Antibodies specifically label the inner retina in patients with primary autoimmune retinopathy

Purpose: To determine the binding site of antiretinal antibodies from two patients with primary autoimmune retinopathy, and to correlate indirect immunohistochemical findings with physiologic testing. Methods: Serum from two patients with photopsias, ring scotomata, abnormal electroretinograms (ERGs), normal appearing ocular fundi, and antiretinal antibody on Western blot testing were evaluated for presence of specific immunolabeling of retinal tissue. Donor tissue was embedded, frozen, sectioned, and incubated with patient serum. Peroxidase-conjugated goat anti-human IgG was used to identify bound antibodies. Results: Each patient's serum showed specific labeling of the inner plexiform layer of the retina. Control sera of unaffected patients were negative. The ERG of one patient showed abnormal oscillatory potentials and selective loss of the b wave, suggesting dysfunction of the inner retinal layers. The ERG of the other patient was nonrecordable. Conclusions: The sera of two patients with primary autoimmune retinopathy showed specific antibody binding to the inner retina, which matched the ERG abnormality. This inner retinal dysfunction is a pattern which has not previously been described.