Impact of Microbiome on Ocular Health

Abstract

The ocular surface is continuously exposed to the environment and, therefore, it is surprising that it harbors only few commensals with low degree of diversity. This unique aspect of the ocular surface physiology prompts the question whether there are core ocular commensal communities and how they affect ocular immunity. The purpose of this review is to provide an overview of what is known about the ocular surface commensals in health and disease and what we would like to learn in the near future. In addition, we discuss how microbiota at sites other than the eye may influence ocular immune responses. The information discussed in the review has been gathered using PubMed searches for literature published from January 1982 to December 2015.

Keywords: IgA; contact lenses; microbiota; ocular surface.

Figure 1

Microbiota drives ocular surface IgA levels. A. Haematoxylin-eosin staining of lacrimal gland sections derived from conventional and germ--free Swiss-Webster (SW) mice. The individual lymphoid follicles are circled. The lacrimal glands from germ-free mice contain decreased presence of lymphocytes in the lymphoid follicles, signifying the role of microbiota in the formation of EALT. B. Germ-free mice have significantly lower levels of IgA transcripts in the lacrimal glands compared to conventional mice. Quantitative RT-PCR assay was used to compare the levels of IgA heavy chain transcripts between the individual cohorts of mice. The data are representative of two experiments including at least 5-7 mice per group. Mann Whitney test, P=.0001. C. Oral administration of antibiotic cocktail decreases significantly lacrimal gland IgA transcripts, signifying the role of bacterial driven-IgA synthesis. The data are representative of two experiments including at least 5-7 mice per group. Mann Whitney test, P=.02.