Orthokeratology

Cornea

Orthokeratology, practiced at the Kings Cross Eye Clinic in London (Islington, N1) involves using specially designed rigid gas-permeable contact lenses to alter the shape of the cornea in order to reduce or correct myopia (short-sight). The aim of Orthokeratology is to be free of both contact lenses and spectacles during waking hours making it a viable alternative to refractive surgery. In the last few years advances in technology have made it possible to accurately scan the cornea and manufacture lenses which achieve a controlled and precise reduction in spectacle prescription. New developments in lens materials enable this to be done safely with overnight wear.

A series of Orthokeratology contact lenses, are fitted in progressive stages to gently reshape the cornea. Most of the visual changes occur rapidly in the first few weeks requiring frequent examinations and progressive lens changes. Stabilization procedures then follow at a slower pace over the next few months. The cornea is highly elastic, however, and always eventually returns to its original shape. For this reason retainer lenses are necessary to maintain the improvement in vision. They are worn either overnight or for 2-3 hours during the day after the ideal corneal shape has been reached.

Advantages of Orthokeratology

Topography colour map illustrating corneal shape

• Good vision without spectacles or contact lenses for most of the day
• Children can be treated effectively and there is evidence to suggest that increasing myopia (short sight) is retarded.
• It is not a surgical procedure and it does not cause the permanent hazy vision experienced by some patients following laser surgery.
• It is modifiable and reversible meaning that changes in prescription can be easily dealt with.
• It does not hurt
• Well established contact lens fitting techniques mean that there are very few risks

Web links:

• ORTHO K – patient site
• BRITISH ORTHO-K SOCIETY