Conjunctival microbiome changes in soft contact lens users and contact lens discomfort patients

IntroductionContact lens discomfort (CLD) acts as a challenging problem, and the associated conjunctival microbiome changes were unclear.Material and MethodsConjunctival sac swab samples were collected from 12 eyes of nonwearers (NW), 12 eyes of asymptomatic contact lens (ACL) wearers, and 11 eyes of CLD. The V3-V4 region of the 16S rRNA gene sequencing was used to investigate differences among three groups.ResultsNo differences in alpha diversity were observed among the three groups. The beta diversity showed a distinct microbiome composition between ACL and CLD group (P = 0.018) with principal coordinate analysis. The relative abundance of Firmicutes was significantly higher in CLD (48.18%) than in ACL (13.21%) group (P = 0.018). The abundance of Bacillus in patients with ACL (0.05%) or with CLD (0.02%) were significantly lower than that in the NW (1.27%) group (P = 0.024, 0.028, respectively). Moreover, the abundance of Firmicutes was positively correlated with the OSDI scores in CLD patients (r = 0.817, P < 0. 01, Spearman).DiscussionsPatients with CLD have various degrees of bacterial microbiota imbalance in the conjunctival sac, compared with NW and ACL groups.ConclusionFirmicutes may serve as a potential biomarker for the CLD patients. Clinical SignificanceIn the current study, we investigated the conjunctival microbiome changes among nonwearers (NW), asymptomatic contact lens (ACL) wearers, and contact lens discomfort (CLD) patients using high-throughput 16S rRNA gene sequencing, and correlated relative abundances of the microbiota with clinical parameters.The relative abundance of Firmicutes was higher in CLD than that in ACL group. The abundance of Bacillus was lower in ACL or CLD group than that in NW group. The abundance of Firmicutes was positively correlated with the OSDI scores in CLD patients.Firmicutes may serve as a potential biomarker for the CLD patients.