Corneal Evaluation in Healthy Brazilian Children Using a Scheimpflug Topography System

Abstract

Purpose: To identify the distribution and variation in corneal topography, thickness, and elevation in healthy Brazilian children as measured by the Pentacam Scheimpflug system (Oculus Optikgerate GmbH, Wetzlar, Germany).Methods: Healthy children between 7 and 11 years of age were scanned using the Pentacam Scheimpflug corneal topography system (Oculus Optikgerate GmbH, Wetzlar, Germany). The exclusion criteria were inability to undergo the ocular exam, history of any ocular diseases (including strabismus, amblyopia, cataracts, retinal disorders, and allergic conjunctivitis), and topographic diagnosis of corneal ectasia based on the modified Rabinowitz/McDonnell criteria for keratoconus. The right eye of each subject was selected for analysis. The parameters evaluated were central corneal thickness (CCT), thinnest pachymetry (TP), average pachymetric progression index (PPIave), anterior and posterior elevation (AE and PE), anterior and posterior best fit sphere (ABFS and PBFS), pachymetric difference between the apex and the thinnest point (PDAT), Ambrosio's relational thickness (ARTMax), overall Belin/Ambrosio Enhanced Ectasia display score (BAD-D), simulated keratometry (SimK), astigmatism in SimK (SimK astig), maximum keratometry (K max), asphericity (Q value), and anterior chamber depth (ACD).Results: A total of 160 children (69 male, 91 female) were included in this study. The mean age of the children was 8.82 ± 1.23 years (ranging from 7 to 11 years). 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 in 93.125% (149) eyes. The mean PPIave was 1.00 ± 0.14, similar to that of normal adults. The mean ABFS and PBFS values were 7.49 ± 3.26 and 10.54 ± 6.25, respectively. ART Max and D averaged 446.57 ± 81.20 and 0.78 ± 0.65, respectively. Mean ± SD values for SimK, SimK astig, and K max were 43.35 ± 1.31 D, 0.92 ± 0.66 D, and 44.40 ± 1.45 D respectively. The K max and SimK astig values were close to those reported by other topographic systems for children. Q value and ACD averaged -0.39 ± 0.12 and 3.065 ± 0.2745 mm.Conclusion: This study provides 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 this age group.