Schirmer test of lacrimation. Its clinical importance

Lacrimation was tested by a modified Schrimer test, ie, by the soaking of strips of filter paper hooked into th lower conjunctival sac. The test is advocated for the topical diagnosis of facial-nerve lesions. Lacrimation was found to be independent of age and sex. There were, however, large inter- and intra-subject variations. Nevertheless, the difference between the two eyes of a given healthy person was much less than that between the eyes of two different persons, making the test clinically useful. In a given patient, a bilateral difference may be assumed to be significant when the lesser value does not exceed 27% of the larger one. Such a test result is indicative of a supraganglionic facial-nerve lesion.