Ascorbic acid content of human corneal epithelium

Area of Science:

• Ophthalmology
• Biochemistry
• Corneal Science

Background:

• Ascorbic acid (vitamin C) is a vital antioxidant found in various body tissues.
• Its concentration and role within the human cornea, particularly the epithelium, require further elucidation.
• Understanding corneal ascorbate levels is crucial for comprehending ocular protection mechanisms.

Purpose of the Study:

• To quantify the concentration of ascorbic acid within the human corneal epithelium.
• To compare corneal epithelium ascorbate levels to those found in the aqueous humor.

Main Methods:

• Human corneal epithelium samples were obtained from postmortem eyes.
• Samples were collected within 4 to 16 hours postmortem.
• Ascorbate concentration was determined using high-performance liquid chromatography (HPLC).

Main Results:

• The mean concentration of ascorbic acid in the corneal epithelium was measured at 1.33 +/- 0.48 mg/gm wet weight.
• This concentration is estimated to be approximately 14 times higher than that found in the aqueous humor.
• The results indicate a substantial presence of ascorbate in the corneal epithelial tissue.

Conclusions:

• The high concentration of ascorbic acid in the corneal epithelium suggests a significant physiological role.
• Ascorbate likely protects the basal epithelial layer by absorbing incident ultraviolet (UV) radiation.
• This protective function may contribute to maintaining corneal health and integrity against environmental stressors.