The study of corneal topography in myopic and hyperopic children.

Objective: To compare the differences of corneal topographies in myopic and hyperopic children and study the effect of Atropin on their changes.

Methods: The refractive components of 136 eyes with different refractive conditions were measured with A-Scan and their corneal topographies with and without cycloplegia were obtained respectively.

Results: The mean corneal power of zones 3mm (MD3, P=0.031) and minor keratometer K2 (P=0.003) of myopia are greater than those of hyperopia without cycloplegia. MD3 (P=0.009) and Keratometer K1 (P = 0.025) increased in hyperopic eyes, while MD3 (P=0.033), K1 (P = 0.035) and K2 (P = 0.002) decreased in myopic eyes significantly after cycloplegia. Similarly, the mean corneal power of zones 5mm (MD5) and 7mm (MD7) in myopic eyes decreased dramatically (P < or = 0.001).

Conclusions: The corneal power was found to be greater in myopia than that in hyperopia. The effect of Atropin on corneal shape of myopia and hyperopia was in the opposite direction.