Elasticity of tissues involved in accommodation.
Uniaxial loading of human lens, zonules, ciliary muscle, and choroid shows a nonlinear relationship between stress and deformation of the specimen, and hysteresis on unloading. Spring constants, at 10% elongation, have been calculated for all specimens and for several combinations. Except for zonules they are significantly correlated with age. They will provide a basis for a model of accommodation. The mean force required for 10% elongation of the lens, at mean age 43, is about 22 x greater than for the zonules; and the mean elongation of the zonules is nearly 7 x that of the lens at a load of 0.01 N (approximately 1 g). Ranges of forces and pressures in the accommodated and nonaccommodated eye are estimated.
van Alphen
G W
GW
The Netherlands Ophthalmic Research Institute, Amsterdam.
Graebel
W P
WP
D000065:Accommodation, Ocular / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D002829:Choroid / Q000502:physiology; D002924:Ciliary Body / Q000502:physiology; D004548:Elasticity; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007908:Lens, Crystalline / Q000502:physiology*; D008875:Middle Aged; D008954:Models, Biological; D013718:Tensile Strength