Visual Defects COPY Flashcards
Patients may find it difficult to articulate their symptoms of visual loss, so need to ask direct questions. What 3 questions can you start with?
- Do things look distorted/crooked?
- Is there a shadow?
- Does the shadow move?
How would ‘blurred vision/fuzziness’ present?
- Out of focus/not sharp
- No distortion or shadowed (no bent/nothing missing)
What are 2 potential causes of blurred vision?
- a refractive problem (cornea, lens, shape of eye)
- a macular problem
How would ‘glare’ typically present?
- Difficulty seeing in bright light
- Low sun
- Driving at night
- Fluorescent light in supermarkets
- Similar effect produced by having dusty car windscreen
- Vision good otherwise
What is ‘glare’ often due to?
Cataract
How would ‘distorted vision’ typically present?
- Things look wavy, jumbled up. Lines not straight/ bent. Kink in lines
- Effect could be produced by having crumpled film in camera (or crumpled photo)
Typical causes of distorted vision?
- Condition affecting retina:
- Wet macular degeneration
- Macular hole
- Macular pucker
- Retinal detachment
What could cause a patient’s vision to be described as ‘pale’?
-
Optic nerve disease:
- Optic neuritis e.g. MS
- Compressive optic nerve disease e.g. pituitary tumour
-
Condition affecting retina:
- Wet macular degeneration
- Central serous retinopathy (fluid beneath the retina)
What is a ‘floater’?
Floaters are tiny pieces of debris in the eye’s fluid, known as the vitreous humour –> important feature is movement
What is a ‘floater’ caused by?
Degeneration in vitreous humour:
- Vitreous syneresis
- Posterior vitreous detachment
- Vitreous haemorrhage
A visual field defect (e.g. part of vision missing/ missing things/ shadow/ thumb print) is always a sign of what?
A serious problem
If the visual field is homonymous, what does this indicate?
same visual field both eyes –> a defect of visual pathways
If the visual field is not homonymous, what does this indicate?
Retinal or optic nerve problem
What is confrontation testing?
Confrontation visual field testing involves having the patient looking directly at your eye or nose and testing each quadrant in the patient’s visual field by having them count the number of fingers that you are showing. This is a test of one eye at a time
Label the types of visual defects:
A. Central B. Cecocentral C. Nasal
D. Arcuate E. Nasal wedge F. Quadrantic
G. Altitudinal H. Hemianopia
I. Paracentral + enlarged blind spot
What is a Glaucoma?
A common eye condition where the optic nerve becomes damaged. Usually caused by abnormally high pressure in eye e.g. due to blocked or restricted drainage in your eye or high blood pressure.