Study findings on tracking pediatric myopia: Refractive error or axial length?

A new study asserts that the most effective method of monitoring the progression of myopia in children is by tracking the changes in the refraction error over time rather than placing the emphasis on the changes in the axial length (AL).

Rupa Wong, MD, and Robert A. Clark, MD, from the Honolulu Eye Clinic, Honolulu, HI, and the South Bay Family Eye, Long Beach, CA, respectively, described their findings at the 2026 annual meeting of the American Association for Pediatric Ophthalmology and Strabismus in Boston from March 18-22.

Wong and Clark explained that while myopia in most patients reaches only low-to-moderate levels, many guidelines “prioritize the axial length (AL) over the spherical equivalent refraction (SER) using fixed thresholds to define high risk, eg, 26 mm and higher, yet a large myopia-related proportion of myopia-related pathology occurs in eyes that never reach those lengths.”

The arguments for the importance of AL have been that the AL is more robust than SER as well as being less affected by accommodation, diurnal variation, and corneal reshaping. This opinion was reinforced by data that indicated that excessively long AL was associated with sharply increased odds of uncorrectable visual impairment, myopic macular degeneration, and other complications in adulthood, they explained.

However, Wong and Clark questioned if absolute AL thresholds actually provide the most informative risk stratification for the typical child with myopia or do they apply to a small subset of eyes with extremely long ALs.

The investigators argued that evidence is suggesting that the exclusive focus on absolute AL levels may be incorrectly associated with the range of global elongation that most children with myopia actually have.

They undertook a systematic review and meta-analysis of population-based observational studies identified in a search of PubMed and Embase from 1990 to July 2025. All studies included 200 or more eyes, included the AL and/or SER values, demographic data, and/or retinal, cataract, or primary open-angle glaucoma outcomes, the investigators recounted.

They compared the SER and AL to determine the normative variation in the AL, the range of emmetropic AL, and the associations of myopia-related pathology with SER compared with AL.

What did the AL/SER analysis show?

Wong and Clark reported, “The SER relative risk for all myopia-related pathology scales was distributed evenly across the range of typical myopia, while the AL relative risk was exponential for retinal pathology but relatively flat for cataract and primary open angle glaucoma. The very low prevalence of retinal pathology at typical ALs, however, means the absolute risk for retinal pathology remains very low until the AL exceeds 26 mm."

Wong and Clark enumerated the takeaways regarding the clinical markers and risk factors of AL variations, the 26-mm threshold, and SER as follows:

• AL variance: the normal AL varies significantly based on age, sex, height, and ethnicity.
• 26-mm threshold: An AL exceeding 26 mm is a major red flag for retinal pathology; however, it only identifies high risk in less than 10% of all myopic eyes.
• Refraction (SER) is a more accurate tracker than AL for monitoring cataract and glaucoma risk within typical myopia ranges.

The investigators concluded, “The most effective way to monitor progression in children is by tracking the changes in refraction over time. To identify and manage "excessive" eye growth, clinicians should use AL growth-curve trajectories rather than single-point measurements.”