Study: Dry eye in Beijing Eye Study

Seems to me a rather remarkable feature of this study is the absence of correlation between symptoms and clinical testing....

And people wonder why it's so hard to get FDA approval for dry eye drugs.

Prevalence of dry eye among adult Chinese in the Beijing Eye Study.
Eye. 2008 Feb 29
Jie Y, Xu L, Wu YY, Jonas JB.

PURPOSE To study the prevalence and associations of dry eye symptoms in adult Chinese.
METHODS The Beijing Eye Study is a population-based study in northern China, which included 4439 of 5324 subjects invited to participate with an age of 40+ years (response rate: 83.4%). For the present study, a random sample was taken consisting of 1957(44.1%) subjects (1112 women; 56.9%). Dry eye symptoms were evaluated with (1) an interviewer-assisted questionnaire; (2) measurement of the tear-film break-up time; (3) assessment of the fluorescein staining of the cornea; (4) slit-lamp-based examination of a meibomian gland dysfunction; and (5) Schirmer's test.
RESULTS Symptoms of a dry eye felt 'often' or 'at all times' were present in 411 subjects (21.0%). In a multivariate analysis, dry eye symptoms were significantly associated with age (P<0.001), female gender (P<0.001; odds ratio (OR): 1.56; 95% confidence intervals (CI): 1.23, 1.98), urban region (P<0.001;OR: 1.89; 95% CI: 1.46, 2.48), low degree of nuclear cataract (P=0.02), and undercorrection of refractive error (P=0.005; OR: 1.42; 95% CI: 1.11, 1.82). All tests for dry eye did not vary significantly between the dry eye group and the normal group.
CONCLUSIONS The dry eye symptoms as evaluated subjectively in a questionnaire occurred in about 21% of the adult population in China, with associations to age, female gender, urban region, and undercorrection of a refractive error. Measurement of the tear-film break-up time, assessment of the corneal fluorescein staining, slit-lamp-based examination of a meibomian gland dysfunction, and Schirmer's test were not significantly associated with dry eye symptoms.