Purpose: To report the long-term follow-up of patients with acute zonal occult outer retinopathy (AZOOR).
Design: Observational consecutive case series.
Methods: Prospective and retrospective review of medical records of patients with AZOOR.
Results: Fifty-one patients (37 women and 14 men) with a median age of 33 years (mean, age 36 years; range, 13-63 years) were followed for a median of 96 months (mean 100 months; range, 36-420 months). At presentation, AZOOR was present in one eye of 31 patients (61%) and both eyes in 20 patients (39%). All patients presented with an acute loss of one or more zones of visual field, and 45 (88%) patients presented with photopsia. Corrected visual acuity was 20/40 or better in 68 (76%) of 90 affected eyes. Funduscopic examination was normal in 82 eyes and revealed signs of AZOOR in 8 eyes. Electroretinographic amplitudes were depressed in all affected eyes. The median delay in diagnosis of AZOOR was 17 months. During follow-up, AZOOR developed in 19 fellow eyes. At final follow-up AZOOR was present in one eye of 12 (24%) patients and both eyes of 39 (76%) patients. Sixteen patients had 23 recurrences of AZOOR. Visual field loss stabilized within 6 months in 37 patients (72%), progressed stepwise in 2 patients (4%), and partly improved in 12 patients (24%). Fourteen patients (28%) had autoimmune diseases, including Hashimoto's thyroiditis in 6 patients and relapsing transverse myelopathy in 4 patients. At last follow-up all patients had residual visual field defects. Final visual acuity was 20/40 or better in 61 (68%) affected eyes. Nine patients (18%) were legally blind. The fundi of 90 affected eyes revealed no changes of AZOOR in 47 eyes (52%) and changes in the pigment epithelium and retina caused by AZOOR in 43 eyes (48%).
Conclusions: Visual loss in AZOOR is characterized by one or more episodes of acute dysfunction, and in some cases, death of retinal receptor cells in one or more zones of one or both eyes. Central vision is often spared, but recovery of visual field occurs infrequently. The etiology of AZOOR is unknown. Electroretinography is essential for early diagnosis. The value of treatment is uncertain.