Transplantation of newborn lacrimal gland cells in a rat model of reduced tear secretion

Background: Decreased lacrimal gland output may cause dry eye syndrome. Using a rat model, we examined the feasibility of transplanting lacrimal gland cells from newborns. Objectives: To restore lacrimal gland function in eyes with compromised tear production. Methods: A model of dry eye in adult rats was developed by unilateral surgical removal of the main lacrimal gland. Tear secretion in both eyes was then assessed by masked Schirmer's test. Lacrimal gland tissue from newborn rats was transplanted into the fibrous connective tissue in which the lacrimal gland had been embedded. Masked Schirmer's test was repeated 4, 8 and 12 weeks after transplantation. Results: Schirmer's test performed in 13 rats 10 days after unilateral lacrimal gland excision revealed significantly less wetting on the side with excised gland compared with the normal side (P< 0.003). The lack of secreting cells on the operated side was verified histologically. The reduction in tear secretion on the operated side remained significant for 8 weeks on average. In the six rats with transplanted lacrimal gland tissue however, there were no differences in tear reduction between the two eyes at 4, 8 or 12 weeks after the operation (P= 0.81, 0.56 and 0.8, respectively). Conclusions: Transplantation of lacrimal gland tissue from newborn rats effectively restored eye wetting in this new model. Further research is needed to evaluate this new approach for treating lacrimal gland dysfunction. Using this model might also facilitate evaluation of potential clinical treatments for dry eyes.