Longitudinal Changes in Relative Peripheral Refraction During Childhood Myopia Onset: A 3-year Prospective Observation.

PURPOSE: To investigate 3-year dynamic changes in relative peripheral refraction (RPR) and their association with axial elongation and myopia progression stages in children.

METHODS

A total of 564 children (mean age 9.22 ± 0.59 years; 51.1% female) completed three annual visits in a longitudinal observational cohort study (2020-2023) in Guangzhou, China. Annual assessments included cycloplegic spherical equivalent refraction (SER), axial length (AL) and multispectral refractive topography. RPR was calculated across annular diameters up to 53° and quadrants; the total RPR (TRPR) was the mean across all regions. Analysis was stratified by baseline refractive status (myopia: SER ≤ -0.50 D, non-myopic: SER > -0.50 D) and 3-year outcomes (remained non-myopic, myopia onset or established myopia). Right eye data were included in the analysis.

RESULTS

In non-myopic children, differences in baseline RPR were observed 1 year before myopia onset. Baseline temporal RPR showed a modest association with myopia onset (odds ratio = 2.24, 95% CI: 1.08-4.66, p = 0.03). Longitudinal hyperopic RPR shifts were more pronounced in the peripheral retina >30°. The 3-year ΔTRPR was higher in the myopia-onset group (0.21 D) and the remaining non-myopic group (0.16 D) than in established myopia (0.06 D). Additionally, significant differences in ΔAL were observed: myopia-onset (+0.91 mm), established myopia (+0.81 mm) and remained non-myopic (+0.45 mm) (p < 0.001). ΔTRPR was correlated with ΔAL in the myopia-onset group (r = 0.32, p < 0.001), but not in established myopia. Baseline SER alone showed strong predictive accuracy for 1-year onset with an area under the curve (AUC) of 0.87, while RPR alone yielded moderate accuracy (AUC = 0.71), outperforming AL alone (AUC = 0.64). Adding RPR to SER did not improve discrimination (AUC = 0.88).

CONCLUSIONS

Baseline central refractive error remains the dominant predictor of myopia onset. Changes in RPR may be associated with myopia development. Dynamic RPR changes may provide complementary information regarding ocular shape remodelling, with limited added predictive value beyond baseline SER.

CLINICAL TRIAL NUMBER: Not applicable.