CV

• What is one indication for a CV assessment during a first visit?

  It is part of your legal clinical record.
• Why might advice be required for tailoring the learning needs of kids?

  To ensure their visual tasks are appropriately supported.
• When is vocational advice required in relation to CV assessment?

  When determining if someone can be a pilot.
• What percentage of men have congenital colour vision deficiencies in European societies?

  Approximately 8.0%.
• What percentage of women have congenital colour vision deficiencies in European societies?

  Approximately 0.5%.
• How does the prevalence of colour vision deficiencies vary?

  It varies with ethnicity, being highest in Europe.

  
• What are the types of tests used for colour vision deficiency (CVD)?

  • Detect (screening tests)
  • Assess severity (grading tests)
  • Distinguish between congenital and acquired deficiencies
• What is the purpose of chromaticity diagrams in testing for CVD?

  They demonstrate colour confusions.

  
• What is one exception to tests that rely on colour confusions in CVD?

  Medmont C-100.
• What are the main types of clinical colour vision tests?

  • Pseudoisochromatic (PIC) Plates
  • Hue discrimination tests
  • Lanterns
  • Anomaloscopes

  
• What is required for a clinical colour vision test to be accepted?

  The patient must name a colour correctly or respond appropriately.
• Why is it necessary to use a battery of tests for a full colour vision diagnosis?

  No single test is all-fulfilling for colour vision diagnosis.
• What is the focus of screening for colour vision deficiencies?

  To determine if a colour vision deficiency is present.
• Which congenital colour vision deficiencies are most prevalent?

  Protan and deutan deficiencies.

  
• Why are tritan colour vision deficiencies considered less impactful?

  Colour coding systems rely less on blue-yellow discrimination.

  
• What is the prevalence of acquired blue-yellow colour vision deficiencies compared to red-green?

  They have at least the same prevalence.

  
• What is the importance of severity diagnosis in congenital colour vision deficiencies?

  • Evaluates suitability for specific occupations
  • Advises patients with abnormal colour vision
  • Mild deficiencies may allow safe task performance
  • More affected individuals represent a real risk
• Why is discrete categorization less appropriate for acquired deficiencies?

  It requires evaluation of subtle variations necessitating a continuous scale.
• What is the basis of colour vision tests according to Lakowski?

  They must be based on the colorimetric principles of the CIE 1976 chromaticity diagram.

  
• What are the design features of pseudoisochromatic (PIC) plates?

  • Use colour camouflage
  • Substitute colours within confusion zones
  • Individual elements are spots of colour
  • Figures emerge differently for normals and CVDs
• What is the most widely used PIC plate for RG screening?

  Ishihara plates.

  
• What does the introduction plate of Ishihara check?

  It checks if visual acuity is sufficient (6/18).

  
• What do the transformation plates in Ishihara combine?

  They combine hidden and vanishing concepts.
• What is the purpose of the vanishing plates in Ishihara?

  To create figures that are invisible to CVD.

  
• How do hidden plates in Ishihara function for normals and CVD?

  Normals see nothing, while CVD sees a figure.

  
• What is the purpose of the classification plates in Ishihara?

  To identify which cone system is defective.

  
• What is the tracing method in Ishihara used for?

  It is suitable for children or patients who can't read numbers.
• Why has the Ishihara test been the test of choice?

  It has high sensitivity and specificity.
• What does sensitivity in the context of the Ishihara test refer to?

  The percentage of CVD correctly identified.
• What does specificity in the context of the Ishihara test refer to?

  The percentage of CV normals correctly identified.
• What is a limitation of the Ishihara test regarding tritan plates?

  It does not include tritan plates.
• Why is the number of errors in the Ishihara test not a good index of severity?

  It does not accurately indicate the severity of the deficiency.
• What are the features of the Richmond HRR plates?

  • Only symbols, no figures
  • Confirmation of Ishihara results
  • May detect tritan defects
  • Diagnostic series provides type and extent of defect
• What are the features of the City University plates?

  • Detect moderate to severe RG and BY defects
  • Differentiate between P, D, and T CVD
  • Scoring based on comparison colours
• What are the features of the Farnsworth F2 plates?

  • May detect tritan defects
  • Consists of two different-coloured squares
  • Background consists of purple-coloured circles
• What do PIC plates at City University detect?

  Moderate to severe RG and BY defects
• How many plates are included in the PIC plates test at City University?

  11 plates, including 1 demonstration plate and 10 test plates
• What is the purpose of the comparison colours on each PIC plate?

  To represent typical confusion colours for P, D, and T CVD
• What should a patient do when using the PIC plates test?

  Identify which of the 4 comparison colours is most identical to the central test colour
• How is the severity of CVD indicated in the PIC plates test?

  By the number of mistakes in the normal column