Chronic actinic keratopathy--a condition associated with conjunctival elastosis (pingueculae) and typified by characteristic extracellular concretions.

Morphologic observations on a peculiar type of corneal reaction with a predisposition for the superficial stroma of the interpalpebral portion of the cornea are reviewed. Histochemical evidence is provided which indicates that the corneal concretions, though not homogenous, are proteinaceous in nature and contain amino acids not normally detectable in the cornea. The corneal concretions were associated with conjunctival elastosis (pingueculae) in all 22 instances in which the eyes were sectioned in the horizontal plane. Identical concretions were identified within these associated pingueculae, as well as in a large percentage of other pingueculae and cutaneous lesions with actinic elastosis. The findings suggest that the abnormal material arises in the pericorneal conjunctival connective tissue from whence it diffuses into, and deposits in, the superficial corneal stroma. The data also raise the possibility that the concretions may be derived, at least in part, from altered elastic tissue. Morphologic and epidemiologic observations on the condition taken together strongly suggest that this unique reaction is a sequel to the cumulative effect of chronic actinic irradiation. Further observations on this keratopathy are needed to establish whether this unique response can be provoked by other noxious stimuli.