title: Baseline visual acuity strongly predicts visual acuity gain in patients with diabetic macular edema following anti-vascular endothelial growth factor treatment across trials.
abstract: OBJECTIVE
  This study was designed to evaluate the correlation of baseline visual acuity (VA) with VA outcome in response to anti-vascular endothelial growth factor (VEGF) in diabetic macular edema using a retrospective analysis of nine clinical trials. The result will help assess the relevance of VA gain comparisons across trials.
  
  
  METHODS
  A correlation analysis was performed between mean baseline VA and VA gain at month 12 for 1,616 diabetic macular edema patients across nine randomized clinical trials (RESOLVE, RISE, RIDE, RESTORE, RETAIN, DRCR.net Protocol I, DA VINCI, VIVID, VISTA) with anti-VEGF treatment regimens ranibizumab 0.5 mg and aflibercept 2 mg.
  
  
  RESULTS
  The mean baseline VA ranged from 56.9 to 64.8 Early Treatment Diabetic Retinopathy Study (ETDRS) letters. The mean VA gain at month 12 ranged from 6.8 to 13.1 ETDRS letters across trials. There was a strong inverse correlation between mean baseline VA and VA gain at month 12 (r=-0.85). The mean VA at 12 months plateaued at ~70 (68.5-73.0) ETDRS letters (20/40 Snellen VA equivalent) for the anti-VEGF treatment groups from all trials, regardless of dosing regimens and agents.
  
  
  CONCLUSIONS
  Cross-trial comparisons based on changes in best-corrected visual acuity should be done cautiously and only after adjusting for best-corrected visual acuity at baseline. Furthermore, the total VA afforded by treatment appears to be subject to a plateau effect, which warrants further exploration.
authors.affiliation: Retinal Consultants of Arizona LTD, Retinal Research Institute LLC, Phoenix, AZ, USA; USC Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
authors.forename: Pravin U
authors.initials: PU
authors.lastname: Dugel
authors.affiliation: Department of Ophthalmology, Julius-Maximilians University, Würzburg, Germany.
authors.forename: Jost
authors.initials: J
authors.lastname: Hillenkamp
authors.affiliation: NIHR Biomedical Research Centre, Moorfields Eye Hospital, London; King's College Hospital, London, UK.
authors.forename: Sobha
authors.initials: S
authors.lastname: Sivaprasad
authors.affiliation: Novartis Pharma GmbH, Nürnberg, Germany.
authors.forename: Jessica
authors.initials: J
authors.lastname: Vögeler
authors.affiliation: Novartis Ireland Limited, Dublin, Ireland.
authors.forename: Marie-Catherine
authors.initials: MC
authors.lastname: Mousseau
authors.affiliation: Novartis Pharma AG, Basel, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Wenzel
authors.affiliation: Novartis Pharma AG, Basel, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Margaron
authors.affiliation: Novartis Pharma AG, Basel, Switzerland.
authors.forename: Ron
authors.initials: R
authors.lastname: Hashmonay
authors.affiliation: Department of Ophthalmology, Hôpital Lariboisière, Assistance Publique des Hôpitaux de Paris, Université Paris Diderot, Paris, France.
authors.forename: Pascale
authors.initials: P
authors.lastname: Massin
keywords: aflibercept; anti-vascular endothelial growth factor; best-corrected visual acuity; cross-trial comparison; diabetic macular edema; ranibizumab