Authors’ response to comments on “Ocular biometric parameters in South-Indian children with myopia – A hospital-based retrospective descriptive analysis”

Dear Editor, We note with interest the comments[1] raised on our original article titled "Ocular biometric parameters in South-Indian children with myopia – A hospital-based retrospective descriptive analysis".[2] We are happy to respond to the concerns raised as below. With regard to the inclusion of 200 children with simple myopic astigmatism into the study, we wish to state that this was a retrospective analysis with the objective 'To determine the ocular biometrics of children who visited our pediatrics outpatient department post pandemic and were diagnosed with myopia and to study the co-relation of AL, CR, ACD, AL/CR with age and myopic spherical equivalent (SE) in the above patient cohort.' We had included all patients with a diagnosis of simple myopia and simple and compound myopic astigmatism for analysis. None of the cases included with simple myopic astigmatism had corneal pathology on clinical exam or abnormal keratometry. Any case with suspicion had corneal topography performed. We had excluded all cases of pathological/syndromic and suspected or frank keratoconus from analysis (refer to - Lines 93 to 96 of text -). Children unable to cooperate for measurements with IOL master 700, delayed development, pathological or syndromic myopia, myopia with prematurity, and manifest and large-angle intermittent strabismus and those with insufficient or absent data were excluded from the analyses. We do wish to clarify that we have not included any case of lenticular myopia. With regard to the statistical analysis, in the initial submission, The results of univariable linear regression to show the individual relationship of spherical equivalent (SE) with each variable (AL, CR, AL/CR ratio).[2] As rightly pointed out, this does not reflect the adjusted relationships accounting for the covariates age and gender. We agree that presenting the multivariable regression model would provide a more comprehensive understanding of how these variables jointly influence SE. Accordingly, we have now performed the multivariable analysis and reported here. This model includes SE as the dependent variable and AL, CR, and AL/CR ratio as independent variables adjusted for age and gender. In response, we have now done multivariable regression models adjusted for gender within each age-stratified group and for both age and gender in the overall model [Table 1]. The results show that AL and AL/CR ratio remain strong and statistically significant predictors of SE across all age groups, with the AL/CR ratio consistently demonstrating the strongest negative association. Although CR showed a significant association in older age groups (6–15 years), its effect was not statistically significant in children aged ≤5 years. These findings confirm that the relationship between ocular biometry and SE persists independently of gender and further highlight the utility of the AL/CR ratio as a robust marker for refractive status in myopic children.Table 1: Multivariable linear regression model for spherical equivalent refraction by AL, CR, and AL/CR ratio adjusted by age and genderMultivariable regression model was performed to assess whether gender-related differences in biometric parameters such as axial length (AL), anterior chamber depth (ACD), corneal curvature (CR), and AL/CR ratio persisted after adjusting for spherical equivalent [Table 2]. Multivariable regression showed that female gender was associated with significantly shorter AL (β = -0.52, 95% CI: -0.58 to -0.47), shallower ACD (β = -0.09, 95% CI: -0.12 to -0.07), steeper CR (β = -0.13, 95% CI: -0.14 to -0.11), and a lower AL/CR ratio (β = -0.02, 95% CI: -0.02 to -0.01), even after adjusting for spherical equivalent.Table 2: Gender comparison of biometric parameters is adjusted for spherical equivalent using multivariable regressionFinancial support and sponsorship: Nil. Conflicts of interest: There are no conflicts of interest.