Acute Vitreoretinal Pathologies Flashcards
what is this and where in the retina does it take place
pre retinal haemorrhage
in the sub hyaloid space
between the post hyaloid and internal limiting membrane
what are the 2 causes of a vitreous haemorrhage
Damage to normal blood vessels
or
Growth of abnormal blood vessels
how does damage to normal blood vessels cause a vitreous haemorrhage and name 2 examples
Retinal blood vessels that are damaged through injury or trauma can cause a vitreous haemorrhage.
Posterior vitreous detachment
Retinal tears
how does growth of abnormal blood vessels cause a vitreous haemorrhage and name 5 examples
Abnormal retinal blood vessels are typically the result of neovascularization due to ischemia in diseases such as:
diabetic retinopathy sickle cell retinopathy retinal vein occlusion retinopathy of prematurity ocular ischemic syndrome
what is this a sign of
which type of px is it more commonly found in
what type of symptoms will the px experience
and where in the retina is this found
Retinal macroaneursym
more common in elderly hypertensive women
haemorrhaging of the arteriole macroaneurysm presents acutely with rapid visual deterioration
multi layered involving the - vitreous, pre retinal, intra retinal and sub retinal spaces
describe how a Rhegmatogenous retinal detachment takes place
This results when a hole, tear, or break in the neuronal layer allows fluid from the vitreous to seep between and separate sensory and RPE layers
describe how a Traction retinal detachment takes place
This results from adhesions between the vitreous gel/fibrovascular proliferation and the retina
describe how a Exudative (serous) retinal detachment takes place
This results from exudation of material into the subretinal space from retinal vessels – ocular tumour
which type of retinal detachment is not present with a vitreous haemorrhage
Exudative (serous) retinal detachment
how does a gas bubble procedure to treat a retinal detachment work
when is it not suitable to do this tx
what is expected of this px after the procedure
The gas bubble keeps the retinal tear dry while the healing takes place . The gas disappears after a few weeks
cannot to is a px is going to travel in air due to air pressure
px is expected to lie face down for a 5-8 days, so the gas bubble floats up and keeps the retina dry
explain how scleral buckling works as a treatment for a retinal detachment
the explant or buckle pushes the outside layers of the eye against the retinal tear to allow it to heal, and to stop the flow of fluid behind the retina
any remaining fluid is then absorbed by the outer layers of the retina
explain how a vitrectomy is carried out
A vitrectomy instrument is used to drain fluid that is behind the retina
a fibre optic light is used to aid this
in order to keep a steady IOP, fluid goes into the eye through a cannula to replace the vitreous that is removed
Name this condition
acute retinal necrosis ARN
with Acute Retinal Necrosis
In 1994, the Executive Committee of the American Uveitis Society refined the definition of ARN based on clinical characteristics and disease course to include what 5 signs
1) one or more foci of retinal necrosis with discrete borders located in the peripheral retina;
2) rapid progression in the absence of antiviral therapy;
3) circumferential spread;
4) evidence of occlusive vasculopathy with arterial involvement
5) a prominent inflammatory reaction in the vitreous and anterior chambers
what are the anterior 4 signs and 2 symptoms of someone with Acute Retinal Necrosis
photophobia and pain
anterior chamber inflammation
secondary KPs
episcleritis and scleritis
corneal oedema
what are the 4 posterior signs and 2 symptoms of someone with Acute Retinal Necrosis
flashes and floaters
vitritis - hazy appearance
vascular/arterialitis - haemorrhages
peripheral retinitis - white patches
swelling of the optic disc
how is acute retinal necrosis ARN treated
anti virals
given intravenously, orally or intravitreally e.g. aciclover, ganciclover
after the antivirals - given steroids to dampen down the inflammation
what is this condition
porn - progressive outer retinal necrosis
what is the difference between porn - progressive outer retinal necrosis and ARN - acute retinal necrosis
