Which statement best describes the progression of corneal ulcers?

• A. Ulcers can progress rapidly from simple to complicated, and complicated ulcers can progress rapidly to site-threatening in a short period of time.
• B. Ulcers progress slowly and never become complicated.
• C. Ulcers heal spontaneously without treatment.
• D. Ulcers cannot progress once they are simple.

Answer: (A)

Corneal ulcers can change in severity very quickly. A simple epithelial defect can deteriorate into a stromal-invading, complicated ulcer, and that in turn can progress to a site-threatening condition with risk of perforation in a short period if not treated promptly. This rapid escalation comes from a combination of aggressive infectious agents producing tissue-damaging enzymes and a vigorous inflammatory response that breaks down corneal tissue faster than it can heal. In horses, virulent bacteria and the resulting proteolysis can drive this swift progression, making early, targeted therapy crucial. Therefore, the best statement reflects the real risk: ulcers can move rapidly from simple to complicated, and from complicated to site-threatening in a short timeframe. The other options imply slow progression, spontaneous healing, or no progression, which does not match clinical reality.