Acanthamoeba keratitis: prevalence, diagnosis, treatment and future trends: a systematic review

Priyanshi Priya; Niraj Kumar Yadav; Nibha Mishra; Apjit Kaur

doi:10.18203/2320-6012.ijrms20253975

Authors

Priyanshi Priya Department of Ophthalmology, Dr KNS Memorial Institute of Medical Sciences, Barabanki, Uttar Pradesh, India
Niraj Kumar Yadav Department of Ophthalmology, Dr KNS Memorial Institute of Medical Sciences, Barabanki, Uttar Pradesh, India
Nibha Mishra Department of Ophthalmology, King George’s Medical University, Lucknow, Uttar Pradesh, India
Apjit Kaur Department of Ophthalmology, King George’s Medical University, Lucknow, Uttar Pradesh, India

DOI:

https://doi.org/10.18203/2320-6012.ijrms20253975

Keywords:

Acanthamoeba keratitis, Contact lens, In vivo confocal microscopy, Polymerase chain reaction, Nanotechnology, Photodynamic therapy

Abstract

Acanthamoeba keratitis (AK) is a rare but severe corneal infection caused by free-living Acanthamoeba species. It is increasingly recognised as a significant cause of visual morbidity, especially among contact lens users. This systematic review follows preferred reporting items for systematic reviews and meta-analyses (PRISMA) 2020 guidelines and analyses studies published between January 2000 and January 2025, focusing on AK prevalence, diagnostics, treatment, and innovations. Our search across databases, including PubMed and Scopus, identified 20 peer-reviewed studies. Findings reveal a 35-50% increase in global AK incidence since 2000, particularly affecting Europe, East Asia, and North America, with 85-90% of cases linked to contact lens wear and the T4 genotype being the predominant strain. Advancements in diagnostics, such as polymerase chain reaction (PCR) testing (with over 95% sensitivity) and in vivo confocal microscopy (IVCM) (with 85-90% sensitivity), have improved early detection. Emerging technologies, including metagenomics sequencing and artificial intelligence (AI)-driven imaging, have further enhanced diagnostic accuracy, achieving a specificity of over 93%. Current treatments rely on a combination of biguanides and diamidines, but prolonged therapies often lead to recurrence, with 20-25% of severe cases requiring keratoplasty. Innovations such as nanocarrier drug delivery, photodynamic therapy (PDT), and genotype-specific antimicrobials are promising. While advancements in the diagnosis and treatment of AK have improved, challenges in reducing the disease burden and improving long-term outcomes remain. The future of AK management hinges on integrating molecular diagnostics and AI into clinical practice, supported by public education on safe contact lens hygiene practices.

Metrics

Metrics Loading ...

References

REFERENCES

Seal DV. Acanthamoeba keratitis update-incidence, molecular epidemiology and new drugs for treatment. Eye. 2003;17:893-905. DOI: https://doi.org/10.1038/sj.eye.6700563

Lorenzo-Morales J, Khan NA, Walochnik J. An update on Acanthamoeba keratitis: diagnosis, pathogenesis and treatment. Parasite. 2015;22:10. DOI: https://doi.org/10.1051/parasite/2015010

Maycock NJR, Jayaswal R. Update on Acanthamoeba keratitis: diagnosis, treatment, and outcomes. Cornea. 2016;35(5):533-40. DOI: https://doi.org/10.1097/ICO.0000000000000804

Gurnani B, Kaur K, Kaur R, Aggarwal P, Singh S. Acanthamoeba keratitis: a review of risk factors, clinical presentation, and treatment modalities. Odisha J Ophthalmol. 2024;31(1):11-27. DOI: https://doi.org/10.4103/odjo.odjo_18_24

Khan NA, Anwar A, Siddiqui R. Acanthamoeba keratitis: current status and urgent research priorities. Curr Med Chem. 2019;26(30):5570-83. DOI: https://doi.org/10.2174/0929867325666180510125633

Diehl MLN, Paes J, Rott MB. Genotype distribution of Acanthamoeba in keratitis: a systematic review. Parasitol Res. 2021;120:845-60. DOI: https://doi.org/10.1007/s00436-021-07261-1

Randag AC, van Rooij J, van Goor AT, Verkerk S, Wisse RBL, Saelens IEY, et al. The rising incidence of Acanthamoeba keratitis: a 7-year nationwide survey. PLoS One. 2019;14:e0222092. DOI: https://doi.org/10.1371/journal.pone.0222092

Simamora RC, Hutabarat JRR, Sitohang R, Nathan DS, Ronald, et al. Insights into the global incidence of Acanthamoeba keratitis: a comprehensive systematic review. Med J Int. 2024;1(1):1-14.

