Orthokeratology lenses fitted by our optometrists in Adelaide or Woodville are worn while you sleep, leaving you with clear vision during the day without the need for contact lenses or glasses.
For more information on orthokeratology, please see the links below:
Orthokeratology may sound dramatic but it's quite simple. Like orthodontics and orthopaedics, the ortho in orthokeratology 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 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 also completely reversible and completely safe for both adults and children. While you might expect children to be at an increased risk of infection from ortho-K wear, there is no significant difference between the groups. The chance of orthokeratology-related microbial keratitis from wearing overnight these lenses is only 13 in 10,000 wearing years, as compared to 25 in 10,000 wearing years for overnight soft contact lens wear.
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.
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.
When myopic eyes are corrected with conventional spectacles and contact lenses, light entering the eye centrally will focus at the retina; however, light entering off centre will focus behind the retina. This is thought to stimulate lengthening at the back of the eye as the retina tries to reach the focal point behind the eye, worsening the condition. This can lead to a number of problems later in life, including an increased risk of retinal detachment and glaucoma.
Ortho-K lenses can slow this growth by changing the shape of the eye surface, allowing central light to focus accurately at the retina and off-centre light to focus in front of the retina. The retina will no longer attempt to elongate. For more information about contact lens options for over 40 year olds click here.
Hyperopic ortho-K has generated far less interest from researchers, contact lens manufacturers and optometrists compared to myopic ortho-K. The first hyperopic ortho-K lenses involved steep-fitting rigid contact lenses to induce central corneal steepening, and was first described by Jessen in 1962. In more recent times, the use of high oxygen-permeable materials and newer designs have sparked a new interest in hyperopic ortho-K.
Today at Innovative Eye Care we fit just as many patients into hyperopic ortho-K lenses as myopic. For more information about contact lens options forhyperopes click here.
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. 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.
CAPTION: A well-fitting myopic ortho-K lens
Ortho-K could not be implemented 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.
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.
Our optometrist Lachlan 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.
CAPTION: Corneal topographies taken before myopic ortho-K treatment (left) and after (right). Exaggerated 3D representation. Central area inside the red-ring has been flattened, correcting the short-sightedness.
CAPTION: A news story on Today Tonight from 2012 about ortho-K, featuring one of our previous optometrists Shonit Jagmohan.