Abstract
Pterygium is a chronic ocular surface condition marked by fibrovascular growth extending from the conjunctiva to the cornea. Emerging evidence suggests that microbial dysbiosis may play a role in its pathogenesis. To elucidate the microbial landscape associated with pterygium, we conducted metagenomic shotgun sequencing on conjunctival sac secretions from 24 patients with pterygium and 23 healthy controls, along with 19 pterygium tissue samples. We observed significantly higher microbial richness in the disease group, with distinct taxonomic profiles compared with healthy and tissue groups. Key species enriched in the disease group included Microbacterium proteolyticum and Bacillus cereus. Functional analyses revealed elevated bacterial motility, chemotaxis, and virulence genes, alongside a notable increase in antibiotic resistance genes such as tetB and AcrAB-TolC. In contrast, pterygium tissue samples showed limited microbial diversity and no detectable virulence or resistance genes. Importantly, the predominance of Vibrio phages in tissue samples, together with the frequent detection of their bacterial host Vibrio diabolicus, suggests a potential region-specific microbial risk factor, particularly relevant in coastal populations. These findings highlight distinct microbiome and functional profiles associated with pterygium, providing new insights into its pathogenesis and possible microbiome-based therapeutic targets.IMPORTANCEUnderstanding how microbial communities contribute to ocular diseases is crucial for advancing both diagnostics and therapy. This study provides the first integrated comparison of healthy ocular surfaces, diseased ocular surfaces, and pterygium tissues, revealing distinct microbial signatures and functional disruptions. The enrichment of specific bacterial taxa, virulence factors, and antibiotic resistance genes in diseased eyes underscores their potential role in shaping local immunity and driving disease progression. Meanwhile, the discovery of distinct viral elements in pterygium tissue expands current understanding of its microecological complexity. These findings lay a theoretical foundation for the development of microbiome-informed diagnostic tools and novel therapeutic interventions for pterygium.