Treatment of canine nictitans plasmacytic conjunctivitis with 0.2 per cent cyclosporin ointment.

Nictitans plasmacytic conjunctivitis, commonly referred to as plasma cell infiltrate of the nictitans or plasmoma, was diagnosed in 12 dogs (23 eyes) on the basis of clinical signs and nictitans conjunctival biopsy specimens. These dogs underwent a clinical therapeutic trial with twice daily 0.2 per cent cyclosporin ophthalmic ointment. Response to therapy was monitored over a six-week period and repeat biopsy specimens were then taken. Significant (P < 0.05) reductions between pre- and post trial scores were recorded for: mucopurulent ocular discharge quantity; degree of bulbar conjunctival hyperaemia; areas of nictitans hyperaemia, thickening and depigmentation. Schirmer tear test values significantly increased between the start and end of treatment. Biopsy specimens were subjected to selective detection procedures for plasma cells (methyl green-pyronin staining) and T lymphocytes (CD3 antigen labelling). Mean cell counts showed a significant reduction in plasma cell numbers, but the trend towards reduced T lymphocyte numbers was not significant.