ESCRS - FPT02.09 - Corneal Bacterial Microbiome In Patients With Keratoconus Using Next-Generation Sequencing-Based 16S Gene Analysis

Corneal Bacterial Microbiome In Patients With Keratoconus Using Next-Generation Sequencing-Based 16S Gene Analysis

Published 2022 - 40th Congress of the ESCRS

Reference: FPT02.09 | Type: Free paper | DOI: 10.82333/sfsp-xn58

Authors: Ugur Tunc* 1 , Ali Rıza Cenk Çelebi 2 , Yusuf Yıldırım 3 , Burcin Kepez Yıldız 3 , Osman Uğur Sezerman 4 , Sinem Öktem Okullu 5 , Berkay Ekren 4 , Sezen Karakus 6

1Department of Ophthalmology,Istanbul Eyupsultan State Hospital,Istanbul,Türkiye;Department of Ophthalmology,Beyoglu Eye Training and Research Hospital,Istanbul,Türkiye, 2Department of Ophthalmology,Acibadem Mehmet Ali Aydinlar University,Istanbul,Türkiye, 3Department of Ophthalmology,Beyoglu Eye Training and Research Hospital,Istanbul,Türkiye, 4Departmant of Bioinformatics,Acibadem Mehmet Ali Aydinlar University,Istanbul,Türkiye, 5Department of Medical Microbiology,Acibadem Mehmet Ali Aydinlar University,Istanbul,Türkiye, 6Wilmer Eye Institute,Johns Hopkins University School of Medicine,Baltimore,United States

Purpose

To investigate the corneal bacterial microbiome in patients with keratoconus using next-generation sequencing and develop a new perspective on the pathogenesis of keratoconus.

Setting

A single tertiary care academic medical center.

Methods

This prospective observational study was conducted at Beyoglu Eye Training and Research Hospital, Istanbul, Turkey, between March 2021 and June 2021. Samples were analyzed at Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey. Corneal epithelial samples were collected from ten patients with keratoconus who underwent a corneal crosslinking procedure and ten healthy controls who underwent photorefractive keratectomy, all aged 18 years or older. Isolated bacterial DNA from corneal epithelial samples was analyzed using 16S ribosomal RNA gene analysis. The relative abundances at the phylum and genus level were calculated. Alpha diversity indices, such as observed richness, Shannon diversity index, and Inverse Simpson Index, were measured.

Results

Eleven phyla and 511 genera of bacteria were identified in all participants. The most abundant phyla were Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes in both groups. Among those, the relative abundance of Bacteroidetes was significantly higher in patients with keratoconus than healthy controls (p=0.01). The most abundant bacterium genus was Aquabacterium (24.8%) in the keratoconus group and Staphylococcus (21.4%) in the control group. Twenty bacteria genera were found significantly less abundant in samples obtained from keratoconus patients than controls (p<0.05). Alpha diversity indices were lower in patients with keratoconus than healthy controls, although the difference did not reach statistical significance (p>0.05).

Conclusions

Our preliminary study suggested that the corneal microbiome in patients with keratoconus is distinct from healthy controls. Patients with keratoconus showed a less diverse corneal microbiome than healthy controls suggesting that the lack of diversity may play a role in disease pathogenesis.