Microbiota of the ocular surface: research methods and modern ideas about the relationship between intestinal dysbiosis and ophthalmopathology

The microbiota (OMT) of the ocular surface (OS), which includes the cornea and conjunctiva and is characterized by relatively low diversity, plays a critical protective role in resisting the invasion of pathogens, while having a significant impact on the immunological activity and barrier effect in relation to the external environment. MBT HP can be influenced by environmental conditions, gender, bad habits, antibiotic treatment, etc., as well as a person’s age. If barrier functions and immune status are impaired, ophthalmopathology may develop. Currently, along with cultural methods for studying MBT HP, molecular genetic methods (PCR diagnostics, chromatography, sequencing and metagenomics) are used. The latest meth ods, for example, sequencing of bacterial 16S rRNA and especially metagenomic sequencing, allow the most complete identification of the diversity of MBT HP. It turned out that in MBT HP, normally more than 80% of all microorganisms, regardless of the method used, are, in descending order, the types Proteobacteria (64%), Actinobacteria and Firmicutes. In the intestine, which is most populated by microorganisms, anaerobic species of bacteria predominate, and the first three ranking places are occupied by Firmicutes (49– 76%) and, to a lesser extent, Bacteroidetes and Proteobacteria. There is reason to believe that at least some eye diseases are closely related to intestinal dysfunction and/or GP. In particular, such ophthalmopathology includes synonymous dry eye syndrome, blepharitis, conjunctivitis, keratitis, trachoma, iridocyclitis, glaucoma, diabetic retinopathy, macular degeneration and some others. Further studies of MBT GP to understand the role of microorganisms in health and pathology will open up new ways not only for the diagnosis and treatment of ophthalmological diseases, but also for their prevention. Key words: microbiota, ocular surface, sequencing, cultural and molecular genetic research methods, intestinal dysbiosis, ophthalmopathology.