title: Screening for prevention of optic nerve damage due to chronic open angle glaucoma.
abstract: BACKGROUND
  Open angle glaucoma (OAG) is a primary, progressive optic neuropathy; the onset is without symptoms and progression occurs silently until the advanced stages of the disease, when it affects central vision. The blindness caused by OAG is irreversible. It has often been assumed to be a condition that fulfils the criteria for population screening, although this has not been supported by other in-depth non-systematic reviews. The focus of this review was to examine the evidence for the effectiveness of screening for OAG.
  
  
  OBJECTIVE
  To determine the impact of screening for OAG compared with opportunistic case findings or current referral practices on the prevalence of and the degree of optic nerve damage due to OAG in screened and unscreened populations.
  
  
  METHODS
  We included any randomised controlled trial (RCT) evaluating population-based screening programmes for OAG with a minimum one year follow up. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (which contains the Cochrane Eyes and Vision Trials Register) (Issue 1, 2006), MEDLINE (1950 to February 2006) and EMBASE (1988 to February 2006). We also searched the National Research Register (Issue 1, 2006) and Zetoc for grey literature (29 June 2006). There were no language or date restrictions in the electronic searches.
  
  
  METHODS
  We planned to include RCTs, including cluster RCTs.
  
  
  METHODS
  Two review authors independently assessed the study abstracts identified by the electronic searches. We did not find any trials that met the inclusion criteria.
  
  
  RESULTS
  As no trials were identified, no formal analysis was performed.
  
  
  CONCLUSIONS
  On the basis of current evidence, population-based screening for chronic OAG cannot be recommended, although much can be done to improve awareness and encourage at risk individuals to seek testing. In wealthy countries with equitable access to high quality eye care and health education, blindness from chronic OAG should become increasingly rare; much greater challenges face poor and emerging economies and countries where there are substantial health and wealth inequalities. Effectiveness of screening for OAG can be established only by high quality RCTs.
authors.affiliation: London School of Hygiene & Tropical Medicine, International Centre for Eye Health, Keppel Street, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Hatt
authors.forename: R
authors.initials: R
authors.lastname: Wormald
authors.forename: J
authors.initials: J
authors.lastname: Burr
mesh_terms: D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D008403:Mass Screening; D009901:Optic Nerve Diseases / Q000209:etiology / Q000517:prevention & control*