Diabetic RetinopathyNCT07137013
Periodontitis Severity in Patients With Diabetic Retinopathy
An observational study of Diabetic Retinopathy and Periodontitis, run by Recep Tayyip Erdogan University Training and Research Hospital at 1 site in Turkey (Türkiye).
Trial summary
The aim of this observational study is to investigate the relationship between periodontal disease severity and retinal layer thickness in patients diagnosed with diabetic retinopathy (DR), using optical coherence tomography (OCT) for assessment. Read more about this study
- Who is it for?
- Ages 60 to 85 yearsHealthy volunteers can take part
- Conditions the study is for
- Diabetic Retinopathy, Periodontitis
- How many people
- 100 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 24 Feb 2025to 23 Jun 2025
- How long will I take part?
- 1 Day
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 60 to 85 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Individuals over the age of 60 who apply to the Department of Ophthalmology at Recep Tayyip Erdoğan University Faculty of Medicine
Who may be able to join
- Men and women aged 60 and over
- Those without systemic disease (control group)
- Patients diagnosed with diabetic retinopathy
- Patients diagnosed with diabetes mellitus (HbA1c>6)
Who cannot join
- Patients with any autoimmune disease, osteoporosis, or cancer
- Patients taking immunosuppressive medications, oral contraceptives, or bisphosphonates
- Pregnancy
- Patients with acute or chronic eye diseases such as vitreoretinal, optic nerve, or choroidal vascular diseases, cataracts, glaucoma, retinal degeneration, uveitis, Behçet's disease, or scleritis
- Patients undergoing refractive or intraocular surgery
- Presence of active infectious disease (acute hepatitis, tuberculosis, AIDS)
- Chronic use of medications affecting periodontal tissues (cyclosporine A, phenytoin)
- Patients taking antioxidant supplements
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Department of Ophthalmology of the Faculty of Medicine of Recep Tayyip Erdogan University
Rize, Rize Province, 53200
About this study
Official title: Evaluation of the Relationship Between Periodontal Disease Severity and Retinal Layer Thickness in Patients With Diabetic Retinopathy Using Optical Coherence Tomography
The aim of this observational study is to investigate the relationship between periodontal disease severity and retinal layer thickness in patients diagnosed with diabetic retinopathy (DR), using optical coherence tomography (OCT) for assessment.
The main question this study seeks to answer is:
Read more
Do measurable changes in retinal layer thickness occur as periodontal disease severity increases in patients with diabetic retinopathy?
Participants will include adult individuals with a confirmed clinical diagnosis of DR. Periodontal status will be assessed through standard clinical parameters, including plaque index, probing pocket depth, clinical attachment loss, and bleeding on probing. Retinal layer thickness will be measured using high-resolution OCT and OCT angiography (OCTA) devices. The study aims to analyze potential associations between periodontal disease severity and morphological as well as vascular changes in the retina.
Read the detailed description
This observational study will aim to evaluate the possible relationship between periodontal disease severity and retinal layer thickness in patients with diabetic retinopathy (DR). Adult individuals with a confirmed clinical diagnosis of DR will be included in the study. Periodontal health status will be assessed using standard clinical parameters such as plaque index, probing pocket depth, clinical attachment loss, and bleeding on probing. Retinal layer thickness will be measured using high-resolution imaging with optical coherence tomography (OCT). Optical coherence tomography angiography (OCTA) will be used to evaluate vascular changes. The collected data will be analyzed to determine whether periodontal disease severity is associated with possible changes in retinal morphology and vascularity. This study is expected to provide new scientific evidence on the interaction between systemic diabetic complications and oral health, as well as to highlight the importance of multidisciplinary approaches.
