Ortho K Lenses
Used in the treatment and correction of short-sightedness, Ortho K lenses are worn at night so that good vision is achieved through the daytime. The overnight contact lenses work by gently reshaping the cornea while the wearer sleeps to bring about eyesight correction without the need of glasses or contact lenses during the day.
Orthokeratology is based on a process known as corneal refractive therapy, or CRT, where the lenses are referred to as ‘corneal reshaping contact lenses’. Ortho K is usually used by people who have mild to moderate myopia, but the technique is also being investigated to correct refractive errors on the eye due to hyperopia and astigmatism, as well.(1)
The special Ortho K lenses are rigid, ‘breathable’ gas permeable lenses that allow night wear. They apply a very slight pressure to gently flatten the cornea and achieve the correct optical result for good vision. Once the cornea has been reshaped by the lenses, it reverts slowly to its original shape over the course of the day, or several days.
To maintain optimal vision, Ortho K lenses should be worn every night, though they could also be worn alternate or every third night, depending on cornea rigidity and the severity of the condition. The orthokeratology process works well for prescriptions up to 4.00 or 5.00 dioptres of myopia.(1)
Interested in Ortho K Contacts?
Ortho K lenses must be fitted and adjusted by an optometrist who is trained and experienced in the orthokeratology process. The cornea is scanned, using a painless procedure, to map the curvature of the eye surface, in order to customise the treatment in terms of lens prescriptions. Once the first ortho k lenses have been fitted, regular checks on progress and eye health are required, as well as modified sets of lenses, when necessary, to achieve the goal of good vision.
Since this treatment allows the wearer to be free of glasses or contact lenses during the day, it is suitable for people who work in dirty environments, sportsmen and women and young children. In fact, Ortho K lenses can help to slow the progression of near-sightedness, or myopia, in children, when compared with children who wear glasses.(2)
Risks & side effects of Ortho K lenses
It is essential that instructions are followed carefully by wearers of ortho k contacts, since the lenses are worn at night, in a closed eye. The wearer will ideally have good eye health, as well as being in good general health. They must be able to care for the lenses and take the necessary hygiene precautions as well as carrying out insertion and removal of the lenses.
If you are interested in sight correction without the need for glasses or contact lenses during waking hours, please don’t hesitate to contact us or mention it at your next appointment. Chris McMahon Quality Eyecare Optometrists will assess your suitability for this treatment and ensure that it is carried out safely to provide you with the most benefit.
References:
- https://www.optometry.unsw.edu.au/research/research-groups/research-orthokeratology-rok
School of Optometry and Vision Science, University of New South Wales, Kensington, Sydney, Australia. - Overnight Orthokeratology Lens Wear Slows Axial Eye Growth in Myopic Children, H.A. Swarbrick, A. Alharbi, K. Watt, E. Lum. School of Optometry & Vision Science, University of New South Wales, Kensington, Sydney, Australia.