08 Jan Myopia and Ortho K
Myopia is a condition in which objects nearby are clear but distant objects appear blurred.
It is caused by an increase in eye length or increase in the power of the cornea so light from far
away objects is focused in front of the retina. Myopia is becoming increasingly common in global
The prevalence of myopia differs between different populations around the world. 1
but the overall prevalence of myopia is greatest in Asian children.1-3
The onset of myopia usually occurs at approximately 8 years of age and usually continues to progress until at least 15 or 16 years of age, 4,5 although this range can differ from child to child.
Due to the heightened risk of diseases (such as maculopathy, glaucoma and retinal detachment) that
results from increasing levels of myopia, myopia control at an early age is an important
consideration for parents and eyecare practitioners.
Ortho K custom made lenses shape the cornea in a unique way. This leads to a change in the way the eye
focuses light on the retina and thus can slow down the progression of myopia. 1,6
1. Smith M, Walline J, Jeffrey J. Controlling myopia progression in children and
adolescents. Adolescent Health, Medicine and Therapeutics 2015; 6: p. 133-140.
2. Ip JM, Huynh SC, Robaei D, Rose KA, Morgan IG, Smith W, Kifley A, Mitchell P. Ethnic
differences in the impact of parental myopia: findings from a population-based study of
12-year-old Australian children. Invest Ophthalmol Vis Sci 2007; 48(6): p. 2520-8
3. Kleinstein RN, Jones LA, Hullett S, Kwon S, Lee RJ, Friedman NE, Manny RE, Mutti DO,
Yu JA, Zadnik K. Refractive error and ethinicity in children. Arch Ophthalmol 2003;
121(8): p. 1141-7.
4. Goss DA, Cox VD. Trends in the change of clinical refractive error in myopes. J Am
Optom Assoc 1985; 56(8): p. 608-13.
5. Thorn F, Gwizada J, Held R. Myopia progression is specified by a double exponential
growth function. Optom Vis Sci 2005; 82(4): p. 286-97.
6. Li SM, K.M., Wu SS, Liu LR, Li H, Chen Z, Wang N. Efficacy, safety and acceptability of
orthokeratology on slowing axial elongation in myopic children by meta-analysis. Curr
Eye Res 2016; 41(5): p. 600-8.
2. Summary of Data from 2 important studies on the effect of Ortho K in Children by Dr Rebecca Li
(Optometrist) Cho P, Cheung SW. Protective role of orthokeratology in reducing risk of rapid axial elongation:
a re-analysis of data from the ROMIO and TO-SEE studies
Data from the Retardation of Myopia in Orthokeratology (ROMIO) and Toric Orthokeratology-
Slowing Eye Elongation (TO-SEE) showed that younger children (6-8 years of age) had the largest and most rapid increase in eyeball length at the end of the 24 month period compared to older children. In this group, ortho K lens wear reduced the risk of rapid progression by 88.8%.