The Microbiome and Ocular Surface Disease

Purpose of Review: The human body lives in a symbiotic relationship with the bacteria, viruses, fungi, and protozoa that make up the microbiome. In this review, we discuss the compositions of the gut and ocular surface microbiomes in relationship to health and disease. Recent Findings: The gut microbiome is dominated by Firmicutes, whereas the ocular surface is dominated by Proteobacteria. The compositions of the microbiome are similar between individuals at the phyla level, but differ at the genus level. Alterations in the microbiome have been associated with disease. For example, ocular diseases such as uveitis, dry eye, and keratitis have been associated with gut dysbiosis. In addition, ocular surface dysbiosis has been reported in diseases including dry eye, blepharitis, keratitis, and diabetic retinopathy. Summary: Compositions of the gut and ocular surface microbiomes have been found to differ in disease states compared with controls. Further understanding of dysbiosis specific to a disease is needed to target these surfaces for therapeutic strategies.