Editor’s Perspective

Axial Length is the Target

December 1, 2021

By Dwight Akerman, OD, MBA, FAAO, FBCLA, FIACLE

The prevalence of myopia and high myopia is increasing in the U.S. and globally at an alarming rate, with significant increases in the risks for vision impairment from pathologic conditions associated with high myopia. It is estimated that currently, over one-third of the world’s population is myopic, and by 2050, almost 50% will be myopic — a staggering five billion people. Worse yet, by 2050, it is predicted that 10% of the world’s population, over one billion people, will have high myopia (Holden et al., 2016).

High myopia is defined as a spherical equivalent of greater than or equal to −6.00 diopters with an axial length equal to or greater than 26 mm (Flitcroft et al., 2019, Weng et al., 2015). High myopia is one of the leading causes of legal blindness in Western countries because of complications related to long axial lengths, such as myopic macular degeneration, PSC cataract, retinal detachment, and glaucoma. This highlights the need for myopia management in children with progressive myopia, particularly those at risk of developing high myopia.

In their seminal paper, Association of Axial Length With Risk of Uncorrectable Visual Impairment for Europeans With Myopia, Tideman et al. found that in myopes with an axial length of 26 mm or greater, the frequency of visual impairment was 6.1%, increasing exponentially with age. With the prevalence of high myopia continuing to rise, there is undoubtedly a public health crisis looming.

Reducing axial length growth is the most critical goal when treating myopia (Wu et al., 2019). Axial length rather than myopic refractive error should be the primary target for myopia management. Assessing axial length at each visit with an optical biometer means practicing at the highest level and fulfilling one’s duty of care.

Best professional regards,

Dwight H. Akerman, OD, MBA, FAAO, FBCLA
Chief Medical Editor

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