Do corneal endothelial cells regenerate?

• A. Yes, they regenerate quickly
• B. No, they stretch to compensate for dead cells
• C. They regenerate only after injury with stem cell therapy
• D. They regenerate during childhood only

Answer: (B)

The key idea is that the adult corneal endothelium has very limited ability to regenerate. When endothelial cells die, the remaining cells do not divide to replace them in normal circumstances. Instead, they stretch out and spread to cover the exposed area, preserving the essential pump function that keeps the cornea dehydrated and clear. This compensatory widening and migration helps maintain a single-layer, functioning endothelium, but it reduces overall cell density and can lead to edema if too many cells are lost. So the correct statement—that they don’t regenerate but stretch to compensate for dead cells—is the best fit. The other options imply rapid regeneration, stem-cell–based replacement, or regeneration only in childhood, which doesn’t reflect the typical behavior of the human corneal endothelium.