Orthokeratology lenses are worn while you are asleep, leaving you to see clearly during the day with just your own eyes.
Orthokeratology may sound dramatic but it is quite simple. As in _ortho_dontics and _ortho_paedics, the ortho in _ortho_keratology means correction. Orthodontics corrects teeth. Orthopaedics corrects skeletal injuries. Orthokeratology corrects the cornea: the front surface of the eye.
Orthokeratology (or ortho-K) is a process in which custom contact lenses are used to gently reshape the front surface of the cornea while you are asleep. This is a fantastic alternative for people who don't want to wear contact lenses or spectacles during the day, and would rather avoid eye surgery. The process reduces or even eliminates nearsightedness, farsightedness, presbyopia and astigmatism.
The individual lenses are designed to mold the front surface of your eye as you wear them overnight. The process uses the forces of the tear fluid beneath the lens to re-shape the cornea to the lens design. For treatment of myopia, the lens produces a flatter central cornea and steepens the peripheral cornea, correcting nearsightedness by decreasing the power of the eye. For hyperopia and presbyopia, the reverse geometry design of the contact lens steepens the central cornea and flattens the peripheral cornea, correcting long-sightedness by increasing the power of the eye.
Improvements in vision can usually be seen the very next day. The effect stabilises after approximately one week. With high minus powers (myopia over -6.00D), stabilisation can take two to four weeks. As ortho-K does not make permanent changes, your eyes will revert to their former state within one to four weeks if you stop wearing the lenses.
Ortho-K lenses are surprisingly comfortable. Most people comment that they forget they have lenses in after the first week. The risks of wearing ortho-K lenses are no higher than any other contacts. Of course, proper care is important to minimise the risk of allergies and bacterial infections from poor hygiene.
Overnight contact lenses are a great option for many people: the idea of not wearing daytime contacts or spectacles can be very appealing! Particular groups especially benefit:
In short, ortho-K works best for people who don't want to or are unable to wear glasses or contact lenses all day, but don't mind wearing contact lenses while they sleep. Children and teenagers especially can benefit from the freedom to play sports and wear fashion sunglasses. This also means contact lenses or spectacles will not be left or lost at school or sport. Ortho-K can be an excellent option for those with youth-onset myopia in being able to slow and even halt its progression.
Ortho-K is ideal for children and adults with these prescriptions:
You must have a healthy cornea that is free of disease to wear ortho-K lenses. These criteria are the same as for potential candidates for laser surgeries such as LASIK.
We custom-design our ortho-K lenses with cutting-edge software program EyeSpace by Innovatus Technology. This gives us the highest levels of accuracy for the greatest chance of success when fitting your lenses. In some cases, our bespoke designs can correct high astigmatism, presbyopia and post-LASIK (refractive surgery) with residual myopia or irregular treatment areas. If you want to find out more about ortho-K for your eyes, please book an appointment with us.
A well-fitting myopic ortho-K lens
Ortho-K could not be performed without a corneal topographer. This takes a map or topography of your cornea, which allows us to measure and describe changes during the process of ortho-K molding your eyes.
At your initial appointment we will take a range of measurements in each eye. This data is imported into our lens simulation software, EyeSpace, to design your lenses.
Our optometrist Lachlan Scott-Hoy played a key role in forging EyeSpace, which is now used by contact lens practitioners across the world including Australia, the US, New Zealand and South Africa. EyeSpace customises each lens to your prescription and eye shape to a degree of accuracy smaller than one micron.
Your optometrist will make changes to this lens until it looks optimal in the simulation before ordering. This simulation process means that more complex prescriptions can be treated with ortho-K, and provides the greatest chance of successful lenses with fewer fitting appointments and lens changes.
Corneal topography of myopic ortho-K treatment. Before (left) and after (right). Exaggerated 3D representation. Central area inside the red-ring has been flattened, correcting the short-sightedness.
While your vision is in the process of being corrected you may need to wear spectacles/disposable contact lenses. We provide loan spectacles of 'in-between' powers to use as your prescription changes. Follow-up visits are scheduled regularly to monitor your treatment. It is extremely important to attend these and to diligently follow instructions provided by the optometrist to ensure your eyes remain healthy.
Some patients, especially those with large pupils, notice halos and glare during the evening when using ortho-K lenses. This is caused by the pupil enlarging in low light and allowing light rays from outside the lens treatment zone to enter the eye. This improves over the first one to two months as the ortho-K effect stabilises. It can also be improved with certain eye drops if still noticeable. Our newest ortho-K lens designs have wider treatment zones than ever before to improve night vision.
You can wear your final pair of ortho-K lenses each night, to maintain your vision each day. These can last up to two years.
Some patients with low prescriptions can still see well with the occasional night off! Regular after-care visits three to six monthly are still necessary to ensure the health of your eyes remains uncompromised.
A news story on Today Tonight from 2012 about ortho-K, featuring one of our previous optometrists Shonit Jagmohan.
Research shows a 32%-100% slowing in the rate of myopia progression through using ortho-K; most reports suggest a 50% average. Results in our practice and others in Australasia show complete halting of myopia progression in some patients. Find out more about ortho-K for myopia control here.
Today at Innovative Eye Care we fit just as many patients into hyperopic ortho-K lenses as myopic! Find out more here.
