Interaction Between Near Work and Narrowband Light on Choroidal Thickness

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Near work is a risk factor for myopia progression.
• The impact of light spectrum on ocular structures during near work is not fully understood.
• Choroidal thickness (CT) and axial length (AL) are key indicators of ocular growth and myopia development.

Purpose of the Study:

• To investigate the effects of blue and red light exposure during near work on choroidal thickness (CT) and axial length (AL).
• To assess the impact of different light wavelengths on accommodative responses.
• To determine if blue light can mitigate biomechanical stress on the posterior eye during sustained near work.

Main Methods:

• Twenty-five participants (9 myopes, 16 nonmyopes) underwent near work (5 D demand) under broadband, blue (457 nm), and red (628 nm) light conditions, plus a control.
• Choroidal thickness (CT) and axial length (AL) were measured using optical coherence tomography and biometry.
• Dynamic accommodative responses were recorded under each light condition.

Main Results:

• Near work under broadband and red light led to significant decreases in CT and increases in AL.
• Blue light exposure during near work did not cause significant changes in CT or AL.
• Blue light was associated with a post-task reduction in AL and a significantly reduced accommodative response.

Conclusions:

• Sustained near work under red and broadband light induces acute biomechanical stress on the posterior eye, evidenced by choroidal thinning and axial elongation.
• Blue light exposure during near work may mitigate these biomechanical stresses.
• Blue light's effect on accommodative response warrants further investigation regarding its role in myopia management.