To assess associations between ophthalmological features and the main systemic biomarkers of primary Sjögren's Syndrome (pSS), and to identify systemic biomarkers associated with severe keratoconjunctivitis sicca (KCS) in pSS patients.

In this cross-sectional study, data was retrospectively extracted from the monocentric cohort of the French reference centre for pSS. We analysed data from the initial visit of patients admitted for suspicion of pSS and included patients validating pSS ACR/EULAR classification criteria. Ophthalmological assessment included Schirmer's test, tear break-up time, ocular staining score (OSS), and visual analogue scale (DED-VAS) for dry eye disease (DED) symptoms. Results of minor salivary gland biopsy, unstimulated whole salivary flow rate, anti-SSA/Ro antibodies, anti-SSB/La antibodies, and rheumatoid factor (RF) were collected.

A total of 253 patients (245 females) with confirmed pSS, aged 56.6±13.0 years, were included, among which 37% had severe KCS. Multivariate analysis showed that the presence of anti-SSA/Ro antibodies, anti-SSB/La antibodies and RF were associated with conjunctival OSS (odds ratio–OR–=1.25 per OSS unit increase; confidence interval–CI–95%=1.05–1.49; P=0.01; OR=1.31 per OSS unit increase; CI95%=1.09–1.58, P=0.002, and OR=1.34 per OSS unit increase; CI95%=1.12–1.59; P=0.001, respectively). Both anti-SSB/La antibodies and DED-VAS ≥ 5 were significantly associated with severe KCS (OR=2.03; CI95%=1.03–4.00; P<0.05 and OR=2.52, CI95%=1.31–4.90; P<0.01, respectively).

Association between conjunctival OSS and systemic biomarkers of pSS indicate the crucial importance of conjunctival staining when pSS is suspected as a cause of DED. Conversely, patients with anti-SSB and DED-VAS ≥ 5 features should be prioritized for extensive evaluation by an ophthalmologist due to their association with severe KCS.