Analysing the ocular biometry of new-born infants

Purpose: To model and analyse the ocular biometry of new-born infants.

Methods: This work is based on previously published data of a cohort of 66 new-born infants aged 0-3 days. After exclusion of seven myopic subjects, the available retinoscopy, keratometry and ultrasound biometry data were analysed, along with calculated parameters such as lens power and whole eye power.

Results: Male infants have significantly flatter corneas that female infants (Mann-Whitney U test, p < 0.001), which was associated with a difference in gestational age between genders (multiple linear regression; p = 0.043). No other gender-based differences were seen. Corneal curvature (Pearson, r = 0.575; p < 0.001), lens power (r = -0.681; p < 0.001), and anterior chamber depth (r = 0.654; p < 0.001) were all correlated to axial length, but not refraction (r = -0.114; p = 0.42). Most ocular parameters were associated with gestational age (linear regression analysis; p < 0.05), rather than birth length, birth weight, fertilization method or parental myopia (all p > 0.05), suggesting scaled eye growth during the last weeks before birth. Multivariate Gaussian analysis demonstrated that a statistical eye model can be defined that generates synthetic data that is significantly equal to the original data (non-parametric Mann-Whitney test for equality; all p < 0.05), with similar variability (non-parametric Levene test; all p > 0.05).

Conclusion: The eye undergoes a scaled growth until birth, at which time male and female infants have similar values. The models presented may serve as an early biometry reference.