title: An algorithm for glaucoma screening in clinical settings and its preliminary performance profile.
abstract: OBJECTIVE
  To devise and evaluate a screening algorithm for glaucoma in clinical settings.
  
  
  METHODS
  Screening included examination of the optic disc for vertical cupping (≥0.4) and asymmetry (≥0.15), Goldmann applanation tonometry (≥21 mmHg, adjusted or unadjusted for central corneal thickness), and automated perimetry. In the diagnostic step, retinal nerve fiber layer imaging was performed using scanning laser polarimetry. Performance of the screening protocol was assessed in an eye hospital-based program in which 124 non-physician personnel aged 40 years or above were examined. A single ophthalmologist carried out the examinations and in equivocal cases, a glaucoma subspecialist's opinion was sought.
  
  
  RESULTS
  Glaucoma was diagnosed in six cases (prevalence 4.8%; 95% confidence interval, 0.01-0.09) of whom five were new. The likelihood of making a definite diagnosis of glaucoma for those who were screened positively was 8.5 times higher than the estimated baseline risk for the reference population; the positive predictive value of the screening protocol was 30%. Screening excluded 80% of the initial population.
  
  
  CONCLUSIONS
  Application of a formal screening protocol (such as our algorithm or its equivalent) in clinical settings can be helpful in detecting new cases of glaucoma. Preliminary performance assessment of the algorithm showed its applicability and effectiveness in detecting glaucoma among subjects without any visual complaint.
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: S-Farzad
authors.initials: SF
authors.lastname: Mohammadi
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Sara
authors.initials: S
authors.lastname: Mirhadi
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran ; Student Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Hadi Z
authors.initials: HZ
authors.lastname: Mehrjardi
authors.affiliation: Department of Epidemiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Akbar
authors.initials: A
authors.lastname: Fotouhi
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Sahar
authors.initials: S
authors.lastname: Taba Taba Vakili
authors.affiliation: Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Mercede
authors.initials: M
authors.lastname: Majdi
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Sasan
authors.initials: S
authors.lastname: Moghimi
keywords: Chronic Glaucoma; Clinical Setting Screening; Glaucoma Screening; Screening Algorithm; Screening Test Performance