Mike is a 20-year-old student who presents with three days of blurred vision in the right eye.

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<p>Mike is a 20-year-old student who presents with three days of blurred vision in the right eye. He first noticed this after a paroxysm of coughing.</p><p>He was diagnosed and treated for pertussis three weeks ago, and while the cough is improving, he is still having occasional intense fitful cough.</p><p>He reports central vision loss with intact peripheral vision.</p><p>Mike has a past history of migraine without aura, usually responsive to prn NSAIDs, but has not had a headache for some months.</p><p>There is no associated ocular discomfort, history of trauma, systemic symptoms and no other past history of note.</p><p>On examination, vital signs are normal, pupils are equal and reactive, visual acuity is counting fingers on the right and 6/5 on the left, uncorrected.</p><p>Fundal findings on the right (retinal pole — A, peripheral retina B-D) are pictured.</p><p>The left fundus examines normally.</p>

Dr Kate Kelso is a GP and medical editor at Australian Doctor.