Week 1.06 Intro To Retinal Disease Flashcards
Where are the firm attachments in retina
Optic disc and ora serrata
How many mm behind the limbus does the retina start
Anterior retina starts ~7mm behind limbus
Layers of the retina
Inner limiting membrane
Nerve fibre layer
Ganglion cell layer
Inner plexiform layer
Inner nuclear layer
Outer plexiform layer
Outer nuclear layer
Outer limiting membrane
Photoreceptor layer PRL
Retinal pigment epithelium
Bruch’s membrane
Choriocapillaris
What are the layers of the artery from inner to outer
Tunica intima - endothelium
Tunica media - smooth muscle, regulates blood flow
Tunica externa - connective tissue
What are the layers of vein
Tunica interna - endothelium
Tunica media - thin smooth muscle layer
Tunica externa - connective tissue
Which layers of the retina get their blood supply via the central retinal artery
ILM
NFL
GCL
IPL
INL
OPL
Which layers of the retina get their blood supply via Choroidal vessels
ONL
OLM
PRL
RPE
BM
Is a myelin sheath on nerve fibres benign or malignant
Nerve fibres shouldn’t have a myelin sheath when they come out your optic disc
Don’t need to do anything as its benign
What are some peripheral retinal degenerations
Retinovitreal degenerations:
- lattice, snail track, white with/without pressure
Intraretinal degenerations:
- microcystoid, retinoschisis
Chorioretinal degenerations:
- pavingstone
Snail track
Retinovitreal degeneration
- sharply defined
- frosted appearance
- early stage lattice
- degn of neural layers
Lattice
Risk factor for RD
8% of general population - but 25 - 40% rhegmatogenous detachments have lattice
RPE changes
Sclerosed vessels (white lines)
Snowflakes
Yellow/white dots
Fluffy
Small pale lesions in inner retinal layers
Usually benign if is the only finding
Associated with lattice, snail track, acquired retinoschisis
White with/ without pressure
Retinovitreal degeneration
With pressure = only visible indentation
Without pressure - can see without indenting
Possibly due to: peripheral vitreous traction, abnormal reflex
Can be confused with RD/schisis
Microcystoid
Intraretinal degn
Most common peripheral degn
- increases with age
- greyish white vesicles/vacuoles
- in outer plexiform and inner nuclear layers
- does not predispose to retinal detachment
- benign
Retinoschisis
- Intraretinal degen
- inner/outer retina separate at OPL
- often symptomless
- temporal retina
No cause to it
Choroidal degenerations
Affect choroid and the retina
Paving or cobblestone
- discrete white patches
- pigmented rims
- between OS and equator
- Chorio-retinal atrophy
- temporal retina separate
- 25% normal eyes
- benign
- cobblestones
Honeycomb
Reticular pigmentary lesion
- slight concern
- pigmentation
- vessels
- can get peripheral drusen
- poor Choroidal perfusion
- assoc with AMD
Other peripheral degn
Oral:
- hyperpigmentation
- ora serrata
- age associated
What are some pigmentary lesions
RPE hypertrophy (CHRPE)
Bear track
Choroidal naevus
Choroidal melanoma
Albinism
Retinitis pigmentosa
RPE hypertrophy
Congenital hypertrophy of the RPE (CHRPE)
Unilateral - one eye
Flat
1-3 disc diameters small
Dark grey/black
Not a problem
Bear track
Few CHRPE at once
Multiple lesions
Can be associated with condition predisposing px to colon cancer
Will need to refer for screening of colon cancer
Choroidal naevus
Describe as mole/freckle to px
Super common
Found at routine eye exam
Photograph to monitor change in size or shape
Choroidal melanoma
Most common ocular tumour
Rare
Asymptomatic
METASTATIC- RISK TO LIFE
Needs tx fast
FA indicate blood supply and risk of spread. Requires radiotherapy and or surgical removal
How can you tell the difference between CHRPE, naevus and melanoma
CHRPE and naevus are flat compared to melanoma which is slightly elevated
CHRPE are dark grey/black, naevus slate grey and melanoma white to greenish grey
Melanoma biggest in size
Nauevbus have indistinct margin
Albinism
Lack of pigment
Choroidal vessels visible
Va <6/60
Nystagmus
Bilateral amblyopia
Retinitis pigmentosa
All modes of inheritance
Teenage years
Pigment accumulation in periphery
Progressive and not born with it
Rods lost in early diseases - night blindness
Cones lost later - reduced vision
What are some systemic conditions associated with retinitis pigmentosa
Usher syndrome
Lawrence moon Barnet biedl syndrome
High myopia
Risks of:
- RD
- nuclear cataract to posterior sub capsular
- glaucoma - increased risk of POAG
Optic disc anomalies
Scleral or Choroidal crescents
Myopia
RPE stretched - Choroidal
Choroidal stretched - scleral
Coloboma
Optic disc anomaly
Rare
Uni or bilateral
Reduced va
Superior field defect
May involve inferior retina
Congenital
Disc drusen
Benign
Usually due to waste products and form over time
Px usually born with these disc drusen
Hypertension
20% of pop affected
90% hypertensives have no known cause
Unless px is very young hypertensive changes occur alongside other ageing changes
Cotton wool spots
Hypoxia lack of oxygen and nutrients
Nerve fibre layer doesn’t have enough oxygen so spills out the content
What is the difference between arteriosclerosis and atherosclerosis
Arteriosclerosis - progressive narrowing and hardening of arteries with time (affects whole artery)
Atherosclerosis - deposition of material in arterial walls to form plaques (affects certain sections)
What are the signs of arteriosclerosis
Salus sign - deflection of vein as it crosses artery. Looks like an s. 90º crossing
Bonnet sign - banking of veins distal to A/V crossings
Gunn sign - tapering of veins on either side of A/V crossings
Retinal artery occlusion
- acute severe painless loss of vision
- whitening of the retina
- cherry red spot at macula
Retinal vein occlusion
- reduced vision
- haemorrhage in 4 quadrants
- cotton wool spots
- Exudates
- Neovascularisation
