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.