Acanthamoeba Keratitis: An Overview

Background:First discovered in the early 1970s, Acanthamoeba keratitis has remained a major eye infection and presents a significant threat to the public health, especially in developing countries. The aim is to present a timely review of our current understanding of the advances made in this field in a comprehensible manner and includes novel concepts and provides clear directions for immediate research priorities.Methods:We undertook a search of bibliographic databases for peer-reviewed research literature and also summarized our published results in this field.Results:The present review focuses on novel diagnostic and therapeutic strategies in details which can provide access to management and treatment of Acanthamoeba keratitis. This coupled with the recently available genome sequence information together with high throughput genomics technology and innovative approaches should stimulate interest in the rational design of preventative and therapeutic measures. Current treatment of Acanthamoeba keratitis is problematic and often leads to infection recurrence. Better understanding of diagnosis, pathogenesis, pathophysiology and therapeutic regimens, would lead to novel strategies in treatment and prophylaxis.

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Endothelial Cell Density and Central Corneal Thickness following Penetrating Keratoplasty of Acanthamoeba Keratitis Patients – A Retrospective Cross-Sectional Observational Study

Klinische Monatsblätter für Augenheilkunde ◽

10.1055/a-1353-5171 ◽

2021 ◽

Author(s):

Lei Shi ◽

Fabian Norbert Fries ◽

Kassandra Xanthopoulou ◽

Tanja Stachon ◽

Loay Daas ◽

...

Keyword(s):

Endothelial Cell ◽

Observational Study ◽

Cell Density ◽

Central Corneal Thickness ◽

Penetrating Keratoplasty ◽

Corneal Thickness ◽

Acanthamoeba Keratitis ◽

Endothelial Cell Density ◽

Cross Sectional ◽

Time Point

Abstract Purpose To analyze endothelial cell density (ECD) and central corneal thickness (CCT) following penetrating keratoplasty (PKP) in Acanthamoeba keratitis (AK) patients. Patients and Methods In this retrospective, clinical, single-center, cross-sectional, observational study, patients were enrolled who underwent PKP at the Department of Ophthalmology of Saarland University Medical Center, Homburg/Saar, Germany between May 2008 and December 2016 with the diagnosis of AK. In all, 33 eyes of 33 patients (14 males, 42%) were enrolled; their mean age at the time of surgery was 39.5 ± 14.3 years. Postoperatively, AK patients received topical polyhexamethylene biguanide, propamidine isethionate, neomycin sulphate/gramicidin/polymixin B sulfate, and prednisolone acetate eye drops (5 ×/day each), and the topical treatment was tapered sequentially with 1 drop every 6 weeks over 6 months. CCT was recorded using Pentacam HR Scheimpflug tomography and ECD with the EM-3000 specular microscope before surgery and 3 and 6 months after surgery as well as after the first and second (complete) suture removal. Results ECD tended to decrease significantly from the time point before surgery (2232 ± 296 cells/mm2) to the time point 3 months after surgery (1914 ± 164 cells/mm2; p = 0.080) and to the time point after the first suture removal (1886 ± 557 cells/mm2; p = 0.066) and decrease significantly to the time point after the second suture removal (1650 ± 446 cells/mm2; p = 0.028). CCT did not change significantly over the analyzed time period (p ≥ 0.475). Conclusion In AK, endothelial cell loss does not seem to be accelerated following PKP, despite the postoperative use of diamidine and biguanide. A subsequent prospective comparative study should confirm our retrospective longitudinal analysis.

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Continuous Real-Time Motility Analysis of Acanthamoeba Reveals Sustained Movement in Absence of Nutrients

Pathogens ◽

10.3390/pathogens10080995 ◽

2021 ◽

Vol 10 (8) ◽

pp. 995

Author(s):

Allison Campolo ◽

Valerie Harris ◽

Rhonda Walters ◽

Elise Miller ◽

Brian Patterson ◽

...

Keyword(s):

Contact Lens ◽

Contact Lenses ◽

Axenic Culture ◽

Acanthamoeba Keratitis ◽

Ocular Infection ◽

Glass Coverslip ◽

E Coli ◽

Total Distance ◽

Care Systems ◽

Different Strains

Acanthamoeba keratitis is a serious ocular infection which is challenging to treat and can lead to blindness. While this pathogen is ubiquitous and can contaminate contact lenses after contact with water, its habits remain elusive. Understanding this organism’s natural behavior will better inform us on how Acanthamoeba colonize contact lens care systems. Acanthamoeba trophozoites were allowed to adhere to either a glass coverslip or non-nutrient agar (NNA) within a flow cell with nutrients (Escherichia coli or an axenic culture medium (AC6)) or without nutrients (Ringer’s solution). Images were taken once every 24 s over 12 h and compiled, and videos were analyzed using ImageJ Trackmate software. Acanthamoeba maintained continuous movement for the entire 12 h period. ATCC 50370 had limited differences between conditions and surfaces throughout the experiment. Nutrient differences had a noticeable impact for ATCC 30461, where E. coli resulted in the highest total distance and speed during the early periods of the experiment but had the lowest total distance and speed by 12 h. The Ringer’s and AC6 conditions were the most similar between strains, while Acanthamoeba in the E. coli and NNA conditions demonstrated significant differences between strains (p < 0.05). These results indicate that quantifiable visual tracking of Acanthamoeba may be a novel and robust method for identifying the movement of Acanthamoeba in relation to contact lens care products. The present study indicates that Acanthamoeba can undertake sustained movement for at least 12 h with and without nutrients, on both rough and smooth surfaces, and that different strains have divergent behavior.

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