Effects of Topical Human Amniotic Fluid and Human Serum in a Mouse Model of Keratoconjunctivitis Sicca

Abstract

Purpose: : To compare the effects of topical human amniotic fluid (HAF), topical human serum (HS), and topical artificial tears for the treatment of ocular surface disease in a dry eye model.

Methods: : Thirty C57BL/6 mice were divided into 3 treatment groups: HAF, HS or preservative-free artificial tears. Under direct visualization with an operating microscope, mice received a transconjunctival injection of 0.05mL of botulinum toxin B (BTX-B) solution into the left lacrimal gland. Tear production and ocular surface fluorescein staining were evaluated in each mouse in 6 time points during a 4-week experiment period. Goblet cell density was assessed in stained histological sections. Apoptotic keratocytes were evaluated by TUNNEL-test assay.

Results: : No differences among groups were found at baseline. Significant decrease in tear production was observed 3 days after BTX-B injection in all groups. At week 1, HAF and HS groups were able to improve tear production compared to control group (P <0.001 and P=0.003, respectively). The control group never reached its tear production baseline values in 4 weeks of therapy. The fluorescein staining started appearing noticeably at day 3. At week 2, HAF improved significantly the staining score compared to HS (P=0.043) and control (P=0.007) groups. HS group demonstrated statistically significant difference when compared to control group only at week 4 (P=0.047). Goblet cell density was significantly decreased in the control group compared to HAF and HS groups (P<0.001), but no statistical difference was obtained between the latter groups. We did not observe any difference in the amount of TUNEL positive keratocytes among the different groups.

Conclusions: : HAF was superior to HS and artificial tears to improve corneal staining within 2 weeks of therapy in this induced mouse model of KCS. Further studies need to be performed to validate the efficacy of these promising medications and to ascertain whether the findings of this study can translate into a clinical benefit to patients with ocular surface epithelial disorders associated with dry eye.

Keywords: cornea: tears/tear film/dry eye • cornea: clinical science • apoptosis/cell death