The Association of Dry Eye Symptom Severity and Comorbid Insomnia in US Veterans

PURPOSE: To investigate the association between dry eye (DE) and insomnia symptom severity. METHODS: Cross-sectional study of 187 individuals seen in the Miami Veterans Affairs eye clinic. An evaluation was performed consisting of questionnaires regarding insomnia (insomnia severity index [ISI]) and DE symptoms, including ocular pain, followed by a comprehensive ocular surface examination. Using a two-step cluster analysis based on intensity ratings of ocular pain, the patient population was divided into two groups (high and low ocular pain groups: HOP and LOP). A control group was ascertained at the same time from the same clinic as defined by no symptoms of DE (Dry Eye Questionnaire 5 [DEQ5], <6). The main outcome measure was the frequency of moderate or greater insomnia in the DE groups. RESULTS: The mean age of the study sample was 63 years, and 93% were male. All insomnia complaints were rated higher in the HOP group compared with the LOP and control groups (P<0.0005). Most (61%) individuals in the HOP group experienced insomnia of at least moderate severity (ISI≥15) compared with the LOP (41%) and control groups (18%) (P<0.0005). Black race (odds ratio [OR], 2.7; 95% confidence interval [CI], 1.2-6.0; P=0.02), depression severity (OR, 1.2; 95% CI, 1.1-1.3; P<0.0005), and DE symptom severity (DEQ5; OR, 1.1; 95% CI, 1.01-1.2; P=0.03) were significantly associated with clinical insomnia (ISI≥15) after controlling for potential confounders. CONCLUSIONS: After adjusting for demographics and medical comorbidities, we show that DE symptom severity is positively associated with insomnia severity.