Non-Paraneoplastic Autoimmune Retinopathy: The First Case Report in Korea

Autoimmune retinopathy (AIR) is an immune-mediated retinopathy, resulting from an immunologic process caused by the aberrant recognition of retinal antigens as autoantigens. The diagnosis of AIR involves the detection of antiretinal antibodies with concurrent clinical and electrophysiological evidence of retinopathy. A 40-year-old patient presented with progressive loss of bilateral vision over several months. A fundus examination was unremarkable. Spectral domain optical coherence tomography revealed a blurred photoreceptor ellipsoid zone at the subfoveal region in both eyes with more prominent disruption in the left eye. Full-field electroretinography (ERG) showed relatively normal rod and cone responses in the right eye, and decreased photopic bwaves with minimal attenuation of a-waves in the left eye. Multifocal ERG demonstrated slightly reduced amplitude of the inner segment ring in the right eye and decreased amplitudes and delayed latencies of all modalities in the left eye. The patient was suspected to have AIR and it was supported by positive Western blots for 23-kDa protein, enolase (46-kDa), aldolase (40-kDa), 62-kDa and 78-kDa proteins and by immunohistochemical staining of human retinal bipolar and ganglion cells. Despite the immunosuppressive treatment, the destruction of the retinal photoreceptors progressed, and immunosuppressive interventions produced very little visual improvement. We report on what is, to the best of our knowledge, the very first case of serologically confirmed nonparaneoplastic AIR in Korea.

A Case of Nonparaneoplastic Autoimmune Retinopathy

PURPOSE: To report a case of nonparaneoplastic autoimmune retinopathy diagnosed using serum anti-retinal autoantibodies. CASE SUMMARY: A 60-year-old female complained of progressive visual loss in both eyes over 3 months. Her best corrected visual acuity was hand motion in the right eye, 0.9 (decimal) in the left eye, and no definite abnormal findings were identified on fundus examinations. Automated visual field test revealed severely depressed visual fields in both eyes. Standard full-field electroretinogram (ERG) revealed nearly extinguished scotopic b-waves and spectral-domain optical coherence tomography (SD-OCT) showed subtle obscuration and interruption of the inner segment/outer segment (IS/OS) junction of the photoreceptors. Using Western blotting with human retinal proteins and the patient's serum, we diagnosed nonparaneoplastic autoimmune retinopathy and performed posterior subtenon steroid injection in the right eye, systemic corticosteroids, and oral mycophenolate mofetil. Full-field ERG after treatment showed slightly increased amplitude but there was no subjective visual improvement. OCT after treatment did not reveal significant changes in the photoreceptor layer. CONCLUSIONS: This is the first reported case of nonparaneoplastic autoimmune retinopathy in Korea diagnosed using Western blotting with anti-retinal autoantibodies. Autoimmune retinopathy should be considered in patients with visual field and ERG impairment without definite fundus abnormalities.