LAUSR

Background: Primary Sjögren’s syndrome (pSS) is an autoimmune disease characterized by lymphocytic infiltration of exocrine glands and other organs, resulting in dry eye, dry mouth, and systemic findings. [1] Objectives: The American College of Rheumatology/AECG group diagnostic criteria for pSS have included three items related to ocular involvement: The Schirmer test type 1, van Bijsterveld score, and Ocular Staining Score (OSS). They are time-consuming and employ costly dyes and instruments. In this context, we analyzed 66 patients with pSS to ascertain correlation between these tests and assess the possibility of streamlining ophthalmologic examination. Methods: Sixty-six patients (180 eyes) from the Federal University of Sao Paulo outpatient cornea clinic were analyzed prospectively from 2017 to 2018. Those with suspicion of pSS were tested according to the 2016 ACR-EULAR diagnostic criteria. A protocol consisting of the Schirmer, tear-film break-up time (TBUT), van Bijsterveld, and OSS tests was applied to all patients by a cornea specialist. Results were analyzed for correlation and interrater reliability using the kappa coefficient. Results: Of the 66 patients, 64 were female; 36 were white; median age was 53.3 (11,3) years. The Schirmer I test was done in 177 eyes, it was positive in 57.6%. TBUT was tested in 175 eyes and was positive in 96%. The van Bijsterveld score was done in 128 eyes and was positive in 61.7%. The OSS was done in 177 eyes and was positive in 68.9%. All four tests could be performed in 128 eyes. The results were confirmed at the same proportions. Correlation between tests was then calculated through the kappa coefficient (Table 1). Overall agreement was weak (κ = 0.340, p<0.001). Agreement between TBUT and other tests was particularly poor (κ = 0.112–0.144). On the other hand, good agreement was observed between the van Bijsterveld score and OSS (κ = 0.781, p<0.001). Overall and pairwise kappa coefficients are illustrated in Figure 1. Conclusion: Schirmer’s test without anesthesia has been part of the AECG diagnostic criteria for pSS since 1989. [2]. Our study demonstrates the low sensitivity of the Schirmer I test and the possibility of removing it from the diagnostic criteria. Limitations include our small sample size and lack of comparison group. We hope that, in future, use of objective tests for pSS will become routine ophthalmology practice, reducing costs and facilitating diagnosis. References [1] Shiboski CH, Shiboski SC, Raphaèle S, et al. 2016 American College of Rheumatology/European League Against Rheumatism classification criteria for primary Sjögren’s syndrome. Ann Rheum Dis 2016;0:1–8. [2] Workshop on Diagnostic Criteria for Sjögren’s syndrome. I. Questionnaires for dry eye and dry mouth. II. Manual of methods and procedures. Clin Exp Rheumatol 1989;7:212–19.Figure 1 – Overall and pairwise kappa coefficientsTable 1 – Kappa coefficients for classification of primary Sjogren’s syndrome Kappa Standard Error z p Observed agreement Expected agreement Pairwise comparison 0.340 0.036 9.42 < 0.001 - - Schirmer I x Break-Up Time 0.112 0.041 2.76 0.003 63.28% 58.64% Schirmer I x Van Bijsterveld 0.428 0.088 4.85 <0.001 72.66% 52.20% Schirmer I x OSS 0.469 0.088 5.35 <0.001 75.00% 52.93% Break-Up Time x Van Bijsterveld 0.123 0.043 2.90 0.002 65.63% 60.80% Break-Up Time x OSS 0.144 0.046 3.15 0.001 69.53% 64.40% Van Bijsterveld x OSS 0.781 0.088 8.87 <0.001 89.84% 53.66% Disclosure of Interests: None declared