title: Acute-onset floaters and flashes: is this patient at risk for retinal detachment?
abstract: BACKGROUND
  Acute onset of monocular floaters and/or flashes represents a common presentation to primary care physicians, and the most likely diagnosis is posterior vitreous detachment (PVD). A significant proportion of patients with acute PVD develop an associated retinal tear that can lead to retinal detachment and permanent vision loss if left untreated.
  
  
  OBJECTIVE
  To quantify the association between relevant clinical variables and risk of retinal tear in patients presenting with acute-onset floaters and/or flashes and PVD.
  
  
  METHODS
  Structured MEDLINE (January 1950-September 2009) and EMBASE (January 1980-September 2009) searches and a hand search of references and citations of retrieved articles yielded 17 relevant studies.
  
  
  METHODS
  Studies of high-level methods that related elements of the history or physical examination in patients presenting with floaters and/or flashes and PVD to the likelihood of retinal tear.
  
  
  RESULTS
  For patients with acute onset of floaters and/or flashes who are self-referred or referred to an ophthalmologist, the prevalence of retinal tear is 14% (95% confidence interval [CI], 12%-16%). Subjective visual reduction is the most important symptom associated with retinal tear (likelihood ratio [LR], 5.0; 95% CI, 3.1-8.1). Vitreous hemorrhage on slitlamp biomicroscopy is the best-studied finding with the narrowest positive LR for retinal tear (summary LR, 10; 95% CI, 5.1-20). Absence of vitreous pigment during this examination is the best-studied finding with the narrowest negative LR (summary LR, 0.23; 95% CI, 0.12-0.43). Patients initially diagnosed as having uncomplicated PVD have a 3.4% chance of a retinal tear within 6 weeks. The risk increases with new onset of at least 10 floaters (summary LR, 8.1-36) or subjective visual reduction (summary LR, 2.3-17) during this period.
  
  
  CONCLUSIONS
  Primary care physicians should evaluate patients with acute-onset floaters and/or flashes due to suspected PVD, or patients with known PVD and a change in symptoms, for high-risk features of retinal tear and detachment. Physicians should always assess these patients' visual acuity. Patients at increased risk should be triaged for urgent ophthalmologic assessment.
authors.affiliation: Department of Ophthalmology, Queen's University, Kingston, ON, Canada. hussein.hollands@yahoo.com
authors.forename: Hussein
authors.initials: H
authors.lastname: Hollands
authors.forename: Davin
authors.initials: D
authors.lastname: Johnson
authors.forename: Anya C
authors.initials: AC
authors.lastname: Brox
authors.forename: David
authors.initials: D
authors.lastname: Almeida
authors.forename: David L
authors.initials: DL
authors.lastname: Simel
authors.forename: Sanjay
authors.initials: S
authors.lastname: Sharma
mesh_terms: D000208:Acute Disease; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008875:Middle Aged; D009885:Ophthalmology; D009887:Ophthalmoscopy; D011320:Primary Health Care; D012017:Referral and Consultation; D012163:Retinal Detachment / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D012167:Retinal Perforations / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D014786:Vision Disorders / Q000209:etiology* / Q000503:physiopathology; D014792:Visual Acuity; D020255:Vitreous Detachment / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D014823:Vitreous Hemorrhage / Q000175:diagnosis