Jules Stein Eye Institute, Department of Ophthalmology, Research and Education Institute at Harbor-UCLA Medical Center, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA. isenberg@ucla.edu
OBJECTIVE: To evaluate corneal curvature by direct topographic analysis during the first 6 months of life. METHODS: We evaluated corneal topography in 200 infants using a specialized handheld topographic instrument at a mean of 1.6 days after birth, and in some again at 3 and 6 months in the newborn nursery and ophthalmology clinic of a public hospital. 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 astigmatism measured 6.0 D (95% CI, 5.6-6.3 D), usually "with the rule" (80%) with a mean axis of 95 degrees . The mean astigmatism on the semimeridian map at 3 mm was 6.4 D (95% CI, 6.0-6.8 D); and at 5 mm, 5.9 D (95% CI, 5.4-6.3 D). At birth, neonates delivered vaginally had a greater frequency of with-the-rule astigmatism than those delivered by cesarean section (P = .02). By 6 months, the mean central corneal power and astigmatism decreased to 43.0 (95% CI, 41.3-43.1) D and 2.3 (95% CI, 1.4-3.2) D, respectively (P<.005 for each). CONCLUSIONS: Newborns have steep, high, astigmatic (generally with-the-rule) corneas at birth that flatten significantly by the age of 6 months. The method of delivery can affect the astigmatic axis at birth.