Abnormal dry eye tests are common in students: how healthy is the young population?

Background: Dry eye is common in older people and this condition is believed to be normal in young people.Objective: To evaluate abnormal dry eye test frequency in young population.Method: This is a cross-sectional study conducted on healthcare students (University of Chile) for the evaluation of dry eye disease (DED).Each student answered the Ocular Surface Disease Index (OSDI) questionnaire and underwent evaluation by the Schirmer test (with or without anaesthesia) and the tear Ferning test (TFT).Patients with normal DED results were further studied with tear break-up time (TBUT) and ocular surface staining.Five participants failed to complete the full assessment.Results: A total of 149 subjects (298 eyes) were enrolled in the study, of whom 64 (43.0%) were female.The mean age was 20.6 (SD 2.2) years and the OSDI was abnormal in 30.2% (n = 45) of the participants.Schirmer without anaesthesia and with anaesthesia were abnormal in 26.2% (n = 39) and 22.1% (n = 33), respectively.TFT had the highest abnormal results (71.8%; n = 107).Only 36 (24.2%) students had normal values in all tests.This subset of students was further assessed with TBUT and staining, finding abnormal results in 5.5% (2/36) and 0% (0/36), respectively.Overall, the frequency of students with at least one abnormal test was as high as 77.2% (115/149).However, the correlation between tests was poor.Conclusion: Abnormal DED diagnostic tests were found in a rather high percentage of students.Therefore, finding subjects with normal tests may be a major difficulty, even in a young population.