This prospective cross-sectional study aims to evaluate the association between serum endocan, alarin, and galanin-like peptide levels and the stages of diabetic retinopathy (DR), as well as their relationship with optical coherence tomography (OCT) findings.
A total of 120 participants will be included: 30 patients without diabetic retinopathy, 30 with non-proliferative diabetic retinopathy, 30 with proliferative diabetic retinopathy, and 30 healthy control subjects. In addition to routine preoperative blood sampling, an additional 5 mL of venous blood will be collected for biomarker analysis using ELISA. Macular and peripapillary retinal nerve fiber layer measurements will be obtained using OCT. Serum biomarker levels will be compared across DR stages and analyzed for correlation with OCT parameters.