What is causing this patient's worsening vision?

Colleen B. Grassley is a PA fellow in emergency medicine at the Mayo Clinic in Rochester, Minn. Leonid Skorin, Jr., is a consultant in the Department of Ophthalmology at the Mayo Clinic Health System in Albert Lea, Minn. The authors have disclosed no potential conflicts of interest, financial or otherwise.

Allison Rusgo, MPH, PA-C, department editor