Benefit of polyhexamethylene biguanide in Fusarium keratitis

To report a series of 3 patients with soft contact lens-related Fusarium keratitis. Two of them were treated with the antiamoebic polyhexamethylene biguanide 0.02% (PHMB) in combination with antifungal drugs, and 1 patient was treated with PHMB as sole antifungal regimen.

Chart review of 3 patients treated with PHMB in Fusarium keratitis. Two of them were refractory to the commonly used therapy. The antifungal power of PHMB and propamidine isethionate was tested against the patients' isolates as well as against the clinical isolates from another 9 patients with ocular mould infections.

An excellent outcome could be achieved in 2 patients with Fusarium solani keratitis refractory to common antifungal treatment by the additional use of PHMB 0.02%. In another patient PHMB alone was sufficient to resolve Fusarium proliferatum infection. The drug was well tolerated. In all patients repeated abrasion was done for better penetration of the drugs. PHMB revealed a marked in vitro antifungal activity for the three Fusarium isolates as well as for another 9 isolates of ocular infections from other patients including also the genera Scedosporium, Aspergillus and Rhizopus giving minimal inhibitory concentrations ranging from 1.56 to 3.12 µg/ml.

Fusarium keratitis is a severe ocular infection. We report on the use of PHMB in 3 patients given additionally or as sole antifungal drug. We emphasize the benefit of PHMB 0.02% in Fusarium keratitis which might be considered as a therapeutic option especially in cases refractory to common antifungal therapy and possibly in keratitis due to other fungi.