Prevalence of Antiretinal Antibodies in Acute Zonal Occult Outer Retinopathy: A Comprehensive Review of 25 Cases

Abstract

To perform a comprehensive review and to investigate the presence and role of autoimmune antibodies in 25 cases of acute zonal occult outer retinopathy (AZOOR) identified using the classification originally proposed by J. Donald Gass. Observational case series. Setting: Institutional. Twenty-five patients were identified by characteristic symptoms (abrupt onset of photopsias, followed by large scotomata at or connected to the blind spot), ocular findings (paucity of pigmentary changes with no sign of vitreous inflammation and abnormal electroretinogram in at least 1 eye), and a negative family history for retinitis pigmentosa. Patients underwent a full comprehensive ophthalmologic examination, fundus retinography, Goldmann kinetic visual field (GVF), and full-field electroretinogram (ffERG). Blood samples were also obtained to verify for the presence of antiretinal antibodies by Western blot analysis. MainOutcome Measures: Clinical presentation, best-corrected visual acuity (BCVA), fundus abnormalities, visual field defects, ffERG changes, and presence of antiretinal antibodies. Sixteen patients (64%) presented with photopsias, 56% (14/25) with night blindness, and 56% (14/25) with loss of peripheral vision. Sixty-four percent (16/25) of cases were bilateral. All patients demonstrated retinal vascular attenuation, optic nerve head pallor, and mottling of retinal pigment epithelium. The most common visual field changes included enlargement and expansion of the blind spot extending into large pericentral or other types of scotomata (64%). Both scotopic and photopic ffERG values were abnormal and affected to a similar degree in our patients. Nine patients (36%) had a greater than 20% asymmetry in ERG values between the 2 eyes. All patients had antiretinal antibodies on Western blot with an average of 6.6 bands. Evidence suggests that AZOOR is a unique form of autoimmune retinopathy and retinal manifestation suggests possible antiretinal antibody leakage from the disc margin with spread of immune products under the retina, resulting in large scotomata that connect to the optic nerve head.