Büchele MLC, Nunes BF, Filippin-Monteiro FB. Diagnosis and treatment of Acanthamoeba keratitis: a scoping review. Contact Lens Anterior Eye. 2023;46(4):101844. DOI: https://doi.org/10.1016/j.clae.2023.101844

Azzopardi M, Chong YJ, Ng B, Recchioni A, Logeswaran A, Ting DSJ. Diagnosis of Acanthamoeba keratitis: past, present and future. Diagnostics. 2023;13(16):2655. DOI: https://doi.org/10.3390/diagnostics13162655

Varacalli G, Di Zazzo A, Mori T, Dohlman TH, Spelta S, Coassin M, et al. Challenges in Acanthamoeba keratitis: a review. J Clin Med. 2021;10(5):942. DOI: https://doi.org/10.3390/jcm10050942

Fanselow N, Sirajuddin N, Yin XT, Huang AJW, Stuart PM. Acanthamoeba keratitis, pathology, diagnosis and treatment. Pathogens. 2021;10(3):323. DOI: https://doi.org/10.3390/pathogens10030323

Papa V, Bodicoat DH, Duarte AA, Dart JKG, Francesco MD. The natural history of Acanthamoeba keratitis: a systematic literature review. Ophthalmol Ther. Ophthalmol Ther. 2025;14(7):1369-83. DOI: https://doi.org/10.1007/s40123-025-01152-9

Petrillo F, Tortori A, Vallino V, Galdiero M, Fea AM, Sanctis UD, Reibaldi M. Understanding Acanthamoeba keratitis: an in-depth review of a sight-threatening eye infection. Microorganisms. 2024;12(4):758. DOI: https://doi.org/10.3390/microorganisms12040758

Shareef O, Shareef S, Saeed HN. New Frontiers in Acanthamoeba Keratitis Diagnosis and Management. Biology. 2023;12(12):1489. DOI: https://doi.org/10.3390/biology12121489

Abjani F, Khan NA, Yousuf FA, Siddiqui R. Targeting cyst wall is an effective strategy in improving the efficacy of marketed contact lens disinfecting solutions against Acanthamoeba castellanii cysts. Cont Lens Anterior Eye. 2016;39(3):239-43. DOI: https://doi.org/10.1016/j.clae.2015.11.004

Marques-Couto P, Monteiro M, Ferreira AM, Costa JP, Morgado RV. Acanthamoeba keratitis management and prognostic factors: a systematic review. J Clin Med. 2025;14(7):2528. DOI: https://doi.org/10.3390/jcm14072528

Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71. DOI: https://doi.org/10.1136/bmj.n71

Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JPA, et al. The PRISMA statement for reporting systematic reviews and meta-analyses. PLoS Med. 2009;6:e1000097. DOI: https://doi.org/10.1371/journal.pmed.1000097

Moola S, Munn Z, Tufanaru C, Aromataris E, Sears K, Sfetcu R, et al. Systematic reviews of aetiology and risk: Joanna Briggs Institute Reviewer’s Manual. 2020. DOI: https://doi.org/10.46658/JBIRM-17-06

Szentmáry N, Daas L, Shi L, Laurik KL, Lepper S, Milioti G, et al. Acanthamoeba keratitis: clinical signs, differential diagnosis and treatment. J Curr Ophthalmol. 2019;31(1):91-8. DOI: https://doi.org/10.1016/j.joco.2018.09.008

Lim N, Goh D, Bunce C, Xing W, Fraenkel G, Poole TRG, et al. Comparison of polyhexamethylene biguanide and chlorhexidine as monotherapy agents in the treatment of Acanthamoeba keratitis. Am J Ophthalmol. 2008;145(1):130-5. DOI: https://doi.org/10.1016/j.ajo.2007.08.040

Sharma S, Garg P, Rao GN. Patient characteristics, diagnosis, and treatment of Acanthamoeba keratitis: a 10-year review from a tertiary eye care centre in South India. Cornea. 2019;38(9):1102-09.

Niyyati M, Dodangeh S, Lorenzo-Morales J. A Review of the Current Research Trends in the Application of Medicinal Plants as a Source for Novel Therapeutic Agents Against Acanthamoeba Infections. Iran J Pharm Res. 2016;15(4):893-900.

Shi Q. Development and validation of a comprehensive machine-learning diagnostic model for Acanthamoeba keratitis with early clinical signs identification. Invest. Ophthalmol. Vis. Sci. 2025;66(8):4487. DOI: https://doi.org/10.1167/iovs.66.9.71