Retrospective Chart Review of Patients With Acanthamoeba Keratitis Who Have Received 0.8 mg/mL Polihexanide as Part of the "Medicines in Special Situations" (Medicamentos en Situaciones Especiales) Program in Spain.

Primary objective: • To describe the efficacy of 0.8 mg/ml polihexanide in the clinical resolution of AK in all patients that satisfy the inclusion criteria of the study, as measured by the proportion of patients cured at the end of the study period, confirmed at the 30-day follow-up (when available). Secondary objectives: • To describe the efficacy of 0.8 mg/ml polihexanide in the clinical resolution of AK in full compliant patients. • To describe the efficacy of 0.8 mg/ml polihexanide in the improvement of visual acuity (VA). • To describe the efficacy of 0.8 mg/ml polihexanide in the improvement of ocular clinical findings. • To describe de efficacy of 0.8 mg/ml polihexanide in the reduction of pain. • To determine the rate of patients requiring ocular surgery. • To determine the rate of patients using topical ophthalmologic steroids or other relevant medications. • To determine the time from start of treatment until clinical resolution. • To determine the proportion of patients with concomitant fungal or bacterial corneal infections. • To describe the efficacy of 0.8 mg/ml polihexanide in preventing disease relapse.