Serum Endocan, Alarin, and Galanin-Like Peptide Levels in Diabetic Retinopathy

Association of Serum Endocan, Alarin, and Galanin-Like Peptide Levels With Diabetic Retinopathy Stages and Optical Coherence Tomography (OCT) Findings

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.

Inclusion Criteria:

• Adults aged 40 to 70 years.
• Diagnosis of diabetes mellitus (for diabetic groups).
• For control group: absence of diabetes mellitus and no retinal or optic nerve pathology.

Exclusion Criteria:

• Presence of systemic or ocular inflammatory disease.
• Any ocular disease other than diabetic retinopathy that may affect the retina or optic nerve.