Comparison of microRNA expression in pseudoexfoliation syndrome with and without glaucoma

Pseudoexfoliation syndrome (PXS) is associated with increased risk of glaucoma, but the underlying molecular mechanisms remain unclear. This study aimed to compare microRNA (miRNA) expression profiles between PXS with glaucoma (PXSG) and PXS without glaucoma (PXSWG).

We enrolled 24 PXS patients undergoing cataract surgery, dividing them into PXSG (n=16) and PXSWG (n=8) groups. miRNA expression in anterior lens capsule tissue was analysed using NanoString nCounter technology. Differentially expressed miRNAs were identified, and functional pathway analysis was conducted using the Kyoto Encyclopedia of Genes and Genomes (KEGG). The correlations between miRNA expression and clinical variables, including glaucoma severity, endothelial cell counts (ECCs) and systemic factors identified in serum blood tests, were also examined.

Using a panel of 827 miRNAs, 23 upregulated miRNAs in PXSG were identified, miRNA-(miR-)887-3 p and miR-933 exhibiting the highest differential expression. The KEGG highlighted enrichment in pathways related to ageing and signal transduction. Elevated levels of several miRNAs, miR-933 and miR-302a-3p, were linked to worse visual field (VF) and thinner peripapillary retinal nerve fibre layer thickness (pRNFLT). Multivariate regression analysis identified associations of miR-302a-3p with lower ECC, miR-302f with thinner pRNFLT and miR-614 with higher triglyceride levels.

This study indicates potential differences in miRNA expression between PXSG and PXSWG, with several showing suggestive associations with key clinical parameters. These preliminary findings may provide valuable insights into processes relevant to PXS and glaucoma but require validation in larger, independent cohorts to clarify their biomarker potential.