Cornea plana congenita is a rare hereditary anomaly in which the normal protrusion of the cornea from the sclera is missing. Clinical features include hyperopia, slight microcornea, an extended limbus zone, and arcus lipoides seen even before the age of 20. Cornea plana congenita occurs in a mild autosomal dominant (CNA1) and a more severe autosomal recessive (CNA2) form. CNA2 has a high prevalence in the Finnish population due to strong founder effect.
