Orthokeratology (Ortho-K)
What is Orthokeratology
Orthokeratology: contact lenses worn while sleeping.
Orthokeratology or corneal reshaping therapy refers to specially designed rigid gas permeable lenses. The lenses are tailored to the wearer’s corneal curvature and degree of myopia. These lenses are rigid lenses that have been proven effective in controlling the progression of myopia, making it a reliable method for myopia management. It is considered the most effective myopia control therapy.
1) What is the principle of ortho-K lenses?
Ortho-K lenses are rigid, gas-permeable contact lenses. The principle behind using ortho-K lenses to treat myopia is to alter the cornea’s refractive power, rather than changing the length of the eyeball.
The lenses are worn overnight for at least 8 hours, and is removed in the morning. During the night, the cornea is “flattened,” temporarily changing its refractive power. This altered refractive power is maintained throughout the day, allowing myopic individuals to see clearly without wearing glasses during the day.
If the use of ortho-K lenses is discontinued, the cornea will return to its original state within a few weeks.
2) Are ortho-K lenses effective?
Research indicates that ortho-K lenses can reduce myopia progression by 45 to 60% on average with some studies reporting reductions as high as 85-93%.
3) Are ortho-K lenses harmful?
When worn correctly, ortho-K lenses do not damage the cornea. Our cornea has a layer of epithelial tissue on its surface that continually regenerates. In rare cases, eye infections can occur which are generally associated with poor contact lens hygiene. Good hygiene habits can significantly reduce the risk of infection. Since ortho-K lenses are primarily used by children and adolescents, parents should pay close attention and assist their children in perfecting proper lens care and wearing techniques, and ensure timely and regular follow-ups at the office.
What are the advantages of ortho-K lenses?
- Clear vision without the need for glasses
- Non-surgical and non-invasive, suitable for those who fear surgical procedures (e.g., laser vision correction)
- Allow for better school and sports performance
- Easy to use at home (parents can supervise children)
- Suitable for growing children and adolescents to slow the progression of myopia
