Nutritional Optic Neuropathy Caused by Copper Deficiency After Bariatric Surgery.

A 47-year-old woman developed severe bilateral visual loss 4 years after a Roux-en-Y gastric bypass and 24 years after vertical banded gastroplasty. Her serum copper level was 35 μg/dL (normal, 80-155 μg/dL). She was prescribed elemental copper tablets. Because her methylmalonic acid was slightly elevated, she received vitamin B12 injections as well. Five weeks later, she reported that her vision had improved and, at 10 months, her vision had recovered from 20/400 bilaterally to 20/25 in each eye. This case highlights the importance of checking copper levels in addition to the "more routine" vitamin levels, such as B1, B6, B12, E, and serum folate in patients with suspected nutritional optic neuropathy after bariatric surgery, particularly if it involved a bypass procedure.