A 58-YEAR-OLD white woman was examined because of a 5-day history of
an enlarged blind spot in her left eye. She was taking azathioprine, 50 mg
once daily, for Crohn disease. Her visual acuity was 20/30 OU. A peripapillary,
annular gray-white ring was seen in the left fundus (Figure 1). A week later, the ring had enlarged to involve the fovea
(Figure 2). Her visual acuity deteriorated
to hand movements, and she developed a left afferent pupillary defect. Photopic
electroretinographic responses were delayed and reduced. A fundus fluorescein
angiogram showed a hypofluorescent ring with a hyperfluorescent area within
(Figure 3, Figure 4, and Figure 5),
which was also seen in the late phase (30 minutes) of the indocyanine green
angiogram (Figure 6). The optic
disc appeared normal with no leakage of dye. Acute annular outer retinopathy
was diagnosed, and treatment was begun with oral prednisolone, 60 mg once
daily, and acyclovir, 400 mg 4 times daily. The peripapillary ring faded during
a period of 6 weeks, but no visual improvement was noted.