The Role of the Ocular Surface Microbiome (OSM) in Diseases of the Anterior Segment and Ocular Surface

Purpose of Review In this article, we define the ocular surface microbiome (OSM) and review the literature investigating its putative role in anterior segment diseases. Recent Findings The complex networks of microorganisms that compose the OSM play integral roles in many physiologic processes. The three most common bacterial phyla that contribute to the microbiome are Proteobacteria, Firmicutes, and Actinobacteria, although the composition has been found to vary by anatomic site, age, and systemic disease. Multiple ocular conditions have definitive associations with OSM alterations, some with specific signature colonization of atypical genera or species, while others have more broad changes in abundance or alpha diversity of natural microbiota. Summary Dysbiosis of the OSM appears to play a role in multiple ocular surface and anterior segment diseases. Future larger, longitudinal, and multicentered studies investigating its composition will lend insight into the pathophysiology of disease and potential methods for therapeutic interventions.