Anterior shift of zonular insertion onto the anterior surface of human crystalline lens with age.

Abstract

This study aimed to investigate the age-related changes in the position of zonular insertion onto the anterior lens capsule. The study design was an experimental cadaveric eye study. Two hundred twenty-three cadaveric eyes (range, 16-100 years old) from eye banks in the United States were studied. The zonular insertion onto the anterior capsule was detected using a modified posterior photographic technique. The distances from the anterior zonular insertion (AZI) to the lens equator and to the ciliary sulcus, size of zonular-free zone, lens diameter, ciliary sulcus diameter, and axial length of the globe were measured. Multiple regression analysis showed that age, lens diameter, and axial length of the globe had significant correlations with AZI (r2 = 0.748), among which age showed the highest relevance with AZI. Multiple regression equation was expressed as AZI = (0.0079 x age) + (0.202 x lens diameter) - (0.041 x axial length of the globe) + 0.0114. The increase in AZI was accompanied by a decrease in the size of zonular-free zone with age (r = -0.206, P < 0.001). Aging correlates with an increase in the distance from the anterior zonular insertion to the lens equator and a decrease in zonular-free zone.