Local cyclosporine therapy for experimental autoimmune uveitis in rats
R. B. Nussenblatt, W. J. Dinning, L. S. Fujikawa, C. C. Chan and A. G. Palestine
The use of locally applied cyclosporine was investigated in the retinal
S-antigen-induced experimental autoimmune uveitis (EAU) model in Lewis
rats. A 2% cyclosporine solution applied topically four times a day for 14
days effectively prevented the expression of EAU. This treatment, however,
produced circulating cyclosporine levels in the therapeutic range. Lower
concentrations of cyclosporine applied topically did not produce
therapeutic levels and were not capable of reliably preventing disease.
Intraocular levels of cyclosporine, measured by radioimmunoassay, were
extremely low and outside the accepted therapeutic range. Intravitreal
cyclosporine therapy appeared to protect eyes from EAU, without producing
significant circulating cyclosporine levels. These findings show that, in
its present form, cyclosporine in oil is not an efficacious topical
therapy. Therefore, a local cyclosporine preparation with enhanced
penetration into the globe may be a practical approach to therapy in the
future.
