Serum Cholinesterases, Paraoxonase, and Cardiovascular Risk After Intravitreal Bevacizumab

NCT07550777 | Recruiting

• 1 other identifier: B.30.2.ATA.0.01.00/346
• Study Type: observational
• Target: 180
• Locations: 1 country
• Sites: 1

Brief Summary

Bevacizumab, an anti-VEGF (vascular endothelial growth factor) agent used in the treatment of diabetic retinopathy and macular edema associated with retinal vein occlusion, is commonly administered in ophthalmology clinics through intravitreal injection. The systemic use of bevacizumab has been associated with serious conditions such as thromboembolism and bleeding. Although intravitreal bevacizumab is administered in smaller amounts and has limited systemic circulation, it requires repeated injections over a long period. These long-term intravitreal anti-VEGF therapies may lead to adverse outcomes, particularly thromboembolism, due to systemic inhibition of VEGF. However, limited information is available regarding the potential effects of this treatment on the systemic and cardiovascular systems. To evaluate this risk, the study aims to assess changes in the activities of paraoxonase 1 (PON1), acetylcholinesterase (AChE), and butyrylcholinesterase (BChE), which are closely associated with lipid metabolism, coronary artery disease, and atherosclerosis. These enzymes are known biomarkers of cardiovascular health and play significant roles in protection against oxidative stress and inflammation. For this purpose, a case-control study is planned. Serum BChE and PON1 activities, as well as triglyceride (TG)/high-density lipoprotein (HDL) and TG/glucose ratios, will be determined in patients receiving repeated intravitreal bevacizumab injections and in control groups, and cardiovascular disease risk will be assessed. This study may help us better understand the safety profile of this treatment by revealing the effects of bevacizumab on serum enzyme activities and cardiovascular risk factors. These findings could contribute to optimizing treatment strategies in clinical practice.

Conditions

Diabete Mellitus; Age Macular Degeneration; Retina Vein Occlusion

Keywords

bevacizumab; paraoxonase; retinal vein occlusion; age-related macular degeneration; diabetic retinopathy; acetylcholinesterase; butyrylcholinesterase

Outcome Measures

Primary Outcomes (1)

• Serum butyrylcholinesterase (BChE) activity

  Description: Measurement of serum butyrylcholinesterase (BChE) activity in participants who received at least 2 consecutive intravitreal bevacizumab injections. Serum samples will be collected after the most recent injection, and BChE activity will be compared among subgroups defined by the number of previous consecutive injections (early: 2-3 doses; mid: 4-6 doses; long: \>6 doses).

  Within 7 days after the most recent intravitreal bevacizumab injection

Secondary Outcomes (1)

• Serum acetylcholinesterase (AChE) activity

  Within 7 days after the most recent intravitreal bevacizumab injection

Other Outcomes (1)

• Serum paraoxonase-1 (PON1) activity

  Within 7 days after the most recent intravitreal bevacizumab injection

Study Arms (4)

diabetic macular edema

Procedure: blood test

retinal vascular occ

Procedure: blood test

age macular degeneration

Procedure: blood test

control

Procedure: blood test

Interventions

blood test PROCEDURE

Serum samples will be collected from the patient group included in the study starting from at least the second dose of intravitreal bevacizumab treatment. Serum samples will be collected within one week after the last injection.

age macular degeneration; control; diabetic macular edema; retinal vascular occ

Eligibility Criteria

• Age: 50 Years - 80 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

The patient group consists of individuals receiving repeated doses of intravitreal bevacizumab treatment for diabetic macular edema, retinal vein occlusion, and age-related macular degeneration-related macular edema, along with a control group (the control group will also be divided into two subgroups: individuals with diabetes but without macular edema or diabetic retinopathy, and completely healthy individuals).

You may qualify if:

• Age ≥ 55 years.
• Ability to provide written informed consent.
• Patient group: Diagnosis of macular edema secondary to diabetic retinopathy, retinal vein occlusion, or age-related macular degeneration, and having received repeated intravitreal bevacizumab injections (≥2 doses).
• Control group: Healthy volunteers with no ocular pathology other than cataracts and not receiving intravitreal anti-VEGF treatment.

You may not qualify if:

• Chronic inflammatory disease.
• Chronic infectious disease.
• History of cardiovascular disease (e.g., coronary artery disease, heart failure, arrhythmia requiring treatment).
• History of cerebrovascular disease (e.g., stroke, transient ischemic attack).
• Any additional ocular pathology that may affect the study outcomes (other than the index retinal condition in the patient group and cataract in the control group), such as:
• glaucoma
• uveitis
• retinal dystrophies
• significant media opacity preventing adequate ocular evaluation
• \- Use of systemic medications or conditions known to affect cholinesterase activity markedly

Sponsors & Collaborators

• Ataturk University: lead

Study Sites (1)

Ataturk University Research Hospital, Department of Ophthalmology

Erzurum, Erzurum, 25240, Turkey (Türkiye)

RECRUITING

MeSH Terms

Conditions

Diabetes Mellitus; Retinal Vein Occlusion; Macular Degeneration; Diabetic Retinopathy; Pain; Butyrylcholinesterase deficiency

Interventions

Hematologic Tests

Condition Hierarchy (Ancestors)

Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases; Retinal Diseases; Eye Diseases; Venous Thrombosis; Thrombosis; Embolism and Thrombosis; Vascular Diseases; Cardiovascular Diseases; Retinal Degeneration; Diabetic Angiopathies; Diabetes Complications; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Investigative Techniques

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: assistant professor

Study Record Dates

• First Submitted: February 19, 2026
• First Posted: April 24, 2026
• Study Start: November 3, 2025
• Primary Completion (Estimated): June 10, 2026
• Study Completion (Estimated): July 10, 2026
• Last Updated: April 24, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)