Presbyopia Due to More Than Just Loss of Focusing Ability

July 2, 2012 — Although women are more at risk of developing presbyopia than men, this appears not to be the result of a physiologic difference in accommodation. Instead, it seems to be the result of other sex differences, such as those pertaining to tasks performed and viewing distances.

Adam Hickenbotham, DO, PhD, from the University of California in Berkeley, and colleagues published the results of a metaanalysis online April 24 in Investigative Ophthalmology & Visual Science. The study concluded that aged-based correction nomograms for presbyopia consider sex differences when prescribing.

A total of 15 studies were found that reported presbyopia data with the sex of the participants; 9 were included in the current analysis.

The authors note that the different studies included in the metaanalysis used different measurements of presbyopia. This resulted in highly heterogeneic studies as assessed using the chi-square statistic for heterogeneity (P = .01).

The overall metaanalysis showed a slight increase in risk for presbyopia in women compared with men. Specifically, female sex was found to be statistically significant in predicting early onset of presbyopia (adjusted confidence interval [CI], using the Shore method of 95% CI, 1.02 - 1.45). The adjustment was made for heterogeneity.

When the metaanalysis was limited to studies that measured only accommodative amplitude, female sex was not associated with presbyopia in a fixed effects model (95% CI, .49 - 1.07).

Another subanalysis of near add powers for presbyopic prescriptions revealed that women need higher power near adds than do men of an equivalent age. These results were reinforced by a recent study (not included in the metaanalysis) that also concluded that women require higher add powers than men of a similar age.

Studies have consistently reported that women require reading glasses or bifocal lenses at a younger age than men. The current study concludes that the need for near vision correction is due not just to the loss of focusing ability but also to the habitual reading distance and depth of focus. The authors suggest that the arm length, occupation, indoor light levels, and specific conditions related to desired tasks may underlie the sex differences.

The authors have disclosed no relevant financial relationships.

Invest Ophthalmol Vis Sci. Published online April 24, 2012. Abstract