Climatic and Environmental Correlates of Dry Eye Disease Severity: A Report From the Dry Eye Assessment and Management (DREAM) Study

PURPOSE: Correlate climate, weather parameters, and environmental exposures with the severity of symptoms and signs of dry eye disease (DED) in Dry Eye Assessment and Management (DREAM) study participants. METHODS: Participants from five distinct climates completed the Ocular Surface Disease Index (OSDI) and were examined for corneal and conjunctival staining, tear breakup time (TBUT), and Schirmer's testing at baseline, 3, 6, and 12 months. Climate, weather parameters, and pollutants including ozone (O(3)), carbon monoxide (CO), nitrous oxides (NO(2), NO(x), NO(y)), sulfur dioxide (SO(2)), particulate matter, and optical depth were obtained from governmental databases. Multivariate analysis and partial correlation coefficients (ρ) were used to assess associations, adjusted for age, sex, and the presence of Sjögren disease. RESULTS: Among 535 participants, 81% were female and mean age was 58 years. Participants from the Mediterranean climate demonstrated better corneal fluorescein staining, better TBUT, and higher Schirmer's test scores throughout the calendar year (each P < 0.0001). Greater corneal fluorescein staining was associated with lower humidity (P < 0.0038). TBUT measurements positively correlated with temperature, humidity, and dewpoint and inversely correlated with NO(2) levels (P < 0.0038). Paradoxically, some airborne pollutants were associated with less severe signs of dry eye (P < 0.0038). Windspeed was not correlated with signs of DED, and OSDI scores did not correlate with individual environmental exposures. CONCLUSIONS: Dry eye signs differed between climates and local humidity levels. With the exception of NO(2), airborne pollutants were not associated with detrimental dry eye features. TRANSLATIONAL RELEVANCE: These results support limiting dry air exposure for patients with DED.