Pivotal role for SD‐OCT in the diagnosis of acute zonal occult outer retinopathy

Abstract

AbstractPurpose Acute Zonal Occult Outer Retinopathy (AZOOR) is characterized by an acute partial loss of outer retinal function with corresponding visual field defects and electroretinographic (ERG) abnormalities in one or both eyes. Spectral domain optical coherence tomography (SD‐OCT) findings are described as a key to the early diagnosis of AZOOR in a patient.Methods A 25 ‐year‐old man developed acute painless central vision loss together with photopsia in the right eye (RE). He underwent a full ophthalmological work‐up including fluorescein and ICG‐angiography, SD‐OCT, specialized imaging, visual field testing (VFs) and electrophysiological testing.Results On initial evaluation visual acuity was 15/10 in both eyes. Fundoscopy revealed a subtle loss of the foveal reflex with very limited foveal mottling in the RE. Fluorescein and ICG‐angiography were unremarkable. Static and kinetic perimetry showed an absolute scotoma inferotemporal of fixation and a slightly enlarged blind spot in the RE. Most remarkable were the inner/outer segment boundary defects visible on SD‐OCT. One month later, small changes were observed on infrared imaging and reduced responses were seen on multifocal ERG corresponding to the scotoma on VFs. A full‐field ERG and EOG were normal. The unilateral scotoma stabilized over the next 2 months.Conclusion AZOOR is a rare condition with subtle and often vague signs and symptoms, which makes diagnosing it quite a challenge. The added value of SD‐OCT is that it allows identification of specific inner segment/outer segment boundary defects at presentation.