To evaluate age-related changes in anterior and posterior corneal astigmatism in Koreans.

The anterior and posterior corneal astigmatisms of 160 subjects with age ranging from 11 to 92 years, none of whom experienced any complications, were measured with a rotating Scheimpflug camera (Pentacam®). Using this data, the changing proportions of with-the-rule to against-the-rule and changing tendency of anterior and posterior corneal astigmatisms with age were evaluated using polar value analysis according to the Naeser method.

For the anterior cornea, the proportion of with-the-rule astigmatisms decreased with age ( p < 0.0001). On the other hand, for the posterior cornea, the proportion of against-the-rule astigmatisms decreased with age ( p = 0.012). In the polar value analysis, there was a trend toward against-the-rule astigmatism associated with increasing age for the anterior cornea ( p < 0.0001) and toward with-the-rule astigmatism for the posterior cornea ( p < 0.0001).

In previous studies, the anterior corneal surface shifted from with-the-rule to against-the-rule astigmatism with increasing age, whereas the posterior corneal surface remained as against-the-rule astigmatism in most cases. But, our results showed that the proportion of against-the-rule astigmatisms of the posterior cornea decreased with age. Thus, evaluation of posterior corneal astigmatisms should be performed before cataract surgery in old patients, especially when using a multifocal or toric intraocular lens.