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 mm 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 determine differences among age and ethnic groups

RESULTS

The mean central corneal thickness (CCT) was 549 +/- 46 microm. Paracentral corneal thickness mean values, as measured 3 mm from the corneal center, were as follows: superior, 575 +/- 52 microm; nasal, 568 +/- 50 microm; inferior, 568 +/- 51 microm; and temporal, 574 +/- 47 microm. 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 microm; 2 to 4 years, 546 +/- 41 microm; 5 to 9 years, 566 +/- 48 microm; and 10 to 18 years, 554 +/- 35 microm (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.