Study: Aberrations decrease, then increase with age

Optical aberrations of the eye’s visual system appear to increase and decrease as a function of age, a group of researchers suggests. They suggest that the definition of emmetropia be expanded to include the reduction of higher order aberrations with age.

Isabelle Brunette and colleagues at the University of Montreal studied monochromatic aberrations of the eye in 114 subjects with spherical equivalents of ±3.5 D from emmetropia. All subjects had corrected visual acuity of 20/40 or better and normal findings in an ophthalmic examination. Subjects ranged in age from 5 years to 82 years of age, with a mean age of 43 years.

The researchers found that the root mean square error, for a 5-mm pupil, for aberrations from the third to the seventh order; as a function of age was modeled by a second-order polynomial regression. The error decreased progressively through childhood, adolescence and early adulthood, reached a minimum in the fourth decade of life, then increased progressively with age.

For a 5-mm pupil, the mean modulation transfer function was reduced during ages 5 to 20 and ages 61 to 82, compared to the middle-aged adult group (41-60 years of age).

The study is published in the December issue of Investigative Ophthalmology & Visual Science.