The course of corneal and intraocular pressure changes during pregnancy

Objective: To determine concurrent changes in corneal thickness, intraocular pressure (IOP), and corneal topography measurements during normal pregnancy. Design: Prospective cohort study. Participants: We studied 50 eyes from 25 healthy women whose ages ranged from 21 to 35 years and who were first seen during the 10th week of pregnancy. Methods: Measurements included IOP (noncontact tonometry); corneal thickness (ultrasound pachymetry); and corneal topography (TMS 2N, TOMEY, Nagoya, Japan). Changes in IOP, central corneal thickness (CCT), and corneal power were calculated at 4 time periods: first trimester, second trimester, third trimester, and 3 months postpartum. Results: The mean IOPs in the second and third trimesters of pregnancy were found to be lower than those in the first trimester and at 3 months postpartum (p = 0.001). The mean CCT in the second and third trimester of pregnancy was measured to be higher than in the first trimester and at 3 months postpartum (p < 0.001). Both IOP and CCT returned to first-trimester levels following delivery. In the third trimester, a 3.1% increase in CCT was associated with a 9.5 % decrease in IOP. Topographic measurements did not show statistically significant changes throughout the trimesters or after pregnancy. Conclusions: An increase in CCT was accompanied by a decrease in IOP in the second and third trimesters. Physiologic changes occurring in CCT and IOP should be considered in the management of glaucoma during pregnancy. © 2012 Canadian Ophthalmological Society