DISTRIBUTION OF ASTIGMATISM IN THE ADULT-POPULATION

We have quantified statistically the astigmatic frequency distribution . Vectorial analysis was used, as it enables formal multivariate stati stical techniques to be applied to astigmatic data, allowing the simul taneous inclusion of both modulus and axis in the analytical procedure . These methods were applied to population data for each of total, cor neal, and residual astigmatism from a sample of 198 adults. Right and left eyes were analyzed separately. All the distributions were found t o depart significantly from a normal distribution. All the distributio ns were significantly leptokurtic (p < 0.005), and the distributions o f total right eye, corneal right eye, and residual left eye astigmatis m were also found to be significantly skewed(p < 0.05). Significant mi ld correlations were found between total and corneal astigmatism(p < 0 .05). These findings add to the database of knowledge of astigmatic re fractive error and may be of interest to those investigating refractiv e-error development.