Retinal Adaptation to Intensified Insulin Therapy and Bariatric Surgery in Patients With Diabetes

Study Overview
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Brief Summary
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Retinal function is highly dependent on the glucose supply. Thus, functional adaptations occur in response to both acute and long-term changes in glycaemia. The purpose of this study is to examine functional and metabolic aspects of retinal adaptation to long-lasting changes in glycaemic control in patients with diabetes. The adaptational phenomena will be characterized by electroretinography, dark adaptation, measures of retinal perfusion and oximetry as well as diabetic retinopathy grading and (OCT).

Official Title
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Retinal Adaptation to Intensified Insulin Therapy and Bariatric Surgery in Patients With Diabetes

Conditions
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Diabetes Mellitus, Diabetic Retinopathy

Intervention / Treatment
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* Other: Insulin pump
* Other: Multiple daily insulin injections
* Procedure: Bariatric surgery
* Other: Medical therapy for type 2 diabetes


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with type 1 diabetes and suboptimal metabolic regulation. Patients with type 2 diabetes and suboptimal metabolic regulation. Exclusion Criteria: Significant cataract Glaucoma Proliferative diabetic retinopathy fulfilling ETDRS treatment criteria. Clinically significant macular edema fulfilling ETDRS treatment criteria. Age-related macular degeneration Prior surgery to the eye Other serious eye disease Hypertension

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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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Type 1 Insulin Pump<br>Patients with type 1 diabetes starting insulin pump treatment | Other: Insulin pump<br>* Insulin pump therapy<br>|
| Type 1 conventional therapy<br>Patients with type 1 diabetes continuing treatment with multiple daily insulin injections. | Other: Multiple daily insulin injections<br>* Multiple daily insulin injections<br>|
| Type 2 Bariatric surgery<br>Patients with type 2 diabetes who are enrolled in pre-operative weight loss protocol prior to bariatric surgery. | Procedure: Bariatric surgery<br>* Pre-operative weight loss and bariatric surgery.<br>|
| Type 2 conventional<br>Severely obese patients with type 2 diabetes who are to continue with non-surgical treatments of diabetes and obesity and with no planned bariatric surgery. | Other: Medical therapy for type 2 diabetes<br>* Medical glucose-lowering therapy and non-surgical weight-lowering interventions.<br>|
| Type 1 insulin pumpe follow-up<br>Patients with type 1 diabetes previously followed in an observational study with electrophysiological and psychophysical measures of retinal function. | Other: Insulin pump<br>* Insulin pump therapy<br>|
| Healthy<br>Healthy volunteers. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in dark adaptation kinetics and threshold values, amplitudes/implicit times, retinal vessel diameters, perfusion velocity and oximetry. |  | Baseline, 1 week, 1 month, 4 months, 7 months, 12 months, 18 months, 24 months, 42 months | 
| Changes in visual acuity, diabetic retinopathy grading and OCT |  | Baseline, 1 week, 1 month, 4 months, 7 months, 12 months, 18 months, 24 months, 42 months |