title: Assessment of the Density of Suppression to Identify Risk of Intractable Diplopia in the United Kingdom.
abstract: Occlusion used to treat amblyopia towards the end of the developmental component of the critical period gives a risk of inducing intractable diplopia. In the United Kingdom, the density of suppression is assessed via the Sbisa/Bagolini filter bar, but there is very little research evidence to guide clinical practice or interpretation of the tests used. The aims of this study were to determine current practice and estimate the incidence of intractable diplopia following amblyopia treatment.
  
  
  
  Current practice and incidence of intractable diplopia following amblyopia were determined via a questionnaire distributed to head orthoptists in every eye department in the United Kingdom. The questionnaire explored testing and test conditions, interpretation of the test results, and cases of intractable diplopia over the last 5 years.
  
  
  
  There was considerable variation in clinical practice of the measurement of the density of suppression and interpretation of the results to guide the treatment of amblyopia. The minimum age of patients taking the test ranged from 2 to 8 years and the minimum filter considered still safe to continue treatment ranged from 4 to 17. It is estimated there were 24 cases of intractable diplopia over the last 5 years.
  
  
  
  The issue of intractable diplopia and amblyopia treatment is likely to become increasingly important as there appears to be greater plasticity and scope to treat amblyopia in teenagers and adults than was previously thought. Lack of knowledge of how to evaluate the risk may lead to more cases of intractable diplopia or alternatively treatment being withheld unnecessarily.
authors.affiliation: a Directorate of Orthoptics and Vision Science , University of Liverpool , Liverpool , United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Newsham
authors.affiliation: a Directorate of Orthoptics and Vision Science , University of Liverpool , Liverpool , United Kingdom.
authors.forename: Anna R
authors.initials: AR
authors.lastname: O'Connor
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000550:Amblyopia / Q000628:therapy*; D001458:Bandages; D002648:Child; D002675:Child, Preschool; D004172:Diplopia / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008027:Light; D008297:Male; D009988:Orthoptics; D018570:Risk Assessment; D012683:Sensory Deprivation; D011795:Surveys and Questionnaires; D006113:United Kingdom / Q000453:epidemiology
keywords: Amblyopia; Bagolini filter bar; Sbisa bar; intractable diplopia; suppression