Changes in anterior segment, ocular aberrations, and aqueous humour density during pregnancy and postpartum

PurposePregnancy induces hormonal changes that can affect various organ systems, including ocular structures. This study aimed to evaluate changes in anterior segment (AS) parameters, higher-order aberrations (HOAs), and aqueous humour (AH) optical density (OD) in pregnant women compared to healthy controls.MethodsThis prospective case-control study included 45 healthy pregnant women and 47 age-matched non-pregnant controls. Comprehensive ophthalmological examinations were performed, including best-corrected visual acuity (BCVA), intraocular pressure, spherical equivalent, axial length, central corneal thickness, corneal volume, corneal curvature (K1, K2, Km), AS parameters, and endothelial cell metrics. HOAs (coma, trefoil, spherical aberration) and AH OD were also assessed. Ocular surface evaluations included the OSDI questionnaire, Schirmer test and tear break-up time. Pregnant participants were assessed in each trimester and three months postpartum, with comparisons conducted both cross-sectionally against healthy controls and longitudinally within the pregnancy cohort across trimesters and postpartum.ResultsRMS-HOA was higher in the third trimester (0.41 ± 0.19 µm, p = 0.003) and postpartum (0.39 ± 0.31 µm, p = 0.041). RMS-total increased in the second (1.64 ± 0.21 µm, p = 0.031) and third trimesters (1.63 ± 0.46 µm, p = 0.022). Coma was higher in the second (1.64 ± 0.34 µm, p = 0.045) and third trimesters (1.61 ± 0.29 µm, p = 0.040), and trefoil increased in the third trimester (1.50 ± 0.35 µm, p = 0.027). AH OD was higher than in controls at every time point, measuring 4.74 ± 0.41% in the first trimester (p = 0.007), 4.81 ± 0.50% in the second (p = 0.001), 4.96 ± 0.42% in the third (p = 0.001), and 4.79 ± 0.46% postpartum (p = 0.020). BCVA was unchanged.ConclusionIn pregnancy, small increases in HOAs and AH OD are typically subclinical and reflect physiological change rather than pathology.