Orthokeratology is the use of contact lenses to change the shape of the cornea (the clear front surface of the eye) to correct myopia (short sightedness) or astigmatism (irregular shape of the cornea). Special oxygen-permeable contact lenses are worn overnight to change the shape of the cornea to give clear vision without glasses or contact lenses during waking hours.
Ortho-K has been practiced for more than forty years, however its recent success is due to advances in computerised corneal mapping and improved contact lens technology. It requires a high level of expertise in contact lens fitting and sophisticated computerized equipment.
Who is suitable for Ortho-K?
The treatment is most suitable for patients with low to moderate amounts of myopia (Less that -3.50 Diopters). Patients with higher amounts of myopia (- 6.00D) can also be fitted with Ortho-K lenses, but the process itself can take longer, and there will be some initial problems with flaring of light at night.
Apart from those who do not want to wear a visual correction during the day, Ortho-K is ideal for sportspeople, swimmers, people working in dusty environments and in those occupations where glasses or contact lenses are a disadvantage. (For example: Policemen, Firemen, professional sportspeople etc.).
The procedure is not suitable for patients with very high prescriptions and certain types of astigmatism. It is not suitable for older people who have been prescribed simple reading glasses, bifocals or multifocals. In addition, it is not suited to those with conditions such as dry eye, severe allergies or other eye health problems.
To work well, Ortho-K requires an appropriate corneal shape which can be determined by computerised corneal mapping.
What is the fitting procedure?
There are several stages to the fitting procedure:
Stage 1
A general examination is required to determine whether a patient would be suitable for Ortho-K.
This involves assessment of the health of the eyes, measurement of the degree of myopia and computerised corneal mapping to plot the corneal shape.
The test results are then discussed with the patient and a decision is made whether or not to proceed with an initial overnight trial.
Stage 2
Trial lenses are selected and the patient wears lenses for an overnight period. Instruction in insertion, removal and care of the lenses is then carried out.
After the trial, the lenses are removed and corneal mapping is repeated to measure the change in corneal shape.
The improvement in vision is also measured. If the trial lens is working correctly, then the patient wears the lenses for 10 to 12 nights so that they can become fully adapted to the process and then determine if they wish to proceed. The custom designed lenses are then ordered.
Stage 3
Since the improvement in vision may occur rapidly in the first few days or may require weeks, review appointments are arranged to monitor the progress.
Stage 4
Once the corneal shape has been stabilised, patients will obtain vision without glasses or contact lenses during waking hours.
To maintain this effect, patients must continue to wear the Ortho-K lenses for three to seven nights a week.
Six to twelve monthly review visits are required to monitor the progress.
As with all forms of over-night wear of contact lenses, there is an increased risk of eye infection. The proper care and maintenance of the lenses is paramount in reducing the risks associated with over-night wear.
What are the fees for Ortho-K?
The total cost for the Ortho-K procedure is $2000/eye. This cost includes all professional fees for the fitting, care and management of the Ortho-K procedure for a period of twelve months. It also covers computerised corneal mapping and the required lenses, including modifications if necessary.
The procedure works by temporarily and non surgically changing the shape of your eye.