title: Ocular neovascularization associated with central and hemicentral retinal vein occlusion.
abstract: OBJECTIVE
  To investigate the incidence of ocular neovascularization (NV) in central and hemicentral retinal vein occlusion.
  
  
  METHODS
  The study comprised consecutive 912 (673 nonischemic and 239 ischemic) central retinal vein occlusion and 190 (147 nonischemic, 43 ischemic) hemicentral retinal vein occlusion eyes. Ophthalmic evaluation at initial and follow-up visits included recording visual acuity, visual fields, and detailed anterior segment and fundus examinations and fluorescein fundus angiography.
  
  
  RESULTS
  In ischemic central retinal vein occlusion, within 6 months from time of onset, the cumulative probability of development of iris NV was 49%, angle NV 37%, NV glaucoma 29%, retinal NV 9%, and disk NV 6%. More severe peripheral retinal hemorrhages were significantly associated with iris NV (P = 0.005), angle NV (P = 0.0004), and NV glaucoma (P = 0.012). Eyes that developed disk NV had more cotton wool spots (P = 0.058) than those without. In ischemic hemicentral retinal vein occlusion, within 12 months of onset, the cumulative probability of development of retinal NV was 29%, disk NV 12%, and iris NV 12%; within 6 months of onset, angle NV was found in 10% and NV glaucoma in 5%. Anterior chamber flare was associated with anterior segment NV and may precede the development of NV. Patients who developed NV were significantly younger, and there was a greater prevalence of NV glaucoma in patients with primary open angle glaucoma.
  
  
  CONCLUSIONS
  In ischemic central retinal vein occlusion, anterior segment NV is much more common than posterior segment NV, and the cumulative chance of developing anterior segment NV is maximum during the first 6 months. In ischemic hemicentral retinal vein occlusion, posterior segment NV is much more common than anterior segment NV.
authors.affiliation: Department of Ophthalmology and Visual Sciences, College of Medicine, University of Iowa, Iowa City, Iowa 52242-1091, USA. sohan-hayreh@uiowa.edu
authors.forename: Sohan Singh
authors.initials: SS
authors.lastname: Hayreh
authors.forename: M Bridget
authors.initials: MB
authors.lastname: Zimmerman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000869:Anterior Eye Segment / Q000098:blood supply*; D005260:Female; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D015355:Glaucoma, Neovascular / Q000209:etiology*; D006801:Humans; D015994:Incidence; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D015861:Retinal Neovascularization / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D012170:Retinal Vein Occlusion / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D055815:Young Adult