Myopic progression in children is a major concern among parents in regions where the prevalence of myopia is high, for example, in Hong Kong, China, Singapore and Japan. Ortho-K treatment is probably a major method to deal with myopic progression in children.  In this issue, Prof. Pauline Cho at PolyU’s School of Optometry shared the findings of her recent studies on the effectiveness of Ortho-K treatment for slowing myopic progression in myopic children.

What is Ortho-K? What are the benefits of Ortho-K?

The term “Ortho-K” is “Orthokeratology” in full. It is a non-surgical treatment to correct the vision of myopes and to slow myopic progression in children. Severe myopia increases the risk of sight threatening diseases such as glaucoma, macular degeneration and cataract.

In Ortho-K treatment, myopes wear specially-designed rigid gas-permeable contact lenses at night. The lenses reshape the corneas leading to a decrease in the overall refractive power of the eyes. This results in a ‘correction’ of myopia and allows the eyes to see clearly in the daytime without the need of spectacles or contact lenses, bringing convenience to the daily activities of myopes, including children.

Please elaborate your recent studies on the effectiveness of Ortho-K.

My research team at the School of Optometry has conducted three studies on the effectiveness of Ortho-K. One study, on children aged 7 to 10 years old, with 0.50D to 4.00D myopia showed that myopic progression of those received Ortho-K were 43% slower, compared to the other group of children wearing spectacles. The study also found that among children with more than 1.00D of myopia progression annually, 65% were wearing spectacles whereas only 20% were receiving Ortho-K treatment.

A two-year study on children aged 8 to11 years, with myopia more than 5.00D concluded that those receiving Ortho-K treatment (reduction up to 4.00D) with over-spectacles (residual refraction) showed smaller increase in refraction (myopia) compared to those using spectacles (0.13D versus 1.00D respectively). This study showed that the children in the Ortho-K group had slower eyeball elongation (by 63%) compared to those who wear spectacles only.

Another two-year study on 6 to 12 year-old children with myopia and moderate to high astigmatism showed that children in the Ortho-K group had significantly smaller increases in eyeball elongation than those wearing spectacles. The rate of eyeball elongation in these children was about 52% slower compared to children wearing spectacles.

The results of our studies showed that Ortho-K treatment is an effective way of slowing down myopic progression in children.

What should Ortho-K users and parents be cautious of during the treatment?

Children aged 6 to 12 years old can benefit from Ortho-K treatment to retard myopic progression with diligent parental guidance and assistance. Children must have self-discipline in wearing the lenses and must strictly follow the instructions provided by optometrists. Parents should assist their children in wearing and cleaning lenses, and bring their children to optometrists for regular eye examinations. In short, parents and children should collaborate closely with their eyecare practitioners to ensure safe Ortho-K lens wear and to achieve the best outcome.