title: Correlation of visual acuity and macular thickness measured by optical coherence tomography in patients with persistent macular edema.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the correlation between best-corrected visual acuity (BCVA) and macular thickness in patients with persistent macular edema treated with a dexamethasone intravitreal drug delivery system (dexamethasone DDS).
  
  
  METHODS
  In a randomized, multicenter, controlled, parallel-group, dose-ranging study, patients with macular edema lasting at least 90 days despite treatment were randomized to observation or treatment with 350- or 700-microg dexamethasone DDS. Macular thickness was assessed in 80 patients using optical coherence tomography. Best-corrected visual acuity was measured using Early Treatment Diabetic Retinopathy Study methodology.
  
  
  RESULTS
  At baseline, macular thickness was significantly inversely correlated with BCVA (r = -0.406, P < 0.001). Patients treated with 350- or 700-microg dexamethasone DDS showed a significant decrease in macular thickness from baseline to Day 90 (P = 0.002). In the 700-microg dexamethasone DDS treatment group, there was a modest inverse correlation between changes in macular thickness from baseline to Day 90 and improvement in BCVA (r = -0.530, P = 0.009). In the 350-microg dexamethasone DDS treatment group, the correlation was weaker and not statistically significant (r = -0.206, P = 0.304).
  
  
  CONCLUSIONS
  The correlation between baseline BCVA and macular thickness in patients with persistent macular edema was modest. Improvement in BCVA after treatment with 700-microg dexamethasone DDS was consistent with changes in macular thickness measured using optical coherence tomography.
authors.affiliation: Department of Ophthalmology, Stanford University School of Medicine, Stanford, California 94305, USA. mark.blumenkranz@stanford.edu
authors.forename: Mark S
authors.initials: MS
authors.lastname: Blumenkranz
authors.forename: Julia A
authors.initials: JA
authors.lastname: Haller
authors.forename: Baruch D
authors.initials: BD
authors.lastname: Kuppermann
authors.forename: George A
authors.initials: GA
authors.lastname: Williams
authors.forename: Michael
authors.initials: M
authors.lastname: Ip
authors.forename: Matthew
authors.initials: M
authors.lastname: Davis
authors.forename: David V
authors.initials: DV
authors.lastname: Weinberg
authors.forename: Connie
authors.initials: C
authors.lastname: Chou
authors.forename: Scott M
authors.initials: SM
authors.lastname: Whitcup
mesh_terms: D001837:Body Weights and Measures; D002648:Child; D003907:Dexamethasone / Q000008:administration & dosage*; D016503:Drug Delivery Systems; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D008269:Macular Edema / Q000188:drug therapy* / Q000503:physiopathology*; D012160:Retina / Q000473:pathology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology*; D014822:Vitreous Body
chemical_list: D005938:Glucocorticoids; D003907:Dexamethasone