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| ID | Type | Description | Link |
|---|---|---|---|
| 2024-113 | Other Identifier | Düzce University Non-Interventional Ethics Committee |
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The goal of this observational study is to examine the effects of body composition differences on retinal and choroidal structures. The study aims to investigate how variations in fat distribution and body composition parameters influence ocular microvascular structures.
The main questions it aims to answer are:
Participants will:
This study does not involve any new treatments, drugs, or interventional procedures. The findings aim to provide insights into the relationship between body composition and ocular microvascular health, contributing to early detection and prevention strategies for obesity-related ocular complications.
Study Overview
This study is a prospective observational research planned to be conducted at Düzce University between July 1, 2024, and October 1, 2024. The aim of this study is to evaluate the potential effects of body composition differences on retinal and choroidal microvascular structures using non-invasive imaging techniques. The study is designed to investigate how obesity-related changes in fat distribution, metabolic parameters, and vascular structures may influence ocular health.
A total of 200 participants are planned to be enrolled, consisting of individuals who will visit the ophthalmology clinic for routine eye examinations and will be confirmed to have no pre-existing ocular pathologies. Participants will be classified into five groups based on Body Mass Index (BMI):
Each group is expected to include 40 participants.
Planned Study Procedures and Measurements Ophthalmologic Evaluations
All participants will undergo a comprehensive ophthalmologic examination, including:
Study Objectives and Clinical Significance
This study aims to determine the relationship between body composition differences and retinal/choroidal microvascular changes to better understand how systemic metabolic alterations influence ocular structures. The results are expected to contribute to:
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Underweight | Participants with BMI <18.5 |
| |
| Normal Weight | Participants with BMI between 18.5 and 24.9 |
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| Overweight | Participants with BMI between 25 and 29.9 |
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| Obese | Participants with BMI between 30 and 34.9 |
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| Severely Obese | Participants with BMI >35 |
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| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Optical Coherence Tomography (OCT) and Body Composition Analysis | Other | This observational study included non-invasive diagnostic assessments to evaluate retinal, choroidal, ocular, and body composition parameters. Optical Coherence Tomography (OCT) measured macular and peripapillary retinal parameters, including retinal volume and cup/disc ratio. Enhanced Depth Imaging OCT (EDI-OCT) assessed choroidal thickness and vascularity, while Optical Coherence Tomography Angiography (OCTA) analyzed vessel density and foveal avascular zone (FAZ) metrics. Optical biometry measured axial length, anterior chamber depth, lens thickness, K1, K2, and central corneal thickness. Autorefractometry and tonometry were part of the routine ophthalmologic examination, including slit-lamp biomicroscopy. Bioelectrical impedance analysis (BIA) assessed body composition, including BMI, fat percentage, muscle mass, and metabolic age. These assessments were for research purposes only, without therapeutic intervention. |
| Measure | Description | Time Frame |
|---|---|---|
| Central Macular Thickness (CMT) | Measurement of central macular thickness (CMT) in micrometers using spectral-domain Optical Coherence Tomography (OCT). The measurement focuses on the 1 mm central foveal region. | Baseline (Cross-sectional) |
| Peripapillary Retinal Nerve Fiber Layer (RNFL) Thickness | Measurement of peripapillary RNFL thickness in micrometers using spectral-domain OCT. RNFL thickness is assessed around the optic disc at baseline. | Baseline (Cross-sectional) |
| Choroidal Thickness | Subfoveal choroidal thickness (in micrometers) measured using Enhanced Depth Imaging OCT (EDI-OCT). Measurements are taken at the fovea and at predefined intervals (e.g., 500 µm, 1000 µm) on either side of the fovea. | Baseline (Cross-sectional) |
| Choroidal Vascularity Index (CVI) | Calculation of the choroidal vascularity index (CVI) as the ratio of luminal area to total choroidal area in EDI-OCT images. Measurements are performed at the subfoveal region and analyzed using ImageJ software. | Baseline (Cross-sectional) |
| Retinal Microvascular Parameters (OCTA) | Evaluation of retinal microvascular parameters using Optical Coherence Tomography Angiography (OCTA). Metrics include vascular density, vessel length, and foveal avascular zone (FAZ) area/circularity in both superficial and deep capillary plexuses. | Baseline (Cross-sectional) |
| Measure | Description | Time Frame |
|---|---|---|
| Composite Association Between Body Composition and Ocular Parameters | This composite outcome measure includes correlation analyses between BIA parameters (fat percentage, muscle mass, visceral fat, metabolic rate) and multiple ocular structures (central macular thickness, RNFL thickness, choroidal thickness, CVI). The aim is to determine whether body composition influences overall microvascular integrity. |
| Measure | Description | Time Frame |
|---|---|---|
| FAZ Area | Measurement of the foveal avascular zone (FAZ) area (in mm²) using OCT Angiography to evaluate differences across BMI groups. | Baseline |
| FAZ Perimeter | Measurement of the FAZ perimeter (in mm) using OCT Angiography to assess potential variations in foveal microcirculation among different BMI categories. |
Inclusion Criteria:
Exclusion Criteria:
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This study aims to evaluate changes in ocular microvascular structures in healthy individuals aged 18-65 years with different body mass index (BMI) categories. Participants included in the study have no systemic or ophthalmologic diseases, and their refractive error is within the ±4 diopter range.
