The role of lactate in retinal health and disease: mechanisms and potential therapeutic strategies. A narrative review.

key messagesWHAT IS KNOWN : • The retina, one of the most energy-demanding neural tissues in the human body, predominantly relies on glycolysis for energy production even under aerobic conditions. Lactate is the primary metabolic byproduct of glycolysis, and its functional scope significantly surpasses that of a mere metabolic waste product. • Lactate exerts extensive influence over diverse biological processes and cellular metabolic pathways. Notably, lactate can serve as a precursor for a novel post-translational modification of proteins, known as lactylation. Emerging research has increasingly emphasized the non-metabolic roles of lactate, particularly in modulating cell signaling pathways and epigenetic mechanisms. WHAT IS NEW: • Lactate and lactylation can act as "double-edged sword" for retina. Under physiological conditions, lactate and lactylation promote retinal development, function and optic nerve protection, playing essential roles in maintaining retinal homeostasis. During pathological conditions such as retinopathy, dysregulated levels of lactate and lactylation can become key pathogenic factors, accelerating disease progression. • Sustaining lactate homeostasis may serve as a promising therapeutic target for retinal diseases, and the "metabolism-epigenetics-metabolism" feedback loop provides novel insights and potential therapeutic targets for early intervention in retinal neurodegenerative diseases.