Which of the following is an example of an alkali agent that can cause corneal damage?

• A. Sulfuric acid
• B. Nitric acid
• C. PAVA
• D. Airbag residue

Answer: (D)

Alkali burns to the cornea behave differently from acid burns because alkaline substances readily penetrate tissue and cause liquefactive necrosis. They saponify lipids in cell membranes and basement membranes, allowing the chemical to keep diffusing into the cornea and stroma, often leading to deep, progressive damage. This is why alkali injuries can be more severe and require urgent, thorough irrigation to remove the material and halt penetration.

In the listed options, acids are acids and tend to cause surface coagulative necrosis that can form a barrier to deeper penetration, so they are not examples of an alkali mechanism. PAVA is a pepper-spray irritant with no strong alkali behavior. Airbag residue, on the other hand, can contain alkaline dust and residues that contact the eye and produce an alkali chemical burn, illustrating the kind of alkali exposure that can damage the cornea. Immediate flushing to remove the residue is critical to limit injury progression.