Axial length-based reference values for corneal sensitivity in a pediatric population

To investigate the relationship between axial length (AL) and corneal sensitivity (CS) in healthy pediatric eyes and to establish preliminary corneal sensitivity reference values across different AL groups.

This prospective, cross-sectional study included 353 children aged 5-18 years. AL was categorized into four groups: ≤22 mm, 22.01-23.99 mm, 24.0-25.99 mm, and ≥ 26 mm. CS was assessed in five corneal quadrants (central, superior, inferior, nasal, temporal) using a Cochet-Bonnet esthesiometer. Subgroup analyses were performed according to age groups. Non-parametric statistical analyses were applied to compare sensitivity values among AL groups.

CS differed significantly across AL groups in all measured quadrants (overall p-values: central p = 0.005; superior p = 0.009; inferior p < 0.001; nasal p < 0.001; temporal p < 0.001). In eyes with AL≥26 mm, corneal sensitivity was significantly reduced in all quadrants compared with the AL≤22 mm group (all p ≤ 0.002). However, not all pairwise comparisons reached statistical significance, particularly those involving the 22.01-23.99 mm and 24.0-25.99 mm groups. Spearman correlation demonstrated a weak negative association between AL and CS across all quadrants (r = - 0.125 to - 0.212, p = 0.019 to < 0.001). In the primary adjusted model including age, sex, and CCT, AL remained independently associated with lower corneal sensitivity across all corneal quadrants.

In pediatric eyes, CS differed across AL groups and was lower in eyes with AL≥26 mm. This association remained evident after adjustment for age, sex, and CCT; however, given the uneven distribution of age-stratified subgroups, these findings should be interpreted with caution. These results provide preliminary reference data for pediatric corneal sensitivity and suggest that axial elongation may be associated with alterations in corneal sensory function.