Orthokeratology (also known as Ortho-K/overnight contact lenses) refers to the use of an extremely high oxygen permeable contact lens to temporarily reshape the cornea. The contact lenses are worn while sleeping and taken out upon wakening. This means that your child’s sight will be good during the day hence allowing him/her to go to school, exercise, and swim without needing glasses or contact lenses.
For adults who are interested in wearing Ortho-k lenses, you can visit here for more information.
What can we achieve with Ortho-K?
The aim of Ortho-K is to control progression of myopia, also known as short-sightedness, with the additional benefit of independence from glasses and contact lens in the daytime. These night lenses reshape the cornea to focus the light rays on the retina for sharp vision. The corneal reshaping effect of Ortho-k is temporary and lasts for about a day. As our cornea is flexible, if the lens is not worn, the cornea will revert to its original shape.
How does Ortho-K control myopia?
Studies have shown that hyperopic blur in the peripheral of the retina may be a significant stimulus for axial elongation and therefore, myopia progression. Conventional spectacles and contact lenses only focus the light rays on the centre of the retina (known as the fovea) with hyperopic blur (as it is not well focused in the peripheral part of the retina) and results in elongation of the eye. This is because the retina curved whilst the lens of the glasses is flat and of same prescription throughout.The cycle therefore continues, with your child becoming more and more myopic.
In Ortho-K, the central cornea is flattened while the peripheral is steepened. The flattened area focuses the light rays directly on the fovea so allowing you to see clearly, while the steepened part corrects the previously hyperopic periphery. Younger children at age 6-8 years old tend to have faster axial elongation and hence may benefit from early Ortho-K treatment especially if their myopia is high. Our clinic provides eye screening for children from the age of 4 for early detection of any potential eye problems so they can be managed early.
On average, it was shown that children on Ortho-K had their axial elongation slowed down by about 43% as compared to children on conventional spectacles
Is it safe?
Is your child a candidate?
Your child is a candidate for Ortho-K lenses if he/she:
- Is 6 years old and above
- Does not want to wear glasses in the day
- Myopia of up to 800 degrees
- Astigmatism of up to 300 degrees
How do we get started?
Call the clinic to make an appointment for your child and state that you are keen on Ortho-K/Night lens.
What to expect on your child’s first visit:
- Refraction will be done to determine your child’s prescription. To ensure the accuracy of the prescription, refraction is performed once before and once after instillation of an eye drop that temporarily paralyzes the ciliary muscles in the eye to determine the true refractive error of the eye.
- Dr Lee will check that there are no structural eye abnormalities such as cataracts, glaucoma and retinal conditions.
- A non contact, quick and painless topography to map the cornea is then done to customize your child’s Ortho-k lens.
Sufficient time will be allocated for your consultation to ensure that your concerns are answered and that you are comfortable with your child going through this program.
The fitting of the contact lenses are checked before being dispensed. Both the child and the parents will be taught how to properly remove and insert the lens, the cleaning regimen, and the safety measures of wearing contact lenses. The lenses are then dispensed.
There will be multiple follow ups to monitor the corneal changes, and the health of the eye.
How long does Ortho-K take to work?
Ortho-k takes 10-14 days when first worn to reshape the cornea. Vision will be better day by day until cornea is molded to its optimal shape.
Is Ortho-K comfortable?
Just like any type of contact lens wear, it is very common for the person to feel the lens in the eye. However, unlike the normal rigid gas permeable (RGP) contact lens, Ortho-K does not hurt as the lenses are worn at night when your child is sleeping hence the lid-lens interaction is reduced. Moreover, as the Ortho-K lenses are customized to each individual, they do not move as much as a typical RGP lens.
Why choose Ortho-K?
The main reasons why Ortho-K lenses are preferred to other options are:
- It reduces and stabilises the progression of myopia in children
- It provides good vision without spectacles or contact lenses during the day. This is good not just for controlling myopia but also for children who lead active lifestyles. Ortho-K gives the freedom from spectacles and contact lenses especially for water sports and contact sports such as rugby.
- It is a non-surgical procedure and is reversible. The cornea will go back to its original shape if the lenses are not worn for some time, thus going back to the child’s original prescription.
- It increases the child’s self esteem and confidence by reducing the reliance on spectacles in the day.
What should you look out for?
Though rare, the Night Lenses may be displaced during sleep. This causes distortion of vision upon wakening. This distortion of vision may not be immediately corrected with spectacle lenses.
You and your child will have to be prepared for multiple visits to our clinic upon beginning Ortho-K lens wear.
Caring for your lenses
Before dispensing the Night Lenses, both you and your child will be taught on proper insertion and removal of the lenses. A detailed education session will also be provided on the proper hygiene needed when handling contact lenses, and the care and maintenance of the Ortho-K lenses. We will only dispense the lens after we have ensured that both you and your child are competent in the insertion and removal of the lenses and that the care and maintenance of the lenses are properly understood. Due to wear and tear, it is advisable to replace the lenses at least once a year.
Click here to know more on how you can care for your Ortho-K.
Ortho-K or Atropine?
Every child has different needs and lifestyle. Here at The EyeClinic, we offer both options of Ortho-k and Atropine, allowing for an unbiased discussion on which is better suited for your child.
To learn about how Atropine eye drops work to control myopia, click here.