- Conditions
- Diabetic Retinopathy, Periodontitis
- Keywords
- Diabetic Retinopathy, Periodontitis, Optical Coherence Tomography, Optical Coherence Tomography Angiography
- Medical subject headings
- Diabetic Retinopathy, Periodontitis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Control | without systemic disease | |
| DM+ DR- | Diagnosed with Diabetes Mellitus and not diagnosed with Diabetic Retinopathy | |
| NPDR+ DMÖ- | Diagnosed with non-proliferative Diabetic Retinopathy without diabetic macular edema | |
| NPDR+ DMÖ+ | Diagnosed with non-proliferative DR with diabetic macular edema | |
| PDR | Diagnosed with proliferative Diabetic Retinopathy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Optical Coherence Tomography (OCT) Measurement
A macular thickness map (ETDRS = Early Treatment Diabetic Retinopathy Study) is examined using OCT, with the center at the fovea centralis. According to the ETDRS map, the central 1 mm represents the fovea, the surrounding 3 mm area represents the inner retinal layers, and the outermost 6 mm area represents the outer retinal layers.
Measured: Day 1
Optical Coherence Tomography Angiography (OCTA) Measurement
OCTA is a non-invasive technique that allows the evaluation of microvascular changes at the capillary level and imaging of the retinal plexuses layer by layer.
Measured: Day 1
Retinal Layer Thickness
Definition: Retinal thickness is the distance between the internal limiting membrane (ILM) and the retinal pigment epithelium (RPE), measured by optical coherence tomography (OCT).
ETDRS Mapping: The macular region is divided into nine sectors based on the ETDRS grid:
Central subfield: A 1 mm diameter circle centered on the fovea. Inner ring (parafoveal region): 1-3 mm diameter, divided into superior, inferior, nasal, and temporal quadrants.
Outer ring (perifoveal region): 3-6 mm diameter, also divided into four quadrants.
Measured: Day 1
Choroidal Thickness (CSI Reference)
Definition: The choroid is the vascular layer beneath the RPE. Choroidal thickness is the perpendicular distance from Bruch's membrane to the choroid-sclera interface (CSI).
Measurement: Typically obtained with enhanced depth imaging OCT (EDI-OCT), mapped according to the ETDRS grid.
Measured: Day 1
Ganglion Cell Layer (GCL) Thickness
Definition: The GCL is composed of the cell bodies of retinal ganglion cells, located between the inner plexiform layer and the retinal nerve fiber layer.
Measurement: OCT can quantify GCL alone or GCL + inner plexiform layer (GCL+IPL), usually reported using the ETDRS 9-sector mapping.
Measured: Day 1
Retinal Nerve Fiber Layer (RNFL) Thickness
Definition: The RNFL consists of the unmyelinated axons of ganglion cells, located at the innermost surface of the retina.
Measurement: Often assessed in the peripapillary region or in the macular area using ETDRS mapping.
Measured: Day 1
Choroid-Sclera Interface (CSI)
Definition: The CSI is the outer anatomical boundary of the choroid where it transitions into the sclera.
Role in Thickness Measurement: Serves as the lower reference point for choroidal thickness measurements (Bruch's membrane to CSI), which can be mapped according to the ETDRS grid.
Measured: Day 1
Superficial Retinal Layers
Definition: The inner portion of the retina, located closer to the vitreous side.
Typically associated with the superficial capillary plexus. These layers are among the first affected in diseases such as glaucoma, optic neuropathies, and ischemic retinopathies.
Measured: Day 1
Deep Retinal Layers
Definition: The middle and outer portions of the retina, located closer to the photoreceptors.
Associated with the deep capillary plexus. Clinical relevance: Important changes are observed here in conditions such as macular edema, diabetic retinopathy, and age-related macular degeneration.
Measured: Day 1
Foveal Avascular Zone (FAZ)
Definition: A circular area at the center of the fovea devoid of retinal capillary vessels.
Location: In the central fovea, approximately 500-600 micrometers in diameter.
Characteristics:
Contains the highest density of photoreceptors (especially cones). Avascular nature means nutrition is supplied via diffusion from the choroid. Responsible for the highest visual acuity. Clinical relevance: FAZ size, measurable by OCT angiography (OCTA), is an important biomarker in diabetic retinopathy, retinal vein occlusion, and macular ischemia.
