THE STRUCTURE OF THE ANTERIOR CORNEA EPITHELIUM OF THE SUS SCROFA DOMESTICUS AT THE CRYOPHIXATION

Abstract

The classic histological picture of the anterior corneal epithelium, known from the results of standard histological techniques and light microscopy of preparations of chemically fixed material, describes the presence of three cell layers: basal - germinative, middle and superficial. On preparations of cryofixed material, another homogeneous layer is identified above the cells of the third layer, which is usually identified as the precorneal tear film, that is, a layer of liquid. Analysis and comparison of known data allows us to identify a scientific problem, which is as follows. The structure of the homogeneous layer has not been previously studied, its structure is unknown, therefore, the identification of the homogeneous layer with the precorneal tear film is not justified. We assume that the histological picture of the anterior epithelium on preparations of chemically fixed material is incomplete, and the homogeneous layer is a structural component of the anterior epithelium. Purpose of the study: the structure of the anterior epithelium and homogeneous layer on preparations of cryofixed material. The material for the study was preparations of the eyes of the domestic pig Sus scrofa domesticus, the research method was light microscopy. As a result of the study, it was established for the first time that the homogeneous layer is a structural component of the anterior corneal epithelium. Between the homogeneous layer and the layer of flat cells of the anterior epithelium, another layer is determined in the form of a microscopically detectable thin strip. Taking into account the established fact, it should be concluded that the anterior epithelium of the cornea consists of five layers. The cells in the layers are in a compacted state, the degree of which increases from the basement membrane to the frontal surface of the epithelium, reaching a maximum at the level of the homogeneous layer. The cells of the surface layer are anucleate, filled with an oxyphilic mass, presumably keratin, which indicates the process of keratinization of epithelial cells. The results of the study confirmed the assumption that the histological picture on preparations of chemically fixed material is incomplete. The identification of a homogeneous layer with the precorneal tear film is unfounded.