The Effects of Different Outdoor Light Exposure Modes on Retinal Blood Flow
Condition: Myopia
MeSH terms: Myopia
Study type: Interventional

Summary: 
      In 2020, the overall myopia rate among children and adolescents in my country was 52.7%. The
      COVID-19 pandemic has increased students' time of indoor eye-using, and it showed that the
      light exposure intensity of myopic students is lower than that of non-myopia students.
      Studies have found that the light wave bandwidth has a significant impact on the
      emmetropization of the eye, and white light can promote emmetropia more than monochromatic
      light. It shows that outdoor exercise has a protective effect on the occurrence and
      development of myopia in children and adolescents, but the specific mechanism is still
      unclear. Retinal blood flow is sensitive to myopic stimuli, and is a short-term indicator of
      the relationship between light environment and myopia. This study selected retinal blood flow
      as the primary outcome, aiming to compare the effects of different outdoor light exposure
      modes on retinal blood flow after 1 hour of intense eye use, and provide clues for the
      prevention and control of myopia.
    

Detailed description: 
      In 2018, eight departments including the Ministry of Education jointly issued the
      Implementation Plan for Comprehensive Prevention and Control of Myopia in Children and
      Adolescents. As of 2020, the overall myopia rate among children and adolescents in my country
      was 52.7%. The COVID-19 pandemic has increased students' time of indoor eye-using, and it
      showed that the light exposure intensity of myopic students is lower than that of non-myopia
      students. Studies have found that the light wave bandwidth has a significant impact on the
      emmetropization of the eye, and white light can promote emmetropia more than monochromatic
      light. It shows that outdoor exercise has a protective effect on the occurrence and
      development of myopia in children and adolescents, but the specific mechanism is still
      unclear. Retinal blood flow is sensitive to myopic stimuli, and is a short-term indicator of
      the relationship between light environment and myopia. Also, there is a theory that reduced
      choroidal blood flow causes scleral hypoxia, which leads to the development of myopia.
      Therefore, this study selected retinal blood flow as the primary outcome, aiming to compare
      the effects of different outdoor light exposure modes on retinal blood flow after 1 hour of
      intense eye use, and provide clues for the prevention and control of myopia.
    

Intervention name(s): Weak outdoor light; Strong outdoor light
Intervention type(s): Behavioral; Behavioral
Intervention description(s): Stay and stare far on the balcony or under the tree; Stay and stare far in the sunlight
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: The participants were randomly divided into the following two groups:
4000Lux natural light exposure;
10000Lux natural light exposure.
Masking: Single (Participant)
Primary purpose: Prevention
Keywords: myopia; retinal blood flow; accommodative micro-fluctuation; outdoor light exposure