title: Retinal characteristics during 1 year of insulin pump therapy in type 1 diabetes: a prospective, controlled, observational study.
abstract: OBJECTIVE
  To investigate changes in retinal metabolism, function, structure and morphology in relation to initiation of insulin pump therapy (continuous subcutaneous insulin infusion, CSII).
  
  
  METHODS
  Visual acuity, retinopathy level, dark adaptation kinetics, retinal and subfoveal choroidal thickness, macular perfusion velocities, retinal vessel diameters and blood oxygen saturations were measured at baseline and after 1, 4, 16, 32 and 52 weeks in 31 patients with type 1 diabetes who started CSII and 20 patients who continued multiple daily insulin injections (MDI).
  
  
  RESULTS
  One year of CSII reduced haemoglobin A1c (HbA1c ) by 1.6% (17.8 mmol/mol) compared with 0.3% (3.1 mmol/mol) in the MDI group (p < 0.0001). Central retinal thickness increased by 1.5% in the CSII group (within-group p = 0.0098; between-group p = 0.063) without producing macular oedema. No detectable change was found in any other primary outcome measure. The proportion of patients with retinopathy worsening did not differ between groups. At baseline, longer disease duration was associated with higher retinal artery oxygen saturation (p = 0.014) and lower macular venous perfusion velocity (p = 0.045).
  
  
  CONCLUSIONS
  One year of CSII led to an HbA1c reduction relative to continued MDI and a small increase in retinal thickness but not to early retinopathy worsening or to changes in retinal vascular, structural or functional characteristics. Longer duration of type 1 diabetes appears to be associated with lower macular venous perfusion velocity and higher retinal artery oxygen saturation. The latter could potentially reflect cumulative glycaemia.
authors.affiliation: Department of Ophthalmology, Rigshospitalet, University of Copenhagen, Glostrup, Denmark.|Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Oliver Niels
authors.initials: ON
authors.lastname: Klefter
authors.affiliation: Steno Diabetes Center, Gentofte, Denmark.
authors.forename: Eva
authors.initials: E
authors.lastname: Hommel
authors.affiliation: Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.|Department of Ophthalmology, Roskilde Hospital, Roskilde, Denmark.
authors.forename: Inger Christine
authors.initials: IC
authors.lastname: Munch
authors.affiliation: Department of Endocrinology, Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Nørgaard
authors.affiliation: Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.|Department of Endocrinology, Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark.
authors.forename: Sten
authors.initials: S
authors.lastname: Madsbad
authors.affiliation: Department of Ophthalmology, Rigshospitalet, University of Copenhagen, Glostrup, Denmark.|Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Michael
authors.initials: M
authors.lastname: Larsen
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult; D001786:Blood Glucose / Q000378:metabolism; D003623:Dark Adaptation / Q000502:physiology; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy / Q000378:metabolism; D003930:Diabetic Retinopathy / Q000378:metabolism; D006442:Glycated Hemoglobin / Q000378:metabolism; D038321:Glycemic Index; D007004:Hypoglycemic Agents / Q000008:administration & dosage; D055104:Infusions, Subcutaneous; D007328:Insulin / Q000008:administration & dosage; D007332:Insulin Infusion Systems; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D011446:Prospective Studies; D012160:Retina / Q000378:metabolism; D012171:Retinal Vessels / Q000502:physiology; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; D010100:Oxygen
keywords: choroidal thickness; dark adaptation; diabetic retinopathy; insulin pump; macular perfusion velocity; retinal oximetry; retinal thickness; retinal vessel diameter