title: Papilledema Outcomes from the Optical Coherence Tomography Substudy of the Idiopathic Intracranial Hypertension Treatment Trial.
abstract: OBJECTIVE
  To assess treatment efficacy using spectral-domain (SD) optical coherence tomography (OCT) measurements of papilledema in the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT), which evaluated the effects of acetazolamide and weight management and of placebo and weight management in eyes with mild visual loss.
  
  
  METHODS
  Randomized double-masked control clinical trial of acetazolamide plus weight management compared with placebo plus weight management in subjects with mild visual field loss and previously untreated idiopathic intracranial hypertension (IIH).
  
  
  METHODS
  Eighty-nine (43 acetazolamide treated, 46 placebo treated) of 165 subjects meeting IIHTT entry criteria.
  
  
  METHODS
  Subjects underwent perimetry, papilledema grading (Frisén method), high- and low-contrast visual acuity, and SD OCT imaging at study entry and 3 and 6 months. Study eye results (worse perimetric mean deviation [PMD]) were used for most analyses.
  
  
  METHODS
  Retinal nerve fiber layer (RNFL) thickness, total retinal thickness (TRT), optic nerve (ONH) volume, and retinal ganglion cell layer (RGCL) measurements derived using 3-dimensional segmentation.
  
  
  RESULTS
  Study entry OCT values were similar in both treatment groups. At 6 months, the acetazolamide group had greater reduction than the placebo group for RNFL thickness (175 μm vs. 89 μm; P = 0.001), TRT (220 μm vs. 113 μm; P = 0.001), and ONH volume (4.9 mm(3) vs. 2.1 mm(3); P = 0.001). The RNFL thickness (P = 0.01), TRT (P = 0.003), and ONH volume (P = 0.002) measurements also showed smaller increases in subjects who lost 6% or more of study entry weight. The acetazolamide (3.6 μm) and placebo (2.1 μm) groups showed minor RGCL thinning (P = 0.06). The RNFL thickness, TRT, and ONH volume measurements showed moderate correlations (r = 0.48-0.59; P ≤ 0.0001) with Frisén grade. The 14 eyes with RGCL thickness less than the fifth percentile of controls had worse PMD (P = 0.001) than study eyes with RGCL in the fifth percentile or more.
  
  
  CONCLUSIONS
  In IIH, acetazolamide and weight loss effectively improve RNFL thickness, TRT, and ONH volume swelling measurements resulting from papilledema. In contrast to the strong correlation at baseline, OCT measures at 6 months show only moderate correlations with papilledema grade.
mesh_terms: D000086:Acetazolamide / Q000627:therapeutic use*; D002257:Carbonic Anhydrase Inhibitors / Q000627:therapeutic use*; D004311:Double-Blind Method; D005500:Follow-Up Studies; D006801:Humans; D009412:Nerve Fibers / Q000473:pathology; D010211:Papilledema / Q000188:drug therapy* / Q000503:physiopathology; D011446:Prospective Studies; D011559:Pseudotumor Cerebri / Q000188:drug therapy* / Q000503:physiopathology; D012160:Retina / Q000473:pathology; D012165:Retinal Ganglion Cells / Q000473:pathology; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D058609:Visual Field Tests; D015431:Weight Loss
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D000086:Acetazolamide