253Motoko KAWASHIMA, et al.: Screening of dry eye in visual display terminal workers test are simple, noninvasive, and inexpensive methods for screening DED during occupational health examinations. (J Occup Health 2015; 57: 253-258) Key words: Dry eye disease, Occupational health examination, Ophthalmologists, Quality of life, Screening, Visual display terminal Dry eye disease (DED) is a multifactorial condition causing ocular discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface 1) . Occupational changes such as increased VDT use have raised its prevalence among office workers in Japan. For example, 10.1% of the men and 21.5% of the women in an epidemiological study of Japanese office workers using VDTs were clinically diagnosed with DED; severe symptoms were observed in 26.9% and 48.0% of the male and female subjects, respectively 2). VDT use is a remarkable risk factor for dry eye symptoms 2,3) . The daily duration of VDT use is linearly related to dry eye symptoms 4) . Prolonged use is associated with symptoms such as dryness, ocular fatigue, and visual difficulty, which are reported more often than musculoskeletal pain and mental stress 4) . However, current occupational health examinations for VDT users cover only some dry eye symptoms, and DED screening is not routinely performed 5) . Further, few reports of occupational health examinations focusing on DED have been published 6,7) . The aim of this study was to estimate the prevalence of DED among Japanese VDT workers and identify simple methods for screening DED during occupational health examinations. The participants completed questionnaires on dry eye and physical symptoms affecting QoL, and their ability to keep their eyes open for 10 seconds was tested for DED screening. They also underwent assessment of conjunctival and corneal vital staining with lissamine green and fluorescein, measurement of tear film breakup time, and Schirmer's test for DED diagnosis. Sensitivity, specificity, and positive predictive value of the screening methods were assessed. Results: The DED group included 218 (definite, 14; probable, 204) participants. They had markedly high frequencies of 11 dry eye symptoms, especially ocular fatigue (OR, 17.1; 95% CI, 9.9 to 29.7) and dry sensation (OR, 8.2; 95% CI, 3.6 to 18.4), and were more often unable to keep their eyes open for 10 s. With either ocular fatigue or dry sensation as the cutoff criterion, the sensitivity, specificity, and positive predictive value were 89.9, 66.9, and 79.7%, respectively. Conclusions: Approximately 60% of the VDT workers were diagnosed with DED on the basis of diverse eye symptoms affecting their ability to work. The dry eye symptom questionnaire and 10-s eye-opening

Acceptable PPV and NPV were obtained by setting three discriminate categories. This improved version of the DE screening method may be acceptable for practical use in VDT workers.