with porn - there is no haziness, you get a clear view of the retina because the inflammatory response is not to the same degree as ARM
which type of people does porn affect
people with compromised immune systems e.g. AIDS
what are the clinical signs of porn - progressive outer retinal necrosis and how is it treated
what risk is there with someone who has porn
areas of: haemorrhages white areas of retinitis and sheathing of the retinal vasculature
Tx = antiviral agents given intravitrially
Risk of - retial detachment
what is this condition called
what 2 characteristics do you see and why do these occur
Neuroretinitis
optic nerve oedema
and
macula star/stellate maculopathy
because of inflammation due to increased permeability of the optic disc vasculature which causes a secondary macula star
this can be from infective causes of vasculitis
what 2 parts of the retina are inflamed with Neuroretinitis
optic nerve
and
neuroretina
what causes the characteristics of Neuroretinitis
optic disc swelling
list 7 infective causes of Neuroretinitis
bartinella cat scratch disease syphilis tuberculosis lyme disease leptospirosis toxoplasmosis
what organism is in cat scratch disease which can cause neuroretinitis and how does this get transmitted
Bartonella hensela
transmitted from a flea to the cat and then to the human host
what condition is this
what is this caused from
what characteristics do you see
what is the visual prognosis
commotio retinae
caused by anterior segment trauma - that produces a contusion injury by a countertop mechanism / blunt trauma
transient well defined greyish/white opacification of the retina - it can involve large areas of the peripheral retina or be confined to the macula
vision can be normal if confined to peripheral retina unless the macula is involved
which layer of the retina is damaged with commotio retinae
photoreceptor outer segments
what is the term called if commotio retinae affects the macula
berlins macula oedema
what is this condition called
what clinical characteristics does it have
Terson’s syndrome
presence of any intra ocular haemorrhages e.g. vitreous haemorrhage subhyaloid haemorrhage intra or sub retinal haemorrhages
what is the lead pathogenesis/theory of Tarsen’s syndrome
intracranial pressure causing a rapid efflux of cerebrospinal fluid or haemorrhages into the optic nerve sheath into the orbit which compresses the central retinal vein, objecting the venous outflow and rupturing the smaller retinal venules.
what is an alternative pathogenesis of Terson’s syndrome
acute IOP which can cause increased orbital venous pressure, leading to a back fill of blood into the retinal veins
what systemic issue will a px with Terson’s syndrome have
intra cranial haemorrhage or traumatic brain injury
what is the visual outcome of someone with Tersen’s syndrome
usually good depending on extent of haemorrhages
can take weeks or months for advanced haems to clear
what is this condition called
name 3 clinical signs
Pertschur’s Retinopathy
haemorrhages
cotton wool spots
pertchur flacken - polygnal layers of retinal whitening with a clear demarcating line
give examples of 3 traumatic and 5 non traumatic causes of Pertschur’s Retinopathy
Traumatic
- head trauma
- chest compressions
- fracture of long bone e.g. femur such as from orthopaedic surgery or weight lifting
Non traumatic
- acute pancreatitis
- pancreatic adenocarcinoma
- fat embolism
- preeclampsia
- globulinemia
how many % of Pertschur’s Retinopathy is bilateral and what type of visual issues does a person have with it
60%
Reduced VA associated with VF loss, centrally, paracentral, or arcuate scotoma - peripheral VF is usually preserved
list 4 types of vascular occlusions
Central Retinal Vein Occlusion CRVO
Branch Retinal Vein Occlusion BRVO
Central Retinal Artery Occlusion CRAO
Ocular Ischaemic Syndrome
what is the incidence of CRVO
what % of CRVO px’s have the contralateral eye affected and within how many years
what mean age group of px’s are affected by CRVO
Incidence 2-8/1000
5-10% contralateral eye affected within 5 yrs
Mean age 60-70 years
what is the aetiology of a CRVO
Multifactorial
• Compression by a sclerotic central retinal artery & cribiform plate
- Haemodynamic disturbances leading to stagnation and primary thrombus formation
- Degenerative/inflammatory disease within the vein e.g. sarcoidosis
