Cycloplegic refractions of infants and young children: the axis of astigmatism.

Review of the cycloplegic refractions of all children who were first examined at Children's Hospital Medical Center in Boston between 1968 and 1978 revealed that 281 children between the ages of 0 and 9.5 years had astigmatism of 1 diopter (D) or greater but no other ophthalmological or neurological problems. In the 85 children under 3.5 years of age, against-the-rule astigmatism was 2.5 times more common than with-the-rule astigmatism, whereas in the 103 children over 5.5 years of age, with-the-rule astigmatism was three times as common as against-the-rule astigmatism. Eleven children who had been astigmatic as infants were recalled; follow-up refraction at ages 5-11 years revealed that all but three had at least a 0.75 D decrease in astigmatism. The remaining three had astigmatism equal in magnitude and axis to the astigmatism they had as infants. Thus, there is a high prevalence of against-the-rule astigmatism in infants and toddlers, which disappears by the time the children reach school age.