Opthalm Flashcards
4 essential components of the ophthalmoscope
on off switch
lenses
light
diaphragm
how should an ophthalmoscope be held
as a microphone
no wrist flexation
always keep index finger on lens dial
ophthalmoscopes provide a high magnification of approx 15x but have a small field of view which between x and y degrees
6.5-10
why will you not be able to see a sterioscopic/ 3d vision
using one eye
will you be able to see the macula?
no
what will take up the whole field of view
optic disc !!
what should you ask patients before doing the examination
pain
glasses
you must set the ophthalmoscope according to the patients refractive error, what should it be set to if the patient wears contact lenses
0
if patients do wear glasses but only for reading what should you set then refractive error to
0
if a patient wears glasses for distance such as driving or tv what should then ask them
long or short sighted
how can you work out for a patient if they are long or short sighted
look through glasses if things appear smaller they are short sighted if things appear bigger they are long sighted
if a patient is short sighted/ myopic should you set the dial to what colour numbers
red
if a patient is long sighted/ hypermetropic what colour should you set the dial to (can also be yellow/green/white)
black
if things appear a lot smaller or larger in a patients glasses that means that their lenses are thick and relatively strong. What would this prompt you to do in relation to dials
set to a high number
how can you make carrying out the examination easier for yourself
bright scope - halogen bulb, new batteries
dark room
comfortable patient
dilate pupils
after hand hygiene and introducing yourself to the patient you should give the patient clear instructions and explain what you are going to do. What would you instruct them to do at this stage
remove glasses
fixate on distant object
blink and breathe as normal
If YOU wear glasses, what should you do during exam? to make it easier
keep them on… else can take off and add error to dial
when carrying out the examination where is an appropriate place to place your hands on the patient
shoulder
you use the red reflex to detect any opacities in the media such those caused by…. 2
cataract
retinoblastoma
how do you test the red reflex
set lens to 0
shine light at pupil from arms length
observe red reflex
compare in each eye
should be both eyes red
what would you observe in a patient with cataract when you look at the red reflex
absent
what colour glow do you expect in the eyes when you do a red reflex test
yellow or orange glow
when doing direct ophthalmoscopy should you start with your dominant or non dominant eye
dominant and close non dom
you use your
right eye
right hand
and right index finger on dial to check the patients
left or right eye
right
what is the angle of approach temporal to the patient in degrees
15 NOT 45
why is angle of approach 15 degrees
its where the blind spot or optic disc is
what should you use as your aiming beam ie keep visualised as you get nearer to the patient
red reflex
why is it important to get close to the patient
increases field of view
what 3 parts of the optical media are you trying to assess
cornea
lens
vitreous
what 2 parts of the fundus are you trying to see
optic disc
retina
what 2 parts of the retina are able to be viewed
macula
blood vessels
one key structure to observe is the optic disc, what are the 3 Cs to think about
cup disc ratio
colour
contour
what would you expect to see when you visualise the eyes of a diabetic patient potentially
new vessels
what changes to the cup disc ratio would you expect to see in glaucoma
bigger vertical CDR
what would you expect to see in optic disc pallor/ optic atrophy
disc margins appear sharp and disc is pale
some symptoms of papilloedema
headaches
worse when coughing
transient visual obscurations
elevated disc
blurred disc margins
disc haemorrhages
absence of spontaneous venous pulsation
normal vision in initial stages
what else can be seen when checking retinal BV?
arterioles and veins
calibre
new vessels, collateral vessels
what else can be seen when looking at macula (if pupil dilated)
foveal relfex
any other finding in macula = abnormal
- haemorrhages
- microaneurysms
- exudates
- cotton wool spots
- drusen
- atrophy
2 types of age related macula degeneration
dry and wet: green, red splodges
what does diabetic retinophy look like?
lots of BV and light spots
