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.