Occult Acute Macular Neuroretinopathy.

A 19-year-old Caucasian woman developed an upper respiratory infection, took a cold formulation containing 5 mg of phenylephrine, and developed a very rare and unusual form of acute macular neuroretinopathy (AMN) that could not be detected on fundoscopic examination, visual fields, nor electrophysiological testing. Spectral-domain optical coherence tomography (SD-OCT) revealed a lesion limited to the fovea. This case illustrates the value of SD-OCT, in light of otherwise normal testing, in a variant of AMN the authors call "occult AMN".