Fundus photograph in a 24-years-old male patient complaining of loss of central vision. VA < 20/400 OU. He had tuberculosis and was treated with ethambutol until 3 months ago, when this medication was suspended. He started treatment with intramuscular injections of B1, B6 and B12 vitamins. Note the pale optic disc surrounded by a yellow ring, suggestive of toxic optic neuropathy.

Fundus photograph in a 24-years-old male patient complaining of loss of central vision, presenting with VA <20/400 OU. He had tuberculosis and was treated with ethambutol until 3 months ago, when this medication was suspended. He started treatment with intramuscular injections of B1, B6 and B12 vitamins. Note the pale optic disc surrounded by a yellow ring, suggestive of toxic optic neuropathy.