To evaluate the primary indications, surgical outcomes, causes and risk factors for graft failure in patients with three or more penetrating keratoplasty (PKP) surgeries.

We retrospectively analyzed indications for the initial corneal graft, survival periods, causes and risk factors for failure in 25 patients (26 eyes) who had undergone three or more PKP with minimum follow-up periods of nine months.

The most common primary indications were herpes simplex keratitis (26.9%), followed by fungal keratitis (19.2%) and bacterial keratitis (11.5%). The average survival period of graft in three or more PKP was 12.9 ± 9.1 months. As the frequency of PKP increased, the survival period became shorter; the survival period was the longest in pseudophakic bullous keratopathy and the shortest in herpes simplex keratitis. The most common cause of graft failure was allograft rejection (82.8%), and the risk factors for graft failure were short interval between penetrating keratoplasties and corneal neovascularization.

In three or more PKP, as the frequency of PKP increases, the survival period becomes shorter. Short interval between keratoplasties and cornel neovascularization were risk factors for graft failure; this results must be considered before surgery.