Shanghai High Myopia Study

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the long-term visual outcome of the cataract surgery using a large-scale and comprehensive database of high myopic cataract and age-related cataract patients. The investigators will further investigate into the various genetic and environmental factors that may contribute to the pathogenesis of high myopic cataract.

Detailed Description
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High myopic cataract (HMC) has become a major high-risky type of cataract in China, which accounts for nearly 30% of cataract in recent years. Compared to age-related cataract, HMC is characterized with earlier onset, severer lens opacities, higher incidence of vitreoretinopathy and postoperative complications compared to age-related cataract(ARC). The main purpose of this study is to evaluate the long-term visual outcome of the cataract surgery using a large-scale and comprehensive database of high myopic cataract, when compared to those age-matched ARC patients. On the other hand, due to the lack of research in the pathogenesis of HMC, it is difficult for the investigators to precisely evaluate its risk and prognosis, and to improve its prevention and treatment. The previous study of investigators majored in a large-sample analysis on the clinical features and related genes of HMC. After preliminary screening, eight genes were selected for further investigation: 1) genes related to pathogenesis of HMC: CRYAA/ GSTP1/ TXNRD2;2) genes related to vitreoretinopathy: MCP1/ VEGFA/ CFH; 3) genes related to postoperative complications: TGFB2/ CERS2. In the present study, in order to establish a risk model of HMC from the aspect of precision medicine, the investigators are preparing to set up a comprehensive clinical database for further sequencing of selected genes (including exons, promoters, 5' UTR and 3' UTR sequences) on a large scale, to intensively investigate into the sites and functions of single nucleotide polymorphism (SNP) correlated with clinical features of HMC. The research aim to evaluate the long-term visual outcome of the cataract surgery using a large-scale and comprehensive database of high myopic cataract, to thoroughly illustrate the influence of HMC-related genes to its prognosis and to elucidate the pathogenesis of HMC, for further promotion in the disease prevention and prognosis as well.

Official Title
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Visual Outcome Evaluation and Genetic Analysis: Shanghai High Myopia Study

Conditions
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High Myopia, Cataract, Visual Outcome, Genetic Anticipation

Intervention / Treatment
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* Other: Cataract


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Clinical diagnosis of cataract Must be able to cooperate with the ophthalmic examination Exclusion Criteria: Clinical diagnosis of mental illness Mentally disabled

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 100 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| High myopic cataract group<br>Cataract patients with high myopia. | Other: Cataract<br>* The genetic and environmental factors concerning to the pathogenesis of cataract in the three groups.<br>|
| Age-related cataract group<br>Age-related cataract patients. | Other: Cataract<br>* The genetic and environmental factors concerning to the pathogenesis of cataract in the three groups.<br>|
| Ametropic cataract group<br>Cataract patients with ametropia. | Other: Cataract<br>* The genetic and environmental factors concerning to the pathogenesis of cataract in the three groups.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in the clinical phenotypes and visual outcomes of high myopic cataract patients | Cataract type and severity of high myopic cataract patients are evaluated using LOCSIII grading system. Visual outcomes are also evaluated including visual acuity with or without correction, intraocular pressure, fundus function, contrast sensitivity and other visual outcome measurements. | Follow-up until five years after surgery | 
| Differences in the clinical phenotypes and visual outcomes of age-related cataract patients | Cataract type and severity of age-related cataract patients are evaluated using LOCSIII grading system. Visual outcomes are also evaluated including visual acuity with or without correction, intraocular pressure, fundus function, contrast sensitivity and other visual outcome measurements. | Follow-up until five years after surgery | 
| Differences in the clinical phenotypes and visual outcomes of ametropic cataract patients | Cataract type and severity of ametropic cataract patients are evaluated using LOCSIII grading system. Visual outcomes are also evaluated including visual acuity with or without correction, intraocular pressure, fundus function, contrast sensitivity and other visual outcome measurements. | Follow-up until five years after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Genetic diversity based on biological specimen samples of three groups | Sequencing of selected genes (including exons, promoters, 5' UTR and 3' UTR sequences) on a large scale to intensively investigate into the sites and functions of single nucleotide polymorphism (SNP) correlated with clinical features of HMC, compared to age-related cataract and ametropic cataract patients. | Analyzed within six months after surgery |