Comparison of 1% cyclosporine eye drops in olive oil and in linseed oil to treat experimentally-induced keratoconjunctivitis sicca in rabbits.

PURPOSE: To evaluate the effectiveness of topical 1% cyclosporine eye drops diluted in either of the two vehicles-olive and linseed oil-and that of the oils themselves in treating experimentally-induced keratoconjunctivitis sicca (KCS) in rabbits. METHODS: KCS was induced in 25 New Zealand rabbits using 1% atropine sulfate eye drops for 7 days before treatment and throughout the treatment period (12 weeks). The rabbits were divided into five groups: one control (C) group without KCS induction and four treatment groups in which KCS was induced and treated topically with olive oil (O), linseed oil (L), cyclosporine in olive oil (CO), and cyclosporine in linseed oil (CL). The animals were evaluated using Schirmer tear test 1 (STT), the fluorescein test (FT), tear-film break-up time (TBUT), the rose bengal test (RBT), and histopathological analysis. RESULTS: Values of STT and TBUT significantly decreased 1 week post-induction (p<0.05) and were similar to initial values after the 4th week of treatment, in all groups. After KCS induction, there was significantly less corneal damage in group L than in group CL, as assessed FT and RBT. Histopathology demonstrated that Groups L and CL presented less edema and corneal congestion. There was no significant difference in the goblet cell density (cells/mm2) between the groups (p=0.147). CONCLUSION: Cyclosporine diluted in olive oil or linseed oil was effective in the treatment of KCS, although it had better efficacy when diluted in linseed oil. Linseed oil presented better effectiveness, whether associated or not, than olive oil. These results may contribute to the creation of novel topical ophthalmic formulations for KCS treatment in future.

Comparison of 1% cyclosporine eye drops in olive oil and in linseed oil to treat experimentally-induced keratoconjunctivitis sicca in rabbits / Comparação da ciclosporina 1% em óleo de oliva e óleo de linhaça no tratamento da ceratoconjuntivite seca experimentalmente induzida em coelhos

ABSTRACTPurpose:To evaluate the effectiveness of topical 1% cyclosporine eye drops diluted in either of the two vehicles-olive and linseed oil-and that of the oils themselves in treating experimentally-induced keratoconjunctivitis sicca (KCS) in rabbits.Methods:KCS was induced in 25 New Zealand rabbits using 1% atropine sulfate eye drops for 7 days before treatment and throughout the treatment period (12 weeks). The rabbits were divided into five groups: one control (C) group without KCS induction and four treatment groups in which KCS was induced and treated topically with olive oil (O), linseed oil (L), cyclosporine in olive oil (CO), and cyclosporine in linseed oil (CL). The animals were evaluated using Schirmer tear test 1 (STT), the fluorescein test (FT), tear-film break-up time (TBUT), the rose bengal test (RBT), and histopathological analysis.Results:Values of STT and TBUT significantly decreased 1 week post-induction (p<0.05) and were similar to initial values after the 4th week of treatment, in all groups. After KCS induction, there was significantly less corneal damage in group L than in group CL, as assessed FT and RBT. Histopathology demonstrated that Groups L and CL presented less edema and corneal congestion. There was no significant difference in the goblet cell density (cells/mm2) between the groups (p=0.147).Conclusion:Cyclosporine diluted in olive oil or linseed oil was effective in the treatment of KCS, although it had better efficacy when diluted in linseed oil. Linseed oil presented better effectiveness, whether associated or not, than olive oil. These results may contribute to the creation of novel topical ophthalmic formulations for KCS treatment in future.

RESUMOObjetivo:Avaliar a eficácia do uso tópico do colírio de ciclosporina 1% em dois veículos, óleo de oliva e linhaça, e dos óleos separados, no tratamento da ceratoconjuntivite seca experimentalmente induzida (KCS) em coelhos.Método:Vinte e cinco coelhos Nova Zelândia foram induzidos para KCS com colírio de sulfato de atropina a 1% por sete dias antes e durante o período de tratamento (12 semanas) e foram divididos em 5 grupos, um grupo controle (C), sem indução de KCS e quatro grupos de tratamento tópico com ciclosporina em óleo de oliva (CO), ciclosporina em óleo de linhaça (CL), óleo de oliva (O) e óleo de linhaça (L). Os animais foram avaliados utilizando o teste lacrimal de Schirmer I (STT), teste de fluoresceína (FT), teste de ruptura do filme lacrimal (TBUT), teste de rosa bengala (RBT) e análise histopatológica.Resultados:Os valores de TBUT e STT diminuíram significativamente uma semana pós-indução da KCS (p<0,05) e foram semelhantes aos valores iniciais após a quarta semana de tratamento, em todos os grupos. Após a indução de KCS, houve menor dano na córnea no grupo L em relação ao grupo CL, quando avaliados FT e RBT. A histopatologia demonstrou que os grupos L e CL apresentaram menos edema e congestão da córnea. Não houve diferença significativa na densidade das células caliciformes (células/mm2) entre os grupos (p=0,147).Conclusão:Ciclosporina diluída em óleo de oliva ou linhaça foi eficiente no tratamento da CCS, porém teve uma melhor eficácia quando diluída no óleo de linhaça. O óleo de linhaça, isoladamente ou associado, apresentou melhor eficácia quando comparado ao óleo de oliva. Estes resultados podem contribuir no futuro com novas formulações oftálmicas tópicas no tratamento da CCS.