Purpose
To determine the range and distribution of measures of eye size and shape obtained by Magnetic Resonance Imaging (MRI), and to determine the associations of race and parental myopia with eye dimensions and shape in newborn children.
Methods
This study was conducted on a subset of the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort study. 173 newborn children underwent MRI. Eye volume and surface area were measured. Longitudinal axial length (LAL, the length from the posterior corneal surface to the retinal surface), horizontal width, and vertical height along the cardinal axes were measured. Eye shape was assessed qualitatively from three-dimensional models, and quantitatively by calculation of an index of eye shape, the oblateness (oblateness = 1-AL/width or 1-AL/height). A spherical shape was oblateness=0, and prolate and oblate shapes were oblateness <0 and >0 respectively.
Results
In total, 346 eyes of 173 full-term newborn children were included. Eyes with longer AL had greater widths, heights, volumes and surface areas (p<0.001 for all). The mean oblateness value calculated in relation to width was -0.06±0.05(95% confidence interval -0.23 - 0.08), and the mean oblateness calculated in relation to height was -0.05±0.04 (-0.19 - -0.001). Using width to calculate oblateness, most eyes were prolate (312 eyes(90.2%)), and, using height, most eyes were also prolate(194 eyes(56.1%)). With increasing AL, eyes assumed increasingly prolate profiles using both eye width and height to calculate oblateness. However, even amongst the eyes with the longest AL, the globe shape appeared spherical from inspection, without evidence of a marked prolate or oblate bias.(Figure) Race but not parental myopia was associated with the size of the eye at birth, with children of Malay mothers having larger eye volumes and surface areas.
Conclusions
Most newborn Singaporean Asian children are born with spherical or slightly prolate eyes. Race but not parental myopia is associated with the size of the eye at birth.
Keywords: 677 refractive error development •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
605 myopia