Eye Health, Myopia, Strabismus
Conditions
Brief summary
This project proposes to conduct a prospective, multicenter registry study in rural China to evaluate, under real-world conditions, the implementation effectiveness of an integrated child eye health service model centered at the county level and coordinated across county, township, village, and school tiers. The target population will include all children and adolescents within participating counties, and the primary exposure will be the annual coverage and implementation intensity of this service model. The study will focus on its impact on clinical outcomes such as refractive error correction rates and referral rates following eye disease screening, while also examining annual trends in disparities in access to different eye care services. Through long-term and systematic observation, the project aims to clarify the sustained effects of this eye health service model on improving the management of pediatric eye diseases, enhancing visual function, and promoting health equity, thereby providing evidence-based support for optimizing the rural child eye care system in China.
Detailed description
This project aims to address gaps in child eye health services in rural areas of China by developing an accessible, affordable, high-quality, and sustainable model of pediatric eye care. Childhood represents a critical stage of development, and if visual problems are not identified and treated in a timely manner, they may substantially impair motor, language, emotional, social, and cognitive development, with long-term adverse consequences for lifelong health and socioeconomic participation. At present, the leading cause of visual impairment among children in China is uncorrected refractive error, accounting for more than 90% of cases. China has one of the highest prevalences of refractive error in the world. In 2020, the overall prevalence of myopia among Chinese children and adolescents was 52.7%; the prevalence was 14.3% at age 6, 35.6% in primary school, 71.1% in junior high school, and 80.5% in senior high school. Myopia has become a major public health issue affecting population health. Although wearing spectacles is a safe and cost-effective intervention for myopia correction, inadequate parental awareness, misconceptions about spectacle use, and the lack of high-quality refraction services at the primary-care level together constitute major barriers to effective correction of refractive errors. In addition to refractive error, amblyopia is also relatively common in children, with a prevalence ranging from 1.0% to 5.0%. Among the approximately 300 million children in China, it is estimated that at least 3 million are affected by amblyopia. Risk factors for amblyopia include refractive error, anisometropia, strabismus, and congenital cataract, and the condition is most commonly seen during the preschool years, which are critical for visual development. If not detected and treated early, amblyopia may progress to persistent visual impairment. Although vision can often be improved through standardized treatment and training, treatment effectiveness declines with age; therefore, early screening and intervention are central principles of amblyopia prevention and control. At present, the distribution of ophthalmic resources in China is mismatched with the geographic distribution of patients: approximately 70% of ophthalmic patients are located in primary-level settings, whereas high-quality resources are concentrated in urban areas. In rural regions, eye care services are markedly inadequate in terms of availability, accessibility, affordability, and acceptability, which seriously constrains efforts to prevent and manage childhood eye diseases. Therefore, a key scientific and practical challenge is how to establish and sustainably operate an integrated child eye care system in resource-limited settings. Against this background, the project proposes to explore a pediatric eye care model tailored to rural China by conducting eye health screening among children and adolescents, establishing a county-level referral system for pediatric eye diseases, and strengthening pediatric ophthalmic service capacity in county hospitals. The project will also develop related service guidelines and implementation plans, with the ultimate goal of improving children's visual health and quality of life.
Interventions
OTHERSchool-based Eye Health Screening
This intervention consists of standardized annual school-based eye health examinations conducted under routine field conditions. Basic demographic information, including sex and age, is first recorded. Visual acuity testing is performed before intraocular pressure measurement or any other examination that may affect vision. Uncorrected visual acuity and, where applicable, presenting visual acuity are measured using a standard logarithmic visual acuity chart or ETDRS chart. For participants whose visual acuity is worse than 0.8, pinhole visual acuity is additionally assessed. Intraocular pressure is measured using non-contact tonometry (NCT). For children suspected of strabismus or amblyopia, further assessments may include ocular position examination, alternate cover testing, corneal light reflex testing, angle measurement, and an automatic smartphone-based Digital Ruler of Strabismus (DRS). Refraction is measured using a computerized autorefractor. This screening workflow enables syst
Sponsors
Zhongshan Ophthalmic Center, Sun Yat-sen University
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
3 Years to 18 Years
Healthy volunteers
Yes
Inclusion criteria
* Aged 3 to 18 years; Enrolled in schools within the study areas, including kindergartens, primary schools, junior high schools, and senior high schools, in Yangxi County, Jiexi County, Huidong County, and Yingde City of Guangdong Province, as well as Fengqing County of Yunnan Province, or are children and adolescents who are permanent residents within these jurisdictions. * Written informed consent has been provided by their legal guardians. * For children aged 8 years and older, assent from the child is also required.
Exclusion criteria
* Presence of severe systemic diseases (such as severe congenital heart disease or intellectual developmental disorders) that preclude cooperation with ophthalmic examinations. * Refusal by the legal guardian to participate, or inability of the legal guardian to cooperate with scheduled follow-up visits.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Annual Eye Health Screening Coverage Rate | Through study completion, assessed once per year, with completion expected within 3 years. | The proportion of children who actually received eye health screening among the total number of target children in the study area during a given year, calculated as: number of children screened / total number of target children in the catchment area × 100%. This indicator reflects the reach and implementation coverage of the annual screening program. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| DRS Sensitivity | Through study completion, assessed once per year, with completion expected within 3 years. | Sensitivity is defined as the proportion of true strabismus cases that are correctly identified as positive by the DRS. |
| Refractive Error Correction Rate | Through study completion, assessed once per year, with completion expected within 3 years. | At annual reassessment, children previously diagnosed with refractive error but not yet corrected will undergo repeat refraction to determine whether they are now wearing appropriately prescribed spectacles. This indicator reflects the extent to which identified refractive errors have been corrected in the target population. |
| Effective Refractive Error Correction Coverage (eREC) | Through study completion, assessed once per year, with completion expected within 3 years. | The proportion of individuals in need of refractive error correction who have received correction, such as spectacles, contact lenses, or refractive surgery, and have achieved an effective or adequate visual outcome. This indicator measures not only access to refractive correction, but also the quality and effectiveness of that correction. |
| Strabismus/Amblyopia Screening Detection Rate | Through study completion, assessed once per year, with completion expected within 3 years. | The proportion of children screened who are identified as having strabismus or amblyopia, calculated as: number of children screened positive for strabismus or amblyopia / total number of children participating in eye health screening × 100%. This indicator reflects the program's yield in detecting major pediatric ocular alignment and visual development disorders. |
| Referral Rate After Eye Disease Screening | Through study completion, assessed once per year, with completion expected within 3 years. | The proportion of children with positive screening results who are successfully referred to county-level hospitals, calculated as: number of screen-positive children who actually attended referral at county-level hospitals / total number of screen-positive children × 100%. This indicator reflects the effectiveness of the referral pathway and the linkage between screening and follow-up care. |
| DRS Specificity | Through study completion, assessed once per year, with completion expected within 3 years. | Specificity is defined as the proportion of non-strabismus cases that are correctly identified as negative by the DRS. |
| DRS Positive predictive value (PPV) | Through study completion, assessed once per year, with completion expected within 3 years. | PPV is defined as the proportion of DRS-positive cases that are confirmed as true strabismus by the reference standard. |
| DRS Accuracy | Through study completion, assessed once per year, with completion expected within 3 years. | Accuracy is defined as the proportion of all screened subjects who are correctly classified by the DRS. |
Countries
China
Contacts
CONTACTWenyong Huang, Professor
Outcome results
None listed