Enhancements to the conjunctival impression cytology technique and examples of applications in a clinico-biochemical study of dry eye.

The conjunctival impression cytology (CIC) technique was optimized for cell pick-up and resolution of cytologic detail. Use of surfactant-free smaller pore-size Millipore filters yielded consistently high cell pick-up and resolution of cell detail. Staining by the modified Papanicolaou technique in a free-floating format allowed quantitative evaluation of cytologic features. Air exposure of CIC specimens for up to 8 minutes before fixing (as occurs with Nelson's standardized technique) did not adversely affect cell appearances. The optimized method was applied to a group of 50 patients with dry eyes. CIC features were correlated with symptoms, clinical test results, and serum and tear protein levels of dry eye patients.