Patient recruitment was not sufficient to achieve the needed patient numbers.

The purpose of this study is to determine whether systemic administration of darbepoetin alpha results in the progression or regression of diabetic macular edema.

Inclusion Criteria:

Group A:

• Males and females aged 18 to 80 yrs
• Diabetes mellitus type 1 or 2
• Haemoglobin level above the treatment threshold level (as described in the drug description)
• Receiving no darbepoetin alfa treatment
• Best Corrected Visual Acuity (BCVA) better than 20/200
• No clinically significant macular edema (CSME) or CSME already treated with laser photocoagulation.

Group B:

• Males and females aged 18 to 80 yrs
• Diabetes mellitus type 1 or2
• Anaemia (due to renal failure), haemoglobin level under the treatment threshold level before the initialisation of the therapy (as described in the drug label)
• Starting to receive darbepoetin alfa treatment (darbepoetin alfa, Aranesp, Amgen)
• BCVA better than 20/200
• No clinically significant macular edema (CSME) or CSME already treated with laser photocoagulation.

Exclusion Criteria:

• History of retinal disease other than DR
• History of intraocular surgery, including laser treatment in the past 4 month
• A major change in the insulin treatment of the patient in the past 4 month or during the follow up period.
• Inability to communicate in German or English
• Dementia; inability to follow commands
• Epilepsy

Diabetic patients with min. Grade 2 renal insufficiency, and in Group B with anemia that is to be treated with systemic ESA therapy.