Evaluation of structural contributors in myopic eyes of preterm and full-term children.

Abstract

We conducted a cross-sectional study to test the hypothesis that the structural contributions to myopia in preterm and full-term born children are different. In this study, 93 children ranging from ages 2 to 13 who had myopia ≥ -3 diopters in at least one eye were examined with A-scans. The following data was collected and analyzed: history of birth, refractive error (RE), cornea thickness (CT) and average corneal curvature (AVK), depth of anterior chamber (ACD), lens thickness (LT), and axial length (AL) of the eye. Eyes were tested and categorized into four groups: myopic eyes in full-term children (group 1), myopic eyes in premature children (group 2), non-myopic eyes in full-term children (group 3), and non-myopic eyes in preterm children (group 4). The RE were similar between group 1 and group2, and between group 3 and group 4. Myopic eyes in group 2 had higher AVK as compared to group 3; 45.4 ± 0.4 D vs. 43.5 ± 0.7 D, p = 0.008. The ACD in group 2 was shallower than that in group 1 (2.5 ± 0.5 vs. 3.2 ± 0.3, p = 0.01). The LT measurements in group 2 were thicker than those in group 1 (mean LT = 4.9 ± 1.0 vs 4.1 ± 0.3mm, p = 0.001, respectively). Finally, AL of myopic eyes in group 1 was longer than that of group 2, p = 0.01. These results suggest that increased axial length plays an important role in myopia in full-term children, whereas corneal curvature and lens thickness are major contributors to myopia in preterm children.