Purpose
To identify the distribution and variation of corneal topography, thickness, and elevation measured by the Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany) Scheimpflug system in healthy Brazilian children.
Methods
Healthy children aged between 7 and 11 years were scanned with the Pentacam Scheimpflug corneal topography system (Oculus Optikgeräte GmbH, Wetzlar, Germany). The exclusion criteria was the Modified Rabinowitz/McDonnell criteria for keratoconus. Right eye of each subject was selected for analysis. The following parameters were evaluated: central corneal thickness (CCT), thinnest pachymetry (TP), average pachymetric progression index (PPI ave), anterior and posterior elevation thinnest point (AETP and PETP), anterior and posterior best-fit sphere (ABFS and PBFS), pachymetric difference between the apex and the thinnest point (PDAT), ART MAX, Belin/Ambrósio Enhanced Ectasia Display overall index (D), Sim K, Sim K astigmatism, K max and Q value.
Results
A total of 160 children (69 boys, 91 girls) were included in this study. Table 1 summarizes our findings. The mean age of the children was 8.82 ± 1.23 years (range, 7 to 11 y). The mean CCT was 553.81 ± 32 µm and mean TP was 547.95 ± 32.06 µm. The TP was most commonly located in the inferotemporal quadrant compared to the corneal apex in 93,125% (149) eyes. The PPI ave mean was 1.00 ± 0.14 comparable to normal adults (Ambrósio et al, J Refract Surg. 2011;27(10):753-758; Vázquez, Am J Ophthalmol. 2014;158:32-40). The mean of ABFS and PBFS was 7.49 ± 3.26 and 10.54 ± 6.25. ART MAX and D had an average of 446.57 ± 81.20 and 0.78 ± 0.65. Mean ± SD values for Sim K, Sim K astig and K max was 43.35 ± 1.31 D, 0.92 ± 0.66 D and 44.40 ± 1.45 D respectively. The indices in K max and Sim K astig were close to what was reported in other topographic systems in children (Reddy, J Pediatr Ophthalmol Strabismus. 2013;50(5):304-310).
Conclusions
This study provides Pentacam normative values for corneal topography, thickness and elevation in healthy Brazilian children. These results may provide helpful information for diagnosis of corneal diseases in children. Further studies are needed to evaluate the role of tomography in identifying early forms of ectasia in children.