Polihexanide 0.8 mg/mL eyedrops as new treatment for severe Acanthamoeba keratitis

Aims/Purpose: Novel effective medical therapy for Acanthamoeba Keratitis. Methods: Interventional observational case series. Compassionate use of Polihexanide 0.8 mg/mL in 2 Acanthamoeba keratits (AK) patients. Two cases of diagnosed Acanthamoeba keratitis were unsuccessfully treated with Poliexamidine biguanide 0.02% and propamidine 0.1% applied hourly then tapered weekly. Clinical worsening was observed up to 4 weeks. Compassionate use of Polihexanide 0.8 mg/mL eyedrops was started. Results: Corneal infection healed completely after 1 month in first case, and after 2 months of therapy in the second case. Corneal opacities and neovascularization decreased slowly, while BCVA (best corrected visual acuity) slightly and progressively increased per 3 months, and no infection recurred. Conclusions: AK is a painful, long‐lasting (12 months) infection that drastically reduces a patient's quality of life. Polihexanide 0.8 mg/mL monotherapy lowers illness duration, chance of recurrence, and need for surgery in high risk settings, improving visual outcomes and quality of life.