Ortho-K (short for orthokeratology) is the practice of using rigid contact lenses to slightly reshape the cornea (the front surface of the eye) to correct myopia, or short-sightedness. These contact lenses are worn overnight to produce their effect and removed in the morning, allowing the wearer to have good distance vision in the daytime without wearing glasses or contact lenses.
The shape and fitting of the lenses have to be very precise to produce this effect, and the range of eye shapes and prescriptions that can be corrected is limited too. However, for those who are suitable, it offers an invaluable vision therapy without surgery. This effect is entirely reversible with suspension of lens wear.
Ortho-K is suitable for patients with short-sightedness between –1.00DS and –4.50DS, and less than –1.50 dioptres of astigmatism. If you are unsure about whether this includes you, please ask any member of the staff. We need to take other measurements to check that you are suitable for Ortho-K. A fitting suitability check will be performed on those who have the above spectacle prescription and are interested in these lenses.
Yes… and no. The practice of orthokeratology has its roots 50 years ago, but has recently become much safer and more accurate with the development of new contact lens materials and new equipment for assessing the shape of the cornea (corneal topography).
We are using a state-of-the-art lens, the EyeDream lens, which transmits plenty of oxygen to the eye while closed, and which is designed for each patient using computerised corneal topography. This provides a precise map of the shape of each eye being fitted which helps us design the best lens and monitor progress.
What is the fitting process?
Patients seeking this therapy will need an eye examination within the last 6 months. The suitability check will begin with a discussion about your thoughts on these lenses, and what we will aim to achieve with them. A thorough examination will then be undertaken of the cornea and external eye, using a diagnostic dye called fluorescein. The intraocular pressure will be measured with the i-care rebound tonometer. Lastly, corneal topography will be assessed using our Keratron Corneal Topographer (pictured).
Other tests of vision and examination of the eyes may be undertaken where relevant, using the practice’s extensive range of equipment. The data is then sent to a lab where the EyeDream lenses are custom-made. This should take less than a week. We will then check the lenses on the eyes, and show you how to apply and remove the lenses and care for them when not worn. The next step is to be reviewed the morning after the first overnight wear.
How often will I need to come back?
The first morning’s examination is important, but the full effect may take 2 weeks to occur. Adjustment of the lenses may be required, which will mean re-ordering and reassessing the lenses. Once a final fitting is estabilished, a contact lens check is required every 3-6 months. Full eye examinations are appropriate annually.
All contact lens wear carries a risk of eye infection, and it is important that you work together with your optometrist to minimise this risk. We believe the risk is no greater than overnight wear of any other type of contact lens, and can be managed.
The most exciting aspect of Ortho-K is that research indicates that Ortho-K in children can slow down the progression of short-sightedness (myopia). Whilst there are no guarantees, many practitioners are noticing that short-sightedness progresses slower in children who wear Ortho-K contact lenses than in those wearing glasses. Myopia control is discussed in more detail in another section of this website.
What about laser surgery?
Laser refractive surgery for myopia involves removing some of the middle layer of the central cornea to flatten it (a similar result to Ortho-K). However, this is a permanent procedure, and also carries its own risks. The options for near-vision correction are also limited and laser surgery is not appropriate for children.
Fitting fees and lens costs are given on the Contact Lenses page of this website. To continue to work well and safely, they will need to be replaced every 6 months.
Return to Cole Martin Tregaskis home page. Updated Feb 2020