Although intraocular pressure is an important risk factor in glaucoma, there is growing body evidence indicating an immunological component in the pathogenesis of normal-tension glaucoma (NTG). The aim of this study was to determine if NTG coexists with elevated levels of autoantibodies detected in rheumatic diseases.We enrolled 105 patients into the study: 35 with NTG, 34 with primary open-angle glaucoma (POAG), and 36 controls. All patients underwent ophthalmic examination and blood tests. Blood was examined for the level of: antibodies against antinuclear antibodies (ANA), antibodies to extractable nuclear antigens (ENA), immunoglobulins (IgG, IgA, IgM), rheumatoid factor, anti-citrullinated protein antibodies (ACPA), and antiphospholipid antibodies (anticardiolipin antibodies, beta2-glycoprotein I antibodies, antiprothrombin antibodies).The level of ANA was increased among 6 patients in the NTG group (17.1%), 8 in the POAG group (23.5%), and 6 in the control group (16.5%). The difference was not statistically significant (p=0.97). None of the patients in the NTG, POAG, or control group had positive antibodies to ENA. The level of immunoglobulins IgG, IgM, and IgA in the 3 groups was similar and within normal values. The median level of rheumatoid factor and ACPA was the highest in the NTG group, but it was within normal laboratory values. There was a statistically significant difference between antiprothrombin antibodies IgG between the NTG and POAG group (p=0.01), but not between the NTG and control group (p=0.24).The results of our study do not confirm the hypothesis that NTG coexists with elevated blood levels of antibodies, which are a characteristic feature of rheumatic diseases.