Acute Zonal Occult Outer Retinopathy Associated With Retrobulbar Optic Neuritis

A 17-year-old girl presented with unilateral retrobulbar optic neuritis as well as bilateral funduscopic findings and outer retinal dysfunction suggestive of acute zonal occult outer retinopathy (AZOOR). Fundus autofluorescence abnormalities, visual field loss, and electroretinographic changes were supportive of bilateral AZOOR. MRI was consistent with the diagnosis of clinically isolated syndrome (CIS), which is defined as a central nervous system demyelinating event that may herald the onset of multiple sclerosis (MS). While AZOOR previously has been linked to MS and demyelinating white matter lesions in the brain, our case seems unique due to concurrent development of AZOOR and retrobulbar optic neuritis as a CIS.