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

Objective: 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).

Methods: 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_s), and excretion fraction (EF). The relation between the aforementioned parameters and TBUT, CFS and SIT were analyzed with SPSS 22.0 software.

Results: 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_s (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 P < 0.05), while no significant correlation was found between the UI, T_s and CFS, TBUT (P > 0.05).

Conclusions: 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.