Urban Eyes at Risk A Scoping Review of Acanthamoeba Keratitis among Malaysian Contact Lens Wearers and Associated Health Impact Strategies

Abstract

Introduction
Acanthamoeba, a free-living amoeba found across diverse ecosystems, can cause Acanthamoeba keratitis (AK), a severe, sight‐threatening corneal infection predominantly affecting contact lens users. In Malaysia, urbanisation has increased the use of contact lenses due to cosmetic preferences and better access to optometric services. This has contributed to a rise in  AK cases, though the true burden remains unclear due to insufficient national surveillance. This review examines AK prevalence, risk factors, and management strategies among Malaysian contact lens users, with the novelty of integrating urban health and environmental factors to guide public health strategies.

Methods
A literature search was conducted across PubMed, Scopus, and Google Scholar from 2020 to 2025, using the keywords "Acanthamoeba keratitis," "contact lens," and "Malaysia." A qualitative synthesis of 60 out of 261 studies with all study designs was performed, with descriptive statistics used to assess positivity rates over time and across demographic groups, including historical data.

Results
The first AK case in Malaysia was reported in 1995. Data from 2010–2012 indicated a positivity rate of 15.6%, which rose to 22.6% between 2013 and 2015, with a significant increase among urban females aged 19–35. Risk factors include poor contact lens hygiene, improper lens wear, ineffective disinfectants, and urban environmental factors like contaminated water and poor sanitation. Advances in diagnostics, particularly polymerase chain reaction (PCR) assays, have significantly improved sensitivity and differentiation from herpes simplex keratitis. Treatment generally involves chlorhexidine and propamidine, though toxicity and resistance remain challenges.

Conclusion
AK is an increasing, underreported threat in Malaysia, exacerbated by urbanisation, poor contact lens practices, and limited treatment options. Public health strategies should focus on enhancing surveillance, enforcing disinfectant regulations, and promoting hygiene education. Integrating urban health and environmental factors into AK management, alongside exploring novel therapies such as drug repurposing and nanotechnology, is essential for improving outcomes.