How does it work?
How does it work?
A corneal mould or corneal retainer is customised and designed based on a person or child’s corneal curvature, corneal steepness, corneal asphericity, corneal depth, corneal diameter and refractive status. This allows the corneal mould, when worn while a person or child is sleeping for 7 - 8 hours, to remould the curvature of the cornea resulting in a change in corneal power. This process results in clear sight throughout the day without the need for glasses or contact lenses.
It is a similar concept to changing the corneal power in laser eye surgery that allows a person to be able to see clearly. The difference being that orthokeratology is non-invasive and non-permanent, allowing the person’s eyes to rebound to its original curvature after ceasing treatment. This enables continued treatment for a person who’s prescription may continue to progress. The corneal mould can be re-adapted to further enhance the person’s vision by altering the remoulding strength of the corneal retainer.
In contrast, laser eye surgery can be performed once or twice, limited by the corneal thickness (in Laser eye surgery, the cornea is usually thinned or a portion of it removed to change the corneal power.)
Why does orthokeratology work?
The cornea is a large refractive surface of 39 to 46 diopters in power. When a person or child requires spectacles or contact lenses to see more clearly, the lenses are worn to either increase or reduce the total refractive power of the eye.
For example, if you are a -2.00 diopter myope, and your corneal power is 43.00D, then you will wear glasses to alter your eye power to a resultant 41.00D. This will result in clear distance vision once again.
When the cornea is reshaped through wearing a corneal mould in orthokeratology, the power of the cornea is increased or reduced to a degree that makes the power of the eye now correct for the person or child enabling them to see clearly without the need for contact lenses or spectacles.