Effect of Topical Olopatadine And Epinastine in The Botulinum Toxin B—Induced Mouse Model of Dry Eye

Abstract

The aim of this study was to compare the effect of topical olopatadine, epinastine, and lubricant eye drops on dry eye ocular surface disease in the botulinum toxin B (BTX-B)-induced mouse model of keratoconjunctivitis sicca. CBA/J mice were randomized into 3 experimental groups of 10 animals each. All mice received a transconjunctival injection of 0.05 mL of 20-mU BTX-B solutions into the left lacrimal gland. Three (3) days after intralacrimal gland injections, each group received treatment with twice-daily topical lubricant as a control, 0.1% olopatadine, or 0.05% epinastine eye drops. To monitor the progression of dry eye tear production, an ocular surface fluorescein staining score was evaluated in each of the 3 experimental groups. Three (3) days after the intralacrimal gland injection of BTX-B, aqueous tear production was significantly decreased (1.95+/-0.64 mm), compared to baseline level (2.69+/-0.66 mm; P<0.001). Similarly, there was a statistically significant increase in the proportion of mice with a corneal staining score of 2 or greater at 3 days postinjection, compared to the preinjection value (P<0.001). There were no statistically significant differences in aqueous tear production between the 3 different medication groups at all time points. Aqueous tear production in neither the olopatadine nor the epinastine-challenged groups was further decreased compared to the lubricant-treated group. Difference in the proportion of mice with a low- and high corneal staining score between the control and study groups did not reach statistical significance throughout the 4-week experimental period. In addition, changes in corneal fluorescein staining of the olopatadine group versus the epinastine group did not show a statistically significant difference. Topical olopatadine and epinastine do not cause significantly additional damage to the compromised ocular surface secondary to dry eye after continuous 4-week, twice-daily application. Topical olopatadine and epinastine appear to have comparable effects on aqueous tear-production and corneal-surface changes in this mouse model.