Ortho-K: Corneal Reshaping

What is orthokeratology?

“Ortho” refers to correction, such as in orthopaedics or orthodontics, and “kera” relates to the cornea, the front surface of the eye. Custom-designed orthokeratology contact lenses are worn overnight, reshaping the cornea so that vision is clear the next day without the need for optical aid. This process is completely reversible and aims to reduce or eliminate refractive error (short-sightedness, long-sightedness, presbyopia and astigmatism). It’s also an immensely powerful tool against the progression of short-sightedness in a process known as myopia control.¹ The following diagram illustrates how ortho-K corrects myopia:

How does ortho-K work?

Ortho-K uses the tears underneath the lens to change the corneal shape, either flattening the centre and steepening the edge to correct short-sightedness or vice versa for long-sightedness.² We can successfully fit ortho-K in children and adults with:

Why ortho-K?

• Immediate improvement: After one night, about half of the total correction needed has been achieved, and within a week vision has completely stabilised. Higher minus powers (over –6.00 D) may find this takes between two to four weeks.
• No daytime wear: Because the reshaping takes place while the lens is worn overnight, no optical aid is needed the next day to see. This is especially helpful for people who play sport, work in dusty or dry environments or those who have dry eyes and allergies. It’s also useful for those who are prone to misplacing or breaking optical aids like glasses and contact lenses.
• Safe and effective: Ortho-K is completely reversible, unlike surgical procedures like LASIK, and the cornea will return to its normal shape within one to two weeks. Research has also found that ortho-K lenses have low levels of red eye events like infections, comparable to other kinds of overnight wear soft contact lenses.^3,4

We’re always finding new solutions

We custom-design our ortho-K lenses with cutting-edge software program EyeSpace by Innovatus Technology. This gives us the highest levels of accuracy for the greatest chance of success when fitting your lenses. Our bespoke designs can correct high astigmatism, presbyopia and post-LASIK (refractive surgery) with residual myopia or irregular treatment areas.

A well-fitting myopic ortho-K lens

Our optometrist Lachlan Hoy played a key role in forging EyeSpace, which is now used by contact lens practitioners across the world including Australia, the US, New Zealand and South Africa. EyeSpace customises each lens to your prescription and eye shape to a degree of accuracy smaller than one micron.

If you want to find out more about ortho-K for your eyes, please book an appointment with us.

Corneal topographies taken before myopic ortho-K treatment (left) and after (right). Exaggerated 3D representation. Central area inside the red-ring has been flattened, correcting the short-sightedness.

References

1. Wildsoet, C. et al. (2019). “IMI – Interventions for Controlling Myopia Onset and Progression Report”. Invest Ophthalmol Vis Sci 60(3): M106-M131.
2. Korszen, E. and P. Caroline (2017). “The Anatomy of a Modern Orthokeratology Lens.” Contact Lens Spectrum 32(March): 30-35.
3. Hiraoka, T., et al., 2018. Safety and efficacy following 10-years of overnight orthokeratology for myopia control. Ophthalmic Physiol Opt 38(3): 281-289.
4. Bullimore, M. A., et al., 2013. The risk of microbial keratitis with overnight corneal reshaping lenses. Optometry and Vision Science 90(9): 937-944.