Tear micro RNA expression signature in primary open-angle glaucoma versus ocular hypertension.

Abstract

Purpose : To study the expression profile of microRNAs in tears of patients diagnosed of primary open-angle glaucoma (POAG) and subjects with ocular hypertension (OHT), to identify specific tear microRNAs as potential biomarkers for better managing the preclinical POAG diagnosis

Methods : A case-control study was carried out in 48 participants, divided into: 24 POAG patients vs 24 OHT subjects. The study was designed in two phases: screening and validation. Socio-demographic data were recorded. Ophthalmologic examination and reflex tear collection were performed in all participants. Tears were processed to total RNA isolation, using the miRCURY™ RNA Kit [Biofluids (Exiqon®)] and quantified in a 2100 Bioanalyzer (Agilent ®). The expression profile of microRNA in tear samples was analysed by next generation sequencing using the Illumina NextSeq500 Technology. TargetScan, miRBase and miRTarBase were used to predict novel micro RNAs. Data were analysed by logistic regression and receiver operating characteristics curve (ROC) to identify micro RNA signatures. Functional analyses was done by the Gene Ontology Consortium database.

Results : 120 microRNAs were identified in tears of the participants. The microRNAs 27a-3p,152-3p, 26b-5p,125b 2-5p, 224-5p, 30e-5p, 151a-3p, and 1307-3p showed significant differences (p<0.05) between the POAG and the OHT samples. All these were statistically analysed to create the ROC, obtaining for all of them an area under the curve higher than 0.65.

Conclusions : Tear samples have provided essential information to differentially identify novel microRNAs between the POAG patients and the OHT subjects. Overall, our data especifically supports that the micro RNAs 26b-5p and 30e -5p found in the present work, may be biomarkers for early identification of the POAG risk in OHT individuals.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.