The paper discusses retrobulbar optic neuritis secondary to multiple sclerosis, Leber’s hereditary optic neuropathy, and Leber’s hereditary optic neuropathy with multiple sclerosis-like disease – Harding’s syndrome. Retrobulbar optic neuritis secondary to multiple sclerosis is the most common disease (neuropathy) of the optic nerve in young adults and often the first clinical manifestation of multiple sclerosis. Despite a characteristic triad of symptoms and evident focal demyelination in brain magnetic resonance, misdiagnoses still occur. Leber’s hereditary optic neuropathy (atrophy) is a genetic mitochondrial disease, which manifests as a subacute painless loss of vision, and thus can be mistaken for retrobulbar optic neuritis. The coexistence of hereditary optic neuropathy and Harding’s syndrome is another diagnostic difficulty. All these three conditions, the peak of incidence of which occurs in the second to third decade of life, initially manifest only with visual symptoms due to uni- or bilateral optic neuropathy. Magnetic resonance imaging of the brain may show demyelination, while optical coherence tomography of the fundus may detect thinning of the retinal nerve fibre layers in all these neuropathies. We present clinical differences, as well as variances in retinal optical coherence tomography and magnetic resonance imaging between retrobulbar optic neuritis secondary to multiple sclerosis, Leber’s hereditary optic neuropathy, and Leber’s hereditary optic neuropathy with multiple sclerosis-like disease.

retrobulbar optic neuritis, Leber’s hereditary optic neuropathy, Leber’s hereditary optic neuropathy with multiple sclerosis-like disease