Elasticity of the bovine sclera measured with real-time holographic interferometry

Real-time holographic interferometry was used to evaluate the elasticity of the posterior scleral hemisphere of fresh and preserved enucleated bovine eyes. Absolute amplitude values of radial distension were determined for specific locations across the sclera as the tissue was subjected to minute increases in intraocular pressure (IOP). Results indicate that different locations on the globe possess different coefficients of elasticity. Specifically, the supralateral aspect of the posterior globe distended relatively more than the inframedial and medial portions of the globe. Elastic moduli were derived by an areal method in which strain was measured as a change in surface area of the globe, and stress was measured as a change in IOP. Coefficients of elasticity in the range of 3.9 to 9.0 megapascals (MPa) were determined for locations across the posterior scleral hemisphere of the fresh eye used in this study.