The change in ocular refractive components after cycloplegia in children.

PURPOSE To study the change in ocular refractive components after cycloplegia in children. METHODS Anterior chamber depth, lens thickness, vitreous chamber length, and ocular axial length were measured in 135 Chinese children (270 eyes) before and after cycloplegia. The corneal curvatures of 136 selected eyes were studied before and after cycloplegia with a computerized video keratoscope. RESULTS Anterior chamber depth increased (P <.001) while both lens thickness and vitreous chamber length decreased (P <.001) significantly after cycloplegia regardless of the refractive state. However, axial length increased in hyperopic eyes (P =.027) but decreased in myopic eyes (P =.008) after cycloplegia. Mean corneal power of zones 3 mm (MD3, P =.009) and keratometer K1 readings increased (P =.025) in hyperopic eyes, while MD3 (P =.033), K1 (P =.039) and K2 (P =.003) readings decreased in myopic eyes significantly after cycloplegia. Similarly, mean corneal power of zones 5 mm and 7 mm in myopic eyes decreased dramatically (P <or=.001). In both hyperopic and myopic eyes, there was significant difference (P <.001) in the mean value of the upper and lower half of the vertical meridian, as well as the medial and lateral half of the horizontal meridian, respectively. CONCLUSIONS Cycloplegia has a great influence on various refractive components in children. There is asymmetry of the corneal surface within the same horizontal or vertical meridian.