The Retina Flashcards
What is the purpose of the photoreceptors?
Turn light in to electrical energy
Which letter is the photoreceptor layer?
C
Which letter is the nerve fibre layer
A
Which letter is the tapetum?
D
Which letter indicates the outer nuclei layer?
B
Which is where on this photo?
Where is the choroid and vitreous ?
Vitreous above A
Choroid below D
What can you see when you look at the back of the eye?
The tapetum and blood vessels
The tapetum is made up of what type of cells?
These contain reflective material, in the dog this is?
Cat?
Polyhedral iridocytes
Dog - cysteine
Cat Riboflavin
The retinal pigment epithelium is pigmented or non pigmented;
Over the tapetum?
The rest of the eye?
Tapetum- non pigmented
Rest of the eye- pigmented
What are Stars of Winslow?
Dots throughout the tapetum (don’t see often in dogs, see in the cats)
End on blood vessels in the choroid
When is the development of the tapetum done in dogs?
When does it start?
4months
7weeks
How are colour dilute animals non tapetal fundus different to normal animals?
Colour dilute animals have lightly or non pigmented non tapetal fundus so can see choroidal vasculature
How many layers are there in the retina?
10 layers
Where do the blood vessels come from that supply the;
Outer retina?
Inner retina?
Outer retina is supplied by the choroid
Inner retina is supplied by the retinal vessels
In the area centralis is this area rod or cone dense?
Where is this area?
Are there blood vessels here?
Cone dense
Lateral to the optic disc
No
What is the central depression in the optic nerve called?
What is the outer elevated portion called?
Physiological cup
Papilla
The optic nerve head in dogs is what colour?
Cats?
Why?
Dogs- White due to myelination
Cats- grey due to being unmeylinated
What is Pseudopapilloedema?
Which breed do you often see with this?
When myelin extends beyond the margin of the optic disc in to the nerve fibre layer
Golden retriever
Which species is this fundus?
What are the larger vessels?
Smaller vessels?
Dog
Paired arterioles and veins
Anastamosing ring
Arterioles
What species is this fundus?
Dog
What type of species and type is this a fundus of?
Colour dilute dog
Which species is this?
Cat
Which species is this? What type?
What are the dots on the choroid?
Colour dilute cat
Stars of Winslow
What does degeneration/ atrophy of Retina cause?
Hyperreflectivity
What causes the tapetum to become hyporeflective?
Retinal detachment
Choroidal effusion
Inflammatory exudates
Neoplasia
What causes pigmentary changes in the tapetum?
Inflammation (in response to RPE hypertrophy)
Which layer is which;
Tapetum
Retina
Choroid
How would you describe this tapetum?
Hypo or hyper reflective?
What is the arrow pointing at?
Hyporeflective
Chorioretinitis- inflammatory cells under retina making it look greyish/ dull
How would you describe this retina?
Hypo or hyper reflective?
Hyper reflective
In the non tapetum what does inflammation cause?
Clumping or loss of pigment?
Loss of pigment
In the non tapetum what does retinal degeneration cause?
Clumping or loss of pigment?
Clumping of pigment
Which one causes attenuation of blood vessels?
Degeneration conditions
Inflammatory conditions
Hyperviscosity syndromes
Anaemia/ lipaemia
Degeneration conditions
Which one causes dilation of blood vessels?
Degeneration conditions
Inflammatory conditions
Hyperviscosity syndromes
Anaemia/ lipaemia
Inflammatory conditions
Which one causes sausaging/ box carring of blood vessels?
Degeneration conditions
Inflammatory conditions
Hyperviscosity syndromes
Anaemia/ lipaemia
Hyperviscosity syndromes
Which one causes perivascular cuffing of blood vessels?
Degeneration conditions
Inflammatory conditions
Hyperviscosity syndromes
Anaemia/ lipaemia
Inflammatory conditions
Which one causes colour changed of blood vessels?
Degeneration conditions
Inflammatory conditions
Hyperviscosity syndromes
Anaemia/ lipaemia
Anaemia/ lipaemia
What does an infundibular retinal detachment look like?
What the retina firmly attached to to cause this?
Marquee roof
Ora serrata and optic disc
What is happening to this retina?
Bulous retinal detachment
What pattern does a subretinal haemorrhage cause?
- Large, dark
- Smaller, lighter (dots and blots)
- Flame shaped, follow nerve fibres of ganglion cells
- Keel boat, form in virtual space between neuro retina and vitreous face
Large, dark
What pattern does a intraretinal haemorrhage cause?
- Large, dark
- Smaller, lighter (dots and blots)
- Flame shaped, follow nerve fibres of ganglion cells
- Keel boat, form in virtual space between neuro retina and vitreous face
Smaller, lighter (dots and blots)
What pattern does a superficial haemorrhage cause?
- Large, dark
- Smaller, lighter (dots and blots)
- Flame shaped, follow nerve fibres of ganglion cells
- Keel boat, form in virtual space between neuro retina and vitreous face
Flame shaped
What pattern does a vitreal haemorrhage cause?
- Large, dark
- Smaller, lighter (dots and blots)
- Flame shaped, follow nerve fibres of ganglion cells
- Keel boat, form in virtual space between neuro retina and vitreous face
Keel boat
What is Papilloedema?
Swelling of the optic nerve head
What changes to the optic nerve head does glaucoma cause?
Cupping
What has happened to this optic nerve?
Atrophy
For ERG do you dilate or constrict the pupil?
Dilate
In regards to an ERG which wave causes which activity;
A wave
B wave
C wave
Bipolar cell activity
Photoreceptor activity
RPE activity
Which one is not usually seen in routine protocols?
A wave - Photoreceptor activity
B wave - Bipolar cell activity
C wave - RPE activity
C wave
Which species do you have to be careful with IV fluorescein?
Cats- can cause anaphylaxis
Which area has a high density of cone cells?
Area centralis
Is collie eye anomaly acquired or congenital?
What is the hallmark lesion? M
Secondary complications?
How is it inherited?
Uni or bilateral?
Which breeds?
When is this best seen?
Congenital
Choroidal hypoplasia +/- coloboma of ONH or peripapillary area (around ONH)
Retinal haemorrhages and detachments
Autosomal recessive
Bilateral
Smooth collie, border collie, Shetland sheepdog, Lancashire heeler, novascotia duck tolling retriever
5-7weeks
What condition does this indicate?
Collie eye anomaly
Choroidal hypoplasia
What is happening in the optic nerve?
Optic nerve head coloboma
This is a colour dilute animal with what condition?
Collie eye anomaly with choroidal hypoplasia