Cytokine/Chemokine Expression in Reflex Tears from Employers Exposed to Computer Screens in a Healthy Office Environment

Objective: To inform employees exposed to computer screens (CSs) about the risk of dry eye disorders (DEDs) and how to prevent them. Methods: From a total of 800 public-sector employees, eighty-eight CSs users were randomly selected to participate in an interview and an ophthalmic examination, and compared to thirty-six healthy volunteers no CSs users including family members, nurses and assistants. Environmental conditions in the workplace were documented. Reflex tear samples were collected simultaneously from both eyes and were later subjected to a multiplexed particlebased flow cytometry assay. A specific set of immune response biomarkers was analyzed. Results: The mean age was 52.17 (5.17) years; 27% were men and 73% women. DEDs were newly diagnosed in 86% of the participants. Mean CS exposure was 4.8 (1.27) hours. Environmental workplace conditions complied with general standards. Schirmer test results and blinking frequency were pathologic in up to 2/3 of the employers exposed to CSs. Immune response biomarkers were detected in 90% of tear samples. Compared with records of healthy, non-exposed control subjects in a pre-existing database, tear samples of the participants exposed to CSs had significantly higher levels of interleukins (IL) (IL1B, IL2, IL6, IL8), GM-CSF, IFG, and VEGF. Conclusion: Employee exposure to CSs was a major risk factor for DED, being inflammation a main contributor to ocular surface pathogenesis.