Comparison of topical dry eye medications for the treatment of keratoconjunctivitis sicca in a botulinum toxin B-induced mouse model.

PURPOSE: To compare the effects of topical dry eye medications including anti-inflammatory agents and lubricant eyedrops for the treatment of keratoconjunctivitis sicca (KCS) in a botulinum toxin B (BTX-B)-induced mouse model.

METHODS

CBA mice were randomized into 10 groups. The first 5 groups received a transconjunctival injection of saline into the lacrimal gland, and the remaining groups were injected with 0.05 mL of 20 mU BTX-B. Each group received treatment with 0.1% fluorometholone (FML), 0.05% cyclosporine A (CsA), a 50:50 combination of FML and CsA, artificial tears, or saline 3 days after injections. Tear production, corneal staining, and blink rate were compared in each of the 10 groups.

RESULTS

Tear production in BTX-B-injected CsA-treated, FML-treated, and combined-treated groups started to return to baseline level within 2 weeks of treatment, whereas those treated with saline or artificial tears still exhibited reduction of lacrimation up to 4 weeks after injection. Topical FML significantly reversed the staining score within 1 week of treatment. The improvement of corneal staining in BTX-B-challenged combined-treated and CsA-treated groups occurred later within 2 weeks after treatment. No significant improvement in corneal staining was observed for the BTX-B-injected mice treated with artificial tears or saline. No significant changes were noted in blink frequency between the control and study groups undergoing the various dry eye therapies.

CONCLUSION

The therapeutic effects of dry eye medications in a BTX-B-induced mouse model of KCS are similar to the human response.