Diagnosis and differential diagnosis of acute zonal occult outer retinopathy

Abstract

To study the clinical manifestations of acute zonal occult outer retinopathy (AZOOR) and to differentiate it from other retinal diseases. Six patients diagnosed AZOOR had complete eye examinations including fundus photography, fundus fluorescein angiography (FFA), electroretinography (ERG), visual evoked potentials and visual field examination. Medical consultation and neurological consultation were performed in those patients. All patients were followed up and the data were collected for analysis, discussion, diagnosis and differential diagnosis. Six patients (five female and one male) aged 26 - 42 years (mean 35 years) with AZOOR were followed up for 4 - 18 months [mean (7.5 +/- 3.2) months]. All of them were affected bilaterally and their visual acuity were slightly reduced except one eye was CF/40 cm. Half of them had photopsia. At least one eye of each patient had visual field defect or decreased sensitivity in local area or blind-spot enlargement. Biomicroscopic examination revealed vitreous cells in 10/12 eyes and anterior chamber inflammatory cells and keratic precipitate in 4/12 eyes. Minimal (10/12 eyes) or no (2/12 eyes) fundus changes were found in their initial examination. Funduscopic examination revealed yellow-white dots (4/12 eyes) and gray dots (6/12 eyes) at the posterior pole of deep retina or retinal pigment epithelium-Bruch membrane-choroid capillary complex layer. FFA showed depigmentation (2/12 eyes) or hyperfluorescein spots (10/12 eyes) that identical to the retinal lesions. In the follow-up examination, the visual acuity was reduced in one eye and visual field defect enlarged in both eyes of one patient; the number of retinal dots increased in one eye, decreased in one eye and extinguished in one eye. ERG or mERG revealed abnormal in all of their eyes with no changes in their follow-up examination. All of the initial diagnoses of six patients were not consistent with final diagnosis. AZOOR is a rare eye disease, usually occurs in young females, with the characteristics of photopsia, visual field defects, abnormal ERG and slight changes in the fundus. The differential diagnosis of this disease is relatively complicate and is easily to be misdiagnosed.