Ortho-k and Corneal Refractive Therapy

Ortho-keratology, also known as Corneal Refractive Therapy (CRT), is corneal reshaping through overnight use of specialty hard, gas-permeable lenses to temporarily reduce myopia.  Hence, it allows users to be independent of glasses or contact lenses throughout the daytime. 


How does it work?

Myopia (nearsightedness) is caused by excessive length between the cornea and the retina.  CRT lenses flattens the cornea throughout the night, thus reducing that length.  That effectively gets rid of myopia during the daytime when the lenses are not worn.   


CRT is for those

  • who have mild to moderate myopia and would like not to wear any glasses or contact lenses during daytime.

  • who want to reduce myopia progression.  Clinical studies have shown that children wearing CRT lenses have 40% less myopia progression than the control group.

What to expect during the contact lens fitting

After the first night of wearing CRT lenses, most patients will able to achieve independent, uncorrected vision the day after.  Follow up visits after a week, two weeks and a month of initial wear are required to obtain optimal fit of the lenses.  

CRT is a generally safe procedure when used properly and has been FDA-approved since 2002. Since it involves overnight contact lens wear, there is a small risk of corneal infection, and thus, close monitoring of corneal health is required. Regular visits every 3-4 months are required to monitor corneal health.