Cytomorphology of Conjunctival Epithelium in Ocular Surface Disorders

Introduction: To study cytomorphological changes in various ocular surface disorders and find out the sensitivity, specificity and the diagnostic accuracy of impression cytology.
Materials and Methods: One hundred and ten patients (84 cases and 26 controls) were included in this study. Out of these 84 cases, 25 cases having vitamin A deficiency (VAD), 19 cases are having vernal keratoconjunctivitis (VKC), 30 of dry eye and 10 of chemical burn. Impression cytology was performed with each patient and the results were noted. Biopsy was done in 2 patients from each group. Patients were examined for goblet cell density in the form of clumping of goblet cells and degree of squamous metaplasia in terms of loss of cell cohesion, altered cell morphology and keratinisation.
Results: On impression cytology, all cases of vitamin A deficiency showed loss of goblet cells and 92% showed squamous metaplasia. In case of vernal conjunctivitis showed clumping (37%), loss of goblet cells (63%) and squamous metaplasia (64%). In dry eye group, severe reduction of goblet cells (73%) with moderate to severe grade of squamous metaplasia (88%) was seen. All cases of chemical burn showed marked reduction of goblet cells and squamous metaplasia. Control group, showed mild reduction in goblet cells (23%) and mild grade of squamous metaplasia (15%). Sensitivity, specificity and diagnostic accuracy of impression cytology was 89.28%, 76.92% and 86.36% respectively. Cytological findings are well correlated with histological findings.
Conclusion: Impression cytology was found to be good technique for diagnosing metaplastic changes in various ocular surface disorders.