Tear production and ocular surface changes in experimental dry eye after elimination of desiccating stress

To investigate the severity and duration of desiccating stress-induced dry eye disease between mice with and without a genetic predisposition to spontaneous autoimmunity.

Experimental dry eye was induced in 12- to 16-week-old wild-type C57BL/6 and autoimmune NOD.B10.H2(b) mice by subcutaneous injection of scopolamine with exposure to an air draft for 10 days. Tear volume and corneal smoothness were measured at baseline, 5 and 10 days after desiccating stress, and 3, 7, 14, and 28 days after the removal of desiccating stress. Periodic acid-Schiff staining and immunohistochemistry were performed to evaluate the densities of conjunctival goblet cells and CD4(+) T cells in each group. Interleukin (IL)-1β and IL-6 concentrations in conjunctival tissues were measured by multiplex immunobead assay.

Signs of experimental dry eye were noted at 5 and 10 days after desiccating stress in both strains. After the removal of desiccating stress, in C57BL/6 mice, tear production and corneal smoothness improved at 3 and 7 days, respectively, and conjunctival goblet cells and CD4(+) T-cell densities and cytokine levels returned to baseline levels at 14 days. In contrast, in NOD.B10.H2(b) mice, none of the parameters recovered to baseline levels during a period of 28 days after the removal of desiccating stress.

After the removal of desiccating stress in experimental dry eye, tear volume and ocular surface parameters recovered within 2 weeks in C57BL/6 mice, whereas they remained unchanged in NOD mice. In contrast to autoimmune mice, experimental dry eye can be reversed after the elimination of desiccating stress in nonsusceptible mice.