Effects of androgen on ultrastructure of corneal epithelium and function of the tear film in BALB/c mice.

Abstract

The aim of this study was to investigate the effects of androgen on the ultrastructure of corneal epithelium and function of the tear film in a mouse model. Healthy adult male BALB/c mice were randomly apportioned to normal control, sham-operated, or orchiectomy groups. In the orchiectomy group, 4 subgroups with treatment [blank group, dihydrotestosterone (DHT) eye drop group, DHT injection group, and dimethyl sulfoxide (DMSO) eye drop group] were further established at 3 weeks after orchiectomy. Tear production, tear break-up time, and corneal fluorescein staining were evaluated in all groups at multiple time points. Serum androgen concentrations were measured by competitive radioimmunoassay, and ultrastructure of corneal epithelial cells was examined by transmission electron microscopy. Before orchiectomy, the mean serum concentration of androgen was 43.4 ng/μL, which decreased to approximately 0 ng/μL at 1 week after orchiectomy. Significantly less tear production, shorter tear break-up time, higher corneal fluorescein staining score, shorter and flattened corneal epithelial microvilli, and looser intercellular desmosomes were observed in mice after orchiectomy. DHT supplements increased serum androgen levels, and some of the tear film functions and morphological features of microvilli and desmosomes were gradually close to those at baseline in the DHT injection group. Persistent corneal staining, decreased tear production, short break-up time, and unhealthy corneal ultrastructure were observed in mice that received orchiectomy for at least 8 weeks. A mouse that received orchiectomy could be used as a dry eye model. Exogenous DHT supplement improved corneal epithelial ultrastructure and tear film function in this model.