What is orthokeratology?
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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.
- Sportsmen
- 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