Therapeutic Effects of Taurine and Histidine Supplementation in Retinal Diseases

Amino acids are basic building blocks of structural proteins and enzymes. They also act as signaling molecules and as fuel. They are characterized as essential if sufficient quantities must be supplied exogenously or as non-essential if they can be endogenously synthesized. Appropriate intake of amino acids not only prevents the development of metabolic diseases but also can reduce the progression of some disease states. Amino acids are strongly associated with retinal metabolism in physiology and pathology. Nonetheless, there is a lack of robust clinical studies supporting the benefits of amino acid supplementation in retinopathy. In this review, we summarize preclinical evidence concerning the potential of supplementing the amino acids taurine and histidine to provide protection against diabetic retinopathy, glaucoma, and age-related macular degeneration. We suggest further directions for studying amino acid-based therapeutic interventions for eye diseases.