Longitudinal biomechanical analysis of the postnatal mouse cornea

The cornea is a transparent lens at the forefront of the eye. It is a structural barrier that protects the eye and provides 2/3 of the eye’s refractive power. The shape of the cornea is important for proper function and is determined by a balance between the mechanical properties of the cornea and the intraocular pressure. Disease in the cornea often involves corneal malformations that diminish its refractive properties and degrade vision quality. To prevent disease or intervene in its progression, we can look to eye development to better understand how the eye is properly formed and identify where the potential for disease arises. In this work, we have utilized the postnatal mouse eye to characterize corneal biomechanics using optical coherence elastography. We have identified that central corneal thickness (CCT) increases as the eye develops from birth to adulthood. Our measurements identified that CCT is dynamic, peaking on postnatal day (PN) 12, decreasing as it remodels from PN12 to PN18, and finally increasing as the mouse prepares to enter early adolescence after postnatal day 24. From PN6 to PN24, we observed elastic speeds decrease as the cornea swelled from PN6 to PN12, and then continued to drop until PN24. After PN24, the postnatal eye increases in thickness until it stabilizes in early adulthood. Elastic wave speeds increase in adulthood as the eye gradually increases in thickness. Our findings suggest that the postnatal eye is a dynamic structure, and through its development uncouples corneal elasticity from corneal thickness.