Clinical trial NCT06888765: Effects of Differences in Body Composition on Retina and Choroid
Official title: The Impact of Changes in Body Composition on the Retina and Choroid
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Obesity
Obesity, Morbid
Body Composition
Keywords: Obesity
Retina
Choroid
Body Mass Index (BMI)
Body Composition Analysis
Optical Coherence Tomography (OCT)
Microvascular Structures
Lead sponsor: Duzce University
Sponsor class: OTHER
First posted: 2025-03-21
Enrollment: 261
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: OTHER
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: 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.

Brief summary: 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:

* How do differences in body composition (BMI, waist circumference, bioelectrical impedance parameters) affect retinal and choroidal microvascular structures?
* Are there significant structural changes in the retina and choroid among individuals with different body composition profiles?

Participants will:

* Be classified into five groups based on their Body Mass Index (BMI) (underweight, normal weight, overweight, obese, and severely/morbidly obese).
* Undergo detailed body composition analysis using bioelectrical impedance analysis (BIA) to assess fat mass, muscle mass, visceral fat index, and metabolic age.
* Receive comprehensive ophthalmologic evaluations, including Optical Coherence Tomography (OCT) and Optical Coherence Tomography Angiography (OCTA), to measure retinal thickness, choroidal thickness, and microvascular parameters.
* OCTA images will be analyzed using the OCTAVA software to compute vascular parameters.

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.

Detailed description: 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):

* Group 1: Underweight (BMI \<18.5)
* Group 2: Normal weight (BMI 18.5-24.9)
* Group 3: Overweight (BMI 25-29.9)
* Group 4: Obese (BMI 30-34.9)
* Group 5: Severely/Morbidly Obese (BMI \>35)

Each group is expected to include 40 participants.

Planned Study Procedures and Measurements Ophthalmologic Evaluations

All participants will undergo a comprehensive ophthalmologic examination, including:

* Autorefractometry to assess refractive errors
* Intraocular pressure (IOP) measurement using a non-contact tonometer
* Detailed slit-lamp biomicroscopy to examine anterior and posterior segment structures Body Composition Analysis
* Bioelectrical Impedance Analysis (BIA) will be performed to assess:
* Total body fat percentage, visceral fat index, muscle mass, and metabolic age
* Segmental body composition (fat and muscle mass in arms, legs, and trunk)
* Extracellular and intracellular water distribution
* Waist circumference, waist-to-hip ratio, waist-to-height ratio OCT and OCTA Imaging
* Optical Coherence Tomography (OCT) and Enhanced Depth Imaging-OCT (EDI-OCT) will be used to obtain:
* Macular and peripapillary retinal thickness measurements
* Retinal nerve fiber layer (RNFL) thickness
* Optic disc and cup-to-disc ratio analysis
* Choroidal thickness at the subfoveal region and 500 µm intervals
* Optical Coherence Tomography Angiography (OCTA) will be performed to analyze:
* Superficial and deep retinal capillary plexus vascular density
* Foveal avascular zone (FAZ) area, perimeter, and circularity
* Vascular tortuosity and branchpoint density Image Processing and Analysis
* OCTA images will be analyzed using the OCTAVA software, where:
* Vessel area density, vessel length density, total vessel length, mean vessel diameter, median vessel diameter, branchpoint density, fractal dimension, and vessel tortuosity will be calculated.
* FAZ metrics (FAZ area, perimeter, and circularity) and vascular density values will be evaluated using ETDRS grid segmentation and FD-300 analysis.
* Choroidal Vascularity Index (CVI) will be calculated from EDI-OCT images using ImageJ software.

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:

* Identifying early ocular biomarkers associated with obesity
* Developing preventive strategies for obesity-related retinal and choroidal complications
* Enhancing the clinical use of non-invasive imaging techniques in metabolic disease monitoring No new treatment, drug, or interventional procedure is planned to be applied in this study, and no life-threatening risks are anticipated.

Eligibility criteria: Inclusion Criteria:

* Age between 18 and 65 years,
* No detected pathology in routine ophthalmologic examination,
* Providing written informed consent for participation.

Exclusion Criteria:

* Presence of ocular diseases such as glaucoma, uveitis, diabetic retinopathy, amblyopia, or retinal vein occlusion,
* History of previous ocular surgery,
* Refractive error exceeding ±4 diopters,
* Use of medications that may affect choroidal or retinal vascular structures,
* Pregnancy or breastfeeding,
* Presence of metallic prostheses, pacemakers, or other implants that could interfere with body composition analysis.

Primary outcomes:
measure: Central Macular Thickness (CMT)
timeFrame: Baseline (Cross-sectional)
measure: Peripapillary Retinal Nerve Fiber Layer (RNFL) Thickness
timeFrame: Baseline (Cross-sectional)
measure: Choroidal Thickness
timeFrame: Baseline (Cross-sectional)
measure: Choroidal Vascularity Index (CVI)
timeFrame: Baseline (Cross-sectional)
measure: Retinal Microvascular Parameters (OCTA)
timeFrame: Baseline (Cross-sectional)
Secondary outcomes:
measure: Composite Association Between Body Composition and Ocular Parameters
timeFrame: Baseline
measure: Composite Regional Vascular Density Changes in Retinal and Choroidal Layers
timeFrame: Baseline
Other outcomes:
measure: FAZ Area
timeFrame: Baseline
measure: FAZ Perimeter
timeFrame: Baseline
measure: FAZ Circularity Index
timeFrame: Baseline
measure: Axial Length
timeFrame: Baseline
measure: Autorefraction Measurements
timeFrame: Baseline
measure: Intraocular Pressure Measurements
timeFrame: Baseline
measure: Anthropometric Measurements (Waist, Hip, and Height)
timeFrame: Baseline
measure: Body Composition Analysis
timeFrame: Baseline
Locations:
city: Düzce
country: Turkey
facility: Duzce Univ. Fac. of Medicine, Dept. of Ophthalmology
Study officials:
affiliation: Duzce University Faculty of Medicine, Department of Ophthalmology
name: MURAT KAYA, Prof. Dr.
role: PRINCIPAL_INVESTIGATOR
affiliation: Duzce University Faculty of Medicine, Department of Ophthalmology
name: BAYRAM MEYDAN, MD, Research Assistant
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.
citation: 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.
citation: 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.