Purpose: To report the proportion of ocular involvement in primary Sjögren syndrome (pSS) and to analyze various dry eye indexes and serum titers of markers depending on whether ocular involvement has occurred or not.Methods: This retrospective study considered 214 patients referred from the rheumatology department for pSS workup. Symptom questionnaires, ocular surface stain score (OSS), Schirmer test, tear breakup time (TBUT), meibomian gland dropout, meibum quality, meibum expressibility, lid margin abnormalities, and lipid layer thickness were evaluated. Anti-Ro, anti-La, and antinuclear antibodies, rheumatoid factor, erythrocyte sedation rate, and C-reactive protein were included as systemic serum titers of markers. Patients with (group 1) and without (group 2) ocular involvement were compared. We conducted a further subgroup analysis of group 1 by dividing it into two groups based on whether or not the cases met all the ocular criteria for pSS diagnosis.Results: Among the 214 referred patients, 118 were diagnosed as pSS: 87 out of 118 (73.7%) in group 1 and 31 (26.3%) in group 2. Group 1 showed higher meibum quality scores (<i>p</i> = 0.016), meibum expressibility (<i>p</i> = 0.010), and lid margin abnormalities on the lower lid (<i>p</i> = 0.029) and lower TBUT (<i>p</i> = 0.016) than group 2. OSS, TBUT, and the Schirmer test statistically differed (<i>p</i> < 0.001, <i>p</i> = 0.041, and <i>p</i> = 0043, respectively) between the patients who satisfied both ocular criteria (n = 46) and those who satisfied only one criterion (n = 41). There were no statistical differences in serum titers of markers between the two groups.Conclusions: About half of patients referred from the rheumatology department for diagnosis of pSS were diagnosed with pSS. The proportion of ocular involvement in the pSS patients was 73.7%, and half of these patients met both ocular criteria. Only anti-Ro antibodies negatively correlated with TBUT. Also, OSS, TBUT, and Schirmer test were statistically different between the two subgroups.
