A 54-year-old man comes to the physician for a 3-day history of double vision, dizziness, and burning pain in his right big toe. He also reports a 3-month history of burning sensations over his legs. Vitals are within normal limits. Examination shows a bluish hue of the right big toe. Laboratory studies show:
Hemoglobin 19.0 g/dL
Leukocytes 12,000/μL
Platelets 400,000/μL
Hb O2 saturation 94%
Ferritin 250 ng/mL
Which of the following interventions will most likely rapidly correct this patient’s visual disturbances?
