Environmental Effects on Dry Eyes in Primary Sjogren's Syndrome

Purpose: To investigate the effects of humidity, temperature, and fine particulate matter (PM2.5) on dry eye disease (DED) parameters in primary Sjogren's syndrome patients.Methods: We retrospectively analyzed the medical records of 18 primary Sjogren's syndrome patients who underwent DED treatment and had more than two follow-up visits. Symptom Assessment in Dry Eye (SANDE) scores, tear secretion, tear film breakup times, ocular surface staining scores, and tear osmolarity were assessed. Temperature, humidity, and PM2.5 concentrations during the week before the patient visits were calculated using public data and their relationships with DED parameters were analyzed.Results: All patients were females, with an average age of 57.6 ± 12.4 years. High temperature was significantly correlated with humidity and PM2.5 concentration (p = 0.004 and = 0.006, respectively). The high humidity, high temperature, and low PM2.5 groups had lower SANDE scores (p = 0.017, = 0.063, and = 0.049, respectively) and tear osmolarity (p < 0.001, = 0.009, and < 0.001, respectively). Multiple regression analysis showed that temperature and humidity had stronger correlations with tear osmolarity (p = 0.005 and = 0.012, respectively) compared to PM2.5 concentrations.Conclusions: Ocular discomfort and tear osmolarity were correlated with temperature, humidity, and PM2.5 concentrations. Among the DED parameters, tear osmolarity was the most sensitive indicator of exposure to environmental factors.