Acute Idiopathic Blind Spot Enlargement and Acute Zonal Occult Outer Retinopathy: Potential Mimics of Neuro-Ophthalmic Disease

Abstract

In 1988, William Hoyt, MD, et al described “acute idiopathic blind spot enlargement” (AIBSE) in 7 symptomatic patients who had no apparent abnormalities of the optic disc or surrounding retina. With the use of multifocal electroretinography, they showed that the scotoma was caused by occult retinal dysfunction. In 1992, J. Donald Gass, MD, described “acute zonal occult outer retinopathy” (AZOOR) in 13 patients who had sudden loss of often large zones of visual field without fundus abnormalities. Most patients developed zonal atrophy of retinal pigment epithelium and had no improvement in vision. Gass believed that AZOOR, multiple evanescent white dot syndrome, multifocal choroiditis, and AIBSE were all variants of the same disorder. Despite over 3 decades of numerous reports, the classification of these entities, their pathogenesis, and treatment remain controversial. AIBSE and AZOOR may be mistaken for an acute optic neuropathy, so it behooves the neuro-ophthalmologist to be familiar with these disorders. This review describes the initial recognition of AIBSE and its relationship to AZOOR.

Acute Zonal Occult Outer Retinopathy (AZOOR) Results from a Clinicopathological Mechanism Different from Choriocapillaritis Diseases: A Multimodal Imaging Analysis

“…AZOOR was included by Gass in the spectrum of “white dot syndromes” including MEWDS, AIBSE, Multifocal choroiditis and others now known to be inflammatory diseases of the choriocapillaris. Reports including AZOOR in this spectrum, lumping it together with choriocapillaritis entities, continued to be published up to recently after Gass put forward this hypothesis [ 4 , 6 , 8 , 9 , 10 , 11 , 12 ]. Thanks to multimodal imaging it is now possible to clearly distinguish and split AZOOR from choriocapillaritis entities.…”

“…This assumption by Gass was put forward as the patient characteristics of these inflammatory choriocapillaropathies were similar to those of AZOOR patients and because there was a number of reports in which choriocapillaritis patients were subsequently found to present AZOOR [ 2 ]. Reports on such associations continue to be published indicating that patients can be exposed to both types of diseases which does not necessarily imply that they are caused by the same mechanisms but probably represent different disease types caused by different physiopathologies [ 5 , 6 , 7 ]. The goal of the present report was to perform a multimodal imaging analysis of three cases of AZOOR ( Table 1 ) and so determine its clinicopathology.…”

Classification of Non-Infectious and/or Immune Mediated Choroiditis: A Brief Overview of the Essentials

“…This assumption by Gass was put forward as the patient characteristics of these inflammatory choriocapillaropathies were similar to those of AZOOR patients and because there was a number of reports in which choriocapillaritis patients were subsequently found to present AZOOR [ 92 ]. Reports on such associations continue to be published, indicating that patients can be exposed to both types of disease, which does not necessarily imply that they are caused by the same mechanisms [ 94 , 95 , 96 ]. With multimodal imaging, it became clear that the disease is a retinopathy and choriocapillaris is not involved, at least not primarily.…”

Coarsening of choriocapillaris on optical coherence tomography angiography as a sign of acute idiopathic blind spot enlargement

“…Acute idiopathic blind spot enlargement (AIBSE) syndrome is a rare, peripapillary retinopathy first described by Fletcher et al, in 1988 as a temporary steep edged scotoma centred on the blind spot in the presence of normal fundoscopic findings. 1 It was later classified within the Acute Zonal Occult Outer Retinopathy (AZOOR) spectrum of diseases that also comprised of Multiple Evanescent White Dot Syndrome (MEWDS) and Acute Macular Neuroretinopathy (AMN). 1 …”

“… 1 It was later classified within the Acute Zonal Occult Outer Retinopathy (AZOOR) spectrum of diseases that also comprised of Multiple Evanescent White Dot Syndrome (MEWDS) and Acute Macular Neuroretinopathy (AMN). 1 …”