To investigate the prevalence of microbial keratitis, predisposing risk factors, the spectrum of pathogens and the prognosis for graft survival and visual outcome in patients who developed microbial keratitis following penetrating keratoplasty (PK).Methods
We reviewed 14 cases (14 patients) of microbial keratitis after PK from January 1 2007, to December 31 2011. In all cases, corneal scrapings were obtained and microbiologically analyzed. Efficacy of treatment was evaluated by anatomical clarity of graft.Results
There were 100 PKs performed and 14 (1,4%) cases of culture-positive keratitis during the study period. Principal indications for PK were corneal perforation (6 cases) and pseudophakic bullous keratopathy (3 cases). Fifty per cent of infections occurred within 1 year of PK. Principal predisposing risk factors were suture-related problems (64,8%), epithelial defect (50%) and microbial keratitis in the previous graft (50%). Fifty of the scrapings were positive according to the microbiological evaluation with gram-positive cocci (42,85%), fungi (7,14%). We found 1 case of polymicrobial infection in renal graft. After medical and surgical treatments, 3 patients (21,42%) had a clear graft.Conclusion:
The development of bacterial keratitis after PK is a serious complication that is associated with a high incidence of graft failure and poor visual outcome. Postoperative control of risk factors and early recognition of infectious complications may decrease the incidence of severe microbial keratitis after PK.