OBJECTIVES: To estimate the health-related quality of life (HRQoL) of patients with Acanthamoeba keratitis (AK) and to explore the impact of Acanthamoeba infection, treatment and visual acuity on HRQoL.

METHODS: The ODAK (Orphan drug for Acanthamoeba keratitis) Phase 3 trial aimed to evaluate efficacy, safety, and tolerability of 0.8 mg/ml polihexanide (PHMB) plus placebo compared with 0.2 mg/ml polihexanide plus 1 mg/ml propamidine for AK treatment (ClinicalTrials.gov NCT03274895). The main outcome was the cure rate, defined as clinical evidence of Acanthamoeba elimination 90 days after discontinuing anti-inflammatory and antiamoebic therapy. Secondary outcomes included the improvement of best-corrected visual acuity (BCVA) and EQ-5D-5L. BCVA was defined as good vision:≥20/40 Snellen; poor vision:≥20/200 and <20/40; severe vision loss:<20/200. Descriptive analyses were conducted on the full analysis population (n=127). A mixed model for repeated measures (MMRM) was fitted to map the relationship between HRQoL (EQ-5D-5L), BCVA levels and cure at each visit. Utilities were calculated using the Hernandez-Alava mapping. Treatment arms were pooled for analysis.

RESULTS: Baseline HRQoL data were collected for 123/127 patients; the mean health utility score was 0.66 (SE=0.02). In the pooled analysis of all study visits, the mean utility score was 0.79 (SE=0.01) for all patients, 0.80 (SE=0.01) for 114 patients with unilateral disease, and 0.74 (SE=0.02) for 13 patients with bilateral disease; suggesting that patients with bilateral disease have a lower HRQoL. The estimated mean EQ-5D-5L utility is 0.90 (UK general population) considering the mean baseline age and percentage of males from ODAK trial. The MMRM showed that patients who were not cured had lower utility scores than when having achieved a cure. Furthermore, patients cured with good vision had higher utility scores than those cured with poorer vision.

CONCLUSIONS: These results emphasise that Acanthamoeba infection, bilateral disease, cure, and resulting quality of vision impact on patients’ HRQoL.