The intraocular pressure in the human bulbus requires that the "wall" of the eye shows a certain (bio)mechanical strength. The human cornea represents the anterior portion of this wall. Since several years, there is a growing interest in the ophthalmological community for identifying factors modulating the biomechanical stability of the human cornea. Reasons are twofold: advances in keratoconus research and the increasing numbers of refractive laser surgery procedures with (correspondingly) increasing numbers of complications due to non-respecting the limits of corneal biomechanics.

There is evidence that oestrogen, but also thyroïd hormone changes have a major impact on corneal biomechanics. A number of recent observational studies have reported on keratoconus and refractive laser surgery patients with decompensating biomechanics during pregnancy.

Both hormones also show physiological changes during pregnancy and little is known about the impact of these physiological changes on the human cornea.

The aim of this study is to establish baseline values for physiological changes in the human cornea during pregnancy.

Inclusion Criteria:

• Older than 18 years
• Pregnancy confirmed by echography
• Before gestation week 14

Exclusion Criteria:

• Pre-existing corneal disease
• Previous eye surgery
• Inability to understand the nature of the study
• Patient with legal guardian

Pregnant women at the Dept. of Gynecology and Obstetrics of the University Hospital of Geneva