title: Intervention with vitamins in patients with nonproliferative diabetic retinopathy: a pilot study.
abstract: BACKGROUND
  The purpose of this study was to determine whether a combination of vitamins B6, B9, and B12 is an effective intervention for reducing the signs and symptoms of nonproliferative diabetic retinopathy.
  
  
  METHODS
  Ten subjects with type 2 diabetes mellitus (n = 20 eyes) with clinically diagnosed mild to moderate nonproliferative diabetic retinopathy were recruited from a private practice ophthalmology clinic for this open-label, uncontrolled, prospective six-month study. Metanx® vitamin tablets (containing 3 mg L-methylfolate calcium, 35 mg pyridoxal-5'-phosphate, and 2 mg methylcobalamin) were administered at a dosage of two tablets daily. Primary outcome indicators were the percent change in mean retinal sensitivity threshold measured by macular microperimetry and the percent change in mean central retinal thickness measured by spectral-domain optical coherence tomography.
  
  
  RESULTS
  Three subjects were lost to follow-up. In the remaining seven subjects, two of 14 eyes had foveal edema that prevented microperimetry measurements due to poor fixation. The remaining 12 eyes showed a nonlinear improvement in mean threshold retinal sensitivity (P < 0.001). Overall change in mean central retinal thickness in 14 eyes was linear (R(2) = 0.625; P = 0.034), with a significant reduction between one and six months (P = 0.012).
  
  
  CONCLUSIONS
  In this pilot study, the Metanx intervention appeared to have some beneficial effects with respect to reducing retinal edema and increasing light sensitivity in subjects with nonproliferative diabetic retinopathy.
authors.affiliation: CLEVER Eye Institute, Slidell, LA, USA.
authors.forename: Michael K
authors.initials: MK
authors.lastname: Smolek
authors.forename: Neil F
authors.initials: NF
authors.lastname: Notaroberto
authors.forename: Arley G
authors.initials: AG
authors.lastname: Jaramillo
authors.forename: Lisa R
authors.initials: LR
authors.lastname: Pradillo
keywords: diabetes; diabetic retinopathy; homocysteine; microperimetry; nitric oxide; vitamin B
references.citation: Rev Neurol Dis. 2011;8(1-2):39-47
references.pmid: 21769070
references.citation: Am J Med. 2013 Feb;126(2):141-9
references.pmid: 23218892
references.citation: Invest Ophthalmol Vis Sci. 2007 Apr;48(4):1441-6
references.pmid: 17389469
references.citation: Int Wound J. 2011 Dec;8(6):658-60
references.pmid: 21854546
references.citation: Curr Vasc Pharmacol. 2012 Jan;10(1):19-32
references.pmid: 22112354
references.citation: J Gerontol A Biol Sci Med Sci. 2012 May;67(5):537-43
references.pmid: 22156506
references.citation: Invest Ophthalmol Vis Sci. 2009 Aug;50(8):3607-12
references.pmid: 19369240
references.citation: Invest Ophthalmol Vis Sci. 2013 Mar 28;54(3):2288-95
references.pmid: 23425693
references.citation: Subcell Biochem. 2012;56:131-61
references.pmid: 22116698
references.citation: Clin Chem Lab Med. 2003 Nov;41(11):1444-54
references.pmid: 14656024
references.citation: Br J Ophthalmol. 2012 May;96(5):704-7
references.pmid: 22353698
references.citation: Eye (Lond). 2004 May;18(5):460-5
references.pmid: 15131674
references.citation: Diabetes Care. 2004 Oct;27(10):2540-53
references.pmid: 15451934
references.citation: Mol Vis. 2011;17:1946-56
references.pmid: 21850169
references.citation: Amino Acids. 2007;32(4):561-72
references.pmid: 17285228
references.citation: Clin Chem Lab Med. 2005;43(10):1020-5
references.pmid: 16197292
references.citation: Eye (Lond). 2008 Aug;22(8):989-93
references.pmid: 18064053
references.citation: Clin Chem Lab Med. 2003 Nov;41(11):1392-403
references.pmid: 14656016
references.citation: Lancet. 1997 Apr 12;349(9058):1102-3
references.pmid: 9107272
references.citation: Med Hypotheses. 2011 Dec;77(6):1088-93
references.pmid: 21963358
references.citation: PLoS One. 2011;6(11):e26747
references.pmid: 22069468
references.citation: Pan Afr Med J. 2012;12:48
references.pmid: 22937188
references.citation: Diabetes Metab J. 2011 Dec;35(6):595-601
references.pmid: 22247902
references.citation: Diabetes Res Clin Pract. 2012 Oct;98(1):151-8
references.pmid: 22727498
references.citation: Invest Ophthalmol Vis Sci. 2011 Aug 01;52(9):6059-65
references.pmid: 21807933
references.citation: Arch Intern Med. 2009 Feb 23;169(4):335-41
references.pmid: 19237716
references.citation: Am J Clin Nutr. 2013 Jul;98(1):129-35
references.pmid: 23636242
references.citation: J Peripher Nerv Syst. 2012 Jun;17(2):191-6
references.pmid: 22734904
references.citation: Phys Ther. 2008 Nov;88(11):1254-64
references.pmid: 18801858
references.citation: Arch Intern Med. 2000 Oct 23;160(19):2984-90
references.pmid: 11041907
references.citation: Curr Clin Pharmacol. 2011 Nov;6(4):260-73
references.pmid: 22082324
references.citation: J Am Geriatr Soc. 2012 Jun;60(6):1057-63
references.pmid: 22690982
references.citation: Nature. 1997 Dec 18-25;390(6661):694-8
references.pmid: 9414163
references.citation: Diabetes Metab Res Rev. 2007 Mar;23(3):193-201
references.pmid: 16845688
references.citation: Clin Chim Acta. 2006 Apr;366(1-2):293-8
references.pmid: 16343469