J Korean Ophthalmol Soc.  2007 Jan;48(1):125-134.

Effect of Amoebicidal Agents on the Human Corneal Keratocytes in Vitro

• Lee JE
• Lee JS
• Choi HY
• Yoo HS

Abstract

PURPOSE: To evaluate the effect of polyhexamethylene biguanide (PHMB) and chlorhexidine on Acanthamoeba cysts and cultured human keratocytes.
METHODS
Each well of two-fold diluted PHMB and chlorhexidine were treated on the Acanthamoeba cyst suspension of 5 x 10(4) cysts/ml for 8, 24, and 48 hours to measure the minimal cysticidal concentration (MCC) of each disinfectant and was exposed to the human corneal keratocytes of 5 x 10(4) cells/ml for same hours to measure the survival rate of keratocytes. Inverted phase-contrast micrograph and electron microscopy for observing the morphologic changes were evaluated.
RESULTS
MCC of PHMB was 9.42 microgram/ml, 5.62 microgram/ml, and 2.37 microgram/ml, and chlorhexidine was 24.32 microgram/ml, 10.02 microgram/ml, and 7.02 microgram/ml respecitvely in 8, 24, and 48 hours. The survival rate of keratocytes at MCC was 91.7%, 64.6%, and 49.7% in PHMB of which significant decreases were found at 24 and 48 hours, and 95.7%, 90.6%, and 78.1% in chlorhexidine of which significant decrease was only found at 48 hours. The higher the concentration of disinfectants, cysts and keratocytes demonstrated more damaged appearance.
CONCLUSIONS
The amoebicidal efficacy of PHMB and chlorhexidine was similar. However, in consideration of toxic effect on keratocytes by disinfectants, chlorhexidine is suggested to be more clinically useful than PHMB.

Keyword

Acanthamoeba; Chlorhexidine; Human corneal keratocyte; Minimal cysticidal concentraion; Polyhexamethylene biguanide

MeSH Terms

Acanthamoeba
Chlorhexidine
Corneal Keratocytes*
Disinfectants
Humans*
Microscopy, Electron
Survival Rate
Chlorhexidine
Disinfectants