Cornea plana congenita (CNA2) is a recessively inherited eye disease affecting development of the cornea, and leading to moderate impairment of visual capacity. The corneal changes are caused by structural abnormalities in keratocan, a leucine-rich protein component of a small proteoglycan, which together with other keratan sulfate proteoglycans is important for the transparency of the cornea. The cornea is thin and unusually flat, corneal limbus is hazy, opacities are frequent in the parenchyma, and arcus senilis developes at an early age. Hyperopia, up to +10 D, is the consequence of corneal changes.
Websites explaining the causes, diagnosis and treatment of the eye condition, keratoconus, a disorder that causes progressive thinning and distortion of the cornea.