Animal model of human disease with optic neuritis: neuropapillitis in a rat model infected with Angiostrongylus cantonensis.

Human Angiostrongylus cantonensis (A. cantonensis) is a food-borne parasitic disease and can cause optic neuritis. Increasing clinical angiostrongyliasis cases with optic neuritis have been reported, but the pathogenesis has not been fully understood until now. Here, we applied rats with A. cantonensis infection as an animal model to study the pathogenesis of optic neuritis caused by the infection. We observed that the optic disk of experimental rats appeared hyperemic, the retina vein became thick, and the visual evoked potential (VEP) latency was prolonged. There were obvious inflammatory cell infiltration in the retina and optic nerve adventitia followed with obvious optic nerve fiber demyelination and retina ganglion swelling. We also evaluated the effect of dexamethasone combined with albendazole on optic neuritis of rats infected with A. cantonensis. The results showed it had no obvious effect to prevent progressive visual deterioration for optic neuritis caused by A. cantonensis. The studies provided evidence that the pathogenesis of optic neuritis in infected rats was correlated to optic nerve demyelination and ganglion cell damage caused by optic nerve inflammation, and the common therapy to this disease was not so effective. Based on the above results, it may be necessary to combine neuroprotective agents with common therapy to treat and protect optic nerve and ganglion cells from their secondary injury.