Ambient Light Levels in the Kindergarten and Schools and the Relation to Refractive Development

Study Overview
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Brief Summary
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Myopia, the most common human eye disorder, is a phenomenon characterized by an unconstrained elongation of the eye globe There are number of theories concerning the environmental effect on the emmetropization process, most are related to childhood exposure to outdoor activity, near work and sleep with night light. Studies in lab animals found an association between intensity of ambient lighting and myopia development. In this study, the investigators will examine the ambient light in kindergarten and schools and their relation to refractive error. Diurnal luminance in kindergarten and school class room will be measured and correlated to biometric measures such as refraction, axial length and keratometry.

Official Title
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Ambient Light Levels in the Kindergarten and Schools and the Relation to Refractive Development

Conditions
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Myopia

Intervention / Treatment
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* Other: autorefractometer, A-scan ultrasound


Participation Criteria
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Eligibility Criteria
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Inclusion criteria Every child that have been studying in the same class for the last 6-12 months (kindergarten and school respectively). Exclusion criteria Noncooperative child or parents. Ocular surgery. Ocular genetic disease.

Ages Eligible for Study
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Minimum Age: 4 Years
Maximum Age: 17 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: autorefractometer, A-scan ultrasound|A measurement of refraction will be made by the Autorefractometer. A measurement of the eyes' biometer data will be made by A-scan ultrasound.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the relation between the level of myopia and light intensity | an analysis of the correlation between the two variables. the data will be collected as reported in the secondary outcome measures (number 2 and 5). | change from baseline at the start point of the study, after 6 months and after 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| levels of ambient light intensity | Classes that are influenced by sunlight will be examined for light levels at a specific day of each month . For classes that are not influenced by sunlight, light source and levels will be documented. the measurement will be held until study completion. will be measured by luxmeter. the results will be in LUX (standardised unit of measurement of light intensity) | natural light- start of study and once a month until completion, average of 1 year. artificial light- once at the start point of the study | 
| measurement of axial length | will be measured using A-scan ultrasound. the results will be in millimeters. | change from baseline at the start point of the study, after 6 months and after 12 months | 
| measurement of Visual acuity | will be measured using LogMAR chart. | change from baseline at the start point of the study, after 6 months and after 12 months. | 
| measurement of refraction | will be measured using autorefractometer. the results will be in diopter | change from baseline at the start point of the study, after 6 months and after 12 months. | 
| measurement of cornea curvature | will be measured using autorefractometer. the results will be in millimeters. | change from baseline at the start point of the study, after 6 months and after 12 months. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Effects, Heat, Light