Wuhan High Myopia Study

Study Overview
=================
Brief Summary
-----------------
The study aims to observe the long-term changes of ocular（especially fundus） structure and visual function in patients with high myopia, so as to provide evidence for the prevention, diagnosis and prognosis of high myopia.

Detailed Description
-----------------
High myopia is defined as a refractive error of ≤-6.00D or an axial length greater than 26mm. In recent years, the population of highly myopic individuals has been increasing rapidly. Scholars predict that if no effective interventions are taken, the global incidence rate of myopia is expected to increase from 22.9% in 2000 to 49.8% in 2050, and the visual impairment caused by high myopia will be seven times higher than in 2000 on a global scale. In China, a survey conducted by the National Health Commission in 2018 found that highly myopic students accounted for 21.9% of third-year high school students, indicating that high myopia has become a major public health issue due to its prevalence among younger populations. In recent years, with the development of ocular imaging technologies such as optical coherence tomography (OCT) and corresponding image analysis techniques, high-resolution, non-invasive, fast and in vivo retinal imaging has become more accessible. This has led to the discovery and exploration of various imaging parameters related to optic disc and macula changes in highly myopic patients. We will conduct a 4 years prospective cohort study in the population of 1000 high myopia and controls which have established in mainly college student population, using the latest OCT-A and SS-OCT to observe the long-term changes of fundus structure combined with visual function in patients with high myopia , and explore biomarkers affecting visual function, so as to provide basis for prevention and control of high myopia and prognosis.

Official Title
-----------------
Long Term Observation of Ocular Structure and Visual Function in Eyes With High Myopia：Wuhan High Myopia Study

Conditions
-----------------
High Myopia

Intervention / Treatment
-----------------
* Other: observational


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Voluntarily sign informed consent; Commit to follow the research procedures and cooperate with the whole process of the study; Age ≥18 years old; Best corrected visual acuity ≥0.1; Spherical Equivalent Refraction≤-6.00D or axial length ≥26mm in high myopia group； Exclusion Criteria: Unable or unwilling to sign informed consent; Unable to cooperate with the examination; Astigmatism ≤-1.5D； Patients with refractive interstitial opacity so that fundus images cannot be collected； Patients with fundus diseases such as diabetic retinopathy, hypertensive retinopathy, age-related macular degeneration, retinal vein obstruction, retinal artery obstruction, etc

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| entire cohort<br>entire cohort made up of high myopia patients（observational study） | Other: observational<br>* none (observational study)<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Myopic optic nerve changes | Changes in the optic nerve head morphology and blood supply which are supposed to be related with high myopia，examined by fundus photography，OCT，OCTA，etc | Baseline and 6 months and 1，2,3,4years | 
| Progression of axial length (AL) | Subjects' axial length and its progression collected by IOL master 700 | Baseline and 6 months and 1，2,3,4years | 
| Incidence and progression of visual field (VF) defects | Variety and progression of visual field defects collected by Humphrey 860 perimetry | Baseline and 6 months and 1，2,3,4years | 
| Loss of best corrected visual acuity（BCVA） | Incidence of BCVA loss collected by subjective optometry | Baseline and 6 months and 1，2,3,4years | 
| Incidence and progression of myopic maculopathy | Collected by color fundus photography and ultra-wide fundus photography | Baseline and 6 months and 1，2,3,4years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Relationship between the changes of visual function and pathological changes among patients with high myopia | Relationship between the changes of visual function including best corrected visual acuity and visual field and pathological changes among patients with high myopia | Baseline and 6 months and 1，2,3,4years | 
| Structural parameters of anterior segment | Structural parameters of anterior segment including corneal curvature，lens thickness(LT)，etc | Baseline and 6 months and 1，2,3,4years | 
| Intraocular pressure(IOP) | Incidence of elevated intraocular pressure collected by a non-contact tonometer | Baseline and 6 months and 1，2,3,4years | 
| Mental state and quality of life | Mental state and quality of life collected by a questionnaire | Baseline and 6 months and 1，2,3,4years | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
ocular biometric parameters, Refractive Errors