[Recurrent visual loss in Leber hereditary optic neuropathy: a case report]

We report an unusual case of Leber's hereditary optic neuropathy (LHON) in a 7-year-old boy with recurrent episodes of visual loss.

A 7-year-old-boy developed acute severe bilateral optic neuropathy associated with mild optic disc edema. The patient was treated with high doses of systemic steroids followed by improvement in his vision. When the steroids were stopped his vision deteriorated. By the age of 14, this condition had recurred six times. At the age of 15, steroids were stopped and he was treated with azathioprin. At the age of 16, his visual acuity was 9/10 in his right eye and 8/10 in his left eye. Fundus examination showed bilateral optic atrophy. At the age of 15, his younger brother, 12 years old, developed severe visual loss in his left eye. Leber's hereditary optic neuropathy was suspected. Molecular genetic testing of their mother revealed the 11778 mtDNA mutation.

In most patients with LHON, visual loss remains profound and permanent. However, recovery of even excellent central vision may occur years after visual deterioration. Recurrences of visual loss are extremely rare. LHON should be considered in any patient with acute bilateral optic neuropathy. In this patient, the visual improvement with corticosteroid treatment and no relapse with immunosuppressive treatment raises the problem of interrelated inflammatory optical neuropathy.