Treatment of acanthamoeba keratitis with intravenous pentamidine before therapeutic keratoplasty

Purpose The aim of this study was to evaluate the outcome of pretreatment of Acanthamoeba keratitis with intravenous pentamidine (IVP) before therapeutic keratoplasty (TKP). Methods A retrospective chart review was performed of the medical records of every patient treated with IVP before TKP for Acanthamoeba keratitis at a single, tertiary care eye center between January 1, 2002, and December 31, 2012. The main outcome measures were microbiological cure, graft survival, and visual outcome. Results Eight eyes of 7 patients met the inclusion criteria. Preoperatively, all 8 eyes had failed traditional antiamoebic therapy, including 5 eyes with recurrent infections after previous TKP. The patients were treated with IVP (190-400 mg/d) for a median of 14 days (range, 7-26 days). After 8 TKP, a microbiological cure was achieved, and a clear graft was maintained in 5 (62.5%) eyes during a mean follow-up interval of 31.2 months (range, 1.0-95.7 months). Repeat TKP in 3 eyes with recurrent Acanthamoeba keratitis resulted in 2 additional microbiological cures and 1 more clear graft. The final best-corrected visual acuity was ≥20/40 in 5 (62.5%) eyes and worse than 20/200 in 3 eyes. Overall, the final vision was improved in 6 (75.0%) eyes, remained the same in 1 (12.5%) eye, and was worse in 1 (12.5%) eye. Conclusions The adjunctive use of IVP before TKP may assist with the achievement of microbiological cure, clear graft, and good visual outcome in a majority of eyes with Acanthamoeba keratitis.