Optics of the Corneal Epithelium

Abstract

The corneal epithelium plays an active role in determining the final surface power of the cornea. It accounts for an average of 1.03 D of the power of the eye at the central 2-millimeter diameter zone. The difference in astigmatism suggests that the epithelium does not form a layer of uniform thickness over Bowman's layer. It appears that the epithelium attempts to minimize abrupt changes in surface contour. These findings suggest that in refractive procedures such as photorefractive keratectomy the refractive contribution of the epithelium must be taken into account to improve predictability.