Elastic and related fibres in the normal cornea and limbus of the domestic cat.

The presence of elastic and related fibres in the corneal and limbal tissue of the domestic cat is described. Various ages of animal from birth to maturity were studied by light and electron microscopy. Oxytalan fibres were present throughout the new-born kitten cornea. They were seen in greatest concentration both at the junction of the posterior limiting lamina with the inner substantia propria and beneath the peripheral anterior epithelium. With increasing maturity, oxytalan fibres disappeared from all but the most peripheral parts of the cornea where some of the, by now, thicker oxytalan fibres had matured into elaunin. All ages of animals studied showed an abrupt increase in fibre thickness and numbers at the corneal limbus. Oxytalan fibres predominated in the newborn kitten limbus but material from adult animals showed an increased proportion of elaunin fibres. Occasional elastic fibres were also seen in the more superficial region of the adult limbus. An overall decrease in elastic fibre types with increasing maturity was most obvious in the middle limbal layers.