Vision Loss from Metastatic Colon Cancer to the Planum Sphenoidale and Optic Nerves.

An 80-year-old man was seen in urgent neuro-ophthalmology consultation for bilateral vision loss. He had a past medical history of hypertension and metastatic stage IV colorectal adenocarcinoma. Four months prior to presentation, he developed gradual onset, painless blurred vision in his right eye. He underwent cataract surgery in that eye, but his vision continued to decline to the point of no light perception. He developed new onset, painless, blurred vision in his left eye 3 weeks prior to presentation and woke up with no light perception in his left eye one day prior to presentation.