Correlation between Tear Secretion and Lacrimal Epithelial Cell Damage in a Rat Model of Dry Eye Disease

Objective: To observe the correlation between tear secretion and lacrimal epithelial cell damage in a rat model of dry eye disease. Methods: In this study, 20 SD rats were selected as experimental samples, and the DED model was prepared by exposure and subcutaneous injection of scopolamine, and were randomly divided into 5 groups according to the proposed observation time, with 4 rats in each group, and the tear secretion on the 0th, 7th, 14th, 21st and 28th days after modeling was measured by phenol red line, respectively. The tear gland epithelial cells of five groups of rats were collected at the same time as the tear secretion detection, and the apoptotic cells in the lacrimal gland epithelial cells were observed by TUNEL method,and the expression of positive cells of Fas, Fas L, bcl 2 and Bax-related gene proteins was detected by immunohistochemistry, and the correlation analysis was carried out.Results: The amount of tear secretion in the left eyes of rats was significantly decreased on the 14th day((3.3±1.0) mm) compared with that of the 0-day group, and it further decreased with the extension of time. With the prolongation of the modeling time, the correlations between the numbers of Fas, bcl-2, and Bax gene protein positive cells and the amount of tear secretion in the left eyes gradually strengthened, especially in the 21-day and 28-day groups. The number of apoptotic cells in the lacrimal gland tissue of the left eyes gradually increased over time, and the number of positive cells for Fas, Fas L, bcl-2, and Bax also increased in a time-dependent manner(r<0, P<0.01). Conclusion: In the rat model of dry eye disease, the damage of lacrimal gland epithelial cells was aggravated with the prolongation of lacrimal gland resection time, and the decrease of tear secretion was closely related to the expression of Fas, bcl-2 and Bax-related genes secreted by lacrimal gland epithelial cells.