Effects of 5% sodium chloride ophthalmic ointment on thickness and morphology of the normal canine cornea

OBJECTIVE: To determine the effect of 5% sodium chloride ophthalmic ointment (5% NaCl) on thickness and morphology of the normal canine cornea using ultrasonic pachymetry (USP), in vivo confocal microscopy (IVCM), and Fourier‐domain optical coherence tomography (FD‐OCT). METHODS: Five healthy laboratory Beagles received ophthalmic examinations including USP, IVCM, and FD‐OCT prior to and at fixed intervals following treatment. The right and left eyes were treated with 5% NaCl and artificial tears ophthalmic ointment (AT), respectively, every 2 hours for 4 treatments/d (days 2‐9), and then hourly for 7 treatments/d (day 10). Treatment groups were statistically compared using mixed‐effects linear regression. RESULTS: Treatment with 5% NaCl resulted in a 12 μm decrease in corneal thickness from baseline (P   .05). CONCLUSIONS: Short‐term topical treatment with 5% NaCl decreased corneal thickness in normal dogs with no observable changes in corneal morphology or signs of ocular toxicity.