list 6 systemic risk factors of a CRVO
- Arterial hypertension
- Cardiovascular disease
- Diabetes Mellitus
- Obesity
- Hyperlipidemia
- Smoking
list 5 Thrombophilia causes of a CRVO
Hyperhomocysteinaemia Anti-phospholipid syndrome Increased APC resistance Increased haematocrit Increased plasma viscosity
list 7 local/ocular risk factors of a CRVO
- Glaucoma
- Retinal vasculitis
- Central artery occlusion
- Drusen
- Papilloedema
- Arteriovenous malformation
- Trauma
list 4 Hyperviscosity (abnormalities in the blood) syndrome causes of a CRVO and what investigation should take place due to this
Polycythemia
Macroglobulinaemia
Myeloma
Leukaemia
a blood count should be done urgently
list 3 investogations/tests to differentiate between ischaemic and non ishaemic CRVO
Visual acuity
RAPD
Fluorescein Angiography
how can you investigate the extent the of blurred vision with a CRVO
Determine if macular oedema using OCT
what 3 conditions does a medical work up from a CRVO look for
hyperlipidemia
hypertension
diabetes
what 3 other ocular conditions should you look out for after seeing a CRVO
neovascularisation - 90 day glaucoma - from blockage of the trabecular meshwork
vitreous haemorrhage
retinal detachment
which type of CRVO can cause 90 day glaucoma
ischaemic CRVO
list 2 possible treatments for macula oedema from a CRVO
Anti VEGF
Intravitreal steroid - if don’t want to give anti VEGF to someone who has had a stroke
e.g. Ozurdex - longer acting steroid
what test should be carried out with a CRVO to rule out ischaemia and why
FFA
as OCT alone does not tell us about the full perfusion of the retina
what condition should you suspect if you see a CRVO like this and what clinical signs suggest this
Leukemia
haemorrhages around the optic disc with a white centre = underlying haematological disorder
what types of VA do 90% of people with a CRAO get
CF to PL
which type of artery occlusion does a px with NPL and no cherry red spot have
ophthalmic artery occlusion
what causes a cherry red spot in a CRAO
a continued blood supply to the choroid from the ciliary artery = bright red colouration to the thinnest part of the retina at the macula
list 6 causes of a CRAO
Giant cell arteritis - in older patients Embolus formation Systemic hypertension Diabetes mellitus Cardiac valvular disease Cardiac anomalies
what is the most common cause of an embolism causing a CRAO
list 3 other less common causes
Cholesterol is the most common type
but it can also be from:
calcium, bacteria, or talc from intravenous drug use
what is the leading cause of CRAO in patients aged 40-60 years and how many px’s with this type of cause does it account for
Atherosclerotic disease
Carotid atherosclerosis is seen in 45% of cases of CRAO
what is a common etiology of CRAO in patients younger than 30 years
A hypercoagulable state
such as in patients with sickle cell anemia, polycythemia, or antiphospholipid syndrome or in those taking oral contraceptive
name a secondary cause of a CRAO in young patients
Hyaluronic acid fillers
causes bilateral CRAO and brain infarction/stroke
how to the retinal veins and arteries appear after a CRAO
“Boxcarring” appearance of the impaired blood column can be seen in both arteries and veins
list 3 medical treatments that should be done as soon as a CRAO is detected and why
Ocular massage - to dislodge the embolus
Anterior chamber paracentesis - needle into ant chamber to reduce the IOP and facilitate perfusion of the retina
Medical reduction of intraocular pressure e.g. diamox & facilitate perfusion of the eye
what can occur in 4-5 weeks after a CRAO event and in how many % of people
Neovascularization of the iris occurs in 20% of patients
what condition is panretinal photocoagulation is effective in after a CRAO and in how many % of these patients
iris neovascularization in 65% of patients
what is the mortality rate and over how many years in Patients with visualized retinal artery emboli, regardless of the presence of obstruction?
compared to how many in an age-matched population without retinal artery emboli?
56% mortality rate over 9 years
27% in an age-matched population without retinal artery emboli
what is the life expectancy among patients with CRAO compared to an age matched population without CRAO
5.5 years compared to 15.4 years in an age-matched population
