Insights into the Global Incidence of Acanthamoeba Keratitis: A Comprehensive Systematic Review

Abstract

Background: Acanthamoeba keratitis (AK) is a rare but serious infection of the cornea, primarily affecting contact lens (CL) wearers. Understanding the incidence, risk factors, and outcomes of AK is essential for improving prevention and treatment strategies. This systematic review aims to analyze existing studies on AK to identify trends in incidence, diagnostic methods, and geographic distribution. Methods: A systematic review was conducted using PRISMA 2020 guideline, upon studies that reported AK incidence, diagnosis, and outcomes. Results: Incidence of AK among microbial keratitis (MK) cases ranged from 1.49% to 4.5%, with contact lens wear as a major risk factor in most studies. The ratio of AK to MK was found to be consistent across various studies, with geographic variations largely attributable to environmental factors.  Conclusion: This review confirms that AK remains a rare condition, predominantly affecting contact lens wearers. Geographic and environmental factors, such as water supply contamination, play a crucial role in AK incidence. Future studies should focus on reducing diagnostic delays and standardizing care to improve patient outcomes.