Orthokeratology

What Is Orthokeratology?

Orthokeratology, or OrthoK, involves the use of specially designed rigid gas-permeable (RGP) contact lenses to alter the shape of the cornea in order to reduce or correct myopia (short-sightedness). The lens itself doesn’t touch the cornea, it uses a specially shaped layer of tears between the lens and the eye to gently reshape the front of the eye.

OrthoK can also be effective with low degrees of certain types of astigmatism (where the front of the eye is shaped like an AFL football). It has been practiced in the United States for many years, but previously the results have been disappointing, with a variable and often only a minor degree of reduction of myopia. However, new technology has recently become available to accurately scan the cornea (front surface of the eye) and to manufacture lenses that will achieve a controlled and predictable level of reduction in the eye’s optical imperfection. In addition new developments in lens materials have been made that enable safe overnight wear to be possible.

The technique of OrthoK is a safe, viable and reversible alternative to refractive surgery (LASIK). The cornea, whilst being mouldable, always returns to its original shape if lens wear is stopped. For this reason lens wear must be continued nightly, alternate nights or every third night for some eyes even after the ideal corneal shape has been achieved in order to retain the effect.