Nutritional Supplementation for Myopia Prevention and Control: A Systematic Review of Randomized Controlled Trials

Area of Science:

• Ophthalmology
• Nutritional Science
• Evidence-Based Medicine

Background:

• Nutritional supplementation is explored for myopia prevention and control.
• Mechanisms include antioxidant, anti-inflammatory, and extracellular matrix regulation.
• Key nutrients studied are carotenoids, anthocyanins, and polyunsaturated fatty acids.

Purpose of the Study:

• To systematically review randomized controlled trials (RCTs) on nutritional supplementation for myopia.
• To evaluate effects on refractive error, axial length, macular pigment optical density (MPOD), visual function, and visual fatigue.
• To assess evidence for carotenoids, anthocyanins, PUFAs, and combined nutraceuticals.

Main Methods:

• Systematic review registered on PROSPERO (CRD420251149727).
• Searched PubMed, Web of Science, and Scopus up to August 2025.
• Included RCTs comparing nutritional supplements to placebo/controls; assessed risk of bias using Cochrane RoB 2 tool.

Main Results:

• Nine RCTs were included; studies were generally small, heterogeneous, and short-term.
• Carotenoids (crocetin, lutein, zeaxanthin, astaxanthin) showed modest benefits: improved MPOD, reduced visual fatigue, and slightly less axial elongation in one pediatric trial.
• Anthocyanins improved contrast sensitivity and reduced asthenopia; combined formulations enhanced accommodative facility.
• No consistent clinically significant reduction in myopia progression was observed.

Conclusions:

• Nutritional supplementation may offer benefits for visual function and retinal antioxidant status.
• Current evidence is insufficient to support routine use for slowing myopia progression.
• Larger, long-term RCTs are necessary to establish efficacy in myopia management.