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

NCT07434362 | Completed

• 1 other identifier: EFSH-NIEC-2025-10-15
• Study Type: interventional
• Target: 90
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Diabetic Retinopathy; Diabetes Mellitus; Retinal Microvascular Disease

Keywords

Diabetic Retinopathy; Endocan; Alarin; Galanin-Like Peptide; Optical Coherence Tomography; Retinal Nerve Fiber Layer

Outcome Measures

Primary Outcomes (3)

• Serum Endocan Level

  Serum endocan concentration measured using ELISA and compared across diabetic retinopathy stages.

  At baseline (preoperative blood sampling)

• Serum Alarin Level

  Serum alarin concentration measured by ELISA and analyzed according to diabetic retinopathy severity.

  At baseline

• Serum Galanin-Like Peptide Level

  Serum galanin-like peptide concentration measured using ELISA and compared between study groups.

  At baseline

Study Arms (4)

Diabetes Mellitus Without Retinopathy

OTHER

Patients diagnosed with diabetes mellitus without clinical evidence of diabetic retinopathy. Participants will undergo OCT examination and additional venous blood sampling for biomarker analysis.

Procedure: Venous Blood Sampling; Procedure: Optical Coherence Tomography (OCT)

Non-Proliferative Diabetic Retinopathy (NPDR)

OTHER

Patients with clinically diagnosed non-proliferative diabetic retinopathy who will undergo OCT examination and additional venous blood sampling for serum biomarker measurement.

Procedure: Venous Blood Sampling; Procedure: Optical Coherence Tomography (OCT)

Proliferative Diabetic Retinopathy (PDR)

OTHER

Patients with clinically diagnosed proliferative diabetic retinopathy who will undergo OCT examination and additional venous blood sampling for serum biomarker analysis.

Procedure: Venous Blood Sampling; Procedure: Optical Coherence Tomography (OCT)

Healthy Control Group

OTHER

Age-matched control participants without diabetes or retinal pathology who will undergo OCT examination and venous blood sampling for comparative biomarker evaluation.

Procedure: Venous Blood Sampling; Procedure: Optical Coherence Tomography (OCT)

Interventions

Venous Blood Sampling PROCEDURE

Collection of 5 mL of venous blood in addition to routine preoperative sampling for the measurement of serum endocan, alarin, and galanin-like peptide levels using ELISA.

Diabetes Mellitus Without Retinopathy; Healthy Control Group; Non-Proliferative Diabetic Retinopathy (NPDR); Proliferative Diabetic Retinopathy (PDR)

Optical Coherence Tomography (OCT) PROCEDURE

Non-invasive optical coherence tomography imaging of the macula and peripapillary retinal nerve fiber layer using a Canon OCT device for structural retinal assessment.

Diabetes Mellitus Without Retinopathy; Healthy Control Group; Non-Proliferative Diabetic Retinopathy (NPDR); Proliferative Diabetic Retinopathy (PDR)

Eligibility Criteria

• Age: 40 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

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

Sponsors & Collaborators

• Elazıg Fethi Sekin Sehir Hastanesi: lead

Study Sites (1)

Fethi Sekin City Hospital

Elâzığ, Elaziğ, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Diabetic Retinopathy; Diabetes Mellitus

Interventions

Blood Specimen Collection; Tomography, Optical Coherence

Condition Hierarchy (Ancestors)

Retinal Diseases; Eye Diseases; Diabetic Angiopathies; Vascular Diseases; Cardiovascular Diseases; Diabetes Complications; Endocrine System Diseases; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases

Intervention Hierarchy (Ancestors)

Specimen Handling; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Punctures; Surgical Procedures, Operative; Investigative Techniques; Tomography, Optical; Optical Imaging; Diagnostic Imaging; Tomography

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: February 20, 2026
• First Posted: February 25, 2026
• Study Start: January 30, 2026
• Primary Completion: February 1, 2026
• Study Completion: February 18, 2026
• Last Updated: February 25, 2026

Record last verified: 2026-02

Locations

TU (1)