Morphological changes in the human conjunctival epithelium. II. In keratoconjunctivitis sicca.

A clinicopathological correlation was performed on 24 patients suffering from keratoconjunctivitis sicca (KCS). Examination of conjunctival biopsies by light and transmission electron microscopy revealed stratification of the conjunctival epithelium with separation of the superficial cell layers, and this was directly proportional to the clinical severity of the disease. Counts of goblet cells were found to be inversely proportional to the degree of stratification. The goblet cells were morphologically identical to, but significantly fewer in number than, those found in normal conjunctival tissue. A reduction in epithelial cell stratification and separation and an increase in goblet cell density were closely related to nasolacrimal duct occlusion--an operation performed only in the severe examples of KCS in this series. The possible causes of 'mucous' plaques and 'filaments' are discussed in relation to these phenomena. Moreover, there is a dramatic reduction and deformation in the microplicae on the surface of the conjunctival epithelium. The significance of this was considered in relation to tear film stability.