Metabolic Characterization of Ocular Tissues in Relation to Laser- Induced Choroidal Neovascularization in Rats

Age-related macular degeneration is a metabolic compromise disorder whose main pathological feature is choroidal neovascularization (CNV) formation. Using untargeted metabolomics analysis, we determined to assess the metabolomic alterations in a CNV rat model to provide an insight into its pathogenesis. In the CNV model, there were 24 significantly changed metabolites in the plasma and 71 in various ocular tissues. Pathway analysis showed that certain metabolic pathways changed in interrelated tissues: for instance, in terms of the altered urea cycle, arginine and proline metabolism were increased in the plasma, while spermidine and spermine biosynthesis activities were increased in the retinal pigment epithelium (RPE)/choroid. The retina and RPE/choroid shared the same changed metabolites of branched-chain amino acid metabolism. Fatty acid metabolism was found to be the significant altered metabolic pathway in the retina of this CNV model. Although the metabolism pattern of different substances is specific for each ocular tissue, there is also a certain material exchange between different tissues. Dysregulated metabolomic profiles in differential tissues may point to an interconnected pathway, oxidative stress response, which may lead to RPE cell degeneration and, ultimately, CNV development.