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

Purpose: 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.

Methods: 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.

Results: 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 ± 0.3 mm, p = 0.001, respectively). Finally, AL of myopic eyes in group 1 was longer than that of group 2, p = 0.01.

Conclusion: 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.