We report a rare case of unilateral acute macular neuroretinoapthy in a young male.

A 35-year-old male presented with a 2-day history of paracentral scotoma. He had suffered for 2 days from a flu-like illness, and his best corrected visual acuity was 20/20 OD and 20/20 OS. Pupillary reflex was normal and no relative afferent pupillary defects were not found. Ocular movement test was normal and pain on ocular movement was not noticed. Ophthalmoscopic examination of the left eye revealed multiple exudates lining the nasal macula toward the fovea. A Humphrey visual field study identified small paracentral scotoma. Spectral domain optical coherence tomography (SD-OCT, Heidelberg Engineering, Heidelberg, Germany) of the lesions showed a hyper-reflective lesion located in the outer plexiform layer and inflammatory cell infiltration. Fluorescent angiography was normal in the macula but showed late leak at the disc. The multifocal electroretinogram (mfERG) showed decreased foveal P1 amplitude in the left eye. The patient was diagnosed with acute macular neuroretinopathy and was treated with 60 mg of prednisolone. His subjective symptoms were improved, the paracentral scotoma disappeared, and the lesions appeared different upon SD-OCT; specifically, the hyper-reflective lesion disappeared and the outer plexiform layer showed thinning.

Acute macular neuroretinopathy is a rare disease, and we report a case using SD-OCT and mfERG.