Sex-related differences in corneal astigmatism and shape with age

To compare corneal astigmatism and shape between male and female eyes in relationship to age.

Hayashi Eye Hospital, Fukuoka, Japan.

Prospective case series.

Eyes of men and women in 5 age groups (40 to 49 years, 50 to 59 years, 60 to 69 years, 70 to 79 years, and ≥80 years) had videokeratographic evaluations using a Placido-Scheimpflug system. Corneal astigmatism decomposed to vertical-horizontal (J0) and oblique (J45) astigmatism components was compared between male and female eyes, and corneal shape changes were compared using videokeratography maps.

The study comprised 1000 eyes (100 eyes of male patients and 100 eyes of female patients in each of the 5 age groups). The mean J0 of the total and anterior cornea were significantly smaller in male eyes than in female eyes in all age groups (P ≤ .0269) with no significant difference in the J45 between sexes, indicating greater against-the-rule (ATR) astigmatism in male eyes. The mean J0 of the posterior cornea did not differ significantly between sexes except in the 50 to 59 years group (P = .0105). The ATR astigmatic change per decade did not differ significantly between men and women. Videokeratography maps revealed that the total and anterior corneal shape changed to ATR astigmatism with age in both sexes, and that this ATR change began at a younger age in male eyes than in female eyes. The posterior corneal shape did not differ between sexes at any age.

Against-the-rule corneal astigmatism was greater and the ATR astigmatic change with age began earlier in the male eyes than in the female eyes, suggesting that target astigmatism should be determined separately for men and women when performing astigmatism correction.