Although the cornea is thicker near the periphery, studies have shown the limbal supply of oxygen may reduce swelling in that region; however, peripheral corneal edema with contact lens wear has not been as thoroughly assessed. Looking into this association, researchers from the University of California at Berkeley suggest the limbus may be influential in reducing corneal edema at the periphery during scleral and soft contact lens wear. The investigation was presented as an online abstract as part of ARVO’s 2020 meeting.

The study used a 2D computerized software model of the cornea and sclera to determine limbal influence on edema. The program created swelling profiles for different oxygen permeabilities with and without metabolic support from the limbus. The model also used a pump-leak mechanism and metabolite-kinetic chemistries to create the corneal swelling profiles from the center to the periphery.

Based on the results of the model, the limbus dramatically reduced swelling near the corneal periphery, which researchers attributed to the supply of bicarbonate and oxygen from the limbus to the cornea and the removal of corneal lactate through the limbus to the sclera.

“The developed model reveals the importance of limbal supply of metabolites on corneal edema and suggests lower oxygen demand at the periphery than at the center,” the researchers wrote in their paper.

 Kim YH, Lin MC, Radke CJ. Limbus metabolic supply reduces peripheral corneal edema with contact-lens wear. ARVO 2020. Abstract #1178.