Polihexanide 0.8 mg/mL to Manage Acanthamoeba Keratitis in Clinical Practice: A Multicentre, Retrospective Study in Poland

Acanthamoeba keratitis (AK) is a rare, sight-threatening corneal disease caused by Acanthamoeba spp., ubiquitous free-living amoebae. The purpose of this study is to present the first real-world experience in Poland of AK management with polihexanide 0.8 mg/mL (PHMB 0.08% w/w). This was a retrospective descriptive analysis of clinical records from patients with AK who received PHMB 0.08% (Akantior®) as part of their management for AK (i.e. with other interventions if clinically needed) through an early access programme in two centres in Poland. Disease characteristics, treatment details and clinical outcomes after PHMB 0.08% treatment were assessed. AK resolution was defined as the absence of clinical signs of active infection or inflammation of the cornea after epithelial closure, along with in vivo confocal microscopy (IVCM) criteria. A total of 11 patients were included (age range: 16–54 years; stage ≥ II disease: 81.8%; best-corrected visual acuity [BCVA] ≤ 0.3: 90.9%). Prior treatments consisted mostly of antibiotics and corticosteroids, and 27.3% of patients received prior anti-amoebic therapy (chlorhexidine 0.02% ± propamidine 0.1%). The mean delay to PHMB 0.08% therapy start was 93.7 days. Overall, 10 of 11 (90.9%) patients achieved disease resolution after a mean 187.8 days after symptom onset (range: 60–684 days). The remaining patient was still receiving treatment at time of writing. BCVA improved in all cases of AK resolution. No safety events of clinical relevance were detected. AK disease course and management differed across patients, including cases of bacterial co-infections and the use of various pharmacological and surgical interventions along with PHMB 0.08% therapy. We report the use of PHMB 0.08% for AK management in routine clinical practice in a cohort of patients with relatively advanced disease and poor vision, where most patients achieved disease resolution with BCVA improvements and no clinically relevant safety events were observed. Acanthamoeba keratitis is a rare but serious eye infection of the cornea, the clear outer layer of the eye. It is caused by single-celled organisms called amoebas. The disease is painful, difficult to treat, and can permanently affect vision. This study is the first description of how patients with Acanthamoeba keratitis in Poland were treated with a medicine specifically developed for this disease, called polihexanide 0.8 mg/mL (PHMB 0.08%). All patients were diagnosed using in vivo confocal microscopy (which uses a microscope to examine the eye for signs of amoebas) and then received individualized treatment as part of their clinical care. A total of 11 patients aged 16–54 years with relatively advanced disease were included in the study. Before receiving PHMB 0.08%, many patients had received earlier treatments with antibiotics, which treat bacterial infections, corticosteroids, which treat inflammation, anti-amoeba therapies, or other medicines. Patients started PHMB 0.08% eye drops an average 94 days after their first symptoms. Acanthamoeba keratitis was cured in 10 of the 11 patients (91%) after an average PHMB 0.08% treatment duration of 106 days; the other patient was on treatment at time of writing. Vision improved in all cured patients. Some patients received additional treatments and surgeries along with or after starting PHMB 0.08%. No concerning side effects were seen during treatment with PHMB 0.08%. The results of this study provide more information for eye care specialists on how to care for patients with AK, including use of PHMB 0.08%, in routine medical practice.