Comarison of Acridine Orange and Gram Stains in the Diagnosis of Infectious Keratitis

ABSTRACT

We assessed the comparatice sensitivity and specificity of acridine orange and Gram stains of corneal scrapings from 29 cases of presumed infectious keratitis. The corneal scrapings were placed on two clear glass slides and allowed to air dry. The slides were fixed in 95% methanol for 2 minutes and each slide was stained by Gram and acridine orange stains respectively. Culture was done with another corneal scraping. Cultures were positive in 19 of 29 cases(66%). Among them 14 cases (74%) were positive in Gram stain and 18 cases (95%) were positive in acridine orange stain. So the sensitivity of acridine orange was greater than that of Gram stain. In the specificity, Gram stain (80%) was better than acridine orange stain(50%). This study demonstrates acridine orange stain as well as gram stain is useful as a simple, rapid screening test for the diagnois of suspected infectious keratitis.