Differences in the eyelid and buccal microbiome between open-angle glaucoma and uveitic glaucomaOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study asked whether the eyelid and buccal microbiomes differ between two glaucoma types, uveitic glaucoma and open-angle glaucoma. Researchers used metagenomic 16S rRNA gene sequencing on eyelid and buccal swabs. The taxonomic composition was determined by operational taxonomic unit analysis and diversity analysis. Differential expression analysis and principal coordinate analysis compared taxa between the two groups. Subgroup analyses were run by age and by baseline intraocular pressure.
Who was studied?
The cohort was 96 human glaucoma patients: 34 with uveitic glaucoma and 62 with open-angle glaucoma. Eyelid and buccal specimens were collected from each patient. The work was a single clinical study analysing paired ocular-surface and oral samples. It did not include a separate healthy control arm, comparing the two glaucoma subtypes directly instead.
What were the most important findings?
There was no significant difference in alpha-diversity between the two groups. Principal coordinate analysis showed no eyelid microbiome difference, but a significant buccal microbiome difference, especially in open-angle glaucoma patients with normal intraocular pressure. In the eyelid microbiome, Rhodococcus was enriched in uveitic glaucoma. In the buccal microbiome, Lactobacillus and Proteus were significantly depleted while Enterococcus was enriched in uveitic glaucoma. Reduced Lactobacillus was a notable feature of uveitic glaucoma.
What are the greatest implications of this study?
The findings suggest that microbiome composition, particularly in the buccal area, may be a factor that distinguishes uveitic glaucoma from open-angle glaucoma. Reduced Lactobacillus points to loss of anti-inflammatory bacteria in uveitic glaucoma. Because this was an observational comparison, it cannot establish causation. The differences may reflect the inflammatory disease itself or its treatments, such as anti-inflammatory and anti-glaucoma medications.