Prevalence of Presbyopia (Near Vision Fatigue) and Related Factors Among Working Adults Aged 30 to 55 Years in Shanghai (FOCUS)
Prevalence and Associated Factors of Presbyopia Among Working Adults Aged 30-55 Years in Shanghai, China: A Cross-Sectional Study
This observational study aims to determine how common presbyopia is among working adults aged 30-55 years in Shanghai, China, and identify factors associated with it. Presbyopia is an age-related loss of the eye's ability to focus on nearby objects, which can make reading and other close-up activities difficult.
Participants will undergo eye examinations and complete questionnaires about their vision, work activities, use of digital screens, lifestyle, and need for vision correction. The study aims to obtain valid primary outcome data from at least 1,366 participants. It will also assess how closely the results of the NVC mini-program agree with a professional eye examination. No treatment will be assigned as part of the study.
Visão geral do estudo
Status
Status
Condições
Condições
Descrição detalhada
This cross-sectional observational study will investigate the prevalence of presbyopia (near fatigue) and associated factors among working adults aged 30-55 years in Shanghai, China. Eligible participants must have worked in their current position for at least one year and provide written informed consent.
Industry-stratified two-stage sampling will be used, with the ISIC Rev.5 classification as the industry stratification framework. At the first stage, workplaces are randomly selected from candidate workplace rosters within each industry stratum; the study plans to include at least 15 independent workplaces covering at least 5 ISIC Rev.5 sections. At the second stage, eligible employees are randomly sampled from complete, de-duplicated employee rosters of the selected workplaces; if the number of eligible employees in a workplace does not exceed the planned invitation quota, all eligible employees are invited. The target is at least 1,366 participants with valid primary outcome data. Allowing for an estimated combined nonresponse and unusable primary outcome data rate of 20%, at least 1,708 individuals will need to be invited.
Data collection will include questionnaires and standardized ophthalmic examinations. Questionnaires will assess demographic and occupational characteristics, near-work demands, screen exposure, sleep, outdoor activities, lifestyle, ocular symptoms, awareness of presbyopia, previous correction, and correction needs and preferences. The NAVQ-P and OSDI questionnaires will assess near-vision difficulties and ocular surface symptoms. Examinations will assess distance, intermediate, and near visual acuity, refraction, near addition power (ADD), accommodative function, and ocular health. NVC mini-program outputs, including presbyopia severity categories and recommended ADD ranges, will also be recorded.
The primary outcome is the prevalence of presbyopia. Presbyopia is defined as binocular near visual acuity worse than N8 at 40 cm under best distance correction, improving by at least one line to N8 or better with additional positive spherical lenses, after excluding other ocular diseases sufficient to explain the reduction in near vision.
Secondary assessments will describe visual function, the relationship between accommodative amplitude and age, awareness of presbyopia, and correction needs. Associations with demographic, occupational, refractive, behavioral, and dry-eye-related factors will be examined. Analyses will account for industry stratification, workplace clustering, and unequal sampling probabilities as appropriate.
Agreement between NVC outputs and subjective refraction ADD will be assessed using overall percent agreement, the proportions of classifications differing by one grade and by two or more grades, and Kendall's tau-b correlation between NVC grades and clinical grades. The proportion of reference ADD values falling within the NVC-recommended ranges will also be calculated. No treatment will be assigned as part of this observational study.
Tipo de estudo
Tipo de estudo
Inscrição (Estimado)
Inscrição
Contactos e Locais
Contato de estudo
Contato de estudo
- Nome: Xiangui He MD, PhD
- Número de telefone: 021-53555032
- E-mail: xianhezi@163.com
Critérios de participação
Critérios de elegibilidade
Critérios de elegibilidade
Idades elegíveis para estudo
Aceita Voluntários Saudáveis
Gêneros Elegíveis para o Estudo
Método de amostragem
População do estudo
Working adults aged 30-55 years employed in their current position for at least one year, recruited from at least 15 independent workplaces in Shanghai covering at least 5 ISIC Rev.5 industry sectors (education; manufacturing; construction; human health and social work activities; financial and insurance activities; public administration; professional, scientific and technical activities; administrative and support service activities). Within each workplace, eligible employees are randomly sampled from complete, de-duplicated rosters; if eligible employees do not exceed the planned invitation quota, all are invited. Participants are examined regardless of presbyopia status; the target population includes people with and without presbyopia.
Descrição
Inclusion Criteria:
- Aged 30 to 55 years inclusive, based on date of birth on the national identification card
- Either sex
- Employed in the current position for at least one year
- Willing to participate and able to provide written informed consent
- Able to complete the questionnaire and the ophthalmic examinations
Exclusion Criteria:
- Active ocular inflammation, significant ocular trauma, or other acute ocular condition within the past 3 months that precludes visual function testing
- Previous intraocular surgery that substantially affects refractive status or visual function assessment, such as cataract surgery or refractive lens surgery
- Obvious cognitive impairment, severe psychiatric disease, or other condition preventing cooperation with the survey and examinations
- Markedly reduced best-corrected distance visual acuity with ocular disease sufficient to explain the near vision abnormality, including but not limited to adult amblyopia, significant corneal scarring, keratoconus, severe corneal dystrophy, significant lens opacity, and severe macular or optic nerve disease
- Severe fundus or optic nerve disease, including macular degeneration, significant maculopathy, retinal detachment, optic atrophy or advanced glaucoma
- Any other condition judged by the investigators to make participation unsuitable
Plano de estudo
Como o estudo é projetado?
