×
MedSchool: Ace Your OSCEsThe Medical Company
 
 
 
 
 
GET - On the App Store
View
Signs
 
 

Reduced Visual Acuity

 
Bookmark

Overview

Testing visual acuity is useful as a screening test for identifying reduced vision which may be due to ocular or neurologic disorders.
  • How to Elicit

  • Ask the patient to cover one eye, look at a Snellen chart (wall-mounted at 6m or handheld at arm's length) and identify the smallest line that they can read.
If the patient wears corrective lenses, perform the test with and without them.
If the patient's visual acuity is poor, use a pin hole over their eye to test for refractive error.
  • Causes of Poor Visual Acuity

  • Refractory error
  • Corneal opacification - cataract, infection, trauma
  • Vitreal opacification - intraocular haemorrhage
  • Retinal disorders - macular degeneration, retinal detachment, diabetic retinopathy, retinal artery occlusion
  • Optic nerve disorders - glaucoma (raised intraocular pressure), ischaemia, optic neuritis
  • Intracranial disorders - pituitary disorders, aneurysm
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Want more info like this?
  • Your electronic clinical medicine handbook
  • Guides to help pass your exams
  • Tools every medical student needs
  • Quick diagrams to have the answers, fast
  • Quizzes to test your knowledge
Sign Up Now
   
 
 

Snapshot: Initialising...