Oxytalan fibre formation in the cornea: a light and electron microscopical study.

Oxytalan is a fibrillar protein possessing some of the staining and ultrastructural properties of developing elastic tissue. In a study of human corneae we failed to find fibres of this type in five normal specimens but found them in each of 16 examples of keratoconus and 13 cases of post-traumatic or post-inflammatory scarring. In two cases the microfibrillar nature of the deposits was confirmed by electron microscopy, individual microfibrils measuring 10-12 nm in diameter and having profiles suggestive of a tubular structure. Oxytalan formation was intimately associated with the basal lamina of the covering epithelium with, in areas showing disruption of Bowman's layer and scarring, some extension into the superficial collagenous stroma.