The Diagnostic Value and Accuracy of Conjunctival Impression Cytology, Dry Eye Symptomatology, and Routine Tear Function Tests in Computer Users

AIMS AND OBJECTIVES: To compare the diagnostic value and accuracy of dry eye scoring system (DESS), conjunctival impression cytology (CIC), tear film breakup time (TBUT), and Schirmer's test in computer users. METHODS: A case–control study was done at two referral eye centers. Eyes of 344 computer users were compared to 371 eyes of age and sex matched controls. Dry eye questionnaire (DESS) was administered to both groups and they further underwent measurement of TBUT, Schirmer's, and CIC. Correlation analysis was performed between DESS, CIC, TBUT, and Schirmer's test scores. A Pearson's coefficient of the linear expression (R(2)) of 0.5 or more was statistically significant. RESULTS: The mean age in cases (26.05 ± 4.06 years) was comparable to controls (25.67 ± 3.65 years) (P = 0.465). The mean symptom score in computer users was significantly higher as compared to controls (P < 0.001). Mean TBUT, Schirmer's test values, and goblet cell density were significantly reduced in computer users (P < 0.001). TBUT, Schirmer's, and CIC were abnormal in 48.5%, 29.1%, and 38.4% symptomatic computer users respectively as compared to 8%, 6.7%, and 7.3% symptomatic controls respectively. On correlation analysis, there was a significant (inverse) association of dry eye symptoms (DESS) with TBUT and CIC scores (R(2) > 0.5), in contrast to Schirmer's scores (R(2) < 0.5). Duration of computer usage had a significant effect on dry eye symptoms severity, TBUT, and CIC scores as compared to Schirmer's test. CONCLUSION: DESS should be used in combination with TBUT and CIC for dry eye evaluation in computer users.