Acute zonal occult outer retinopathy (AZOOR) associated with multifocal choroidopathy

Abstract

Acute zonal occult outer retinopathy (AZOOR) may be precipitated by various retinal disorders and is characterised by rapid loss of visual field which cannot be explained by the ophthalmoscopic changes consequent upon the initiating disease. The electroretinogram is abnormal, indicating that the field loss is due to retinal dysfunction. The phenomenon was first recognised in the multiple evanescent white dot syndrome (MEWDS) as the enlarged blind spot syndrome. It was subsequently described with multifocal inner choroidopathy and acute macular neuropathy (AMN). We have identified 7 patients who presented with widespread visual loss associated with multifocal inner choroidopathy in whom functional loss was documented with electroretinography and automated visual field testing. All patients were young, myopic, and otherwise healthy women. Initial photopsia was noted by 4 patients. Fundus findings included scattered small partially pigmented yellowish lesions resembling those in multifocal inner choroidopathy or pseudo presumed ocular histoplasmosis syndrome, disc swelling, vitritis, and secondary choroidal neovascularisation. Two patients had bilateral involvement. All patients had an enlargement of the blind spot, and widespread visual field loss which was not explained by fundus changes. All had an abnormal electroretinogram suggesting widespread retinal disease. In AZOOR retinal dysfunction occurs without corresponding visible retinal lesions. This disorder appears to be precipitated by several conditions, although the causal relationship between the initiating event and the widespread functional loss is unknown.