ACUTE ZONAL OCCULT OUTER RETINOPATHY

Retinal photoreceptor dysfunction is an uncommon and often unrecognize d cause of acute visual loss, Acute zonal occult outer retinopathy (AZ OOR) has been reported to cause acute cone and rod dysfunction, Patien ts with AZOOR may present with normal visual acuity, normal fluorescei n angiography, and a normal fundus examination despite severe loss of visual field. A healthy young white female presented, with acute, unil ateral loss of visual field and an afferent pupillary defect, but norm al visual acuity, color vision, fundus examination, and fluorescein an giogram. A pattern visual evoked potential was normal, but an electror etinogram showed a unilateral peripheral photoreceptor dysfunction con sistent with the diagnosis of AZOOR, Ophthalmologists should be aware of the diagnosis of AZOOR and should consider an ERG in the evaluation of any patient with unexplained visual field loss even in the presenc e of normal visual acuity, color vision, fluorescein angiography, or r etinal examination.