Background: Nonarteritic anterior ischemic optic neuropathy (NAAION) has a poorly understood etiology, and the onset of simultaneous bilateral NAAION in a patient <50 years without identifiable systemic risk factors is rare.
Case report: We present the case of a patient with acute painless monocular vision loss and bilateral optic disc edema who subsequently developed painless vision loss in the fellow eye. The patient's history was significant for diffuse large B-cell lymphoma, and our pressing diagnostic concern was to determine if his vision loss and bilateral optic disc changes represented lymphomatous infiltrates. A complete ocular exam demonstrated findings consistent with simultaneous bilateral NAAION. After an extensive systemic workup for malignancy with central nervous system involvement, vasculitis, and other entities associated with NAAION, we determined that the patient's primary risk factor for developing bilateral ischemic optic neuropathies was his crowded optic discs.
Conclusion: This case supports the hypothesis that a crowded optic disc is a sufficient primary risk factor for developing NAAION.
Keywords: Lymphoma; optic nerve; optic nerve diseases; optic neuropathy–ischemic; papilledema.