A novel diagnostic technique of measuring labial minor salivary gland secretions using sodium fluorescein dye: Implications for patients with dry eyes.

Purpose: To evaluate the lower labial minor salivary glands (MSGs) flow rate using fluorescein dye in healthy individuals and patients with Sjogren's syndrome (SS) and Stevens-Johnson syndrome (SJS).Methods: Thirty consecutive patients with SS (N = 15; mean age 35.7 years) and SJS (N = 15; 57.7 years), and their age- and sex-matched healthy controls (N = 40; mean ocular surface disease index (OSDI) = 6.1) had ocular examination and whole lower labial mucosa evaluation after ophthalmic fluorescein strip application under cobalt blue light. Analyzed parameters include average labial distribution of functional MSGs, their secretory flow rate, and comparison between healthy and diseased groups.Results: The mean salivary flow rate from the lower labial MSGs of normal individuals showed decade-wise decline (2.7 ± 0.29 μl/min, 2.6 ± 0.39 μl/min, 2.3 ± 0.6 μl/min, 1.9 ± 0.95 μl/min) with similar trend for the number of secreting MSG openings (38.7, 37.2, 30, 22). The mean OSDI score was 45.3 in SJS and 28.2 in SS group. Thirty eyes in each SS and SJS group had mean Schirmer I value of 1.5 ± 2.2 mm and 5.1 ± 4.4 mm. The mean lower labial salivary flow rate in SS group was 0.5 ± 0.28 μl/min, and 2.0 ± 0.95 μl/min in SJS group. When compared to normal, SS patients had a significant reduction in the flow rate (p < .00001); however, it was not significant for the SJS group (p = .28). The mean number of secreting MSG openings was reduced in both the groups compared to normal (SJS, 20.5; p = .01 and SS, 12; p < .0001). There was a significant difference between SS and SJS groups in terms of flow rate (p < .00001) and number of MSG openings (p = .001). The MSG flow rate and Schirmer values did not show any correlation in SS or SJS patients.Conclusion: The fluorescein-assisted evaluation of the lower lip can be used as a quantitative method for measuring the labial salivary flow rate in SS and SJS patients.