Schirmer test results: are they associated with topical or systemic medication?

Purpose: To test whether Schirmer test (ST) results are associated with topical or systemic medication and to evaluate the distribution of tear fluid quantity in a 3-min and 5-min ST. Methods: The Gutenberg Health Study is a population-based, prospective, observational cohort study in Germany. ST was assessed in a sub-cohort of 1,999 participants. ST was performed under topical anesthesia for 5 min (ST-5) or of 3 min (ST-3). Anthropometric factors, systemic diseases, use of systemic and eye medications were recorded. We used multivariable quantile regression analysis to assess the influence on ST measurements. Results: The length of wetting of the Schirmer strips for ST-5 was 23.2 +/- 9.31 mm for right and 22.9 +/- 9.0 mm for left eyes. In ST-3, the measurements were 20.0 mm in right and 19.1 mm in left eyes. The clinical cut off of 10 mm for ST-5 corresponded with an 8 mm cut off for ST-3. There was an association of smaller ST-5 measures with male sex, higher age, socioeconomic status and season (all p < 0.001), but not with diabetes or smoking. The use of prostaglandin or beta-blocker eye drops or oral non-steroidal anti-inflammatory drugs, drugs for peptic ulcer and gastro-oesophageal reflux disease, thyroid hormones, progesterone and estrogen combination drugs, and hypnotics and sedatives showed an association with smaller ST-5. Conclusions: For the first time we describe the distribution of tear fluid quantity by ST in a very large cohort of the general population. Furthermore, we found associations of ST measures with topical and systemic medication.