ANTI-RHODOPSIN ANTIBODIES IN SERA FROM PATIENTS WITH NORMAL-PRESSURE GLAUCOMA

Purpose. To explore further the potential role autoimmunity may play i n the pathogenesis of normal-pressure glaucoma (NPG) in some patients, the authors examined the sera of patients with NPG for the presence o f antibodies directed toward retinal antigens, Methods. Using patient sera, immunoblotting was performed on subcellular fractions of retina, purified bovine rhodopsin, and immunoaffinity-purified recombinant hu man rhodopsin. A chemiluminescence-enzyme-linked immunosorbent assay ( ELISA) to detect anti-rhodopsin antibodies was developed and used. Res ults. A patient with NPG was found to have a high titer of immunoglobu lin M-lambda antibody against a 40-kd retina-specific glycoprotein ant igen subsequently identified as rhodopsin. ELISA analysis conducted on sera from 28 patients with NPG and 26 patients with primary open-angl e glaucoma (POAG) revealed highly significant differences in anti-rhod opsin antibody activity between these groups (P < 0.0002, Mann-Whitney test). For example, the majority of patients with NPG (19/28; 68%) ha d anti-rhodopsin antibody activity higher than the highest value obtai ned from among 26 age-matched patients with POAG. Conclusions. An elev ated anti-rhodopsin antibody count is related to NPG. This may indicat e that there is an autoimmune component in the optic neuropathy in the se patients. The specific role of these autoantibodies, if any, in the pathogenesis of the disease remains to be determined.