History and Examination in Ophthalmology

Report
Flashes and Floaters
Hong Woon
SJUH
Flashes and Floaters
Flashes AND Floaters
occurring together
• Virtually pathognomic for
Posterior Vitreous Detachment
Flashes and Floaters
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ΔΔ Flashes or Floaters
Posterior Vitreous detachment
Migraine Aura
Other causes of flashes and
floaters
• Taking a history of flashes or
floaters
• When to refer
Flashes
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or
PVD
Disciform
Choroidal melanoma
CMV retinitis
CRVO
Digoxin toxicity
Optic nerve compression
Optic neuritis
AION
Pituitary tumour
Migraine Aura
Charles Bonnet Syndrome
Floaters
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Vitreous syneresis
PVD
Vitreous haemorrhage
Asteroid hyalosis
Posterior uveitis
Entopic phenomenon
CMV retinitis
• Know how to diagnose confidently
– PVD
– Migraine aura without headache
• High index of suspicion not PVD or
migraine aura if:
– Unusual features to flashes or floaters
– Other symptoms
Posterior Vitreous Detachment (PVD)
• Anatomy of vitreous
• Mechanism of PVD
• Epidemiology
• Symptoms
• Signs
• Complications
Anatomy of vitreous
• Mainly water (99%)
• Collagen filaments
and hyaluronic acid
• Strongly attached at
vitreous base
• Firm attachments at
optic disc
• Attachments to retina
decrease with age
Vitreous degeneration and syneresis
• Depolymerisation of
hyaluronic acid
– Release water
– Pockets of liquefied vitreous
• Collagen filaments
aggregate
– Fibrils
– Collapse of gel (syneresis)
– Visible as small floaters
Posterior Vitreous Detachment
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Posterior vitreous
detached from retina
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Accumulation of lacunae
Fluid escapes into
retrohyaloid space
Large floater
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Weiss’ ring
Posterior hyaloid
membrane
PVD: predisposing factors
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Age
Myopia
Cataract surgery
Trauma
Posterior uveitis
PVD: natural aging change
60
50
Percent
with PVD
40
30
20
10
0
< 50 yrs
50 - 60
60 -70
> 70
Age yrs
• If PVD present 73% chance of PVD in fellow eye if
greater than 60 years of age
Symptoms of PVD
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None
Flashes alone
Floaters alone
Flashes and Floaters
Symptoms of complication
– Vitreous haemorrhage
– Retinal detachment
Photopsia from PVD
• Peripheral arcs of light (Moore’s lightening
streak)
• Occurs on eye movement
• Dim – seen best in dim lighting
• Very brief, but recurrent
• Usually precedes onset of floaters
• May persist for months or years
Floaters from PVD
• Sudden onset floater
• Much more prominent than small
floaters from vitreous syneresis
• Due to Weiss’s ring or prominent
posterior hyaloid membrane
• May be described as curtain or
shadow or blurring of vision
• Can see through curtain or around
shadow
Acute complications of PVD
Vitreous haemorrhage Retinal tear
Retinal detachment
Symptoms of Vitreous
haemorrhage
• Little spots/ Rain drops/ Sand
storm
– Due to seeing individual red
cells
• Black streaks
– Streaks of blood
• Extensive loss of vision
– Large vitreous haemorrhage
• Increased risk of retinal tear
and retinal detachment
Symptom of Retinal tear
• No symptom from tear alone
• ~ 50% risk progression to
Retinal detachment
• May be associated with
small vitreous haemorrhage
Retinal detachment?
• Retinal tear allows retina to separate from retinal pigment
epithelial layer
• Retina dependant on RPE and choroid for function
• Detachment gives rise to loss of function of detached area.
