Abstract
Purpose: :
to investigate the positivity of microbiological results of corneal scrapings collected from patients suspected of having Acanthamoeba keratitis (AK)
Methods: :
this was a cross-sectional analysis of records of patients who had suspected diagnosis of AK. Results from corneal scrapings sent to the Ocular Microbiology Laboratory - UNIFESP/EPM from September 1989 to July 2009 were reviewed. Definition of suspected diagnosis of AK: patients who had relevant risk factors such as duration of the lesion, personal history of contact lens use, symptoms or an ophthalmological examination suggesting an infectious keratitis in which AK could not be excluded.
Results: :
Corneal scrapings were performed in 913 eyes of 884 patients with suspected diagnosis of AK and this condition was confirmed in 252 eyes (27.6%). In 76 eyes we observed concurrent growth of Acanthamoeba and bacteria and in 2 eyes (0,22%) there was fungal co-infection. Isolated bacterial infection was diagnosed in 337 eyes (36.9%) and isolated fungal infection in 14 eyes (1.5%).The most common agent isolated in all eyes was coagulase-negative Staphylococcus followed by Corynebacterium spp and Pseudomonas. The most common fungal isolated was Fusarium spp (7 eyes). There were 308 eyes (33,73%) free from infection.
Conclusions: :
Positivity of laboratory culture was low among suspected cases in our service and there was a high prevalence of bacterial growth. The variation on lab culture indication, previous treatment with antibiotics and the similarity between clinical aspects on infectious keratitis indicates that lab cultures should be performed in our service in order to help with the investigation for an accurate diagnosis of such a challenging condition.
Keywords: Acanthamoeba • keratitis • clinical laboratory testing