Measured: Day 1
Secondary outcomes (5)
Clinical Periodontal Parameters (Plaque Index)
Plaque Index (PI) (Silness and Löe, 1964) This index is used to evaluate the amount of dental plaque accumulation on tooth surfaces. Each tooth's four surfaces (buccal, lingual, mesial, distal) are examined using a probe or visually. Each surface is scored from 0 to 3. The average score is calculated for each tooth. The overall plaque index is obtained by averaging the scores from all examined teeth.
Score Description 0 No plaque.
- No visible plaque, but a slight film of plaque is detected when a probe is run along the gingival margin.
- Visible plaque along the gingival margin, forming a continuous band.
- Abundant plaque covering the gingival area and extending toward the middle of the tooth surface, including the interproximal spaces.
Measured: Day 1
Clinical Periodontal Parameters (Gingival Index)
The Gingival Index is used to assess the presence and severity of gingival inflammation (gingivitis). Four surfaces of each tooth (buccal, lingual, mesial, distal) are examined visually and with a periodontal probe. The evaluation considers color changes, edema (swelling), tissue consistency, and bleeding on probing. Each surface is scored from 0 to 3. The average score per tooth is calculated, and then the overall average is used to determine the individual's GI score.
Score Description 0 Healthy gingiva: normal color and texture, no bleeding
- Mild inflammation: slight color change and swelling, no bleeding on probing
- Moderate inflammation: redness, edema, soft tissue, bleeding on probing
- Severe inflammation: marked redness and swelling, ulceration, possible spontaneous bleeding
Measured: Day 1
Periodontal Clinical Parametres (Bleeding on Probing Index)
This index is used to assess the presence and severity of gingival inflammation by observing bleeding after gentle pressure is applied to the gingival sulcus using a periodontal probe. A thin periodontal probe is gently inserted into the gingival sulcus with light pressure (approximately 20-25 grams). Bleeding occurring within 10-30 seconds is observed. Each measurement site is recorded as either "bleeding present" or "bleeding absent." Presence of bleeding is an early and sensitive indicator of gingival inflammation.
Score Description: 0 No bleeding 1 Bleeding present (mild or severe)
Measured: Day 1
Periodontal Clinical Parametres (Probing Pocket Depth)
Using a Williams periodontal probe, the distance between the gingival margin and the base of the periodontal pocket is measured in millimeters at six sites per tooth: mesiobuccal, midbuccal, distobuccal, mesiolingual, midlingual, and distolingual. All teeth are measured. The values obtained from each site are summed and then divided by the total number of sites measured. This gives the average probing depth for the individual.
Measurement Interpretation 1-3 mm Healthy sulcus 4-5 mm Shallow to moderate pocket
≥6 mm Deep periodontal pocket (advanced disease)
Measured: Day 1
Periodontal Clinical Parametres (Clinical Attachment Loss)
Using a Williams periodontal probe, the distance between the enamel-cementum junction and the base of the periodontal pocket is measured in millimeters at six sites per tooth: mesiobuccal, midbuccal, distobuccal, mesiolingual, midlingual, and distolingual. All teeth are measured. The values obtained from each site are summed and then divided by the total number of sites measured. This gives the average probing depth for the individual.
CAL Value Interpretation 0-1 mm Healthy / minimal loss 2-3 mm Mild attachment loss 4-5 mm Moderate attachment loss
≥6 mm Severe attachment loss
Measured: Day 1
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Aug 2025
- Study start24 Feb 2025
- Primary completion12 May 2025
- Study completion23 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Diabetic RetinopathyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Cross-sectional
- Enrolment
- 100 participants (actual)
- Target duration
- 1 Day
Sponsor and investigators
- Lead sponsor
- Recep Tayyip Erdogan University Training and Research Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dilek KARADOĞAN, Recep Tayyip Erdogan University Training and Research Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07137013
- Sponsor's protocol ID
- DR2025/59
- Status last verified
- Aug 2025
- First submitted
- 11 Aug 2025
- Last updated
- 22 Aug 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 22 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Relationship Between Periodontal Disease Severity and Retinal Layer Thickness in Patients With Diabetic Retinopathy Using Optical Coherence Tomography
- ClinicalTrials.gov ID
- NCT07137013
- Acronym / sponsor ID
- DR2025/59
- Conditions
- Diabetic Retinopathy, Periodontitis
- Keywords
- Diabetic Retinopathy, Periodontitis, Optical Coherence Tomography, Optical Coherence Tomography Angiography
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 100 participants (actual)
- Lead sponsor
- Recep Tayyip Erdogan University Training and Research HospitalUniversity, hospital or other
- Study start
- 24 Feb 2025 (actual)
- Primary completion
- 12 May 2025 (actual)
- Study completion
- 23 Jun 2025 (actual)
- First posted
- 22 Aug 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The aim of this observational study is to investigate the relationship between periodontal disease severity and retinal layer thickness in patients diagnosed with diabetic retinopathy (DR), using optical coherence tomography (OCT) for assessment.
