Inflammation in dry eye associated with rheumatoid arthritis: cytokine and in vivo confocal microscopy study

The purpose of this research was to study ocular surface inflammation in relation to systemic disease activity in rheumatoid arthritis (RA) patients with or without secondary Sjögren's syndrome (SSII and non-SSII respectively). The study was conducted in two phases. In phase I, 12 patients with active RA SSII and 12 with active RA non-SSII were consecutively enrolled. Each completed an Ocular Surface Disease Index (OSDI) questionnaire and underwent a full eye exam and in vivo confocal microscopy examination of the cornea. Tear fluid samples were collected in sponges and analyzed for IL-1α, -6, and -8, and TNF-α. When RA activity was suppressed by systemic treatment the patients entered phase II of the study in which all of the phase I examinations were repeated. In RA SSII patients, OSDI, fluorescein staining dendritic cell density, and concentrations of IL-1α and IL-6 decreased significantly (P < 0.01) between phases I and II. Tear breakup time scores increased significantly. For RA non-SSII patients, there were no significant differences between phases I and II. Differences in the clinical, cellular and cytokine responsiveness to systemic RA treatments show that the ocular surface pathology is dissimilar for RA SSII and RA non-SSII patients.