Omega-3 Polyunsaturated Fatty Acids as a Protective Factor for Myopia

Area of Science:

• Ophthalmology and Vision Science
• Nutritional Science
• Genetics and Epidemiology

Background:

• Animal studies suggest omega-3 polyunsaturated fatty acids (PUFAs) may prevent myopia by influencing choroidal blood flow.
• Clinical evidence supporting the role of omega-3 PUFAs in myopia prevention is limited and inconsistent.
• Mendelian randomization (MR) offers a method to investigate causal relationships using genetic variants.

Purpose of the Study:

• To determine the causal relationship between omega-3 polyunsaturated fatty acids (PUFAs) and myopia.
• To assess the genetic predisposition to higher plasma levels of fatty acids and their association with refractive error and axial length.

Main Methods:

• A two-sample Mendelian randomization (MR) analysis was conducted.
• Genetic variants associated with 18 fatty acid-related traits were used as instrumental variables.
• Genome-wide association study (GWAS) data for refractive error (spherical equivalent refraction, SER), axial length, and choroidal thickness were analyzed.

Main Results:

• Higher genetically predicted levels of omega-3 fatty acids, docosahexaenoic acid (DHA), and related ratios were associated with a more positive SER, indicating a lower risk of myopia.
• Similar trends were observed for axial length, though significance was borderline.
• Increased levels of omega-3, DHA, and other PUFA-related traits were nominally associated with increased choroidal thickness.

Conclusions:

• The findings suggest a potential protective effect of omega-3 fatty acids, particularly DHA, against myopia.
• The mechanism may involve the modulation of choroidal blood perfusion.
• Further randomized clinical trials are necessary to confirm these findings and establish optimal dosage and duration.