Ortho-K
What is Ortho-K?
Ortho-K, also known as “ortho-keratology”, “night contacts” or “OK” lenses, are a form of myopia (short-sightedness) correction. They are hard contact lenses that are worn at night during sleep, and then taken out of the eyes during the day. They allow the wearer to see during the day without the need for any spectacles or contact lenses.
How does it work?
Ortho-K is a hard lens that is worn in both eyes whilst sleeping. When the eyes are shut, the lenses cause the cornea (front of the eye) to gently change shape. After waking up, the lenses are taken out of the eyes, but the eyes keep its changed shape. This changed shape is calculated to match the prescription of the eyes, so that the person can then see for the rest of day without anything in their eyes.
However, the effects do wear off over time. By the end of the day, some people experience a slight decrease in their vision. This means that the lenses need to be worn each night, so that each day the vision is clear and comfortable.
If you do not wear the lenses overnight, the vision would be much poorer the next day. After 1-2 weeks, the eyes go back to exactly where they started before Ortho-K treatment. This means that Ortho-K is completely reversible, and non-permanent, unlike procedures such as LASIK or SMILE.
Why would I get Ortho-K?
Ortho-K provides two major advantages over standard spectacle correction for myopia:
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Lifestyle benefits
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Myopia control
Lifestyle
Glasses are a wonderful tool to help us see and make us look great. But like most things, they have some limitations. They might slip during the day, or fog up when cooking or wearing a mask. They might get knocked off or damaged during sport, and they can’t be worn when swimming.
Soft contact lenses fix a few of these problems, but also have their limitations. They can get dislodged during sport, and are not recommended for wearing whilst swimming due to the risk of eye infections or having the lenses wash out.
Because Ortho-K is worn at night, and nothing is worn during the day, all of these tasks are made very easy. There is no risk of glasses breaking, or lenses falling out during sport. Vision at the beach is easy and comfortable, and there is nothing to worry about during daily tasks. In addition, off-the-shelf sunglasses can be easily worn, without the need for adding in custom-made tinted prescription lenses.
Myopia Control
Myopia (short-sightedness) is a rapidly growing public health problem. Studies estimate that over HALF the world’s population will be short-sighted by 2050. Myopia is not only frustrating and inconvenient, it quite often progresses over time (gets worse with increasing prescription), especially during childhood and young adulthood. Progressing myopia increases the risk of sight-threatening complications later in life, such as retinal detachment, glaucoma and macular damage; and is expensive having to constantly change glasses prescriptions. Therefore, as 21st century optometrists, it is in our best interests to help slow the progression of myopia in our patients.
Ortho-K has been shown to be one of the most effective methods of myopia control, comparable with atropine (prescription eye drops), and specialised glasses (DIMS, or “Miyosmart” lenses). Ortho-K has been found to reduce the rate of myopia progression by an average of almost 50% compared to standard single-vision spectacles. Some Ortho-K wearers even find that their prescription stops changing altogether.
Why haven’t I heard of Ortho-K before? Is it new?
Ortho-K is actually not a new technology! It has been available as a form of myopia correction for 20 years. It was originally invented in the 1960s after the discovery that rigid contact lenses leave behind short-term changes to the eye shape after a period of wear. It was further developed and by 2002, the FDA approved Ortho-K lenses for general wear as a safe and reliable vision correction option. It is most common overseas in East Asian countries such as Singapore, China, Japan and Taiwan, where a very large number of people are short-sighted. Most Australians have not heard of Ortho-K, as far fewer people in Australia have short sightedness, and procedures such as LASIK and SMILE are common.
Ortho-K is but one of many tools we have available to us today for correcting short-sightedness and controlling myopia progression. This particular treatment offers a safe, effective and reversible freedom from regular spectacle wear. It provides convenience for many lifestyles, and is an excellent option for controlling prescription change.
If the benefits outlined above interest you, or if you have any further questions about Ortho-K and your specific eligibility for the process, please speak to one of our Panoptic Vision optometrists, who are more than happy to discuss this topic in person or over the phone.
Dr. Jesse Nixon
Optometrist, Orthokeratologist
B.VisSc M.ClinOptom; Therapeutically Endorsed
Jesse Nixon has lots of experience in wearing, fitting and teaching about many types of contact lenses, including orthokeratology “night contacts” which he himself has been wearing since 2016. He believes that anyone can learn to use, and benefit from contact lenses, whether young or old!
References
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Soni, P. S., Nguyen, T. T., & Bonanno, J. A. (2004). Overnight orthokeratology: refractive and corneal recovery after discontinuation of reverse-geometry lenses. Eye Contact Lens, 30(4), 254-62.
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Zimmerman, A. B., Richdale, K., Mitchell, G. L., Kinoshita, B. T., Lam, D. Y., Wagner, H., . . . Yoder, J. S. (2017, Aug). Water Exposure is a Common Risk Behavior Among Soft and Gas-Permeable Contact Lens Wearers. Cornea, 36(8), 995-1001.
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Holden, B. A., Fricke, T. R., Wilson, D. A., Wong, T. Y., Naduvilath, T. J., Resnikoff, S., . . . Sankaridurg, P. (2016, May). Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050. Ophthalmology, 123(5), 1036-1042.
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WHO; Brien Holden . (2017). The Impact of Myopia and High Myopia. University of New South Wales. Sydney: World Health Organisation.
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Hiraoka, T., Katika, T., Okamoto, F., Takahashi, H., & Oshika, T. (2012, Jun). Long-Term Effect of Overnight Orthokeratology on Axial Length Elongation in Childhood Myopia: A 5-Year Follow-Up Study. Investigative Journal of Ophthalmology and Visual Science, 53, 3913-3919.
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Swarbrick, H. A., Alharbi, A., Watt, K., Lum, E., & Kang, P. (2015, Mar). Myopia control during orthokeratology lens wear in children using a novel study design. Ophthalmology, 122(3), 620-30.
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Lee, Y.-C., Wang, J.-H., & Chiu, C.-J. (2017). Effect of Orthokeratology on myopia progression: twelve-year results of a retrospective cohort study. BMC Ophthalmology, 17, 243.