Pregnancy-induced ocular changes: impacts on intraocular pressure, the cornea, and the anterior chamber

This study aims to comprehensively evaluate the trimester-specific effects of pregnancy on intraocular pressure, corneal biomechanics, anterior segment anatomy, and endothelial cell morphology.

This prospective cross-sectional study included 90 healthy pregnant women (30 per trimester) and 30 age-matched non-pregnant controls. Comprehensive ophthalmological assessments were performed, including IOP measurement using a non-contact tonometer, corneal structure evaluation with Pentacam Scheimpflug imaging, and endothelial cell analysis using a specular microscope.

A significant decrease in IOP was observed in the third trimester compared to the control group (p = 0.016), although no significant difference was noted in the first and second trimesters (p > 0.05). Corneal endothelial analysis revealed a significant decrease in hexagonal cell percentage (HEX) values during the first trimester (p = 0.007). Correlation analysis demonstrated a strong positive relationship between central corneal thickness (CCT) and corneal volume (r = 0.817, p < 0.001) and a moderate positive correlation between CCT and IOP (r = 0.263, p = 0.004). Axial length was strongly negatively correlated with both flat keratometry (r=-0.562, p < 0.001) and steep keratometry (r=-0.538, p < 0.001), and strongly positively correlated with anterior chamber volume and anterior chamber depth (r = 0.380, p < 0.001 and r = 0.384, p < 0.001, respectively). A moderate positive correlation was also identified between gestational trimester and HEX (r = 0.257, p = 0.005).

Pregnancy induces temporary but significant ophthalmological changes, particularly a decrease in IOP in the third trimester and a decrease in HEX in the first. These findings highlight the importance of monitoring ocular health during pregnancy to detect potential risks early and ensure timely intervention.