Impact of contact lenses on the ocular surface microbiome, tear proteome, and dry eye disease.

Although contact lens wear is widespread and known to affect the ocular surface, its impact on the ocular surface microbiome (OSM) remains poorly understood, with existing studies reporting conflicting findings. Additionally, the relationship between contact lens wear, tear proteome, and dry eye disease (DED) is unclear. In this study, we aimed to characterize the OSM (via whole-metagenome shotgun sequencing) and the tear proteome of 25 contact lens wearers and 23 age- and sex-matched controls. The dominant phyla were Actinobacteria, Proteobacteria, and Firmicutes, with Cutibacterium acnes being the most abundant species. No significant differences in microbial composition, diversity, or tear proteome were observed between contact lens wearers and controls. DED parameters (tear breakup time, Schirmer's test, tear osmolarity, and Ocular Surface Disease Index [OSDI]) also showed no significant differences, although contact lens wearers reported a trend toward higher subjective symptoms (OSDI). Sex-stratified analysis revealed a marginal difference in microbial beta diversity between male contact lens wearers and male controls, along with increased tear production in male contact lens wearers. Female contact lens wearers reported a higher OSDI compared to female controls. These findings suggest that contact lens wear does not significantly alter the OSM or tear proteome in healthy individuals, although sex-specific responses may warrant further investigation.IMPORTANCEContact lenses are worn by millions of people, yet the scientific literature contains conflicting reports about their impact on the microbial communities that are naturally present on the eye surface. This study addresses these knowledge gaps by examining both the eye microbiome and tear proteins using advanced sequencing and linking them to dry eye symptoms. Understanding the relationship between contact lens wear, natural eye bacteria, and tear composition is essential for resolving contradictory findings in the field. Additionally, identifying potential sex-specific differences in how individuals respond to contact lens wear could lead to more personalized approaches to contact lens management.