CA-19-9 ELISA TEST - A NEW METHOD FOR STUDYING MUCUS CHANGES IN TEARS

Aims-This study investigated mucus changes in the tears in various eve conditions using impression cytology. The quantity of mucins was meas ured by enzyme linked immunosorbent assay (ELISA) using the tumour mar ker CA 19-9. This assay quantifies the sialylated Lewis(n) structure m ainly associated with ocular mucins. Methods-Impression cytology was p erformed using a cellulose nitrate membrane, on 53 healthy patients, 5 0 glaucoma patients treated with beta blockers, 24 patients suffering from dry eye syndrome, and 45 contact lens wearers. The tear film glyc oproteins were eluted and CA 19-9 was measured. Results-CA 19-9 conten t expressed as kilo units (kU) per mu g of tears was significantly dec reased in drg eye syndrome (25.8 kU (SD 17.3)/mu g) (p<0.05), glaucoma patients over 60 years (28.9 (19.5) kU/mu g) (p<0.05), and contact le ns wearers (28.4 kU (18)/mu g) (p<0.05), when compared with healthy in dividuals (39.4 kU (22.2)/mu g). Conclusion-Impression cytology can be regarded as a valuable method for obtaining samples of glycoconjugate s of mucin. The decrease of sialylated; chains observed with this meth od confirms the hypothesis that some quantitative changes in the tear film may be encountered in ocular surface disorders.