Evaluation of ocular surface microbiota in children with blepharoconjunctivitis.

Purpose: To investigate the conjunctival and eyelid margin bacterial microbiota in children with blepharoconjunctivitis by using 16S rDNA amplicon sequencing.

Methods: In this prospective cross-sectional study, 20 children aged between 3-15 years with blepharoconjunctivitis or blepharokeratokonjunctivitis formed Blepharitis Group and 21 children aged between 3-15 years without any ocular and sysemic diseases except mild refractive errors formed Control Group. Swap samples from all children were taken. The alpha diversity of the ocular surface microbiota within each group were evaluated by using Shannon's, Simpson, and Chao index. Beta diversity was evaluated by Bray Curtis index.

Results: Microbiological diversity was higher in the patient group than in the control group. According to Shannon's, Simpson, and Chao index, there were statistically difference between groups (p: 0.000013, p:000003 p: 0.00235, respectively). According to the Bray Curtis index, the healthy eye microbiome in the control group is observed to be highly similar, consistent with other analyses, and the overlapping cluster with the blepharitis eye microbiome is quite low (pco1: 40.93%). Sphingoblump, Micrococus, Lacnospiracebacterium, Stenothermophilus, Aurelmonass, Micrococus, Blatiabeum, Delfiacdiovorans and Vellonella densities were found to be higher in the patient group.

Conclusion: Both alpha and beta diversity analyses were significantly higher in pediatric age group patients with blepharitis. In addition, Lacnospiracebacterium, Stenothermophilus, Aurelmonass, Micrococus, Blatiabeum, Delfiacdiovorans and Vellonella densities were found to be higher, which may lead to future studies focused on diagnosis and treatment.