Correlation between dry eye and rheumatoid arthritis activity.

PURPOSE To evaluate the incidence of dry eye in rheumatoid arthritis (RA) patients with or without Sjögren syndrome (SS), and to investigate the correlation between dry eye and RA activity. DESIGN Prospective case-control study. METHODS In 72 RA patients, the severity of dry eye was assessed by the Schirmer test, tear break-up time, rose bengal staining, and fluorescein staining. The RA activity was evaluated by the Lansbury index (LI), which is based on the duration of morning stiffness, erythrocyte sedimentation rate (ESR), grip strength, and joint score. RESULTS Ten percent of patients met the Japanese criteria for SS. No difference in dry eye tests or LI was observed between SS patients and non-SS patients. Even in the non-SS group, 90% of patients were diagnosed with probable dry eye. In SS patients, positive correlations were observed between LI and Schirmer test (P = .048), ESR and Schirmer test (P = .035), ESR and rose bengal staining (P = .001), and grip strength and rose bengal staining (P = .047). No such correlations were observed in the non-SS patients. CONCLUSIONS Dry eye is common in RA patients, including those without SS. We found that there was a correlation between LI and Schirmer test in RA patients with SS, but no correlation when the entire group was analyzed. Dry eye always should be taken into consideration regardless of the RA activity, because the severity of dry eye is independent of RA activity.