Objective: To assess the results of 1-minute and 5-minute Schirmer test (ST) when eyes are open (STo) and closed (STc) in normal subjects and patients with dry eye disease.
Methods: In a comparative, observational case series study, 34 normal volunteers (group 1) and 34 patients with dry eye disease (DED) associated with Sjogren syndrome (group 2) were included in the study. STo and STc for 1 minute and 5 minutes were performed separately for all subjects with an interval of at least 24 hours using Whatman No. 41 (5 × 60 mm) with bended end of the paper inserted into the lateral side of the lower conjunctival fornix.
Results: In group 1, there were 19 females and 15 males with a mean age of 20.8 years (range 18 to 23 years). In group 2, there were 29 females and 5 males with a mean age of 53.7 years (range 35 to 75 years). Mean value of STc was significantly less than STo in both 1 minute and 5 minutes in both groups. One-minute STo and STc showed significantly less wetting than the 5-minute test in both healthy and patients with DED. Normal distribution was observed for all the values. A significant correlation between 1-minute and 5-minute tests in both STo and STc were found in the two groups. Therefore, two equations were proposed to calculate the 5-minute from 1-minute ST in each group. Statistical analysis did not provide a reliable equation for calculating the standard ST (5-minute STo) from the most comfortable state (1-minute STc).
Conclusion: Faster and more comfortable ST (1-minute) is a reliable test to calculate the 5-minute ST in both open and closed eyes, using the provided equations. The 1-minute STc is not a reliable test to calculate the 5-minute STo.