title: Baseline and early natural history report. The Central Vein Occlusion Study.
abstract: OBJECTIVE
  To evaluate panretinal photocoagulation for ischemic central vein occlusion and macular grid-pattern photocoagulation for macular edema with reduced visual acuity due to central vein occlusion and to further define the natural history of central vein occlusion.
  
  
  METHODS
  A multicenter randomized controlled clinical trial supported by the National Eye Institute, Bethesda, Md.
  
  
  METHODS
  A total of 728 eyes from 725 patients were entered into one or more of four study groups: perfused, nonperfused, indeterminate perfusion, and macular edema.
  
  
  RESULTS
  Follow-up of study patients is still in progress and no results are available for the randomized groups (nonperfused and macular edema). Thirty-eight (83%) of 46 evaluable eyes in the indeterminate group eventually demonstrated at least 10 disc areas of nonperfusion (28 eyes) or developed iris and/or angle neovascularization before retinal status could be determined (10 eyes). Four-month follow-up information is available for 522 of the 547 eyes in the perfused group. Thirty of these 522 eyes demonstrated iris and/or angle neovascularization at or before the 4-month follow-up visit. An additional 51 eyes had developed evidence of at least 10 disc areas of nonperfusion by the time of the 4-month visit.
  
  
  CONCLUSIONS
  These findings confirm the importance of frequent follow-up examinations, including undilated slit-lamp examination of the iris, and gonioscopy in the management of all patients with recent onset of central vein occlusion.
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004487:Edema / Q000209:etiology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007498:Iris / Q000098:blood supply; D008028:Light Coagulation; D008266:Macula Lutea / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000517:prevention & control; D012164:Retinal Diseases / Q000209:etiology / Q000601:surgery; D012170:Retinal Vein Occlusion / Q000150:complications / Q000503:physiopathology* / Q000601:surgery; D014792:Visual Acuity