Photokeratometric and photorefractive measurements of astigmatism in infants and young children.

We have measured corneal and total astigmatism on 161 eyes of 90 normal infants and young children aged 2 months to 5 years using the techniques of photorefraction and photokeratometry. Both the mean corneal and mean total astigmatism were found to decrease with increasing age. We found large and significant correlations between corneal and total astigmatism in the 0-1, 1-2 and 2-3 year-old infants and children. Previous studies have shown that photorefractive measurements of astigmatism compare well with retinoscopic measurements of the same infants. As part of this study we measured the corneal astigmatism of 19 adults (38 eyes) by photokeratometry and with a clinical keratometer and found that the two measures were well correlated (r = 0.820). We conclude that the major component of total astigmatism seen in uncyclopleged infants of ages 0-3 years is corneal in nature.