Orthokeratology, or ortho-k, is the use of specially designed and fitted contact lenses to temporarily reshape the cornea to improve vision. It’s like orthodontics for your eyes and the treatment is often compared to dental braces. Most ortho-k lenses are worn at night to reshape the front surface of the eye while you sleep. Vision improvements are reversible but can be maintained if you keep wearing the lenses as directed.
Orthokeratology and Myopia Control Q & A
Who is ortho-k for?
Ortho-k is mainly used to correct near-sightedness (myopia). This vision problem can also usually be corrected by eye glasses, regular contact lenses, LASIK or PRK. Orthokeratology is a surgery-free way for some people to leave their glasses behind and not have to wear contact lenses all the time.
Ortho-k is sometimes recommended to correct children’s vision. Vision can continue to change for some children into adulthood and their 20’s. Vision correction surgeries like LASIK are not recommended until vision is stable. There is no firm evidence that ortho-k can slow down the progression of myopia in children, but this is also being studied as a possibility.
How does ortho-k work?
The cornea is a clear, dome-shaped window in the front of your eye that focuses light onto the retina and is responsible for most of the eye’s ability to focus. Its tissue is very flexible.
Your ophthalmologist will map and measure the surface of your cornea using an instrument called a corneal topographer and then design a lens especially for your eye. The cornea map is created by reflecting light off the surface of the eye. The machine doesn’t touch your eye, and there is no pain. The corneal topography map shows your ophthalmologist the shape and curves of your cornea.
The lenses work by flattening the center of the cornea, changing how light is bent as it enters the eye. Most orthokeratology lenses are worn overnight to flatten the cornea, then removed during the day. These overnight lenses are rigid, gas-permeable lenses that are sturdy enough to reshape the cornea, but also allow oxygen through so your eye stays healthy.
When ortho-k lenses are removed the cornea stays flattened for a while and vision is corrected without the need for glasses. If you stop wearing the lenses at night, your eyes will eventually go back to their original shape and the refractive error will return. You have to keep wearing the lenses regularly to keep the vision correction.
What can you expect from ortho-k?
It can take two weeks or longer to attain the maximum vision correction from orthokeratology, although some people experience significant vision improvement in days. In clinical studies of Food and Drug Administration-approved ortho-k lenses, most patients achieved 20/40 vision or better.
You may need a series of temporary ortho-k lenses to see properly until you reach the desired prescription. Typically, up to three pairs of orthokeratology lenses are used, one after the other, to achieve the best vision correction. Once you’ve reached the desired prescription, you’ll use the same shape of lens each night to maintain the correction.
Until you get used to them, you will probably feel the lenses on your eyes until you fall asleep. With time, they usually become more comfortable. Once your corneas have gotten the final desired curve, you will use a retainer lens—as often as your ophthalmologist recommends—to maintain your vision.
Is orthokeratology safe?
Ortho-k is associated with an increased risk of infection (microbial/bacterial keratitis). This risk is especially concerning for children and adolescents, who may be less able than adults to maintain good hand and contact lens hygiene.
Each year, nearly a million Americans go to the doctor because of eye infections. And the biggest risk factor for infections is contact lens wear. Eye infections can have serious consequences including lifelong vision impairment. For this reason, ortho-k may be more dangerous than glasses, which can be used to correct the same conditions. That’s one of the reasons it is important to consult with an ophthalmologist if you are considering ortho-k.
There is no limit to how long you can use orthokeratology lenses. You must see your ophthalmologist for regular check-ups. But if your eyes stay healthy and comfortable, ortho-k could be used for years.
How much do orthokeratology lenses cost?
In most cases, orthokeratology would be an elective treatment. There are often other, cheaper and better-known methods for correcting refractive errors, like eye glasses. But there may be some cases where insurance would recommend and pay for ortho-k lenses. The cost of ortho-k, including follow-up care associated with fitting the lenses, can vary significantly depending on the type and degree of refractive error. Ortho-k prices generally range from $1,000 to $4,000. Ongoing costs for replacement of lenses, lens care solutions and follow-up exams can range between $300 and $500 a year.
What is Myopia and its Dangers?
Myopia is a refractive error in your eyeball. When you look at near objects they are clear but distant objects are not in focus and are blurry.
Here is a really cool Vision Simulator to show you what vision looks like when you are myopic to various degrees:
Myopia has become one of the major health issues on the planet. Myopia is now considered as a disease.
