C C Chui Optical

What is Orthokeratology?

 

Orthokeratology refers to the process of reshaping the cornea (the clear front surface of the eye), to change the overall power of the eye to correct vision.

 

How does it change the power of the eye?

 

The shape of the cornea is a major component of the eye’s overall power. A change in 0.1mm in curvature of the cornea can change the power of the eye by approximately 0.50D (or loosely called 50 “degrees”)
 

The cornea is also a dynamic tissue, which can be shaped by fluid forces of the tear film.  Using this principle,  we can reshape the cornea by using a custom-designed contact lens to use the tear film to reshape the cornea to give a new desired power.   Unlike refractive surgeries such as LASIK, cornea tissue is not removed, but re-organised, so cornea integrity and corneal nerves are not compromised.
 

These special lenses are worn during sleep and removed during waking hours. Imagine waking up to unhindered vision without spectacles!

 

This is not only a non-surgical correction of vision, but has been increasingly proven to help control the progression of Childhood Myopia.
 

 

How is it possible?

Research indicates that light can influence eye growth.
 

Normal spectacles and contact lenses may give clear vision, but focuses light on the retina (the back of the eye which converts light to electrical signals that are then interpreted as vision) that encourages the eyeball to elongate and become myopic.

When eyes are treated with orthokeratology, light is focused on the retina in a different way, not only to provide clear vision, but also to discourage the eyeball from growing longer, therefore retarding myopia.

 

What’s so bad about the eyeball growing longer?
 

Although we don’t see or feel it when eyeballs grow longer, it causes the eyes to be more at risk of the following:

1. retinal detachments

2. macular degeneration

3. cataracts

4. glaucoma

5. distorted vision even with optimal optical correction
 

All the above are commonly known as degenerative conditions of the eye as we age.

In other words, myopic eyes will tend to age faster compared to non-myopic eyes.

Refractive surgeries do not reduce these risks.

That is the main reason why myopia needs to be prevented and retarded as much as possible, because eyeball elongation weakens the eye and carries the risk of blinding diseases at a later age.