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| Name | Affiliation | Role |
|---|---|---|
| MURAT KAYA, Prof. Dr. | Duzce University Faculty of Medicine, Department of Ophthalmology | Principal Investigator |
| BAYRAM MEYDAN, MD, Research Assistant | Duzce University Faculty of Medicine, Department of Ophthalmology | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Duzce Univ. Fac. of Medicine, Dept. of Ophthalmology | Düzce | Düzce | 81620 | Turkey (Türkiye) |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 32725961 | Result | Tapp RJ, Owen CG, Barman SA, Welikala RA, Foster PJ, Whincup PH, Strachan DP, Rudnicka AR; UK Biobank Eye, Vision Consortium. Retinal Vascular Tortuosity and Diameter Associations with Adiposity and Components of Body Composition. Obesity (Silver Spring). 2020 Sep;28(9):1750-1760. doi: 10.1002/oby.22885. Epub 2020 Jul 29. | |
| 36924979 |
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Individual participant data (IPD) will not be shared due to ethical considerations and data privacy regulations. The collected data contain sensitive personal health information, and sharing them could potentially violate patient confidentiality and institutional policies. Additionally, there are no plans for a public data repository for this study.
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| ID | Term |
|---|---|
| D009765 | Obesity |
| D009767 | Obesity, Morbid |
| ID | Term |
|---|---|
| D050177 | Overweight |
| D044343 | Overnutrition |
| D009748 | Nutrition Disorders |
| D009750 | Nutritional and Metabolic Diseases |
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| ID | Term |
|---|---|
| D041623 | Tomography, Optical Coherence |
| ID | Term |
|---|---|
| D041622 | Tomography, Optical |
| D061848 | Optical Imaging |
| D003952 | Diagnostic Imaging |
| D019937 | Diagnostic Techniques and Procedures |
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|
| Baseline |
| Composite Regional Vascular Density Changes in Retinal and Choroidal Layers | This composite outcome measure evaluates retinal and choroidal vascular densities (VAD, VLD) in predefined ETDRS regions (foveal, parafoveal, perifoveal) using OCTA. The objective is to compare these densities across different BMI groups. | Baseline |
| Baseline |
| FAZ Circularity Index | Assessment of FAZ shape using a circularity index. Higher values indicate a more circular FAZ. Comparisons will be made across underweight, normal, overweight, obese, and severely obese groups. | Baseline |
| Axial Length | Comparison of axial length measurements among different BMI categories to identify possible associations with ocular morphology. | Baseline |
| Autorefraction Measurements | Spherical equivalent refraction (in diopters) measured using an autorefractometer. Differences across BMI categories will be assessed. | Baseline |
| Intraocular Pressure Measurements | Intraocular pressure (IOP) measured in mmHg using a non-contact tonometer. Differences across BMI groups will be evaluated. | Baseline |
| Anthropometric Measurements (Waist, Hip, and Height) | This outcome measure includes the measurement of waist circumference, hip circumference, and height. From these, waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) are calculated to assess central obesity. All measurements are performed following standardized protocols at baseline. | Baseline |
| Body Composition Analysis | This outcome measure involves the analysis of body composition parameters using bioelectrical impedance analysis (BIA) with the Tanita BC-418 MA device. Parameters such as body weight, body mass index (BMI), total fat percentage, muscle mass, visceral fat, and basal metabolic rate are recorded. These data are compared across different BMI groups to evaluate overall body composition differences. | Baseline |
| Ozgur G, Gokmen O. Associations between body mass index and choroidal thickness, superficial and deep retinal vascular indices, and foveal avascular zone measured by OCTA. Photodiagnosis Photodyn Ther. 2023 Jun;42:103515. doi: 10.1016/j.pdpdt.2023.103515. Epub 2023 Mar 14. |
| 37797912 | Result | Dogan B, Dogan U, Gedik B, Turkmen B, Cakir RC, Demirer ME, Aslaner A. Optical coherence tomography angiography evaluation of optic disc and retinal vascular densities in obese patients. Photodiagnosis Photodyn Ther. 2023 Dec;44:103826. doi: 10.1016/j.pdpdt.2023.103826. Epub 2023 Oct 4. |
| D001835 |
| Body Weight |
| D012816 | Signs and Symptoms |
| D013568 | Pathological Conditions, Signs and Symptoms |
| D003933 | Diagnosis |
| D014054 | Tomography |
| D008919 | Investigative Techniques |