An alternative way to think about glaucoma screening, using a questionnaire as a tool, Chinese version.

Rationale, Aims And Objectives: To develop a short screening test for the detection of preclinical glaucoma.

Method: This case-control study involved 690 participants aged 40 years or older: 338 patients with glaucoma or suspected glaucoma and 352 patients without glaucoma, who served as a control group. All participants were interviewed by a single trained research assistant. Patients' basic demographic and clinical information, past ophthalmic history and responses on the National Eye Institute 25-item Visual Function Questionnaire were collected. Two glaucoma-trained ophthalmologists examined all the participants using standard procedures to make a diagnosis. The biostatistical differences between the two groups were determined.

Results: Five items were selected for glaucoma screening: 'Sense of worse vision compared with those of the same age', 'Ocular pain or discomfort during the past 6 months', 'History of cataract', 'Family history of glaucoma' and 'Hyperopia'. A score of 2 or more was used to define a group of positive cases with the most appropriate values for sensitivity (79.0%), specificity (76.7%) and predictive power (a positive predictive value of 76.5% and a negative predictive value of 79.2%).

Conclusion: A five-item instrument was developed to detect preclinical glaucoma. Anyone with a score of 2 or more may need further ophthalmic examination and treatment.