ALLERGIC CONJUNCTIVITIS AND UVEITIS MODELS - REAPPRAISAL WITH SOME MARKETED DRUGS

The purpose of this study was to assess the activity of some marketed products in ocular nonimmune and immune type I hypersensitivity reacti ons, and during intra-ocular type III hypersensitivity. In order to co mpare these activities, we improved and validated three different mode ls of ocular allergic reaction already known for their ability to repr oduce allergic conjunctivitis or uveitis. Allergic conjunctivitis was induced by ocular immediate hypersensitivity after instillation of com pound 48/80 in the rat, or an active anaphylaxis reaction with ovalbum in immunisation and challenge in the guinea pig. Uveitis was induced b y a reverse passive anaphylaxis reaction using intra-vitreal rabbit an ti-bovine IgG antiserum sensitisation and intravenous bovine gammaglob ulin challenge in the rabbit. Clinical scores and blood-tissue permeab ility indices were studied. Using the same schedule of ocular instilla tion, the effects of Livostin(R) (levocabastine 0.05%), Almide(R) (lod oxamide 0.1%), Opticrom(R) (sodium cromoglycate 2%), Ocufen(R) (flurbi profen 0.03%), Acular(R) (ketorolac 0.5%) and 0.3% chlorpheniramine ma leate were compared to positive and negative controls. We demonstrated the potent activity of chlorpheniramine maleate 0.3% and Livostin(R) in both allergic conjunctivitis models. Significant activity was also evidenced with Almide(R), which was only active in the non-immune alle rgy model, while Opticrom(R) was definitely not active in these models . In the uveitis model, Acular(R) and Ocufen(R) are active and potent drugs, while Livostin(R) and Almide(R) were not active. These results are discussed with respect to the models used and the mediators involv ed.