[Quantitative evaluation of corneal epithelial barrier function in corneal epithelial edema]

Area of Science:

• Ophthalmology
• Corneal Physiology
• Ocular Surface Disease

Background:

• The corneal epithelium forms a critical barrier against external insults.
• Impaired barrier function is implicated in various corneal pathologies.

Purpose of the Study:

• To evaluate corneal epithelial barrier function in patients with corneal epithelial edema using fluorophotometry.
• To compare barrier function between corneal epithelial edema and corneal stromal edema without epithelial involvement.

Main Methods:

• Fluorophotometry was employed to measure fluorescein uptake.
• Sodium fluorescein was instilled after corneal washing with BSS PLUS.
• Corneal uptake was quantified in normal subjects, patients with corneal epithelial edema, and patients with corneal stromal edema.

Main Results:

• Normal corneal epithelium showed minimal fluorescein uptake (28.1 ng/ml).
• Patients with corneal epithelial edema exhibited significantly increased fluorescein uptake (2,489.7 ng/ml) compared to normal corneas (p < 0.0005).
• Patients with corneal stromal edema without epithelial edema showed moderately increased uptake (99.3 ng/ml), significantly less than those with epithelial edema (p < 0.05).

Conclusions:

• Corneal epithelial edema is associated with a significant breakdown of the corneal epithelial barrier function.
• Fluorophotometry is a valuable tool for quantifying corneal epithelial barrier integrity.
• The degree of barrier impairment is more severe in corneal epithelial edema than in corneal stromal edema without epithelial involvement.