Posters

Rapid diagnosis in mycotic and Acanthamoeba corneal infections

Poster Details

First Author: A.Rodriguez SPAIN

Co Author(s):    E. Castro   A. Chulia   J. Alio del Barrio   J. Alio           

Abstract Details

Purpose:

Acanthamoeba and fungal keratitis are emergencies in the ophthalmological consultation. The rapid diagnosis and correct administration of treatment are essential to improve the patient's visual prognosis. The objective of this work is to investigate the diagnostic modality used in these kinds of microbial infections and the value of using quick and easy tests like the fluorescent brightener calcofluor white (CFW).

Setting:

Study carried out with patients diagnosed with fungal and Acanthamoeba keratitis at Vissum Alicante.

Methods:

We included 39 microbiologically proven cases of Acanthamoeba or fungal keratitis. For the diagnosis corneal scrapings or corneal biopsies specimens were performed in the affected eye of the patients. Direct observation techniques of the smears as Gram staining and calcofluor white, microbiological cultures in solid and liquid media, and polymerase chain reaction (PCR) were used. DNA amplification and sequencing from the corneal samples were carried for the detection and molecular identification.

Results:

14/39 (36%) patients were diagnosed of Acanthamoeba keratitis and 25/39 (64%) patients were diagnosed of fungal corneal infection. 100% of amoebic keratitis were identified by molecular diagnosis using PCR and the CFW was positive in 55% of the cases. In fungal corneal infections, the combination of microscopy and PCR gave positive results in 25 (100%) patients. Gram stains showed a 59% and CFW a 73% of positive results for mycotic elements, cultures were positive in 70% of the cases, and PCR showed positivity in 92.6%.

Conclusions:

PCR proved to be an effective method for the diagnosis of fungal and Acanthamoeba keratitis. The main disadvantage of PCR is the cost in relation to culture techniques and especially when it is compared with the direct methods such as CFW. CFW provide a rapid diagnosis in most of the cases of fungal keratitis and in the half of Acanthamoeba keratitis. Positive results on the same day of the consultation are a great advantage over the other techniques. This rapid diagnosis allows to give the appropriate treatment as soon as possible increasing the possibilities of visual recovery of the patients.

Financial Disclosure:

None