Jennifer Sha, BOptom, BSc(Hons)
BHVI
By 2020 the global prevalences of myopia and high myopia are estimated to be 34% and 5.2%, respectively and are predicted to increase.1
Due to the increased risk of developing associated complications such as retinal detachment, glaucoma, cataract, and myopic macular degeneration, as well as the burden to society, much effort has been made in recent decades to understand myopia progression and methods of slowing its progression.
Emmetropization is the process that occurs during childhood and adolescence whereby the axial length of the eye is regulated to closely match the refractive power.2
Most infants are hyperopic, and while emmetropization reduces the refractive error, children typically converge to a low level of hyperopia by teen years.3
Emmetropization is the process that occurs during childhood and adolescence whereby the axial length of the eye is regulated to closely match the refractive power.2 Most infants are hyperopic, and while emmetropization reduces the refractive error, children typically converge to a low level of hyperopia by teen years.3
However, emmetropization does not always proceed in this manner, and in children who become myopic, axial length is longer and refractive error is less hyperopic than normal for up to 3 years before even the onset of myopia.4
With respect to the level of refractive error that is considered abnormal, the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) study demonstrated that 6 year old children with refraction ≤+0.75D were at an increased risk of developing myopia, as well as 7-8 year old children with ≤+0.50D, 9-10 year old children with ≤+0.25D, and 11 year old children with ≤0.00D.5
