Aqueous Humor Microrna Profiles In Diabetic Patients Undergoing Cataract Surgery

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes mellitus and a major cause of visual impairment worldwide. Increasing evidence suggests that microRNAs (miRNAs) regulate inflammatory, angiogenic, and metabolic pathways involved in DR pathogenesis. This study aimed to investigate the expression levels of selected miRNAs in the aqueous humor of diabetic patients undergoing cataract surgery and to evaluate their potential role as early molecular biomarkers associated with the development of diabetic retinopathy.

This prospective study was conducted at the Department of Ophthalmology, İnönü University Faculty of Medicine, Malatya, Türkiye. Patients scheduled for cataract surgery between December 2023 and March 2024 were enrolled in the study.

Patients were divided into three groups: diabetic patients without diabetic retinopathy (non-DR), diabetic patients with diabetic retinopathy (DR), and age-matched healthy controls. Aqueous humor samples were collected at the beginning of cataract surgery before intraocular manipulation. Expression levels of miR-21, miR-31, miR-126, miR-146, miR-200b, miR-320, and miR-762 were analyzed using real-time polymerase chain reaction (RT-PCR). Quantitative analysis of miRNA expression was performed using the GeneGlobe Data Analysis Center (Qiagen, Germany).

Significant differences in miRNA expression levels were observed between diabetic patients and controls. Compared with the control group, diabetic patients without retinopathy demonstrated increased expression of miR-21 (~5-fold), miR-31 (~5-fold), miR-320 (~6-fold), and miR-762 (~5-fold), while miR-126 (~2-fold), miR-146 (~14-fold), and miR-200b (~50-fold) were decreased. Similar alterations were observed in the DR group, with increased expression of miR-21 (~6-fold), miR-31 (~5-fold), miR-320 (~6-fold), and miR-762 (~5-fold), and decreased expression of miR-126 (~2-fold), miR-146 (~14-fold), and miR-200b (~54-fold).

Altered aqueous humor miRNA expression profiles were detected in diabetic patients undergoing cataract surgery. The observed changes suggest that specific miRNAs may be involved in the molecular mechanisms underlying diabetic retinopathy. These findings indicate that aqueous humor miRNA profiling may provide potential early biomarkers for identifying diabetic patients at risk of developing diabetic retinopathy and for improving understanding of its pathogenesis. Furthermore, analysis of aqueous humor obtained during cataract surgery may provide a valuable opportunity for risk assessment of future retinal disease development in diabetic patients.