Diet-related mercury poisoning resulting in visual loss

A 36-year-old man with progressive peripheral neuropathies was referred to the eye clinic with failing visual acuity. No cause could be found for his ongoing weight loss, poor appetite, disturbed sleep and worsening painful neuropathies after extensive investigations. Blood tests identified a markedly raised mercury concentration, and further inquiries identified his diet to be rich in fish caught in the Caribbean. Tests carried out on the fish he provided showed a high concentration of mercury in the tissue. Electrophysiology showed changes consistent with published reports on patients regularly exposed to high levels of mercury.

A 36-year-old man was referred to the neuro-ophthalmology clinic with a 3-month history of deteriorating vision, with difficulty in reading. He was also being investigated by the neurology service for peripheral neuropathies. He had an 8-month history of numbness and tingling in both feet and in his fingertips.