Light-at-night exposure drives myopia via melanopsin signalling

Area of Science:

• Ophthalmology
• Chronobiology
• Molecular Biology

Background:

• Myopia is a global health issue with unclear mechanisms.
• Daytime light is protective, but nighttime light's role in myopia is debated.

Purpose of the Study:

• Investigate the impact of light at night (LAN) on myopia development.
• Elucidate the role of melanopsin signaling in LAN-induced myopia.

Main Methods:

• Utilized a murine model to study gene expression and ocular growth.
• Analyzed melanopsin-dependent pathways and circadian clock genes.
• Conducted epidemiological analysis in humans.

Main Results:

• LAN exposure disrupted circadian clock genes (Arntl, Cry1, Per1, Per2) and downregulated melanopsin in ipRGCs.
• LAN-induced alterations were linked to axial elongation.
• Melanopsin-knockout mice were resistant to LAN-induced myopia.
• Epidemiological data showed LAN exposure increases myopia onset risk in humans.

Conclusions:

• Established a functional link between environmental light exposure and myopia pathogenesis.
• Identified LAN as a modifiable risk factor for myopia.
• Melanopsin signaling is a potential therapeutic target for myopia prevention and treatment.