Detalhes do projeto
- Modelos de observação: COHORT
- Perspectivas de Tempo: CROSS_SECTIONAL
O que o estudo está medindo?
Medidas de resultados primários
Medidas de resultados primários
Medida de resultado |
Descrição da medida |
Prazo |
|---|---|---|
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Prevalence of presbyopia among working adults aged 30 to 55 years in Shanghai
Prazo: Day 1 (At the single study visit (cross-sectional assessment))
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Proportion of participants meeting the study definition of presbyopia: binocular near visual acuity worse than N8 (equivalent to 20/50) at 40 cm under standard illumination with full distance refractive correction, improving by at least one line to N8 or better after binocular addition of plus lenses, after exclusion of organic ocular disease that could independently explain reduced near vision. Reported as a percentage with 95 percent confidence interval, overall and stratified by 5-year age group, sex, occupation, education level, refractive status and screen exposure level. |
Day 1 (At the single study visit (cross-sectional assessment))
|
Medidas de resultados secundários
Medidas de resultados secundários
Medida de resultado |
Descrição da medida |
Prazo |
|---|---|---|
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Amplitude of accommodation by age group
Prazo: Day 1 (At the single study visit (cross-sectional assessment))
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Amplitude of accommodation in diopters, measured by the push-up method under full distance correction, repeated three times per eye and averaged. Reported as mean and standard deviation or median and interquartile range by 5-year age group, and used to fit the accommodation-age curve. |
Day 1 (At the single study visit (cross-sectional assessment))
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Adjusted odds ratios for factors associated with presbyopia
Prazo: Day 1 (At the single study visit (cross-sectional assessment))
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Association of presbyopia with age, sex, education level, occupation and job type, refractive status, near-work duration, screen exposure, sleep duration and quality, outdoor activity and dry eye measures, estimated by generalized estimating equations or mixed-effects logistic regression with workplace as a clustering variable or random effect. Reported as adjusted odds ratios with 95 percent confidence intervals. |
Day 1 (At the single study visit (cross-sectional assessment))
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Awareness of presbyopia and need for near vision correction
Prazo: Day 1 (At the single study visit (cross-sectional assessment))
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Description: Questionnaire-based assessment of awareness and understanding of presbyopia, previous care-seeking, current correction methods and wearing time, acceptance of correction options, acceptable price range, and future intention to use correction. Near vision-related quality of life assessed with the Chinese version of the Near Activity Visual Questionnaire for Presbyopia (NAVQ-P). Reported as frequencies and percentages. |
Day 1 (At the single study visit (cross-sectional assessment))
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Correlation between presbyopia severity grade and dry eye severity grade
Prazo: Day 1 (At the single study visit (cross-sectional assessment))
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Dry eye graded as mild, moderate or severe based on the Ocular Surface Disease Index (OSDI), non-invasive tear break-up time, tear meniscus height and slit-lamp findings. Correlation with presbyopia severity grade assessed by Spearman rank correlation and, where appropriate, ordinal logistic regression adjusted for age, sex, refractive status, screen exposure and near-work load. |
Day 1 (At the single study visit (cross-sectional assessment))
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Agreement between NVC mini-program outputs and subjective refraction
Prazo: Day 1 (At the single study visit (cross-sectional assessment))
|
The near-fatigue severity grade and recommended ADD range output by the NVC mini-program will be compared with the reference ADD obtained by subjective refraction. Agreement measures include overall percent agreement, the proportion of classifications differing by one grade, the proportion differing by two or more grades, and Kendall's tau-b correlation between NVC grades and clinical grades. The proportion of reference ADD values falling within the NVC-recommended ranges will also be calculated. |
Day 1 (At the single study visit (cross-sectional assessment))
|
Colaboradores e Investigadores
Patrocinador
Patrocinador
Colaboradores
Colaboradores
Datas de registro do estudo
Datas Principais do Estudo
Início do estudo (Estimado)
Início do estudo
Conclusão Primária (Estimado)
Conclusão Primária
Conclusão do estudo (Estimado)
Conclusão do estudo
Datas de inscrição no estudo
Enviado pela primeira vez
Enviado pela primeira vez
Enviado pela primeira vez que atendeu aos critérios de CQ
Enviado pela primeira vez que atendeu aos critérios de CQ
Primeira postagem (Real)
Primeira postagem
Atualizações de registro de estudo
Última Atualização Postada (Real)
Última Atualização Postada
Última atualização enviada que atendeu aos critérios de controle de qualidade
Última atualização enviada que atendeu aos critérios de controle de qualidade
Última verificação
Última verificação
Mais Informações
Termos relacionados a este estudo
Palavras-chave
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Outros números de identificação do estudo
Outros números de identificação do estudo
- IIT2026-015
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