Agenesis of Bowman's layer. A histopathological study of four cases.

Congenital absence of Bowman's layer has been described in Peters' anomaly, sclerocornea, and osteogenesis imperfecta type II. More commonly, Bowman's layer is absent secondary to inflammatory or degenerative processes of the cornea. We present three cases of bilateral absence of Bowman's layer in otherwise unremarkable corneas that were unassociated with other ocular or systemic abnormalities. In a fourth case, similar absence of Bowman's layer was present in a patient with osteogenesis imperfecta type III. In all four cases, the absence of Bowman's layer was unassociated with any evidence of scarring or inflammation. By electron microscopy, the stroma was composed of regularly arranged collagen fibers with a uniform fiber diameter throughout. In the case of osteogenesis imperfecta type III, there was mild irregularity of the anteriormost stroma. The lack of inflammation or scarring in these four cases lead us to conclude that they represent a true congenital absence, or agenesis, of Bowman's layer.