Corneal Topography of Neonates and Infants

Objective To evaluate corneal curvature by direct topographic analysis duringthe first 6 months of life. Methods We evaluated corneal topography in 200 infants using a specialized handheldtopographic instrument at a mean of 1.6 days after birth, and in some againat 3 and 6 months in the newborn nursery and ophthalmology clinic of a publichospital. Results At birth, the mean central corneal power measured 48.5 diopters (D)(95% confidence interval [CI], 48.2-48.8 D; range, 41.4-56.0 D) and astigmatismmeasured 6.0 D (95% CI, 5.6-6.3 D), usually “with the rule” (80%)with a mean axis of 95°. The mean astigmatism on the semimeridian mapat 3 mm was 6.4 D (95% CI, 6.0-6.8 D); and at 5 mm, 5.9 D (95% CI, 5.4-6.3D). At birth, neonates delivered vaginally had a greater frequency of with-the-ruleastigmatism than those delivered by cesarean section ( P  = .02). By 6 months, the mean central corneal power andastigmatism decreased to 43.0 (95% CI, 41.3-43.1) D and 2.3 (95% CI, 1.4-3.2)D, respectively ( P Conclusions Newborns have steep, high, astigmatic (generally with-the-rule) corneasat birth that flatten significantly by the age of 6 months. The method ofdelivery can affect the astigmatic axis at birth.