To report the clinical manifestation, predisposing factors, microbiological profiles and treatment outcome of infectious keratitis following penetrating keratoplasty (PK).

Medical records of the post-PK patients later diagnosed with culture-positive keratitis, between January 2003 and June 2008 at our hospital were retrospectively reviewed.

Among 228 eyes of 226 patients who previously had PK, 18 eyes (7.89%) of 16 patients developed microbial keratitis. Fifteen patients had a bacterial infection, of which a Streprococcus species was the most common causative microorganism (6 eyes, 33.3%). Three eyes had fungal infection; one case was co-infected with bacteria. Six eyes (33.3%) presented with a suture-related problem, and sixteen eyes (88.9%) had been using topical glaucoma medications. The suture-related problem and use of glaucoma medication were significantly associated with the development of infectious keratitis ( p =0.040 and 0.013, respectively). Remission was achieved in all cases within the mean duration of 2.47 months after treatment initiation. However, visual improvement was not achieved in 11 eyes (68.7%) due to graft opacity.

Early identification of predisposing factors and appropriate management at an early stage may prevent the occurrence of graft infection and improve graft survival.