
A lack of clinical studies and poor technology also hindered the adoption rate of orthokeratology.
Since its initial use, several major clinical studies were carried out which greatly improved the scientific community’s understanding of the procedure and its benefits.
Academic studies conducted by the University of California at Berkeley School of Optometry and The Pacific University School of Optometry, to name a few examples, resulted in more funding for research. This not only improved the method of orthokeratology but also furthered the development of new technologies.
Orthokeratology today
Modern Orthokeratology is far removed from its predecessor. In the past, PMMA lenses were used to address refractive errors. Their rigid, flat-fitting design resulted in corneal distortion and corneal edema. What’s more, many users found PMMA lenses uncomfortable, particularly during prolonged use.
The traditional process back then was also slow, costly, and tedious. Myopia reduction was limited and the results did not last long.
Ortho-K designs today offer immediate change. The mechanism of today’s Ortho-K procedure allows the reshaping process to take place rather quickly (for some, after just one night’s wear). There is also a better, safer lens material available with excellent oxygen transmission, allowing lens specialists to predictably correct refractive errors.
Benefits of Ortho-K
As a safe alternative to other vision correction solutions like LASIK, Ortho-K provides several benefits.
For children or young patients with myopia, orthokeratology provides a retarding effect on the progression of myopia. The lenses used today mold the cornea, preventing nearsightedness from worsening. As children are too young to be candidates for corrective eye surgery, Ortho-K is a safe alternative to suppressing eye growth and stabilizing a child’s existing condition.
This is particularly useful for children as active lifestyles and relative carelessness results in eyewear getting scratched, broken, or lost. The long-term cost of Ortho-K far outweighs the cost of replacing eyewear frequently.
Childhood myopia is not the only refractive error that can be treated with Ortho-K. Advancements in corneal topography mean Ortho-K is suitable for patients with hyperopia (farsightedness), presbyopia, and astigmatism.
Improvements in Ortho-K’s lens materials, design, and fabrication make the specialized lenses much more user-friendly. High-tech mapping equipment and computer-driven lathing techniques ensure that the lenses are incredibly precise and customized to the user, greatly reducing the trial and error experience of previous Ortho-K lenses.
Comparing cumulative costs, Ortho-K is a less expensive alternative to LASIK. If you are not a good candidate for LASIK or the procedure is too cost-inhibitive, Ortho-K is a good option for maintaining corrected vision.
As Ortho-K is a reversible procedure, LASIK still remains an option, should you elect to have the surgery done after going through the orthokeratology procedure. Simply discontinue wearing the lenses for some time to allow the cornea to revert to its original shape.
Who is a good candidate for Ortho-K?
As orthokeratology lenses are molded to the candidate’s cornea, any individual seeking to achieve clear vision can undergo an orthokeratology procedure.
This includes candidates with mild to moderate myopia (-0.75 to –5.00D), mild hyperopes (up to +3.00D), or presbyopia seeking monovision corrections. Candidates who have dry eye syndrome can also elect for Ortho-K as a viable alternative to invasive surgery.
Individuals who lead active lifestyles or whose work requires good visual acuity such as pilots or firefighters would most likely appreciate the functional vision that Ortho-K provides.
What are the effects of orthokeratology?
As orthokeratology is a specialized procedure, the treatment can only be carried out by an eye specialist with expertise in this type of lens fitting. Both Ophthalmologists and Optometrists can perform this procedure.
Speak with your eye doctor who will determine if you are a good candidate for this treatment process.
After you’ve been confirmed as a good candidate, the Orthokeratology treatment process is pretty straightforward. Your eye doctor will perform a comprehensive eye exam and an Ortho-K fitting that will consist of a corneal topography measurement to ensure a precise lens fitting.
Depending on your measurements, you may receive your Ortho-K lenses on the same day or your eye doctor may order a custom pair that will arrive at a later appointment. Your doctor will also provide information about what is to be expected with lens wear and include careful instructions on how to care for the lenses.
Candidates who undergo Orthokeratology experience improvements after a day or two.
It can take several weeks before you can experience the full effect of the procedure. While 20/20 vision is the goal of Ortho-K, most patients achieve 20/32 vision or better. Outcomes will vary according to the patient’s original eye condition.
Sources:
Cho P, Cheung, SW, Edwards M. The longitudinal orthokeratology research in children (LORIC) in Hong Kong: a pilot study on refractive changes and myopia control. Curr Eye Res. 2005 Jan;30(1):71-80.
Walline JJ, Jones LA, Sinnott LT. Corneal reshaping and myopia progression. Br J Ophthalmol. 2009 Sep;93(9):1181-5.