Predictive value of dry eye disease signs and corneal in vivo confocal microscopy on serological activity in primary Sjögren disease

The purpose of this study is to investigate the differences in the ocular signs and in vivo confocal microscope (IVCM) findings between dry eye disease (DED) patients with and without primary Sjögren disease (SjD), and to establish a predictive model to evaluate the serological activity of SjD based on IVCM findings: we examined 42 (84 eyes) and 41 (82 eyes) with and without SjD, respectively. IVCM was used to evaluate corneal nerve density (CND) and corneal dendritic cell density (DCD). Tear meniscus height (TMH), and tear film breakup time (BUT), corneal fluorescein staining (FL), serum anti-Ro/anti circular single stranded DNA antibody, anti-La/anti single chain binding protein antibody, IgG, C3, and salivary gland biopsies were performed. Patients with SjD had a lower CND (P < .0001), lower TMH (P < .001), higher DCD (P < .001), and higher corneal FL scores (P = .014) than patients without SjD. The equation for the prediction of SjD was as follows: Y1 = 4.313 + (-0.23) × CND + 0.02 × DCD + -10.89 × TMH (P < .0001). The negative and positive predictive powers of the model were 83.78% and 80.56%, respectively, and the cutoff value for Y1 was 0.392. The predicted serological activity of SjD was as follows: Y2 = -1.271 + 0.014 × DCD + 0.6074 × FL (P = .0002). The negative and positive predictive powers of the model were 68.75% and 84.38%, respectively. The cutoff value of Y2 was 0.427. CND, DCD, and TMH demonstrated good predictive values for distinguishing whether DED is caused by SjD. DED and FL had good predictive values for evaluating the serological activity of SjD.