The main question this study seeks to answer is:
Do measurable changes in retinal layer thickness occur as periodontal disease severity increases in patients with diabetic retinopathy?
Participants will include adult individuals with a confirmed clinical diagnosis of DR. Periodontal status will be assessed through standard clinical parameters, including plaque index, probing pocket depth, clinical attachment loss, and bleeding on probing. Retinal layer thickness will be measured using high-resolution OCT and OCT angiography (OCTA) devices. The study aims to analyze potential associations between periodontal disease severity and morphological as well as vascular changes in the retina.
Detailed description
This observational study will aim to evaluate the possible relationship between periodontal disease severity and retinal layer thickness in patients with diabetic retinopathy (DR). Adult individuals with a confirmed clinical diagnosis of DR will be included in the study. Periodontal health status will be assessed using standard clinical parameters such as plaque index, probing pocket depth, clinical attachment loss, and bleeding on probing. Retinal layer thickness will be measured using high-resolution imaging with optical coherence tomography (OCT). Optical coherence tomography angiography (OCTA) will be used to evaluate vascular changes. The collected data will be analyzed to determine whether periodontal disease severity is associated with possible changes in retinal morphology and vascularity. This study is expected to provide new scientific evidence on the interaction between systemic diabetic complications and oral health, as well as to highlight the importance of multidisciplinary approaches.
Study design
- Observational model
- Case only
- Time perspective
- Cross-sectional
- Target follow-up
- 1 Day
- Number of arms
- 5
| Arm | Type | Receives |
|---|---|---|
| Control | – | –without systemic disease |
| DM+ DR- | – | –Diagnosed with Diabetes Mellitus and not diagnosed with Diabetic Retinopathy |
| NPDR+ DMÖ- | – | –Diagnosed with non-proliferative Diabetic Retinopathy without diabetic macular edema |
| NPDR+ DMÖ+ | – | –Diagnosed with non-proliferative DR with diabetic macular edema |
| PDR | – | –Diagnosed with proliferative Diabetic Retinopathy |
Who may qualify
- Ages
- 60 to 85 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Individuals over the age of 60 who apply to the Department of Ophthalmology at Recep Tayyip Erdoğan University Faculty of Medicine
Key inclusion criteria (4 listed)
- Men and women aged 60 and over
- Those without systemic disease (control group)
- Patients diagnosed with diabetic retinopathy
- Patients diagnosed with diabetes mellitus (HbA1c>6)
Key exclusion criteria (8 listed)
- Patients with any autoimmune disease, osteoporosis, or cancer
- Patients taking immunosuppressive medications, oral contraceptives, or bisphosphonates
- Pregnancy
- Patients with acute or chronic eye diseases such as vitreoretinal, optic nerve, or choroidal vascular diseases, cataracts, glaucoma, retinal degeneration, uveitis, Behçet's disease, or scleritis
- Patients undergoing refractive or intraocular surgery
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Optical Coherence Tomography (OCT) Measurement
Time frame: Day 1
A macular thickness map (ETDRS = Early Treatment Diabetic Retinopathy Study) is examined using OCT, with the center at the fovea centralis. According to the ETDRS map, the central 1 mm represents the fovea, the surrounding 3 mm area represents the inner retinal layers, and the outermost 6 mm area represents the outer retinal layers.
