What is orthokeratology?
Orthokeratology or ortho-K is a new advent in the field of ophthalmology and optometry. It refers to a non-surgical and reversible ophthalmological procedure where specially designed gas permeable contact lenses are used to reshape the anterior surface of the cornea in a gradual and gentle way. It is a kind of vision therapy where cornea is molded according to the type of refractive errors which are myopia (near sightedness; the patient can see clear near objects but not the far ones with accommodation of eyes at rest), hypermetropia or Hyperopia (far sightedness; the patient can see clearly far objects but not the near ones with accommodation at rest), astigmatism (inability of eye to make a sharp focused image of a point object onto the retina, a blurred image is formed) and presbyopia (inability of eyes to focus near object with advancing age).
Ortho-K lenses are worn during sleeping hours only. In other words, these are overnight wear lenses and not to be worn on waking hours. They are removed on waking up and the reshaped surface of the cornea allows clear vision for waking hours without wearing spectacles or contact lenses.
Orthokeratology is recommended for both children and adults with refractive errors ranging from -1.00 to -10.00 dioptres of myopia and from +1.00 to +5.00 dioptres of hypemetropia as well as for low degrees of astigmatisms. In some countries hyperopic Ortho-K contact lenses are not available but low degrees of astigmatism and myopias are corrected as given in the ranges in this paragraph.
It is a non-invasive and reversible as compared to LASIK eye surgery which is invasive and can permanently change the shape of cornea. So, people who avoid undergoing eye surgery for their refractive errors can get benefited from Orthokeratology.
Who are the best candidates for ortho-K therapy?
- Children are the best candidates for Ortho-K treatment as their myopia progression control is good with Ortho-K. Researchers in Hong Kong and the US have conducted clinical studies which revealed that children who wear Ortho-K lenses had 50% less progression in myopia than children who wear spectacles and contact lenses.
- Dry eye complain with contacts
- People who are allergic to contact lenses
- Dusty or hot environment which is not suitable for contact lenses
- Cosmetic purposes for getting rid of spectacles
- Contact dermatitis with spectacle material