In fact, the Centers for Disease Control (CDC) now views progressive myopia as an epidemic disease affecting 1.6 billion children and adults worldwide with expectations that the number will hit 2.5 billion by 2020. 50% of the world’s population will be myopic by 2050. It’s an epidemic. It has gone up 75% in the U.S. since the 1970’s and at current rates there are 400,000 new myopic cases in America per year! Increasing Myopia not only causes blurrier and blurrier distance vision but more importantly it can significantly increase the odds of developing sight threatening conditions like:
Retinal Holes, Tears and Detachments
Here is a table of the risk factor for myopic pathologies depending on the degree of myopia:
For further information see: www.brienholdenvision.org.
The Complications of Myopia – IOVS Meta Analysis 2020
Extensive research has shown that ortho-K can slow the progression of myopia reducing the risk of retinal detachment, cataract, myopic maculopathy and glaucoma as well as the social issues associated with wearing thick, heavy glasses. Ironically, the image focused by glasses and conventional soft lenses may actually contribute to the axial length growth of the eye, increasing myopia. For more information go to: www.orthokacademy.com.
What is the Cause of Myopia?
The causes of myopia is both genetic and environmental/behavioral the latter of which accounts for probably 90%, and is blamed on close range activities such as reading and the extended use of modern day high-tech devices, ie computers, smart phones, tablets and gaming devices. See: D.I. Flitcroft. (2012) The complex interactions of retinal, optical and environmental factors in myopia aetiology. (ABSTRACT)
Early onset of myopia (ages 5 and beyond) notoriously indicates the most rapid increase and is associated with life time eye care and interference with education and normal learning.
Distance vision is blurry because your eyeball is typically too long in measurement from the front to back and the image falling on the retina is not in focus. Uncommonly you could have myopia because your eye’s cornea or lens is too curved. Some people have a combination of these issues that result in their myopia. Other symptoms may include having headaches caused by eye strain as you try to focus on objects in the distance. Near vision is usually great without correction. The landmark study by Earl L. Smith III, OD, showed that peripheral retinal defocus was the cause of myopia progression and that OrthoK lenses bring the peripheral focus back to the plane of the retina thus breaking the feedback loop that tells the eye to stop elongating and stops the myopia progression. Listen to Dr. Earl Smith, OD, PhD as he explains the relationship between refractive error and eye growth: Dr. Earl Smith
Here’s an amazing graphic (MRI) of what selective eye elongation looks like.
Myopia control (MC) – a cure for nearsightedness?
Why should you be interested in myopia control? Because stopping or slowing the progression of myopia may keep your child from developing high levels of nearsightedness that require thick, corrective eyeglasses and have been associated with serious eye problems later in life, such as (with -3.00 Diopters (D) of myopia): cataracts (3X RISK compared to no myopia), glaucoma (4X RISK), maculopathy (9X RISK) or retinal detachment. (10X RISK). Controlling myopia progression by 1 D reduces the risk of myopic maculopathy by 40-67% and the risk of open-angle glaucoma by 20%.
Once -5.00D is reached the risks are: cataracts 5X; myopic maculopathy 40X; retinal detachment 22X.
How can I help my child prevent myopia? Currently, four types of treatments are showing promise for controlling myopia:
- Orthokeratology (“ortho-k”) – Optical
- Atropine eye drops – Pharmaceutical
- Multifocal contact lenses – Optical
- Spending time outdoors especially doing athletic things like playing tennis or volleyball or anything that requires physical action and peripheral vision judgements. And, limiting time on central fixation with electronic devices.
Ortho-K is the gold standard for MC. Evidence suggests nearsighted kids who undergo orthokeratology end up with as much as 85% less myopia compared to children who wear eyeglasses or regular contact lenses during the peak years for myopia progression.
Atropine eye drops have been used for myopia control for many years, with effective results but has significant drawbacks. Three landmark studies, referenced below, ATOM, ATOM2 and the LAMP studies, basically point out the safety and efficacy of various doses. Atropine and ortho-k can be combined very effectively when needed in extreme cases. Read the paper on the efficacy of combined therapy. What is the mechanism of action of atropine in controlling myopia? Read this most recent publication.
Multifocal Contact Lenses afford a similar optical effect as ortho-k but not as precise in controlling myopia and must be worn at all times of waking hours.
Read the following new research paper reviewing all the options: MYOPIA CONTROL IN 2021