Longitudinal study of postoperative astigmatism.

A prospective longitudinal study of 503 eyes that had extracapsular cataract extraction with posterior chamber intraocular lens implantation was conducted. Each patient was followed for a minimum of one year. Data were collected, analyzed, and the following information ascertained: temporal behavior of induced keratometric and cylindrical changes, induced with-the-rule, against-the-rule, and oblique astigmatism, comparison of keratometric and refractive astigmatism, and the effect of cutting sutures upon induced astigmatism. Though a large amount of with-the-rule astigmatism was immediately induced after surgery, by the end of one year over 60% of patients shifted toward against-the-rule.