Age-Related Differences in the Elasticity of the Human Cornea

TY - JOUR

T1 - Age-Related Differences in the Elasticity of the Human Cornea

AU - Cartwright, Nathaniel E. Knox

AU - Tyrer, John R.

AU - Marshall, John

PY - 2011/6

Y1 - 2011/6

N2 - PURPOSE. The goal of this study was to determine age-related variation in the elasticity of the human cornea using nondestructive means. METHODS. Organ cultured human corneoscleral buttons were studied. Changes in strain were measured with a radial shearing speckle pattern interferometer after an increase in intraocular pressure from 15.0 to 15.5 mm Hg. Changes in central corneal displacement were calculated by integration, and a bulk corneal Young's modulus was derived by mathematical analysis. RESULTS. Fifty corneas, including 17 pairs, were studied. Donors were aged between 24 and 102 years (mean, 73.1); 29 (58%) specimens were from male donors and 21 from female donors. Young's modulus of the cornea increased with age, with the line of best fit indicating an approximate doubling from 0.27 MPa at age 20 years (95% confidence interval, 0.22-0.31) to 0.52 (0.50-0.54) MPa at age 100 years (R-2 = 0.70). CONCLUSIONS. The stiffness of the human cornea increases by a factor of approximately two between the ages of 20 and 100 years. This variation is relevant to the algorithms used to predict the response to incisional and ablative refractive surgery and will also affect the formulas used to calculate intraocular pressure by applanation. (Invest Ophthalmol Vis Sci. 2011;52:4324-4329) DOI:10.1167/iovs.09-4798

AB - PURPOSE. The goal of this study was to determine age-related variation in the elasticity of the human cornea using nondestructive means. METHODS. Organ cultured human corneoscleral buttons were studied. Changes in strain were measured with a radial shearing speckle pattern interferometer after an increase in intraocular pressure from 15.0 to 15.5 mm Hg. Changes in central corneal displacement were calculated by integration, and a bulk corneal Young's modulus was derived by mathematical analysis. RESULTS. Fifty corneas, including 17 pairs, were studied. Donors were aged between 24 and 102 years (mean, 73.1); 29 (58%) specimens were from male donors and 21 from female donors. Young's modulus of the cornea increased with age, with the line of best fit indicating an approximate doubling from 0.27 MPa at age 20 years (95% confidence interval, 0.22-0.31) to 0.52 (0.50-0.54) MPa at age 100 years (R-2 = 0.70). CONCLUSIONS. The stiffness of the human cornea increases by a factor of approximately two between the ages of 20 and 100 years. This variation is relevant to the algorithms used to predict the response to incisional and ablative refractive surgery and will also affect the formulas used to calculate intraocular pressure by applanation. (Invest Ophthalmol Vis Sci. 2011;52:4324-4329) DOI:10.1167/iovs.09-4798

U2 - 10.1167/iovs.09-4798

DO - 10.1167/iovs.09-4798

M3 - Article

SN - 1552-5783

VL - 52

SP - 4324

EP - 4329

JO - Investigative Ophthalmology & Visual Science

JF - Investigative Ophthalmology & Visual Science

IS - 7

ER -