Late microbial keratitis after corneal transplantation

Infectious keratitis after penetrating keratoplasty can be devastating to the survival of the graft and its visual outcome. From November 1989 to October 1994, we treated 41 episodes of late microbial keratitis among 354 consecutive penetrating keratoplasty patients and reviewed their medical records retrospectively. The time interval between the corneal transplantation and the onset of graft infection was averaged 10.4 +/- 10.9 months (range: 1-52 months). The precipitating factors of keratitis included epithelial defect (49%), suture-related problems (41%), use of contact lenses (17%), trichiasis (17%), dry eye (12%), and lid abnormalities (10%). Gram-positive cocci and gram-negative bacilli were associated with 51 and 40%, respectively, of the infectious keratitis, with Streptococcus being the most common species. Despite fortified antibiotic treatments, major complications such as graft failure and wound dehiscence could result. The overall result was that clarity was retained in only 43% of our grafts. We conclude that to prevent infectious keratitis there is a need to implement appropriate preventive measures as well as close monitoring of the graft after operation.