Ophthalmology examinations Flashcards
What is the normal pupil size in
a) light
b) dark
light: 2-4mm
dark: 4-8mm
How is visual acuity measured
Snellen chart
A patient stands 6m away from the Snellen chart and can read up to line 18 however gets 3 letter wrong on this line. How is their visual acuity written?
6/18-3
If a patient is unable to read the largest letter on the snellen chart what can be done next?
- Counting fingers (CF)
- Hand movements (HM)
- Perception of light (PL)
If none of the above then the person is classified as no perception of light (NPL)
How is colour vision assessed?
Ishihara plates
How are the visual fields assessed?
Confrontation is used to grossly assess visual fields
Goldman perimetry gives a detailed description
What is the afferent and efferent path of the corneal reflex?
Afferent: ophthalmic division of the trigeminal nerve
Efferent: Facial nerve
What is a normal corneal reflex?
Blinking and watering of the eye
What is a normal and abnormal response to the swinging flash light test?
Normal: both pupils hold their constriction throughout
RAPD/Marcus Gunn: both pupils appear to dilate (less constricted) when the light is shone in to the affected eye
Efferent pathway affected: abnormal eye does not constrict throughout the examination however the normal eye remains constricted throughout
Describe what you see on fundoscopy
Optic cup surrounded by optic disc
Fovea at the centre of the macula
How do you know whether you are looking at an image of the left or right eye on fundoscopy?
Optic cup is located next to the nose i.e. if it is on the left of the image it is the left eye
How do midriatic drops work?
Anticholinergics that inhibit the parasympathetic input to the pupillary sphincter. They also inhibit the ciliary muscles therefore stopping accommodation
When are midriatic drops contraindicated?
Acute closed angle glaucoma
