A novel scraping cytology score system (SCSS) grades inflammation in dry eye patients.

PURPOSE: We propose a conjunctival Scraping Cytology Scoring System (SCSS) as a reliable method to diagnose and score ocular surface inflammation in dry eye. METHODS: Twenty normal subjects and 46 patients with dry eye of various severities were included in the study. Clinical signs were scored 1-4; an Ocular Surface Disease Index (OSDI) questionnaire was used to grade subjective symptoms. Concentrations of serum albumin and interleukin-6 (IL-6) in tears were evaluated. Scraped conjunctival cytology samples were processed and examined with light microscopy. The number of inflammatory cells was staged and sub-scores were assigned. SCSS resulted from their sum and ranged from 0-12. Statistical evaluation was performed by applying the unpaired Student's t-test and the Spearman's correlation test (significance p < 0.05). SCSS was also analyzed for sensitivity, specificity, ROC curves, likelihood ratio LR+, positive (PPV) predictive value. RESULTS: SCSS was positively correlated to clinical sign score, OSDI score, exudated serum albumin, and IL-6 in either control (Spearman's correlation test always p < 0.05) and in dry eye patients (respectively, p < 0.0001, p < 0.01, p < 0.05, and p < 0.0001). SCSS >or= 4 was selected as the cut-off value for moderate dry eye (LR+ 10,9; PPV 22,5), SCSS >or= 9 was selected as the cut-off value for severe dry eye (LR+ 15,6; PPV 26,2). CONCLUSIONS: SCSS can be applied in any trained laboratory. It is correlated with clinical signs and symptoms, and it shows a diagnostic performance to grade inflammation in dry eye, comparable to more expensive cytokine assay.