Multisite Extraocular Dryness is Associated with Symptomatic Dry Eye and Tear-Film Instability Among Adults Without Severe Meibomian Gland Loss

PURPOSE: To evaluate whether a greater number of self-reported extraocular dryness sites is associated with Ocular Surface Disease Index (OSDI)-defined symptomatic dry eye and non-invasive tear break-up time (NIBUT)-defined tear-film instability among community-dwelling adults without severe meibomian gland loss. METHODS: This cross-sectional participant-level analysis used baseline data from the Beijing Adult Dry Eye Cohort (ADEC). Adults with complete OSDI, extraocular dryness, age, sex, and meibomian gland data were included if participant-level maximum upper- and lower-eyelid meibomian gland scores across both eyes were ≤ 2. Extraocular dryness was assessed using a study-specific four-site checklist, and the resulting site count was categorized as 0, 1, 2, and 3-4 sites. Age- and sex-adjusted prevalence ratios were estimated using modified Poisson regression with inference accounting for clustering by community. RESULTS: Among 675 participants, 270 (40.0%), 212 (31.4%), 106 (15.7%), and 87 (12.9%) reported 0, 1, 2, and 3-4 extraocular dryness sites, respectively. The crude prevalence of OSDI-defined symptomatic dry eye increased from 17.0% to 62.1%, and NIBUT-defined tear-film instability from 24.8% to 74.7%. Compared with the 0-site group, the 3-4-site group had adjusted prevalence ratios of 2.91 (95% CI, 1.95-4.34) for symptomatic dry eye and 2.55 (95% CI, 1.90-3.44) for tear-film instability. CONCLUSIONS: Multisite extraocular dryness was associated with higher prevalence of both symptomatic dry eye and tear-film instability in this community-based population without severe meibomian gland loss and may provide clinically relevant phenotypic information. Longitudinal studies are needed to determine whether the association has predictive value.