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Abstract #26459 Published in IGR 12-3
Biaxial mechanical testing of human sclera
Eilaghi A; Flanagan JG; Tertinegg I; Simmons CA; Wayne Brodland G; Ross Ethier CJournal of Biomechanics 2010; 43: 1696-1701
The biomechanical environment of the optic nerve head (ONH), of interest in glaucoma, is strongly affected by the biomechanical properties of sclera. However, there is a paucity of information about the variation of scleral mechanical properties within eyes and between individuals. We thus used biaxial testing to measure scleral stiffness in human eyes. Ten eyes from 5 human donors (age 55.4(plus or minus)3.5 years; mean(plus or minus)SD) were obtained within 24h of death. Square scleral samples (6mm on a side) were cut from each ocular quadrant 3-9mm from the ONH centre and were mechanically tested using a biaxial extensional tissue tester (BioTester 5000, CellScale Biomaterials Testing, Waterloo). Stress-strain data in the latitudinal (toward the poles) and longitudinal (circumferential) directions, here referred to as directions 1 and 2, were fit to the four-parameter Fung constitutive equation W=c(e(Q)-1), where Q=c1E112+c2E222+2c3E11E22 and W, c's and E(ij) are the strain energy function, material parameters and Green strains, respectively. Fitted material parameters were compared between samples. The parameter c(3) ranged from 10(-7) to 10(-8), but did not contribute significantly to the accuracy of the fitting and was thus fixed at 10(-7). The products c
C. Ross Ethier. Department of Bioengineering, Imperial College, London SW7 2AZ, United Kingdom. r.ethier@imperial.ac.uk
Classification:
2.3 Sclera (Part of: 2 Anatomical structures in glaucoma)
