A Short Guide to Orthokeratology
Imagine wearing a special pair of contact lenses right before going to sleep, then waking up in the morning and taking those lenses off only to realize that you have a clear vision without having to wear the glasses lying on your bedside table.
What you just read is no fantasy. It is a simple explanation of how ortho-k lenses or orthokeratology work. Presented below is a brief guide on the subject to help you acquaint yourself with the basics of this technology.
History
The concept behind orthokeratology was first pioneered in the 1960s when scientists discovered that hard contact lenses led to a ‘blurred vision’ once they were taken off. This revealed how malleable the cornea is, and decades later, we now have gas-permeable hard contact lenses (ortho-k lenses) that fix the eye’s refractive errors by changing the shape of the cornea.
How Ortho-k lenses work?
Contrary to regular lenses, you are required to wear these overnight as you sleep. They are specially designed not to harm your eyes. These hard, gas-permeable contact lenses fix refractive errors in your eyes by changing the shape of your cornea to match their own.
Hydraulic forces bring about changes in curvature as the lenses form a vault of fluid over the eye’s surface. This increases hydration (thickness) in some areas and reduces (thins it) in others. The cornea thus gets reshaped to allow for corrected refraction of light and hence a clear vision.
Who should consider orthokeratology?
It is most effective against myopia (nearsightedness) but is also known to treat other refractive issues such as astigmatism, hyperopia (farsightedness), and presbyopia (age-related farsightedness). So, this is a great option for anyone with these problems.
While adults make good candidates for ortho-k lenses, they are considered especially effective for children and young adults with myopia. This technique is also popular among all those who are not eligible for LASIK or other surgical treatments.
What are the risks involved?
Since ortho-k lenses are hard, the main risk associated with them is that of developing hypoxia. This condition can lead to corneal swelling and clouding over time. However, constant improvement in the material used to make these hard lenses has eliminated this risk significantly.
The only other risk that remains is getting an eye infection, even when wearing a soft contact lens. Every year, 1 million Americans go to the doctor with an eye infection of some kind, and orthokeratology has been linked with an increased likelihood of getting an eye infection.
Fittings and Costs
Your optometrist usually fits the lenses after taking a surface measurement of your eye with a corneal topographer. Your optometrist then makes up to three pairs of lenses for you to find the perfect fit. The cost of lenses can range anywhere between $1000-$4000, with an additional follow-up cost of around $500. You can learn more about it here.
In a nutshell
Overall, Orthokeratology is a convenient solution for many vision problems and is becoming popular by the day as more people are getting diagnosed with myopia. If you think you make a good candidate for the process, you are highly recommended to consult your optometrist and discuss your options with them.