Objective  To investigate and analyze the morphological characteristics of corneal topography in pediatric and adult patients with myopia.

  Methods  Topographic measurement and refractive examination were performed respectively on 200 eyes of 100 pediatric and adult patients with myopia admitted to Peking Union Medical College Hospital from August 2008 to August 2010.

  Results  The values of flat keratometric power (K₂, ) surface regularity index (SRI), and surface asymmetry index (SAI) in myopic adults were significantly higher than those in myopic children (P < 0.05). However, the values of steep keratometric power (K₁) and minimum keratometric power (minK) showed no such difference between these two groups (P > 0.05). Furthermore, comparison of these parameters between males and females in both two groups showed the values of K₁, K2 and minK in females were significantly higher than in males (P < 0.05). The SRI and SAI in adult group were significantly correlated with age (SRI:r=0.20, P < 0.05; SAI:r=0.19, P < 0.05), no such correlation was found in children group (P > 0.05). There were no correlation between SRI or SAI and refraction in both two groups (P > 0.05). The central cornea showed bow-type graphics mostly in two groups. Most of the astigmatism was with the rule.

  Conclusion  With the increase of age, the refraction, corneal surface irregularities, and asymmetry index shows certain changes, whereas the axis of astigmatism tends to be vertical.