Age-related Changes in Anterior, Posterior Corneal Astigmatism in a Korean Population

ABSTRACT

PURPOSE: To evaluate age-related changes in anterior and posterior corneal astigmatism in Koreans. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.