● How new is ortho-K vision correction?
The idea of corneal molding to correct myopia may have originated millennia ago when the chinese used bags of sand resting on their closed eyelids to improve their vision. Ortho-K has been around since the 1940s; however, this process originally took a long period of time, was unreliable, and compromised the healthy physiology of the eye. In the past 15 years, ortho-K has reached a safe and predictable level. This is made possible with technological advancements and oxygen permeable contact lens materials.
● Are there age restrictions for ortho-K?
There is no age limit for ortho-K: children as young as six have been successfully and safely treated with ortho-K lenses. As ortho-K has been shown to reduce or halt the progression of myopia (short-sightedness), it is one of the most common methods of vision correction in teenagers and pre-teens in our practice.
● Can the ortho-K contact lenses damage my eyes?
Any contact lenses have the potential to damage your eyes or cause an infection; however, research shows that the rate of infection when using ortho-K lenses is less than half as frequent as overnight wear of soft contact lenses. Correct hygiene, lens care regimes and replacement of lenses every 1-2 years minimises the chance of any complications with ortho-K lens wear. We have had no incidences of microbial keratitis in our ortho-K patients. If the lenses are fitting poorly there is a chance long-term wear may harm your cornea. Our lenses are designed with computer software, rather than just taken out of a case and fitted with trial-and-error, making them much more likely to fit safely from the first lens.
● How different are the ortho-K contact lenses from soft disposable lenses?
Ortho-K contact lenses are made from a specially designed highly oxygen-permeable material quite different to soft contact lenses, making handling quite different. Although they appear like RGP hard contact lenses, the design is quite different on the back surface of the lens to enable reshaping of the corneal tissue.
● Can I see with my ortho-K contact lenses in?
Yes. One of the great features of ortho-K is that if you get up in the night, you will be able to still see reasonably well. We do not recommend extended day-wear, however, as this may compromise corneal health over time.
● Do I need to wear my ortho-K lenses every night?
In the initial period of therapy you will need to wear your lenses every night to ensure you have clear vision during the day. As your correction stabilises you may be lucky enough to find that you may still get great day time vision by wearing the lenses only every second night! Patients with higher prescriptions before Ortho-K will most likely need to wear the lenses every night for optimum treatment.
● What will happen if I forget to wear my lenses for a night?
Because the cornea slowly starts to change back to its pre-ortho-K shape after the lenses are removed you are likely to find your vision is a little blurrier after a night without lens wear. For most patients with high prescriptions they may require low-powered spectacles or soft contact lenses for day-time wear if this is a regular occurrence.
● How long does it take to reach good vision?
Most patients have rapid improvement in the first few days of therapy. Generally 50-70% of the required correction is achieved after only the first night’s wear. Optimum, stable vision will generally require up to 10-14 days of treatment depending on the prescription.
● How often will I have to replace my ortho-K Contact lenses?
We recommend replacing an ortho-K lens every 1-2 years depending on its condition. This is to maximise the quality of the corneal molding, as wear and tear on the back surface of the lens compromises its effect over time, and to decrease the chance of infection or inflammatory events from using an scratched or dirty lens. You should bring your ortho-K lenses to each 6 month follow-up appointment so that your optometrist can examine them under the microscope to check their condition.
● What if my driver’s license says I must wear glasses for driving?
Your driver’s licence may state that corrective lenses are required for driving. Your optometrist can write a letter explaining that you are treated with a vision therapy program that eliminates the need for corrective lenses while you are operating a motor vehicle. If driving you should ensure that you use your ortho-K lenses the night before. See Driving and Vision.
● I live a long distance away and will struggle to make all required appointments. Can I still have ortho-K?
Regular appointments are very important when starting ortho-K to ensure the best vision and eye health. We can, however, accommodate for long-distance patients in a number of ways, including extended appointments with in-office wear time rather than a following-morning appointment. This is assessed case-by-case.
● Why should I not just get laser vision correction?
The cost of ortho-K vision correction is roughly a third of the cost of laser vision correction. It also is completely reversible and does not have the potential to worsen your dry eyes to the same extent as laser correction. As patients reach their mid-forties and start needing help for their near vision (see presbyopia), prtho-K therapy can be modified to give clear vision at all distances without a pair of glasses, unlike a one-off laser procedure.
● How long does the myopia control effect of ortho-K last?
There should be a myopia control effect as long as your use your ortho-K lenses. There is no research or anecdotal reports of patients ‘rebounding’ after ceasing ortho-K contact lenses. It is expected that patients who start ortho-K contact lens wear for myopia control continue to use these until their late teens when myopia tends to stabilise. The decision to stop ortho-K should be made with your optometrist, with your prescription and eye length closely monitored for possible regression. Of course most patients are so happy with their ortho-K lenses that they continue to wear them well into adulthood!
● How do I get started?
A full eye exam at Innovative Eye Care is necessary prior to starting ortho-K, even if you have had a recent eye examination at another optometrist. Several aspects of your eyes including health, vision and corneal shape will have to be assessed to establish if your eyes are suitable. If in the last 12 months you have had a full eye exam with us, you may just need a corneal topography and a quick discussion with your optometrist to see if ortho-K is right for you.
For instructions on the handling and care of ortho-K lenses, see our **Care of Orthokeratology Lenses** page.