Cytology of allergic conjunctivitis. Presence of airborne, nonhuman elements

Two groups of patients suffering from allergic conjunctivitis (32 atopic, 33 nonatopic) were studied. Their conjunctival secretions were subjected to cytologic examination involving morphologic and semiquantitative evaluation. Account was taken of noncellular and nonhuman elements in the smears; they included mucus, Charcot-Layden crystals, pollen grains, vegetal fragments and fungi. In 12 cases scanning electron microscopy was used in conjunction with x-ray microanalysis to identify material of noncellular origin. Similar quantities of inflammatory cells were present in both groups, while epithelial cells, particularly goblet cells, were more numerous in the atopic than in the nonatopic group (21.8% versus 6%). Pollen grains, vegetal fragments and fungi were present in 18%, 55% and 12% of cases, respectively. Exfoliative cytology emerges as a valuable tool for the diagnosis of allergic conjunctivitis, while the presence of noncellular elements is of particular diagnostic significance.