Introduction: Infectious keratitis is one of the leading cause of preventable blindness, proper and early diagnosis of infectious keratitis paves way for treatment and prevention of ocular morbidity. From corneal scrapings is considered to be the Gold standard in microbiological diagnosis of keratitis. Smear from impression technique can be used for laboratory diagnosis of keratitis. Purpose: This study was under taken to know the sensitivity and specificity of impression smear technique in diagnosis of infectious keratitis. Materials and Methods: Study was conducted at tertiary hospital, after taking all enrolled patients with infectious keratitis underwent clinical examination followed by smear examination by impression technique on filter paper and corneal scraping sent to lab for gram staining and KOH mount. Results: Out of 50 cases Male: Female ratio was 3: 1.1. Age group was 3070. Grams stain was positive in 70% patients with impression smear technique and in 64% patients with corneal scrapings. Sensitivity and Specificity of impression smear technique gram staining was 96.8% and 77.77% , positive and negative predictive value were 88.50% and 93.33%, accuracy of test was 90.0%. KOH mount was positive in 20% patients with impression smear technique and in 22% of patients with corneal scrapings. Sensitivity and Specificity of impression smear technique for KOH mount was 81.82% and 97.4%, positive an negative predictive value was 90.0% and 95.00%, accuracy of test was 92%. Specific therapy was started based on initial smear examination. Conclusion: Impression smear technique is safe simple and atraumatic procedure in lab diagnosis of infectious keratitis, with good sensitivity and specificity, it is also helpful in diagnosis of smaller lesions.

Keywords: Corneal Ulcer; Keratitis; Corneal Scraping. welcome