Keratoconus Screening Among Myopic Children

To assess the topographic corneal changes and the incidence of keratoconus among children with high myopia.

It is a prospective study, in which 174 eyes of children with high myopia were studied in the period between August 2015 and June 2018.

All patients were examined to assess the refractive error and corneal examination using Scheimpflug camera to evaluate different corneal parameters.

Studied children aged between 6 and 14 years (11.05±1.98). Males represented 54% of the cases (n=94). The mean spherical error was -7.75±2.97 ranging from -6 to -13.50D. The mean cylindrical error was -4.12±1.78D (-1 to -8). Regarding corneal examination, data recorded were those about maximum K reading (k_max), thinnest location, highest anterior and posterior elevation in 4mm zone, and higher-order corneal aberrations. Analysis of the obtained data revealed 16 eyes (9.2%) with keratoconus. These eyes were considered as a separate group and compared with the remaining eyes. There was significant difference in k_max (p= 0.03), anterior elevation, and posterior elevation (p=0.01 for both). Regarding myopia or astigmatism, there were no significant differences when compared with normal eyes. But high myopia with low astigmatism were found in five eyes of them (31.2%). The main statistically different aberrations were vertical coma (-2.04±0.99) (p=0.01) and spherical aberrations (-0.9±0.78) (p=0.02). Regarding gender, there were 11 eyes in boys (68.7%), and this was statistically significant (p=0.01). Vernal keratoconjunctivitis with frequent eye rubbing was found in 6 eyes (37.5%).

Children with high myopia irrespective of the degree of astigmatism may have corneal abnormalities which are more pronounced in cases with vernal keratoconjunctivitis. Corneal examination should be performed for highly myopic children to detect any corneal abnormality and to treat it as early as possible.