Tear protein profiles vs. clinical characteristics of untreated and cyclosporine-treated canine KCS.

BACKGROUND
Topically administered cyclosporine A (CsA) decreases ocular surface inflammation in canine keratoconjunctivitis sicca (KCS) and exerts lacrimomimetic effects. This study was performed to find correlations between clinical signs and tear protein levels in untreated and CsA-treated canine KCS.


METHODS
Clinical profiles were scored in 16 KCS-affected dogs before and 6 weeks after commencing treatment with 0.2% topical CsA emulsion. Tear samples were also collected using polished micropipettes for specific protein assay by high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA).


RESULTS
Tear levels of serum proteins correlated with conjunctival clinical signs. Levels of lacrimal gland proteins in tears correlated most often with corneal clinical signs.


CONCLUSIONS
The inflammatory features of KCS appear to link conjunctival signs to serum proteins in tears, while corneal signs are linked to lacrimal gland proteins.