title: The Diabetes Visual Function Supplement Study (DiVFuSS).
abstract: BACKGROUND
  Diabetes is known to affect visual function before onset of retinopathy (diabetic retinopathy (DR)). Protection of visual function may signal disruption of mechanisms underlying DR.
  
  
  METHODS
  This was a 6-month randomised, controlled clinical trial of patients with type 1 and type 2 diabetes with no retinopathy or mild to moderate non-proliferative retinopathy assigned to twice daily consumption of placebo or a novel, multi-component formula containing xanthophyll pigments, antioxidants and selected botanical extracts. Measurement of contrast sensitivity, macular pigment optical density, colour discrimination, 5-2 macular threshold perimetry, Diabetic Peripheral Neuropathy Symptoms, foveal and retinal nerve fibre layer thickness, glycohaemoglobin (HbA1c), serum lipids, 25-OH-vitamin D, tumour necrosis factor α (TNF-a) and high-sensitivity C reactive protein (hsCRP) were taken at baseline and 6 months. Outcomes were assessed by differences between and within groups at baseline and at study conclusion using meand ± SDs and t tests (p<0.05) for continuous variables.
  
  
  RESULTS
  There were no significant intergroup differences at baseline. At 6 months, subjects on active supplement compared with placebo had significantly better visual function on all measures (p values ranging from 0.008 to <0.0001), significant improvements in most serum lipids (p values ranging from 0.01 to 0.0004), hsCRP (p=0.01) and diabetic peripheral neuropathy (Fisher's exact test, p=0.0024) No significant changes in retinal thickness, HbA1c, total cholesterol or TNF-α were found between the groups.
  
  
  CONCLUSIONS
  This study provides strong evidence of clinically meaningful improvements in visual function, hsCRP and peripheral neuropathy in patients with diabetes, both with and without retinopathy, and without affecting glycaemic control.
  
  
  BACKGROUND
  www.ClinicalTrials.gov Identifier: NCT01646047.
authors.affiliation: Private Practice, Tacoma, Washington, USA.
authors.forename: A Paul
authors.initials: AP
authors.lastname: Chous
authors.affiliation: Captain James A Lovell Federal Heath Care Center, North Chicago, Illinois, USA.
authors.forename: Stuart P
authors.initials: SP
authors.lastname: Richer
authors.affiliation: Private Practice, Olathe, Kansas, USA.
authors.forename: Jeffry D
authors.initials: JD
authors.lastname: Gerson
authors.affiliation: Kresge Eye Institute, Wayne State University, Detroit, Michigan, USA.
authors.forename: Renu A
authors.initials: RA
authors.lastname: Kowluru
mesh_terms: D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage; D002097:C-Reactive Protein / Q000378:metabolism; D015350:Contrast Sensitivity / Q000502:physiology*; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000503:physiopathology; D003930:Diabetic Retinopathy / Q000188:drug therapy* / Q000503:physiopathology; D019587:Dietary Supplements; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008055:Lipids / Q000097:blood; D065348:Macular Pigment / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D008517:Phytotherapy; D011446:Prospective Studies; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D014786:Vision Disorders / Q000188:drug therapy* / Q000503:physiopathology; D014792:Visual Acuity / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D024341:Xanthophylls / Q000008:administration & dosage
chemical_list: D000975:Antioxidants; D002097:C-Reactive Protein; D006442:Glycated Hemoglobin; D008055:Lipids; D065348:Macular Pigment; D014409:Tumor Necrosis Factor-alpha; D014807:Vitamin D; D024341:Xanthophylls; C517652:hemoglobin A1c protein, human; C104450:25-hydroxyvitamin D
keywords: Clinical Trial; Colour vision; Field of vision; Macula; Retina