Figure 1.

Metabolic pathway analysis performed for significant metabolites reported in human serum (a) and aqueous humor (AH) (b) samples. Metabolic pathway analysis was carried out with MetaboAnalyst 4.0 software. Ten most significant pathways identified for the serum samples: 1. sphingolipid metabolism, 2. citrate cycle (TCA cycle), 3. linoleic acid metabolism, 4. biosynthesis of unsaturated fatty acids, 5. alanine, aspartate and glutamate metabolism, 6. tryptophan metabolism, 7. glyoxylate and dicarboxylate metabolism, 8. tyrosine metabolism, 9. glycerolipid metabolism, and 10. retinol metabolism. Ten most significant pathways identified for the AH samples: 1. arginine biosynthesis, 2. alanine, aspartate and glutamate metabolism. 3. glyoxylate and dicarboxylate metabolism, 4. D-glutamine and D-glutamate metabolism, 5. nitrogen metabolism. 6. pyrimidine metabolism, 7. aminoacyl-tRNA biosynthesis, 8. pantothenate and CoA biosynthesis, 9. citrate cycle (TCA cycle), and 10. sphingolipid metabolism.