Orthokeratology (ortho-k), 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, hyperopia, and astigmatism.
Orthokeratology has been practised in the USA for 35 years, but the results were quite variable and unpredictable. However, in the last ten years new technology has become available to accurately map the corneal shape and manufacture lenses that will achieve a controlled and precise 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 Ortho-k is now a safe, viable and reversible alternative to refractive surgery.
The cornea, whilst being mouldable, always returns to its original shape if lens wear is stopped. For this reason, lenses are always worn nightly, or alternate nights after the ideal corneal shape has been achieved in order to retain the effect.