Myopia Prevalence Among Children in Hong Kong
The prevalence of myopia among Hong Kong schoolchildren increases with age, doubling from 6.3% among preschoolers to 18.3% at age 6, and climbing to 61.5% by age 12. Among adults aged 21–30, the rate of myopia reaches as high as 84.7%.
If it progresses to high myopia, the risk of developing various eye diseases later in life—such as retinal detachment, cataracts, glaucoma, and macular degeneration—will increase significantly.
The goal of orthokeratology for children is not to completely halt the progression of myopia, but to slow down the rate of myopia progression.
Prevention of Myopia
If a child's myopia progresses by 100 degrees per year, this is considered rapid progression, and treatment may be considered. For children, the ideal progression rate is within 50 degrees per year.
Low-dose atropine eye drops have become a commonly used first-line treatment among ophthalmologists in recent years to slow the progression of myopia in children.
Research from the Chinese University of Hong Kong indicates that this method can effectively slow the progression of myopia in children by up to 60%, with rare side effects.
Additionally, a pair of "Multi-Zone Positive Optical Defocus" (DIMS) lenses designed by The Hong Kong Polytechnic University has been proven to slow the progression of myopia by up to 60% in participating children.
The lens comprises a "central optical zone" designed to correct refractive errors, along with a "multi-zone progressive myopic defocus" extending from the central zone to the periphery of the lens.
When the wearer views objects at different distances, DIMS lenses provide clear vision and myopic defocus to correct vision and help slow the progression of myopia.
Finally, children may choose to wear orthokeratology lenses (OK lenses).
It utilizes specially designed rigid orthokeratology contact lenses and the surface tension of tears to alter the curvature and shape of the cornea.
Children undergoing orthokeratology simply need to wear the reshaping lenses while sleeping at night, with the benefit of not needing glasses in the morning.
The only concern is that children may unconsciously rub their eyes during sleep, potentially causing corneal damage or infection. Therefore, this method is only suitable for children aged 8 and above who possess a higher level of self-care ability.
