Topographic indices and pachymetry in healthy adolescents obtained with Sirius topographer

To determine the normal values for the Sirius corneal topography, of some topographic indices and corneal pachymetry, in a healthy young adolescent population.

A total of 176 students (mean age 12.95 ± 0.82 years) took part in this study. 352 eyes were imaged through Sirius topographer. Anterior and posterior meridians, mean pupillary power, central corneal thickness, minimum corneal thickness, and anterior and posterior asymmetry indices were analyzed. Correlations between corneal parameters and differences between anterior and posterior corneal surfaces were evaluated.

Average anterior meridian was 43.37 D (± 1.46); average posterior meridian was 6.16 D (± 0.24); central corneal thickness was 550.81 ± 29.88 micron, minimum corneal thickness was 547.36 ± 29.93 micron; mean pupillary power was 42.95 ± 1.46 D, SIf was - 0.035 ± 0.46, and SIb was 0.012 ± 0.091. Anterior and posterior corneal curvatures correlated negatively with MPP (r = - 0.99; p = 0.000 and r = - 0.85 p = 0.000, respectively). Anterior curvature correlated positively with posterior curvature (r = 0.891; p = 0.000). Positive correlations were found for SIf and SIb (r = 0.58; p = 0.000). Negative correlations were found for SIf and corneal pachymetry (r = - 0.23; p = 0.000) and for SIb and corneal pachymetry (r = - 0.19; p = 0.012). The difference between anterior meridian average and posterior meridian average was 1.29 ± 0.12 and was significative (p < 0.001). No differences between genders were found.

These results provide normal standards for corneal values in adolescents and could represent a useful tool for future comparative studies in this age-group population.