Fundoscopy & Otoscopy Flashcards
What is the fovea?
the darker area which is in the centre of the macula
this has the highest density of cone receptors and therefore provides the clearest vision
What is the definition of the lens?
a transparent, biconvex structure situated behind the iris and pupil
this allows the eye to focus objects onto the retina
What is the definition of the cornea?
a transparent layer to the anterior of the eyeball
this is responsible for refraction of the light entering the eye
What is the definition of the pupil?
central aperture within the iris
this constantly changes in size in response to the sphincter and dilator pupillae muscles
What is fundoscopy?
fundoscopy involves using a fundoscope / ophthalmascope to shine a light through the pupil towards the back of the eye (retina / fundus) to examine its surface
you should see an upright image of a small portion of the retina approx 15x magnification of its actual size
What is the purpose of fundoscopy?
- it can be used to assess the health of the eye, and also other systems within the body
- visualisation of the retina and vessels in the back of the eye can give us clues as to the general health of the patient including their cardiovascular, neurological and endocrine health
What are the indications for fundoscopy?
- head injury
- eye injury
- as part of complete neurological examination to assess for papilloedema
- chronic disease monitoring (diabetes / hypertension)
- to assess health of the eye and retina
- assess for possible infections such as CMV, endocarditis and candidaemia
When explaining the procedure to the patient, what is it important to include?
- you will need to get close to them in this examination
- it shouldn’t hurt but may be uncomfortable, please let us know if it becomes too much
- explain fixing gaze and find appropriate point to look at, this will make the exam easier to perform
- you can blink
After explaining the examination, what is it important to do?
What might you choose to use and why?
- once you have explained the procedure, give the patient the chance to consent and answer any questions
- you may choose to use mydriatic drops (check 5Rs and allergies) and this should be explained fully to the patient
What should the environment be like for fundoscopy?
- a darkened room to maximise the diameter of the pupil
- position for you and the patient - you should be upright and eye level to one another
What eye should you use to examine the patient’s eye?
How should the ophthalmoscope be held?
- you should use your right eye to examine the patient’s right eye and vice versa to avoid facial contact
- hold the ophthalmoscope in a way that allows you to use your index finger to adjust the lens wheel as required
- adjust the brightness and aperture mask prior to commencing examination, in order to maximise patient comfort
What should be looked for when inspecting the eyes at the beginning of the inspection?
- any discharge or foreign bodies
- symmetry of the eyes and eyelids
- surrounding skin including any erythema, oedema or skin abnormalities
What is the red reflex and how can it be found?
- direct beam of light onto patient’s eye from around 1 foot away and from an angle of 15-20o
- move slowly in towards patient’s eye as this directs the beam towards the optic disc
- look for red reflex and use it to guide you closer to the pupil
- the red reflex is a red/orange reflection of the light off the retina
- the red reflex should be round and clear
- opacities or change in colour could indicate vitreous haemorrhage, cataracts or debris
How do you use the fundoscope to see the anterior structures in the eye?
What should you comment on when doing this?
- place hand on patient’s forehead
- approach from 15-30 degrees on the same level as the equator of subject’s eye, directing the beam of light into the pupil (use red reflex to guide you)
- focus on the anterior segment of the eye and comment on any abnormalities
- comment on the pupils - shape, symmetry and size
What do you do once you have a vessel in focus?
- you should adjust the focussing wheel as you get closer to the patient
- once you have a vessel in focus, follow the branching vessels as though they were arrows pointing towards the disc
- follow these “arrows” to locate the disc
What structures are evident at the back of the eye?
What should you identify and comment on?
- focus on the retina
- identify and describe the optic disc
- follow blood vessels into 4 quadrants, commenting on vessels and spaces between
- seek to identify the macula and fovea
- comment on all the above
What are each of the quadrants of this eye?
Is this a left or right eye?
it is a right eye
this is because the optic disc is in the medial position
What 4 aspects are involved in the systematic examination of the retina?
- background
- disc
- vessels
- fovea and surrounding macula area
What is looked for when examining the background of the retina?
