CLINICAL AND HISTOPATHOLOGICAL FEATURES OF SCOPOLAMINE HYDROBROMIDE INDUCED DRY EYE SYNDROME IN SPRAGUE-DAWLEY RATS

Abstract

Dry eye syndrome (DES), is one of the most common and irritating ocular diseases in humans and animals due to deficits in quantities or/and quality of tear film. In this study, a rat model of experimental DES has been developed using the cholinergic inhibitor, scopolamine hydrobromide (SCOP), at the dose of 25[Formula: see text]mg/rat/day via subcutaneous injection, for a consecutive 21 days without low humidity environment. Clinical ophthalmic evaluations were performed by tear volume assessment using endodontic paper point, slit-lamp biomicroscope, and fluorescein staining at day 0, 7, 14, and 21 post-inductions. The results of ophthalmic examination showed that rats with SCOP treatment reduced about 40% of tear secretion. Half of the SCOP-treated rats exhibited diffuse corneal fluorescein staining involving 80% of the corneal surface, minimal keratoconjunctivitis, roughened corneal surface and thin corneal epithelium under histopathological examination. About 30% of the rats showed variable infiltration of lymphocytes in between the tubular acinar glands. This animal model with significant reduction of tear production and diffuse corneal fluorescein staining in rats could be used for the preclinical assessment of therapeutic interventions.