Impact of Age on the Ocular Surface Microbiome
Kara M. Cavuoto; Santanu Banerjee; Darlene Miller; Ta C. Chang; Mehdi Tavakoli; Anat Galor
Bascom Palmer Eye Institute
Miami, Florida, USA
Introduction: 16S sequencing is a technique that uses ribosomal DNA with primers and amplification to identify bacteria. This technology enables analysis of bacterial numbers and proportions, even in paucibacterial environments such as the ocular surface. We sought to characterize the ocular surface microbiome (OSM) via 16S sequencing in children and compare with an adult population.
Methods: Prospective, cross-sectional study using 16S sequencing to evaluate the OSM. Comparisons were made in bacterial yield and composition by (1) age and (2) sampling location (periocular skin, eyelid margin, or conjunctiva). 16S sequencing was performed using Illumina MiSeq 250 and analyzed using Qiime. Statistical analysis was performed using a two-sided student’s t-test and Monte Carlo permutations.
Results: 30 patients (15 children [mean 3.7 years], 15 adults [mean 60.4 years]) were sampled. Bacteria were 1.87-fold more abundant in children. Both principal coordinate analysis and unifrac distance analysis showed significant differences in the OSM composition between children and adults (both p=0.001). The periocular skin and eyelid margin OSM were similar to the conjunctiva in children, but all were distinct in adults (p=0.028).
Discussion: The adult OSM is paucibacterial compared to children, and showed distinct compositional differences between the periocular skin, eyelid margin and conjunctiva. This implies that there is mutual tutoring of the host immune system and the microbial ecosystem with aging.
Conclusion: Age and anatomic location are important distinguishing factors in the composition of the OSM. Future studies can examine the underlying mechanisms for these differences and their impact on ocular surface immunity and metabolism.
References: Not applicable