Acute zonal occult outer retinopathy: a classification based on multimodal imaging

Abstract

Importance: We describe the multimodal imaging in a group of patients showing a distinct clinical entity that best represents acute zonal occult outer retinopathy (AZOOR).

Objective: To propose a classification of AZOOR based on clinical fundus and multimodal imaging.

Design, setting and participants: A retrospective review of patients diagnosed as having AZOOR at 2 centers. After reviewing more than 400 cases diagnosed or referred to us as AZOOR or AZOOR complex, we assembled 30 cases that fit our current definition; (48 eyes) with a median age at diagnosis of 47 years (age range, 17-86 years) and a mean follow-up period of 39 months. Twenty patients were female. Eighteen patients had initially been seen with bilateral lesions, mostly asymmetric (4 cases were symmetric). Most patients had no remarkable medical or ocular history. The median visual acuity at the time of presentation was 20/25 (range, 20/20 to 20/400).

Main outcomes and measures: Multimodal imaging, including fundus photography, fluorescein and indocyanine green angiography, fundus autofluorescence imaging, and corresponding eye-tracked spectral-domain coherence tomography imaging.

Results: Each patient was initially seen with visual symptoms of photopsia and scotoma, and most had a detectable lesion in the fundus evident clinically or detected on multimodal imaging. The clinical appearance of the AZOOR lesions varied depending on their duration and location, but some features were characteristic, including a demarcating line of the progression at the level of the outer retina and a trizonal pattern of sequential involvement of the outer retina, retinal pigment epithelium, and choroid, as well as frequent zonal progression. Advanced cases of AZOOR demonstrated disruption of the inner and outer retina and severe damage or loss of the retinal pigment epithelium and the choroid.

Conclusions and relevance: A specific definition of AZOOR based on multimodal imaging is proposed to help physicians distinguish it from other diseases of the posterior fundus, including white spot syndromes and autoimmune, hereditary, paraneoplastic, toxic, and other inflammatory retinopathies.