Spontaneous canine keratoconjunctivitis sicca. A useful model for human keratoconjunctivitis sicca: treatment with cyclosporine eye drops.

Thirty-six sequential cases of canine keratoconjunctivitis sicca (KCS) were treated with ophthalmic cyclosporine. The effects of topical cyclosporine were twofold: (1) cyclosporine increased tear production by 5 mm/min or greater in all cases of spontaneous KCS having an initial Schirmer's Tear Test value greater than 2 mm/min and in 59% of eyes with an initial Schirmer's Tear Test value of 0 to 2 mm/min, and (2) cyclosporine caused marked regression of chronic corneal neovascularization and granulation even in eyes in which lacrimation failed to improve. Additional benefits of topical cyclosporine were reduced mucopurulent conjunctivitis, rapid healing of nonhealing corneal ulcers, and reduced dependence on frequent topical treatments of KCS. Twelve normal beagles treated with topical cyclosporine also had a reversible increase in lacrimation compared with baseline or placebo control-treated dogs.