Purpose: To evaluate the validity of a dry eye (DE) screening method in visual display terminal (VDT) workers using functional visual acuity (VA) measurement combined with a symptoms questionnaire, and to make recommendations regarding practical use of the screening.
Methods: This prospective cross-sectional study included 369 young and middle-age office workers, who use VDTs. Subjects completed two types of DE questionnaires and underwent DE testing and functional VA measurement. Subjects were assigned to DE and non-DE groups. Sensitivity and specificity of the DE prediction value were assessed. According to the probability distribution of DE and non-DE calculated by the discriminant analysis formula, we classified subjects into three categories based on the most appropriate cut-off levels. Positive predictive value (PPV) and negative predictive value (NPV) of the DE prediction value were also assessed.
Results: Of 369 subjects, 218 and 151 subjects were assigned to the DE and non-DE groups, respectively. Sensitivity and specificity were 93.1% and 43.7%, respectively. Based on the probability prediction, the cut-off levels were defined as probability prediction ≥ 85%, 45% ≤ probability prediction < 85% and probability prediction < 45%. Subjects with a probability prediction ≥ 85% were defined positive (N = 130), while those with values < 45% were defined as negative (N = 73). The PPV and NPV were 83.8% and 80.8%, respectively.
Conclusions: 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.
Keywords: Diagnostic tests/Investigation; Epidemiology; Tears; Vision.
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