Illustrate about the metabolic waste products in the cornea?

Metabolic Waste Products

During the metabolism various waste products including lactic acid, protein ancl fat breakdown products. A major metabolic waste product is 'carbon dioxidc (CO). These metabolic waste products are removed primarily through the tear film, aqueous humor and limbaI circulation.

Contact lenses act as a physical barrier to the transmission of oxygen and carbon dioxide between the atmosphere and cornea. Prolonged wear of contact lens of low water content lens of low permeability lead to a state of hypoxia.

Oxygen supply to the cornea

During prolonged hypoxic conditions, the ATP consumption remains the same but the production decreases (due to stoppage of the kreb's cycle). The EMP pathway continues causing an accumulation of lactic acid. This lactic acid is not metabolised by the cornea and gets accumulated in the layers of the cornea, which imbibes water and causes epithelial and stromal edema.