- any microaneurysms or haemorrhaging
- this includes blot, dot and flame haemorrhages
- hard exudate - such as lipids, proteins & other debris
-
cotton wool spots
- these are also known as soft exudates
- they show areas of ischaemia / infarcts
Where is the macula and fovea found and what should it look like?
- it is lateral to the optic disc
- it is slightly pigmented and has no border
- it is responsible for the central and sharpest vision
- the foveal pit in the centre of the macula sometimes has a glistening appearance due to the light reflex
- this is seen more commonly in young people
- the fovea loses the light reflex as people get older
What should be checked for during examination of the macula?
- hard exudates that are creamy in colour
- haemorrhaging
- proliferation / neovascularisation
- ideally nothing should be in the macula area as it is avascular due to the rods and cones
What should the outline of the optic disc look like?
- in a normal state, it is well-defined and sharp
- there may be a white scleral ring, a dark pigmented ring or a stippled choroidal ring surrounding the optic disc
What is the colour of the optic disc like?
How does this change in oedema and atrophy?
- it is creamy yellow/orange-pink in colour compared to the rest of the retina
- temporal margin is slightly paler than the nasal margin
- in atrophy of the optic nerve, the disc becomes white/greyish
- in oedema of the optic disc, it becomes pinker and resembles the colour of the surrounding retina
What should the vessels of the retina look like?
- branching of vessels forms a “v” that always points towards the optic disc
- main vessels branch in 4 directions
- veins are uniform and burgundy in colour
- arteries have a central pale line and 2 red outer walls
- they are narrower than veins and a brighter colour due to light reflecting from their walls
What should be noted about the features of the vessels in the retina?
- the calibre (width of blood vessels)
- whether they are curvilinear (not too tortuous or straight)
- the points where the vessels cross to check for arteriovenous nipping
What are all the key points to mention about the optic disc in summary?
- sharp margins
- blind spot
- it is round / oval
- it is yellow / orange to creamy pink
- the cup to disc ratio should be < half
What are key points to mention about the vessels of the retina in summary?
- AV ratio - arteries are 2/3 the size of veins
- AV crossing - no indentation
- no arterial light reflex
What is papilloedema?
What does the optic disc look like?
swelling of the optic disc
- there is elevation or obscuring of the vessels at the disc margin
- there is a blurred or absent disc margin
What is the cup of the optic disc?
What is a normal cup-to-disc ratio and what happens in cupping?
- the cup is the pale, central part of the disc
- a normal cup-to-disc ratio is 0.3
- the cup occupies 1/3 of the size of the disc
- cupping can occur due to glaucoma
What types of vessel abnormalities need to be looked out for?
- abnormal crossing / AV nipping
- arterial diameter being < half of vein diameter
- copper wiring
- increased tortuosity of vessels
Where are “flame” and “splinter” haemorrhages found?
- they occur in the nerve fibre layer
- they get their shape from the tracking of blood along the nerve fibre
Where are round / oval “dot” and “blot” haemorrhages found?
- they occur within the inner layer of the retina
- the cells are so compactly arranged that the haemorrhage cannot spread
What causes a hard exudate?
What does it look like?
deposits of lipid and protein which leak from surrounding capillaries
they are yellow, waxy looking and have more defined edges than cotton wool spots
What is a soft exudate?
What does it look like?
- these are nerve fibre layer infarctions
- areas of ischaemia resulting from occlusion of retinal arteries and swelling of the local nerve fibre axons
- they are white with a “fluffy” appearance
What is shown in these photos?
macular degeneration
What is shown in this photo?
this is the tympanic membrane
What should the tympanic membrane look like on examination?
What is it important to look for?
- it should appear relatively flat, pearly grey and translucent
- examine the margin as perforations and pathologies can be present there
- look for perforations, scarring, bulging, retraction and erythema
- note any abnormalities and the position and size of them
What is shown in this image?
otitis media
the membrane is bulging, there is erythema and visible blood vessels
What is shown in this image?
otitis media with effusion
there is a bulging tympanic membrane
fluid is visible, which is indicative of an effusion
What is shown in this image?
perforated tympanic membrane
there are visible blood vessels and erythema
