Why is patching a horse corneal ulcer generally discouraged?

• A. It accelerates healing.
• B. It reduces tear exchange causing dryness.
• C. It can trap heat and debris, reduce tear exchange, impede nutrition, and promote infection and delayed healing.
• D. It enhances antimicrobial penetration.

Answer: (C)

Patching an equine corneal ulcer creates an enclosed surface that disrupts the natural healing environment. The cornea needs a healthy tear film to supply oxygen and nutrients, remove debris, and deliver immune factors. When a patch covers the eye, tear exchange is reduced, so debris and waste linger and nourishment to the healing epithelium is limited. The patch also traps heat and debris, fostering bacterial growth and increasing the risk of infection. All of these factors together slow healing and can worsen the ulcer, rather than aid recovery.