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. It is used to correct mild to moderate degrees of short-sightedness.
What is orthokeratology?
ORTHOKERATOLOGY (also known as ortho-k or corneal refractive therapy – CRT) is a clinical technique of corneal reshaping using specially designed rigid contact lenses. In modern ortho-k, lenses are usually worn only during sleep and are removed first thing in the morning. During the night the contact lenses gently reshape the front surface of the eye, correcting the refractive error and allowing clear vision through all waking hours without the need for spectacles or contact lenses.
Are my eyes suitable for OK?
At the moment we are able to correct low to moderate degrees of myopia (short-sightedness) and astigmatism with ortho-k. If you know your prescription, this translates to up to about -5.00 dioptres of myopia. The correction is achieved by applying gentle pressure to the centre of the cornea (the clear window of the eye) to flatten it slightly. This reduces the optical power of the cornea, thus correcting myopia.
Apart from the refractive status of your eye, there are many other factors that may influence your suitability for overnight lens wear. In general, this procedure is only suitable for people with good ocular (and general) health and relatively low prescriptions. Patients must have the dexterity to handle the lenses for insertion and removal, and must closely follow practitioner instructions on lens wearing schedule and lens care procedures, to ensure safe lens wear.
Is the OK treatment permanent?
No, the effect of overnight Ortho-k lenses on corneal shape is temporary, and wears off over a few days if the lenses are not worn. To maintain the optical effect, lenses must be re-inserted and worn every night (or in some cases, every 2nd or 3rd night).
Is the OK treatment safe?
As with all contact lens wear, there are some risks associated with ortho-k treatment. Strict adherence to practitioner instructions on lens wear, handling and care is absolutely essential to minimise these risks and ensure safe lens wear. This is particularly so because ortho-k lenses are worn in the closed eye, which is a more risky environment than the open eye. In our previous studies we have not experienced any serious adverse reactions to ortho-k lens wear. However, corneal infections resulting in scarring and loss of vision have been reported with this type of lens wear, particularly in Asia where clinical standards are not necessarily as strict as in Australia.
How do I find out if I’m a candidate for Ortho-k?
To assess your candidacy for ortho-k lenses, we would first book you in for topography (measures the curvature of your cornea), discussion and a prescription check with our optometrist Abby Ussher. If you’re eligible, the lenses are ordered and then you, or your child will come back in for a fitting and teaching appointment and then regular review appointments. Both children and adults can be fitted with ortho-K.
Information sourced from UNSW Sydney https://www.optometry.unsw.edu.au/research/research-groups/research-orthokeratology-rok