Habitual Spectacle-Corrected Distance Visual Acuity and Axial Elongation in School-Based Myopia Screening: A Retrospective Cohort Study.

Background/Objectives: Progressive axial elongation is a key structural indicator of myopia progression. In school-based screening, repeated ocular biometry may not always be feasible; routinely collected visual-acuity information may support follow-up prioritization. This study examined the association between stable habitual spectacle-corrected distance visual-acuity profiles and annualized axial length growth. Methods: This retrospective real-world cohort study used the Chengdu school-based myopia screening database. Children aged 7.0-9.9 years with screening-defined as low-to-moderate myopia and three consecutive screening visits-were classified as adequately corrected (ACG), functionally under-corrected (UCG), or uncorrected myopia (UMG) according to stable spectacle-wearing and visual-acuity profiles. The primary outcome was annualized axial length growth from baseline to the second follow-up (ΔAL). The primary analysis used 1:1 propensity-score matching; robustness was assessed using interval-specific outcomes, alternative caliper widths, and full-cohort multivariable regression. Results: The final cohort included 4152 children: 391 ACG, 551 UCG, and 3210 UMG. Matching retained 313 ACG-UCG pairs and 387 UCG-UMG pairs. ΔAL was lower in the ACG than in the UCG groups (0.224 vs. 0.362 mm/year; mean difference, -0.139; 95% CI, -0.165 to -0.112; p < 0.001). No statistically significant ΔAL difference was detected between the UCG and UMG (p = 0.412). Sensitivity analyses yielded consistent findings. Conclusions: Stable habitual spectacle-corrected distance visual-acuity profiles were associated with annualized axial length growth. Achieved visual acuity under habitual spectacle-wearing conditions may provide information beyond spectacle-wearing status alone; however, these observational findings do not establish equivalence, predictive utility, or causality.