Macular Involvement in Diabetic Retinopathy Evaluated With Swept-Source OCT

Study Overview
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Brief Summary
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This study evaluates micro-vascular changes in patients with diabetes. Results of diseased retinas will be compared to healthy controls.

Detailed Description
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The prevalence of diabetes mellitus (DM) is increasing worldwide. Diabetic retinopathy is the most prevalent complication of DM and a leading cause of visual impairment due to closure of capillaries. High-resolution imaging techniques of the retina and its supplying vascular networks can allow novel insight to subtle changes that cannot be appreciated in standard fundus examination. In this study capillary changes of patients with different severity levels of diabetic retinopathy will be investigated with non-invasive imaging technology to better understand the process of disease progression. Imaging will be done with Optical Coherence tomography (OCT) angiography as well as spectral domain OCT and ultra wide-field imaging.

Official Title
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Macular Involvement in Diabetic Retinopathy Evaluated With Swept-Source OCT

Conditions
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Diabetes Mellitus, Diabetic Retinopathy

Intervention / Treatment
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* Device: Optical coherence tomography angiography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥18 Participants can have 1 or 2 study eyes Patient Group: Diabetes mellitus type 1 or 2 Study eye with any DR severity level: no DR, mild NPDR, mod NPDR, sev NPDR, PDR Exclusion Criteria: Substantial media opacities that would preclude successful imaging Active intraocular inflammation (grade trace or above) in either eye like infectious conjunctivitis, keratitis, scleritis, endophthalmitis as well as idiopathic or autoimmune-associated uveitis in either eye Structural damage to the center of macula in the study eye History of prior panretinal photocoagulation History of treatment with intravitreal agents over the prior 6 months Macular edema involving the central subfield Prior history of vitrectomy Atrophy of retinal pigment epithelium, subretinal fibrosis, laser scar within foveal avascular zone (FAZ) or organized hard exudate plaques Substantial non-diabetic intraocular pathology in the study eye including retinal vascular occlusion, retinal detachment, macular hole, choroidal neovascularization, macula dystrophies Intraocular surgery (including cataract surgery, YAG laser capsulotomy) in the study eye within 3 months preceding Day 0, or history of corneal transplantation in the study eye Uncontrolled glaucoma in the study eye (defined as intraocular pressure ≥ 25 mmHg despite treatment with anti-glaucoma medication)or history of glaucoma filtration surgery Inability to obtain fundus images of sufficient quality to be analyzed and graded

Ages Eligible for Study
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Minimum Age: 18 Years

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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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: OCTA<br>Patients with diabetes and healthy controls will be imaged with optical coherence tomography (OCT) angiography, Spectral domain OCT and ultra wide-field imaging. | Device: Optical coherence tomography angiography<br>* Multiple scans of the retina will be recorded to evaluate microvascular changes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Perfusion density | The density of perfused capillaries (metric variable) measured with optical coherence tomography angiography (OCTA) will be compared between the different severity levels of diabetic retinopathy as well as to the control arm. | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Areas of different perfusion density | Perfusion density of the capillary network will be measured at seven different areas and will be compared within the same patient | 6 months | 
| Foveal avascular zone (FAZ) | Size (area) of FAZ will be compared between the different severity levels of diabetic retinopathy as well as to the control arm. | 6 months | 
| Foveal avascular zone (FAZ) | The circularity of FAZ will be compared between the different severity levels of diabetic retinopathy as well as to the control arm. | 6 months | 
| Presence of predominantly peripheral lesions (PPL) | The presence of PPL (categorical variable yes/no) will be correlated with the perfusion density measured with OCTA | 6 months | 
| Retinal layer thickness | Retinal layer thickness measured with optical coherence tomography (OCT) will be correlated with the perfusion density measured with OCTA | 6 months | 
| Change in perfusion density in patients with moderate or severe non proliferative diabetic retinopathy (DR) or low risk proliferative DR over the follow up of one year | Patients with moderate or severe non proliferative diabetic retinopathy (DR) or low risk proliferative DR will be followed over one year. Perfusion density will be measured at each timepoint and followed over the year, | 18 months |