Retinal Neurodegenerative and Vascular Changes in Diabetic Patients

Study Overview
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Brief Summary
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Using Optical Coherence Tomography and ImageJ software the investigators will analyze retinal and choroidal vascular changes and their impact on retinal layers among patients with diabetes without retinopathy and patients with diabetes and retinopathy.

Detailed Description
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Relieving the burden of diabetic retinopathy treatment require a prompt and non-invasive assessment of diabetic patients before the occurence of diabetic retinopathy. Since OCT is capable of imaging retina with such a high precision, retinal changes occuring before any clinical signs of retinopathy, such as microaneurysm or haemorrhages, can now be assessed. In the present study the investigators are analyzing the connection between retinal arteries and veins regarding lumen diameter, vessel wall thickness and their correlation with retinal nerve fiber layer and ganglion cell layer thickness. Moreover, using binarization of the choroid the investigators will assess its relationship with outer retina layers, such as retinal pigment epithelium and photoreceptors.

Official Title
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Retinal Neurodegenerative and Vascular Changes in Diabetic Patients: an OCT-based Comparative Study

Conditions
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Diabetic Retinopathy, Neurodegeneration

Intervention / Treatment
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* Diagnostic Test: Optical Coherence Tomography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: history of type 1DM for more than 1 year history of type 2 DM for more than 3 months diagnosis of no DR or mild Non-proliferative diabetic retinopathy(NPDR) Exclusion Criteria: DR with more than NPDR , Diabetic macular oedema, media opacities such as corneal or lens opacities that could preclude appropriate OCT imaging, presence of other retinal diseases such as Age-related macular degeneration, Vitreo-macular traction, Macular hole, Epiretinal membrane, Retinal vein occlusion, Macular scars, Glaucoma, Optic neuropathies or Neurodegenerative diseases, history of ocular trauma, Refractive errors of more than ±6 diopters (spherical equivalent), previous ocular surgery, focal laser, panretinal photocoagulation or anti-VEGF intravitreal injection
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Control<br> | Diagnostic Test: Optical Coherence Tomography<br>* Spectral Domain Optical Coherence Tomography(SD-OCT) examination will be performed for every patient: posterior pole scan, EDI-OCT(enhanced depth imaging-OCT) and peripapillary RNFL(retinal nerve fiber layer)<br>|
| Diabetes mellitus without Diabetic Retinopathy<br> | Diagnostic Test: Optical Coherence Tomography<br>* Spectral Domain Optical Coherence Tomography(SD-OCT) examination will be performed for every patient: posterior pole scan, EDI-OCT(enhanced depth imaging-OCT) and peripapillary RNFL(retinal nerve fiber layer)<br>|
| Diabetes mellitus with Diabetic Retinopathy<br> | Diagnostic Test: Optical Coherence Tomography<br>* Spectral Domain Optical Coherence Tomography(SD-OCT) examination will be performed for every patient: posterior pole scan, EDI-OCT(enhanced depth imaging-OCT) and peripapillary RNFL(retinal nerve fiber layer)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation between choroid and outer retina using SD-OCT- based binarization technique | starting from EDI-OCT scans the investigators will analyze choroidal parameters such as Luminal area, Stromal area, Total choroidal area, Chorodial vascularity index and correlate them with retinal pigment epithelium (RPE),outer nuclear layer(ONL) and photoreceptors' thickness (PR) | 2018-2019 | 
| Correlation between neurodegeneration and retinal vessels characteristics | using full width at half maximum method, the investigators will measure peripapillary arteries and veins' diameters, their wall thickness and correlate them with RNFL and ganglion cell layer(GCL) thickness | 2018-2019 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation between choroidal parameters and their influence on Best corrected visual acuity(BCVA) | The investigators will analyze if changes in the choroid will influence patients' visual acuity. For statistical reasons, visual acuity will be converted to logMAR(logarithm of the minimum angle of resolution) | 2018-2019 | 
| Correlation between renal function and choroidal parameters | Using estimated glomerular filtration rate(eGFR-mL/min/1.73 m2) the investigators will analyze if a decreased eGFR will produce changes in choroidal architecture | 2018-2019 | 
| Correlation between sistemic factors and choroidal parameters | The investigators will document if the presence of High Blood pressure(yes/no) and current smoking(yes/no) influences choroidal thickness or CVI. | 2018-2019 | 
| Correlation between choroidal parameters and diabetes control | Using HbA1c(Glycated haemoglobin) the investigators will analyze the choroidal's behaviour under different HbA1c levels. | 2018-2019 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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optical coherence tomography, choroid, outer retina