Optical Coherence Tomography Angiography (OCTA) Measurement
Time frame: Day 1
OCTA is a non-invasive technique that allows the evaluation of microvascular changes at the capillary level and imaging of the retinal plexuses layer by layer.
Retinal Layer Thickness
Time frame: Day 1
Definition: Retinal thickness is the distance between the internal limiting membrane (ILM) and the retinal pigment epithelium (RPE), measured by optical coherence tomography (OCT). ETDRS Mapping: The macular region is divided into nine sectors based on the ETDRS grid: Central subfield: A 1 mm diameter circle centered on the fovea. Inner ring (parafoveal region): 1-3 mm diameter, divided into superior, inferior, nasal, and temporal quadrants. Outer ring (perifoveal region): 3-6 mm diameter, also divided into four quadrants.
Choroidal Thickness (CSI Reference)
Time frame: Day 1
Definition: The choroid is the vascular layer beneath the RPE. Choroidal thickness is the perpendicular distance from Bruch's membrane to the choroid-sclera interface (CSI). Measurement: Typically obtained with enhanced depth imaging OCT (EDI-OCT), mapped according to the ETDRS grid.
Ganglion Cell Layer (GCL) Thickness
Time frame: Day 1
Definition: The GCL is composed of the cell bodies of retinal ganglion cells, located between the inner plexiform layer and the retinal nerve fiber layer. Measurement: OCT can quantify GCL alone or GCL + inner plexiform layer (GCL+IPL), usually reported using the ETDRS 9-sector mapping.
Retinal Nerve Fiber Layer (RNFL) Thickness
Time frame: Day 1
Definition: The RNFL consists of the unmyelinated axons of ganglion cells, located at the innermost surface of the retina. Measurement: Often assessed in the peripapillary region or in the macular area using ETDRS mapping.
Choroid-Sclera Interface (CSI)
Time frame: Day 1
Definition: The CSI is the outer anatomical boundary of the choroid where it transitions into the sclera. Role in Thickness Measurement: Serves as the lower reference point for choroidal thickness measurements (Bruch's membrane to CSI), which can be mapped according to the ETDRS grid.
Superficial Retinal Layers
Time frame: Day 1
Definition: The inner portion of the retina, located closer to the vitreous side. Typically associated with the superficial capillary plexus. These layers are among the first affected in diseases such as glaucoma, optic neuropathies, and ischemic retinopathies.
Deep Retinal Layers
Time frame: Day 1
Definition: The middle and outer portions of the retina, located closer to the photoreceptors. Associated with the deep capillary plexus. Clinical relevance: Important changes are observed here in conditions such as macular edema, diabetic retinopathy, and age-related macular degeneration.
Foveal Avascular Zone (FAZ)
Time frame: Day 1
Definition: A circular area at the center of the fovea devoid of retinal capillary vessels. Location: In the central fovea, approximately 500-600 micrometers in diameter. Characteristics: Contains the highest density of photoreceptors (especially cones). Avascular nature means nutrition is supplied via diffusion from the choroid. Responsible for the highest visual acuity. Clinical relevance: FAZ size, measurable by OCT angiography (OCTA), is an important biomarker in diabetic retinopathy, retinal vein occlusion, and macular ischemia.
5 secondary outcomes
Clinical Periodontal Parameters (Plaque Index)
Time frame: Day 1
Clinical Periodontal Parameters (Gingival Index)
Time frame: Day 1
Periodontal Clinical Parametres (Bleeding on Probing Index)
Time frame: Day 1
Periodontal Clinical Parametres (Probing Pocket Depth)
Time frame: Day 1
Periodontal Clinical Parametres (Clinical Attachment Loss)
Time frame: Day 1
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Aug 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Diabetic Retinopathy and Periodontitis, run by Recep Tayyip Erdogan University Training and Research Hospital at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 22 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Optical Coherence Tomography (OCT) Measurement (time frame: Day 1). The study lists 10 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Aug 2025; AzTrials last refreshed its copy on 6 Nov 2026.