Clinical features of Japanese patients with anti-α-enolase antibody-positive autoimmune retinopathy: Novel subtype of multiple drusen.

PURPOSE: To evaluate clinical features of Japanese patients with anti-alpha-enolase antibody-positive autoimmune retinopathy (anti-enolase AIR). DESIGN: Multicenter retrospective observational case series. METHODS: Forty-nine eyes of 25 Japanese anti-enolase AIR patients (16 female and 9 male; mean age at first visit, 60.8 years) were included. Fundus characteristics, perimetry, spectral-domain optical coherence tomography (SD-OCT), electroretinography (ERG), best-corrected visual acuity (BCVA), and complicating systemic tumors were assessed. Protein localization of alpha-enolase was examined by immunohistochemistry in an enucleated eye of 1 patient. RESULTS: Patients were classified into 3 groups: multiple drusen (48%), retinal degeneration (36%), and normal fundus (16%). Drusen varied in size from small deposits to vitelliform-like lesions. Images on SD-OCT revealed dome-shaped hyperreflectivity beneath the retinal pigment epithelium (RPE), corresponding to drusen. Perimetry showed that ring scotoma was the most frequent (39%). Rod-system and/or single-flash cone responses revealed decreased responses in 81% of the eyes. Combined rod and cone system responses demonstrated significantly lower a-wave amplitudes in the degeneration group than in the drusen group (P = .005). BCVA was improved or maintained in 80% of the eyes during follow-up. Malignant or benign tumors were detected in 30% of patients. The RPE and photoreceptor layers were immunopositive for alpha-enolase. CONCLUSIONS: The drusen subtype, scarcely described in the literature, is suggested to characterize Japanese patients with anti-enolase AIR. The different funduscopic features with different functional severities may have resulted from antibody-mediated damage to RPE as well as photoreceptor cells. ((C) 2018 Elsevier Inc. All rights reserved.)