A previously healthy, 28-year-old former gymnast noticed that she was having difficulty seeing fine lines with her left eye. The symptoms progressed over the next day, and she had difficulty discriminating between letters in newspaper headlines. Pain within the depths of the orbit was minor at first, but soon became moderate in severity and was worse with eye movement or pressure on the globe.
On examination, her vision was 20/200 in the left eye and 20/40 in the right eye. There was a central scotoma, and red and blue colors were less intense in the left eye. There was an afferent pupillary defect on the left. The rest of her neurologic exam was normal. A spinal tap showed normal glucose, protein, IgG, 3 white blood cells per mm3, and no oligoclonal bands. Visual evoked potentials were delayed on the left eye at 120 msec and slightly delayed at 112 msec in the right. MRI was normal.
She was not treated, but after 2 weeks, her visual symptoms gradually improved. However, symptoms were worse after 10 minutes in the sauna at her health club for the next 4 weeks. After 3 months, her vision was 20/20 in both eyes, and the central scotoma was gone. Red perception remained slightly reduced on the left. Visual evoked potentials were 115 msec on the left and 110 msec on the right.