Flashes and Floaters

Hong WoonSJUH

Flashes and Floaters

Flashes AND Floaters occurring together

• Virtually pathognomic for Posterior Vitreous Detachment

Flashes and Floaters

• 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 or Floaters

• PVD• Disciform• Choroidal melanoma• CMV retinitis• CRVO• Digoxin toxicity• Optic nerve compression• Optic neuritis• AION• Pituitary tumour• Migraine Aura• Charles Bonnet Syndrome

• 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

• Posterior vitreous detached from retina

– Accumulation of lacunae– Fluid escapes into

retrohyaloid space

• Large floater – Weiss’ ring– Posterior hyaloid

membrane

PVD: predisposing factors

• Age

• Myopia

• Cataract surgery

• Trauma

• Posterior uveitis

PVD: natural aging change

0

10

20

30

40

50

60

< 50 yrs 50 - 60 60 -70 > 70

• If PVD present 73% chance of PVD in fellow eye if greater than 60 years of age

Percent with PVD

Age yrs

Symptoms of PVD

• 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 othersymptoms

• 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