A viscoelastic analysis of scleral strip creep data from tree shrew eyes with form-depriv ation myopla

摘要

Myopia (nearsightedness) is a condition in which the axial length of the eye is longer than the focal plane. Images of distant objects are thereby focused anterior to the retina and vision is blurred. The prolate geometry and thinning of the sclera suggest that myopia progresses through abnormal stretching of the sclera (Curtin, 1985). Siegwart and Norton (1994) found that uniaxial creep rates in myopic scleral strips were generally greater than in paired controls. In the present study, viscoelastic material properties were calculated for scleral strip test data from 4, 11- and 21-day monocularly form-deprived tree shrews. The data were analyzed to determine statistical differences comparing control and deprived sclera in terms of initial elastic strains, primary and steady state creep rates and final strains.