It is frequently hard to name Acanthamoeba Keratitis because of the similarty diagnosing with viral and bacterial infections. It is done as followed methods:
1- Microscopic methods:
The corneal scraping is the best method used to insulate Acanthamoeba and name Acanthamoeba Keratitis ( Karayianis, Genack et Al. 1988 ) . Next the scraping technique, samples can be smeared on glass slides and seen under light microscope. Whereas cysts and trophozoites are easy seen under negatron microscopy ( Mathers, Stevens et Al. 1987 )
2- Culture methods:
( 482 ) found that corneal and conjuctival swabs are extensively non an appropriate for isolation Acanthamoeba. On the other manus, ( 108 ) identified the cysts and trophozoites in stained tissue subdivisions by the corneal scrapings and corneal biopsy specimens.
Several surveies showed that Acanthamoeba has been cultured from contact lenses, lens instances and lens bactericidal solutions but showed at the same clip negative consequences when civilized corneal tissues ( 15,196,314 ) . In another major survey in cultural methods, substancial from a corneal scraping can be laid on to nonnutrient agar with E-coli or inoculate into liquid medium ( 174,220 ) .
3- PCR techniques:
In most recent methods, PCR work out to be amore sensitive diagnostic method than civilization and to corroborate the clinical diagnosing in civilization – negative instances ( Lehmann, Green et Al. 1998 ) . The advantage of this check is that to cognize the subgroups of the Acanthamoeba ( Schroeder, Booton et al. 2001 ) .
The figure of contact lenses wearers are increasing an as a sequence Acanthamoeba Keratitis have been more frequently, which needs a fast public wellness development. To understate the hazard of Acanthamoeba Keratitis, needs patient ‘s conformity and basic hygienic criterions ( Moore 1990 ) .
( 237,288 ) in their animate beings experiment and in afew figure of human patients showed the function of the immune system in Amebic Keratitis. The greater Numberss of inflammatory cell type ‘s distinguished and environing Acanthamoeba trophozoites or cysts are macrophages and neutrophils. Sing to the observations ‘ of Mathers et Al ( 286 ) , Acanthamoeba covers its antigens from cellular immune responses by agencies of that stamp downing macrophages maps or lymphocyte action. However, M cCulles et Al ( 299 ) found that neutrophils are present in a batch of measure in Acanthamoeba Keratitis which ends with stromal mortification in chronic diseases due to peptidases released by neutrophils.
In 2002, alizadeh, in their experiments to kill Acanthamoeba cysts in vitro, involved both neutrophils and macrophages can straight kill cysts at a first line of defense mechanism against Acanthamoeba Keratitis. Macrophages kill the cysts by phagocytosis, neutrophils by the secernment of peptidases.
Contact lens wearers
The adhesion of the Acanthamoeba to the surface of contact lens is the first measure in the pathogenesis of Acanthamoeba Keratitis particularly in contact lens wearers.
Adhesion of Acanthamoeba to reach lens
Contact lenses serve as an first-class transmittal and bringing of micro-organisms to the oculus. ( Ramachandran, Janakiraman et al. 1997 ) , proved that contact lens surfaces have high affinity to Acanthamoeba.
There are several factors influence the ability of Acanthamoeba to adhere to reach lenses:
1. The stuff, ionicity and H2O content of contact lens.
The incidence of Acanthamoeba Keratitis is much higher in soft contact lenses, as compared with stiff types. Attachment of cysts and trophozoites was found to be higher for non-ionic instead than ionic disposable lenses ( Kelly and Xu 1995 ) .
Cutanoes acanthabiasis has been reported more frequently in HIV positive patients than in other instances ( Hunt, Reed et al. 1995 ; Torno, Babapour et Al. 2000 ) .
- Hunt, S. J. , S. L. Reed, et Al. ( 1995 ) . “ Cutaneous Acanthamoeba infection in the acquired immunodeficiency syndrome: response to multidrug therapy. ” Skin 56 ( 5 ) : 285-7.
- Karayianis, S. L. , L. J. Genack, et Al. ( 1988 ) . “ Cytological diagnosing of acanthamoebic keratitis. ” Acta Cytol 32 ( 4 ) : 491-4.
A instance of acanthamoebic keratitis was identified from a corneal grating stained with a modified Papanicolaou discoloration. The characteristic double-walled cyst signifiers were easy identified. Corneal grating cytology provides a rapid, noninvasive agencies of diagnosing and followup for this serious disease.
- Kelly, L. D. and L. Xu ( 1995 ) . “ The consequence of Acanthamoeba concentration on attachment to four types of unworn soft contact lenses. ” Clao J 21 ( 1 ) : 27-30.
- Lehmann, O. J. , S. M. Green, et Al. ( 1998 ) . “ Polymerase concatenation reaction analysis of corneal epithelial and tear samples in the diagnosing of Acanthamoeba keratitis. ” Invest Ophthalmol Vis Sci 39 ( 7 ) : 1261-5.
- Mathers, W. , G. Stevens, Jr. , et Al. ( 1987 ) . “ Immunopathology and electron microscopy of Acanthamoeba keratitis. ” Am J Ophthalmol 103 ( 5 ) : 626-35.
- Moore, M. B. ( 1990 ) . “ Acanthamoeba keratitis and contact lens wear: the patient is at mistake. ” Cornea 9 Suppl 1: S33-5 ; treatment S39-40.
Therefore, for patients who are careless or persist in utilizing nonsterile rinsing solutions, it appears that at least some methods of disinfection will assist forestall Acanthamoeba infection.
- Ramachandran, L. , D. Janakiraman, et Al. ( 1997 ) . “ Effect of clip and rinsing on the adhesion of Acanthamoeba to widen wear disposable hydrogel contact lenses. ” Clao J 23 ( 2 ) : 113-6.
- Schroeder, J. M. , G. C. Booton, et Al. ( 2001 ) . “ Use of subgenic 18S ribosomal DNA PCR and sequencing for genus and genotype designation of acanthamoebae from worlds with keratitis and from sewerage sludge. ” J Clin Microbiol 39 ( 5 ) : 1903-11.
- Torno, M. S. , Jr. , R. Babapour, et Al. ( 2000 ) . “ Cutaneous acanthamoebiasis in AIDS. ” J Am Acad Dermatol 42 ( 2 Pt 2 ) : 351-4.