A novel imaging approach, matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI), is giving researchers new insights into the pathophysiological mechanisms of dry eye disease (DED), according to a study published in The Ocular Surface. The MALDI-MSI technology allows investigators to explore the metabolic profile and spatial distribution of in situ ocular tissues.
The study used the visualization approach to monitor changes to the central corneas, peripheral corneas, fornix conjunctivas, eyelids, conjunctivas, and aqueous humors of Wistar rats to establish how the altered function of metabolic pathways might participate in the pathogenesis of DED.
The investigators were able to reveal 4 findings about the development of DED. The study data indicate that the metabolism of the glycerophospholipids is changed in specific ocular regions in patients with DED. The study also shows levels of phosphatidylethanolamine (a component of the tear film) increases in these patients, at both the central cornea and the aqueous humor. Another component of the tear film, phosphatidylcholine, increases in the fornix conjunctiva, eyelid conjunctiva, and aqueous humor.
Significant alterations to the sphingolipid metabolic pathway, according to the study, also occurred in the peripheral cornea and aqueous humor. Finally, the technology found changes to lipid and amino acid metabolisms in participants with DED.
These region-specific metabolic behaviors in DED may not have been observable in situ without MALDI-MSI visualization. The technology combines high-throughput mass spectrometry and molecular imaging. This allows label-free measurement of metabolites directly in tissue sections, according to the report.
Researchers believe this technology can aid clinical research by “providing new insights and clues to further understand the pathophysiological mechanisms of DED, and set the foundations for personalized clinical interventions at an early stage.”
Chen X, Zhang C, Tian L, et al. In situ metabolic profile and spatial distribution of ocular tissues: New insights into dry eye disease. Ocular Surf. Published online January 3, 2022. doi:10.1016/j.jtos.2021.12.013.