Prevention of computer vision syndrome and dry eye syndrome in workers using video display terminals Eye Diseases
Conditions
Interventions
Current interventions as of 28/08/2026:
Stratified cluster randomization by study site will be performed to allocate clusters to either the intervention or usual-care control group. Participants in
Sponsors
Universitat Pompeu Fabra
Hospital del Mar Research Institute
Eligibility
Sex/Gender
All
Age
18 Years to 70 Years
Inclusion criteria
Inclusion criteria: Current key inclusion criteria as of 28/08/2026: Selected clusters will consist of independent work units, defined as either a standalone building or a clearly delineated work area located on a separate floor within the same building. Eligible participants must be aged 18–70 years, hold a full-time employment contract, have worked in the selected cluster for at least one year, be actively employed at study initiation, and have occupational exposure to video display terminals (VDTs) for at least four hours per workday. _____ Previous key inclusion criteria: Participants must have been working in the selected cluster (independent building) for at least the last year, hold a full-time contract, and be actively employed at the beginning of the study.
Exclusion criteria
Exclusion criteria: Current key exclusion criteria as of 28/08/2026: 1. History of ocular surgery or ocular procedures that may substantially affect the ocular surface, tear film, or visual function 2. Presence of active ocular disease, other than CVS or DES, that may interfere with the assessment of visual or ocular outcomes 3. Presence of systemic diseases known to substantially affect the ocular surface or tear production, including autoimmune or connective tissue diseases such as Sjögren’s syndrome 4. Current use of systemic or topical medications known to substantially affect tear production, tear-film stability, or ocular surface status 5. Any other ophthalmological, systemic, or neurological condition that, in the investigators’ clinical judgment, could substantially interfere with the assessment of CVS or DES or act as a major confounding factor 6. Inability to complete the study questionnaires or undergo the scheduled optometric and ophthalmological examinations 7. Failure to provide written informed consent _____ Previous key exclusion criteria: 1. Workers under 18 or over 70 years old 2. Workers not currently employed in the selected cluster (independent building) for at least the past year 3. Workers with part-time contracts 4. Individuals who, although belonging to any of the intervention or control clusters, are not actively employed at the beginning of the study 5. Individuals who do not consent to sign the informed consent document
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Current primary outcome(s) as of 28/08/2026: 1. Prevalence of Computer Vision Syndrome (CVS) at 12 months. CVS will be assessed using the validated Computer Vision Syndrome Questionnaire (CVS-Q©). A participant will be classified as having CVS when the total CVS-Q© score is =6. CVS will be assessed at baseline (T0), 6 months (T1), and 12 months (T2), with the 12-month assessment representing the co-primary endpoint 2. Prevalence of Dry Eye Syndrome (DES) at 12 months. DES will be assessed using the validated Ocular Surface Disease Index (OSDI©) together with clinical assessment of the ocular surface and tear film. DES will be defined as an OSDI© score =13 in combination with at least one abnormal ocular surface and/or tear-film test result. DES will be assessed at baseline (T0), 6 months (T1), and 12 months (T2), with the 12-month assessment representing the co-primary endpoint _____ Previous primary outcome(s): Prior to the intervention (T0) and at the established follow-up time points: T1 at 6 months and T2 at 12 months: 1. Variable "Prevalence of Computer Visual Syndrome (CVS)" assessed using the CVS-Q© questionnaire. 2. Variable "Prevalence of Dry Eye Syndrome (DES)" assessed using the the OSDI© questionnaire. The presence of Computer Vision Syndrome (CVS) will be defined as a score of =6 on the CVS-Q© questionnaire. In accordance with the recommendations of the Dry Eye Workshop II of the Tear Film & Ocular Surface Society (TFOS DEWS II), the presence of DES will be defined as a score of =13 on the Ocular Surface Disease Index (OSDI©), in combination with at least one abnormal result from ocular surface and/or tear film tests (Wolffsohn et al., 2017). | — |
Secondary
| Measure | Time frame |
|---|---|
| Current key secondary outcome(s) as of 28/08/2026: Process evaluation outcomes: 1. Implementation of the INTERVIS intervention will be evaluated through recruitment, context, reach, dose delivered, dose received, intervention fidelity, participant adherence, and participant satisfaction. Quantitative indicators will be complemented by qualitative information obtained through focus groups. Process indicators will be collected throughout the 12-month intervention period, as appropriate for each intervention component 2. Health-related quality of life and quality-adjusted life years (QALYs): Health-related quality of life will be assessed using the EQ-5D-3L at baseline (T0), 6 months (T1), and 12 months (T2). Utility values will be derived using the Spanish value set, and QALYs over the 12-month study period will be estimated using the area-under-the-curve method Cost-effectiveness outcomes: 3. Costs will be assessed over the 12-month study period from the National Health System and societal perspectives. Separate incremental cost-effectiveness ratios (ICERs) will be estimated for CVS and DES and expressed as the incremental cost per case of CVS prevented and the incremental cost per case of DES prevented, respectively Cost-utility outcome: 4. Cost-utility will be assessed over the 12-month study period by estimating the incremental cost per quality-adjusted life year (QALY) gained, comparing the INTERVIS intervention with usual occupational health care from both the National Health System and societal perspectives _____ Previous key secondary outcome(s): Prior to the intervention (T0) and at the established follow-up time points: T1 at 6 months and T2 at 12 months: 1. Process Evaluation Variables: the variables assessed will include recruitment, context, reach, dose delivered, fidelity, and satisfaction, as previously defined 2. Cost-Effectiveness Variables: costs will be as described in the previous section. Effectiveness will be based on the prevalence outcom | — |
Countries
Spain
Contacts
Public ContactJoana Guerrero Monge
Outcome results
None listed