Corneal thickness in children

OBJECTIVE: To determine normal central and paracentral corneal thickness measurements in the pediatric population and to determine if these measurements are consistent across different pediatric age groups and different racial groups. DESIGN: Prospective observational case series. METHODS: Pachymetry measurements were performed on 198 eyes of 108 children. The measurements were taken centrally as well as at four paracentral sites 3 nun from the corneal center at the 3, 6, 9, and 12 o'clock positions. The two-tailed t test was used for comparison of the continuous means for values of corneal thickness. Analysis of variance (ANOVA) was performed to deter, mine differences among age and ethnic groups. RESULTS: The mean central corneal thickness (CCT) was 549 +/- 46 mum. Paracentral corneal thickness mean values, as measured 3 mm from the corneal center, were as follows: superior, 575 +/- 52 mum; nasal, 568 +/- 50 mum; inferior, 568 +/- 51 mum; and temporal, 574 +/- 47 mum. The mean CCT values were significantly thinner than at each of the mean paracentral points (P < .05 for each comparison, paired t test). Paracentral corneal thickness measurements demonstrated no significant differences between locations (P > .05, variance analysis). The mean CCT +/- SD for each age group was as follows: 6 to 23 months, 538 +/- 40 mum; 2 to 4 years, 546 +/- 41 mum; 5 to 9 years, 566 +/- 48 mum; and 10 to 18 years, 554 +/- 35 mum (ANOVA P = .012). ANOVA performed on central pachymetry values demonstrated no significant differences among racial subgroups. CONCLUSIONS: Pediatric central and paracentral corneal thicknesses increase slowly over time and reach adult thicknesses at 5 to 9 years of age. (C) 2004 by Elsevier Inc. All rights reserved.