Corneal Structural and Response to Elevated CO ₂ Concentrations in Occupational Environment: FTIR and Chemometric Evidence of Proteins and Lipids Remodeling

This study investigates the effects of occupational carbon dioxide (CO₂) exposure on corneal tissue through Fourier transform infrared (FTIR) spectroscopy and chemometric analysis. Human activities have significantly increased atmospheric CO₂ levels, leading to potential health risks, particularly in confined environments such as mining, submarines, and enclosed workspaces. While CO₂ exposure is commonly associated with respiratory and cardiovascular effects, its impact on ocular health remains underexplored. Rats were exposed to three different CO₂ concentrations (3%, 5%, and 10%) in a controlled chamber for 8 h per day over a 30-day period. Second derivative analysis of corneal FTIR spectra revealed significant alterations in protein secondary structures, lipid composition, and phosphate group alterations, indicating CO₂-induced biochemical changes. Notably, exposure led to a shift in the amide I band from 1650 to 1643 cm^-1, suggesting a transition from α-helix to random coil structures in corneal proteins, which compromises tissue integrity. Changes in lipid hydrocarbon chain vibrations and increased gauche rotamers indicated disruptions in membrane order and fluidity. Additionally, phospholipid and nucleic acid modifications were observed, potentially affecting cellular stability. The study provides valuable insights into corneal bio-molecular alterations due to CO₂ exposure, contributing to a deeper understanding of environmental and occupational eye health risks.