Differences in the eyelid and buccal microbiome between open-angle glaucoma and uveitic glaucoma

Area of Science:

• Ophthalmology
• Microbiome Research
• Immunology

Background:

• The human microbiome plays a crucial role in regulating the immune system.
• Microbial dysbiosis is implicated in the pathogenesis of various diseases, including ocular conditions.
• The specific role of microbiomes in uveitic glaucoma (UG) and open-angle glaucoma (OAG) remains underexplored.

Purpose of the Study:

• To investigate and compare the eyelid and buccal microbiomes of patients with uveitic glaucoma (UG) and open-angle glaucoma (OAG).
• To identify potential microbial biomarkers associated with the distinct pathophysiologies of UG and OAG.

Main Methods:

• Collection of eyelid and buccal specimens from 34 UG and 62 OAG patients.
• 16S rRNA gene sequencing and operational taxonomic unit analysis for microbiome composition determination.
• Differential gene expression (DEG) and principal component analyses (PCoA) to identify microbial differences between patient groups.

Main Results:

• No significant differences in alpha-diversity were observed between UG and OAG microbiomes.
• Buccal microbiome composition differed significantly between UG and OAG groups, particularly in OAG patients with normal intraocular pressure (IOP).
• Specific taxa alterations included enrichment of Rhodococcus in UG eyelid samples, and depletion of Lactobacillus and Proteus with Enterococcus enrichment in UG buccal samples.

Conclusions:

• The buccal microbiome composition is distinct in uveitic glaucoma (UG) compared to open-angle glaucoma (OAG).
• A notable reduction in Lactobacillus was observed in the buccal microbiome of UG patients.
• These findings suggest that microbiome alterations may contribute to the pathogenesis of UG, beyond their role in OAG.