Applying the consensus-based salivary glands ultrasound scoring system in lacrimal glands: results of a static image-based OMERACT reliability exercise

Objective This study tested the reliability of an ultrasound scoring system (0-3) for lacrimal glands using an OMERACT semi-quantitative ultrasound scoring system developed for salivary glands in primary Sjögrens Disease pSjD). Methods Fourteen rheumatologists participated in a static image exercise on ultrasound images in order to evaluate the reliability of the existing salivary gland ultrasound (SGUS) scoring system when applied to lacrimal glands. All images were obtained from patients with suspected pSjD using a 6-24 MHz linear hockey stick transducer. One hundred images representing different grades of parenchyma changes in the lacrimal glands were collected for the inter-observer analyses and 32 of these were repeated to assess intra-observer reliability. Kappa statistics were applied. Results Participants had musculoskeletal ultrasound experience ranging from 2–28 years, and SGUS experience from 0–12 years. The majority (11/14) had no prior experience in lacrimal gland ultrasound but 13/14 had experience in SGUS. Intra-observer reliability was good to excellent, with kappa values ranging from 0.63 to 1.00 (95% CI: 0.77–0.89). Inter-observer reliability showed good agreement, with a kappa of 0.63 (95% CI: 0.61–0.65). Conclusion The consensus-based semi-quantitative ultrasound scoring system for salivary glands showed good to excellent intra-observer and good inter-observer reliability when applied to the lacrimal glands using static images. The next step is to assess the reliability when scoring lacrimal glands in video-clips and in live exercises.