Outer Retinal Structure in Patients With Acute Zonal Occult Outer Retinopathy

Abstract

To correlate visual function with high-resolution images of retinal structure using adaptive optics scanning laser ophthalmoscopy (AOSLO) in 4 patients with acute zonal occult outer retinopathy (AZOOR). Observational case series. Four women, aged 18 to 51, with acute focal loss of visual field or visual acuity, photopsia, and minimal funduscopic changes were studied with best-corrected visual acuity (BCVA), Goldmann kinetic and automated perimetry and fundus-guided microperimetry, full-field and multifocal electroretinography (ffERG and mfERG), spectral-domain optical coherence tomography (SD-OCT), and AOSLO imaging. Cone spacing was measured in 4 eyes and compared with 27 age-similar normal eyes. Additional functional testing in 1 patient suggested that cones were absent but rods remained. Serum from all patients was analyzed for anti-retinal antibody activity. In all patients vision loss was initially progressive, then stable. Symptoms were unilateral in 2 and bilateral but asymmetric in 2 patients. In each patient, loss of retinal function correlated with structural changes in the outer retina. AOSLO showed focal cone loss in most patients, although in 1 patient with central vision loss such change was absent. In another patient, structural and functional analyses suggested that cones had degenerated but rods remained. Anti-retinal antibody activity against a ∼45 kd antigen was detected in 1 of the patients; the other 3 patients showed no evidence of abnormal anti-retinal antibodies. Focal abnormalities of retinal structure correlated with vision loss in patients with AZOOR. High-resolution imaging can localize and demonstrate the extent of outer retinal abnormality in AZOOR patients.