Evaluation of impression cytology as rapid non-invasive diagnostic tool in infected corneal ulcer

Background: Microbial keratitis (MK) is caused by bacteria, fungi, and protozoa. It is very important to differentiate between these three causative microorganisms very early as they differ in their treatment, and some of these microorganisms, like Pseudomonas aeurogenosa, may result in eye perforation within 72 hours .The purpose of this study was to evaluate impression cytology smear to be used as a guide for early accurate treatment of cases. This study was conducted on 80 patients suspected of having MK. A corneal smear was taken with impression cytology paper (a non-invasive technique) and transported to the microbiology laboratory for examination. Results: The IC smear examination results were as follows: 30 (37.5%) were Aspergillus fungus, 14 (17.5%) were Acanthamoeba, 15 (18.75%) were Gram-negative bacilli, 4 (5%) were Staphylococci, 1 (1.25%) was Streptococci, 14 (17.5%) were both Gram-negative bacilli and Aspergillus fungus, and 2 (2.5%) were both Staphylococci and Aspergillus fungus. There was no significant difference between the diagnosis of MK by the culture method and the IC smear method. Conclusion: The impression cytology smear can be used as guide for early treatment of MK.