Unexplained Bilateral Simultaneous Corneal Graft Rejection in a Healthy 18-Year-Old Male.

purposeTo report a rare case of unexplained bilateral corneal graft rejection one year after penetrating keratoplasty (PK) in an otherwise healthy individual, who was compliant with topical fluorometholone maintenance therapy. OBSERVATIONS: An 18-year-old gentleman, who underwent successful, sequential, non-simultaneous, bilateral PK for advanced keratoconus, presented one year later with an acute endothelial rejection episode involving both eyes simultaneously. The rejection episode was reversed with a high dose of intravenous (IV) methylprednisolone pulse therapy over three days, topical cyclosporine-A 1%, and prednisolone acetate 1%, and then maintained on cyclosporine-A 1% eye drops, as the patient was a steroid responder. Conclusion and importance: Bilateral corneal graft rejection, although rare, can occur even several months after successful PK. Prompt management is crucial for the successful reversal of an acute corneal graft rejection episode. In steroid responders, Cyclosporine-A 1% can play a role in reducing the need for, or frequency of, potent steroid eye drops in the acute phase, and as a long-term steroid-sparing agent for maintenance.