Associations between Subjective Happiness and Dry Eye Disease: A New Perspective from the Osaka Study

IMPORTANCE Dry eye disease has become an important health problem. A lack of concordance between self-reported symptoms and the outcome of dry eye examinations has raised questions about dry eye disease. OBJECTIVE To explore the association between subjective happiness and objective and subjective symptoms of dry eye disease. DESIGN The study adopted a cross-sectional design. SETTING All the employees of a company in Osaka, Japan. PARTICIPANTS 672 Japanese office workers using Visual Display Terminals (age range: 26-64 years). METHODS The dry eye measurement tools included the Schirmer test, conjunctivocorneal staining, the tear film break-up time, as well as the administration of a dry eye symptoms questionnaire. Happiness was measured by the Subjective Happiness Scale. MAIN OUTCOME MEASURES Dry eye examination parameters, dry eye symptoms questionnaires, and the Subjective Happiness Scale score. RESULTS Of the 672 workers, 561 (83.5%) completed the questionnaires and examinations. The mean Subjective Happiness Scale score was 4.91 (SD = 1.01). This score was inversely correlated with the dry eye symptom score (r = -0.188, p < 0.001), but was not associated with objective findings which include conjunctivocorneal staining, low Schirmer test score, or low tear film break-up time. The level of subjective happiness was the lowest in the group without objective results, but reported subjective symptoms of dry eyes (p < 0.05). CONCLUSIONS AND RELEVANCE There is evidence of the relationship between subjective happiness and self-reported symptoms of dry eyes. Findings of this study revealed a new perspective on dry eye disease, including the potential for innovative treatments of a specific population with dry eye disease.