Relationship between dry eye symptoms and quality of life: associations and mediation analysis

(1) To determine the independent association of dry eye symptoms with health-related quality of life (HRQoL) in the Singapore population and (2) to further investigate which factors mediate this association.

In this cross-sectional study, 7707 participants were included. The presence of dry eye symptoms was defined as experiencing at least one out of the six symptoms either 'often' or 'all the time'. The EuroQoL-5 dimensions (EQ-5D) utility instrument (raw scores converted to UK time trade-off (TTO) values) was used to assess generic HRQoL and the overall score from the Visual Functioning Questionnaire for visual functioning. The association between dry eye symptoms and EQ-5D was investigated using multivariable linear regression, adjusting for demographic and socioeconomic information, comorbidities, systemic and ocular examinations results. Mediation analysis was used to determine whether certain factors mediated this association.

After adjusting for relevant factors, those with dry eye symptoms had significantly lower HRQoL (difference in EQ-5D TTO: -0.062 (95% CI -0.073 to -0.050)), with the inability to open eyes affected the most (-0.101 (95% CI -0.161 to -0.042)), followed by a sandy sensation (-0.089 (95% CI -0.121 to -0.058)), a burning sensation (-0.070 (95% CI -0.105 to -0.036)), red eyes (-0.059 (95% CI -0.082 to -0.036)), a dry sensation (-0.058 (95% CI -0.072 to -0.044)) and crusting of eyelids (-0.040 (95% CI -0.071 to -0.008)). Visual functioning and the presence of recent falls accounted for 8.63% (4.98%-14.5%) and 2.93% (0.04%-5.68%) of the indirect relationship between dry eye and HRQoL, respectively.

Dry eye symptoms were independently associated with poor HRQoL. Moreover, this was partly mediated by reduced visual functioning and experiencing recent falls. Our results suggest that efforts to reduce severity of dry eye symptoms are essential to optimise patients' overall functioning and well-being.