Early retinal and choroidal changes in the macula region associated with axial length in myopic children and adolescents based on swept-source OCTA.

PURPOSE: The study aimed to investigate the association between axial length (AL) and early retinal/choroidal structural and hemodynamic changes in the macula of myopic children and adolescents using swept-source optical coherence tomography angiography (ssOCTA).

METHODS

This cross-sectional study included 136 eyes from 136 myopic participants aged 4-17 years. The participants underwent a comprehensive ophthalmic examination, including AL measurement and 6×6 mm macular ssOCTA scans. Hemodynamic parameters (vessel density and choroidal vessel/stromal volumes) and thickness metrics across retinal and choroidal layers and Early Treatment of Diabetic Retinopathy Study (ETDRS) subfields were analyzed. The participants were grouped based on AL (<26 mm vs. ≥26 mm). Multivariate linear regression (MLR; adjusted for age and sex) was used to assess correlations between AL and OCTA parameters.

RESULTS

Increased AL was significantly correlated with reduced deep retinal vessel density (DVD) in the majority of macular regions (except for the perifoveal inferior region), as well as decreased choroidal vessel volume (CVV) and choroidal stromal volume (CSV). Superficial retinal vessel density (SVD) and choriocapillaris flow showed no significant correlation with AL. Retinal and choroidal thickness significantly decreased with longer AL in the majority of regions (except for the foveal region of the retina). Regional analysis revealed that the perifoveal nasal area exhibited the greatest reduction in CVV and CSV, while the perifoveal inferior area showed the least reduction in DVD. Foveal retinal thickness also decreased to a lesser extent compared to other regions with AL elongation.

CONCLUSION

Axial elongation in young individuals with myopia is associated with specific early microvascular and structural alterations that can be detected using ssOCTA. Deep retinal vascular attenuation and choroidal volumetric loss (CVV, CSV) represent the most prominent hemodynamic changes linked to AL, showing regional variations within the macula. These findings highlight early structural and hemodynamic changes associated with myopic progression in pediatric and juvenile populations.