Inject or Reject

Globally, there are millions of people with corneal blindness. But as countries struggle generally with donor cornea shortages, there is another factor that can affect the availability – and success – of corneal transplants: corneal endothelial cell integrity. If corneal endothelial cell density or function becomes inadequate after the transplant, graft opacity and/or rejection can occur, prompting research into how to boost success rates.

Previous studies have revealed that vasoactive intestinal peptide (VIP) could enhance corneal cell survival during donor cornea storage, so a team from Massachusetts Eye and Ear Institute, Boston, USA, theorized that it could also help after corneal transplantation. “Our experiment revealed that our hypothesis was correct; the postoperative use of VIP improved the survival of corneal grafts in mice,” says Ahmad Kheirkhan, co-author of the paper (1).

The team is currently conducting further studies to unravel the exact mechanisms by which VIP enhances corneal graft survival, but Kheirkhan points to one likely possibility: “VIP increases the migration of corneal endothelial cells, and decreases cell apoptosis by modulating resistance to pro-inflammatory cytokines.”

If the findings successfully translate to the clinic, the implications are significant, says Kheirkhan. “The use of VIP could help a large number of patients with corneal endothelial abnormalities, and enhance the outcome of corneal transplantation.”