Correlations Between Single-Photon Emission Computed Tomography Parameters of Salivary Glands and Dry Eye Tests in Patients With Sjögren's Syndrome

To evaluate the correlations between Single-Photon Emission Computed Tomography (SPECT) parameters of salivary glands and dry eye parameters in patients with Sjögren's syndrome (SS). A total of 28 patients with SS participated in this prospective study. Dry eye assessments include tear film break-up time (TBUT), corneal fluorescein staining scoring (CFS), Schirmer's I test (SIT) examination and SPECT of salivary gland. The following quantitative parameters were derived from SPECT imaging for salivary glands: Uptake index (UI), the time needed to achieve the minimum counts after Vit C stimulation (T ), and excretion fraction (EF). The relation between the aforementioned parameters and TBUT, CFS and SIT were analyzed with SPSS 22.0 software. All the 28 eyes of the 28 subjects were examined. The mean SIT was 6.04 ± 4.64 mm/5 min (0-18 mm/5 min); the mean CFS was 3.07 ± 2.65 (0-10) and the mean BUT was 2.11 ± 1.97 s (0-9 s). The mean EF value was 0.52 ± 0.12 (0.26-0.75) in parotid glands and 0.45 ± 0.10 (0.30-0.67) in submandibular glands, respectively. The mean UI value was 9.33 ± 1.68 (6.03-13.20) in parotid glands and 9.92 ± 1.48 (7.08-12.60) in submandibular glands, respectively. The mean T (min) was 5.32 ± 3.01 (2.00-12.00) in parotid glands and 11.09 ± 7.40 (2.00- 29.00 min) in submandibular glands, respectively. It was found that EF positively correlates with SIT in patients with SS (r = 0.499 and 0.426 in parotid glands and submandibular glands, with < 0.05), while no significant correlation was found between the UI, T and CFS, TBUT ( > 0.05). The EF was positively correlated with SIT in patients with SS, it could reflex the dysfunction of salivary glands in SS patients. So, EF may be a valuable parameter for the diagnosis of SS patients with lacrimal gland secretion dysfunction.