Symptom of Retinal
Detachment
• Shadow
• Progressive
• Requires urgent
surgery
• Visual prognosis best if
macula not detached
Symptomatic Posterior Vitreous Detachment
• Risk of developing retinal tear ( ~ 8%)
• Risk of developing RD: 3 – 7% in symptomatic PVD
• If RD develops, it usually occurs within 6 weeks
Migraine aura without headache
• Any age but more common with increase
age (~ 1% > 50 years of age)
• 77% first occurrence after 50 years of age
• 42% no history of migraine
• 44% migraine with aura sufferers report
aura without headache at times
Migraine aura
without headache
• Wave of depolarisation
across cortex including
occipital lobe
• Slowly evolving nature
of visual symptoms
Forms of migraine
aura
• Photopsia
– Unformed flashes of light
• Fortification spectrum
– White or coloured
• Scotoma
– Often crescent shaped and
shimmering
• Heat waves/ blurring/
hemianopsia
Migraine aura
• Dynamic: grows and moves across visual field
over minutes
• Hononymous but may be difficult for patient to
appreciate
• Spectrum of patterns but usually more formed
than photopsia due to PVD and may be coloured
Other Conditions
Atypical flashes or atypical floaters or other
symptoms
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Optic neuritis
Photopsia and blunt trauma
Toxic, inflammatory or inherited retinal conditions
CMV retinitis
Vitreous syneresis
Asteroid hyalosis
Posterior uveitis
Optic neuritis
• Photopsia present in
70%
• Sparks Flickering
peripheral vision
• May be precipitated by
eye movement
• Main symptom will be
blurring of vision
Photopsia following
blunt trauma
• Indicates VR traction
• Can develop retinal
tears without full
PVD
• Must examine retinal
periphery
Toxic, inflammatory,
inherited retinal
conditions
• Small,
shimmering,
blinking lights
• In affected field
of vision
• Persistent
CMV retintis
• Flashes
• Floaters
• Vision not affected
until macular involved
• Only in HIV or
immunosuppressed
patients
Vitreous syneresis
• Small multiple
floaters
• Lines / tadpoles
• Seen best against
bright background
• Move with eye
• Increased with
myopia
Asteroid hyalosis
• Uncertain pathogenesis
• Degeneration
– Age > 60 yrs
– Calcium laden lipids
• Usually unilateral
• Remarkably few
symptoms
Posterior uveitis
• Idiopathic /
toxoplasmosis
• Very large numbers of
small spots – individual
cells
• + larger floaters
• Similar symptoms for
small vitreous
haemorrhage
Taking a history
of flashes of light
• What are the flashes of light like?
– Arc of light / jagged / colours / brightness
– Where in the vision are they?
– How long does it last for?
– How does it develop?
– Is the vision affected?
• When do the flashes occur?
– Eye movement
– At night
• Timing?
– How often do they occur?
– When did they first start?
• Associated features?
Taking a history
of floaters
• What are the floaters like?
– Size?
– Number?
– See through?
– Movement?
• Are there any flashes of light?
• Is the vision affected?
• Timing
– When did they start?
• Associated features?
– Retinal detachment
– Myopia
– Eye surgery
Why refer PVD?
• To exclude retinal tear / retinal detachment
• Retinal tear should be treated before retinal
detachment develops
• Retinal detachment should be treated before
macular involvement
• Surgery may be considered for floater in
exceptional cases with persistent symptoms
When to refer PVD?
• Symptoms of vitreous haemorrhage
– Rain drops / dark streaks
• Symptoms of retinal detachment
– Shadow
• Recent history
– < 6 weeks
• High myopia / history of RD in fellow eye
What do we do with PVD?
• Dilated examination
– Confirm diagnosis
– Exclude retinal tear / retinal detachment
• Discharge
– Advised to return if new symptoms (increase in
floaters/ shadows)
– Surgery for floater only in exceptional cases
and only when symptoms persist
Summary
• Flashes and floaters often due to PVD
• Flashes alone may be due to migraine aura
without headache
• Small risk if retinal tear and retinal
detachment
• Ask for symptoms or history which may
increase risk of retinal tear/ retinal
detachment
• Risk of retinal detachment considerably
reduced if symptoms greater than 6 weeks

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