Microbial keratitis following lamellar keratoplasty

OBJECTIVE: To determine the predisposing factors, etiologic agents, and clinical and visual outcomes in infectious keratitis following lamellar keratoplasty (LK). METHODS: One hundred thirty-five eyes (135 patients) that had undergone LK were retrospectively analyzed for the occurrence of infectious keratitis following LK. The parameters evaluated were predisposing factors, seasonal variation, indications and type of LK, time interval between LK and infection, site and depth of infection, etiologic organisms, type of treatment, outcome in terms of graft status, secondary surgery, visual acuity, and the donor tissue profile. RESULTS: The incidence of infectious keratitis following LK was 11.11%. The most significant predisposing factor was persistent epithelial defect (3 eyes) and suture abscesses (3 eyes). Most cases occurred between May and August (9/15). Twelve cases developed infection within 2 weeks of surgery (80%). Seven cases (7/15) occurred with onlay grafts, 6 with inlay grafts, and 2 with large-diameter LK. Cultures of corneal scrapings were positive in 11 eyes (73.3%), and the most common isolated organism was coagulase-negative Staphylococcus (CNS). Only 2 eyes responded to medical therapy, and graft sloughing occurred in 9 cases. Six eyes underwent penetrating keratoplasty to either salvage the integrity of globe or for visual rehabilitation of cases where infection resulted in corneal opacity. CONCLUSIONS: Infections after LK may not be amenable to antimicrobial therapy and may necessitate the removal of the graft or a therapeutic penetrating keratoplasty.