Premium
Elastic properties of human lens zonules as a function of age in presbyopes
Author(s) -
MIKIELEWICZ M,
MICHAEL R,
MONTENEGRO G,
PINILLA CORTES L,
BARRAQUER RI
Publication year - 2013
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2013.s080.x
Subject(s) - presbyopia , modulus , elastic modulus , ophthalmology , materials science , lens (geology) , young's modulus , optics , optometry , medicine , composite material , physics
Purpose Ex vivo measurement of the elastic properties of human lens zonules as a function of age in presbyopes. Methods We studied 16 presbyopic human donor eyes (ages 47 to 97). Anterior eye sections with crystalline lens, zonules, ciliary body and sclera were radially stretched. The stretching device consists of a chamber filled with balanced salt solution and eight radial hooks to hold the anterior eye section. Radial stretching was created with a stepper motor connected to a digital outside micrometer for linear displacement and digital balance for force measurement. Three eye globes were used to test our methodology. For 13 eye globes, the spring constant, elastic modulus of the zonular system, and Young's modulus of the zonules were calculated. Results We found linear dependence for force‐elongation and force‐strain relationships at all ages. In young presbyopic eyes (ages 47 to 60), the Young's modulus of the zonules was 340 mN/mm²; whereas in older eyes (ages 83 to 97), it was significantly lower at 270 mN/mm². However, the correlation coefficient between Young's modulus and age (47 to 97 years) was not significant with p = 0.063. Conclusion The zonular system in presbyopic eyes is linear elastic, and the Young's modulus of the zonules decreases 20% from presbyopic age to late presbyopic age. However, there was no significant correlation between Young's modulus and age in presbyopes.