Crystalline lens optical dysfunction through aging

Abstract

Purpose: To evaluate the optical and densitometric changes that take place in the crystalline lens with aging.

Design: Cross-sectional study.

Participants: Seventy-two eyes of 72 patients of different ages (8-80 years) with a clear lens, a visual acuity of 20/25 or better, and no ocular disease.

Methods: In each case, the lens thickness, optical density, modulation transfer function (MTF), and intraocular aberrations were measured.

Main outcome measures: Embryonic and fetal nucleus density, lens thickness, intraocular high-order aberration (HOA), and 0.1 MTF.

Results: Embryonic, anterior, and posterior fetal nucleus densities show a positive correlation with age (P<0.0001, P<0.0001, and P<0.0001, respectively). Lens thickness also shows a positive correlation with age (P<0.0001). Total ocular and corneal HOAs for a 6-mm pupil show a positive correlation with age (P = 0.036 and P<0.0001, respectively). Ocular and corneal Zernike polynomials Z4i+Z6i and intraocular spherical aberration (Z4(0)) also show a positive correlation with age (P = 0.001, P = 0.039, and P = 0.001, respectively). Intraocular coma aberration (Z3(-1)) shows a negative linear correlation with age (P<0.0001). In addition, 0.1 MTF decreased with age from 18.557 to 10.100 cycles per degree.

Conclusion: There is a degradation of the optical quality of the crystalline lens with aging that is associated with morphological changes (thickness and density). These results are important for the consideration of lens replacement in the absence of evident cataract.