disorders of vitreous and vitreoretinal interface

Vitreous anatomy

Transparent avascular and jelly like

Occupies 67-75% eye volume (4l)

Function of vitreous

Acts as shock absorber

Give shape to eye

Provides optical clarity

Acts as shock absorber

Inhibits neovascularisation

Anatomical points on vitreous

Vitreous cortex/posterior hyaloid surface

-strong vitreoretinal adhesion at certain points

What are the certain points of adhesion

Vitreous base - optic nerve - scars - blood vessels, macula

What happens in the ageing vitreous

Liquefaction

Increase in fibre density

Shrinkage(syneresis)

Explain liquefaction (synchysis)

Increases by 2nd decade

-lacunae (fluid filled spaces) develop increase in size and coelesce

-by 70 years =50% liquefaction

Explain the increase in fibre density

Increases by 40yrs

-collagen forms clumps which reduce light transmission

-vitreous strands and floaters

Explain syneresis (shrinkage)

Vitreous pulls away from retina - PVD posterior vitreous detachment

NB - areas of strong vitreoeretinal adhesion can lead to abnormalities

What are vitreous floaters

Benign

-small dark or translucent dots/filaments

-occur all age groups

Causes of floaters

Most often are due to normal ageing vitreous

-earlier in myopes, trauma, inflammation

-keep in mind serious cases , when floaters present with symptoms

Symptoms of floaters

Report floating object

-dots

-lines

-spider web

-shapes

-most obvious against white background

Signs of floaters

Not always detectable with opthalmoscope

How do we manage floaters

Reassurance main therapy

-can be surgically removed if troublesome

Congenital vitreous anomalies

Persistent hyaloid artery

Mittendorf dot

Bergmeisters papillae g

Mittendorf dot

Mittendorf dot

Bergmeisters papilla

Persistent hyaloid artery regression

-coming from the disc -with or without blood

What is Mittendorf dot

Small opacity on posterior lens capsule

-benign no treatment needed

Bergmeister papilla

Clump of glial tissue on disc (white part on image)

-benign , no treatment needed

Gilal remnants

Hyaloid artery remnant

Vitreous abnormalities

-persistent foetal vasculature

Vitreous cysts

Asteroid hyalosis

Synchysis scintilans

Vitreous haemorrhage

Persistent foetal vasculature

Incomplete regression can also lead to PHPV (persistent hyperplastic primary vitreous

-also leads to fibrovascular proliferation

-due to abnormality during development not due to remnants left over

Affects vision

Where does the anterior form

Around the lens

How do we manage this

Immediate referral and treatment by paediatric ophthalmologist

What else does persistent foetal vasculature associate with

Other congenital anomalies

-cataract

-glaucoma

-microphthalmos (small eye)

What do persistent hyperplastic primary vitreous look like

Vitreous cysts

Very rare

Incidental finding or associated w ocular pathology

Image vitreous cysts

Congenial Vitreous cysts -located?

Hyaloid canal

-are non pigmented pearly grey smooth surface

What are congenital ones normally associated with

Mittendorfs dot

Bergmeister papilla

Acquired vitreous cysts - caused by?

Trauma inflammation infection

Retinal disease (RP, choroidal atrophy)

-retinal detachment surgery

Usually reduced VA

Asteroid hyalosis

Can be called bensons disease

-common in > 55 year olds and unilateral

-static - so when px looks around they remain in same space

What are they

Small yellow white spheres

Composed of calcium phospholipid complexes suspended through vitreous and is stable

What are the symptoms

Usually asymptomatic

No effect on vision

Self limiting

Benign

What is the recall

Routine review px

Asteroid hyalosis retinal view

Synchisis scintillans

Rare

-looks similar to asteroid but is mobile in the vitreous

What are they

Numerous reflective small angular yellow crystals floating in vitreous

-vitreous is fluid and crystals floating around in shower then settle to bottom of vitreous

What are they composed of

Cholesterol (not associated with high serum cholesterol )

Symptoms

Asymptomatic

Through to follow trauma or inflammation

Image of synchisis scintillans

Anatomy of vitreoretinal interface

Where vitreous meets the retina

Vitreous cortex is adjacent to internal limiting membrane ILM

-molecular glue between the two (composed of collagen fibrils ,lamamin , fibronectin)

-these substances keep retina and vitreous in place

-chondroitin Sulfate present at site of strong vitreoretinal adhesion

Image of vitreoretinal interface

Disorders of the vitreoretinal interface

Vitreous haemorrhage

Posterior vitreous detachment

Types of vitreous haemorrhage

Intraretinal - have shape to it, no pooling

Pre retinal haemorrhage -spread out and smooth , pooling blood darker cool

Vitreous haemorrhage - woolly appearance

Causes of vitreous haemorrhage- how blood enters vitreous

Through disc vessels, retinal vessels, choroid

Causes of vitreous haemorrhage

Diabetic retinopathy mainly

Trauma

Retinal tear or detachment

Posterior vitreous detachment

What are the other causes

Retinoschisis

Vein occlusion

Sickle cell retinopathy

AMD

Symptoms of V haemorrhage

-painless loss of vision

-sudden increase no. And size of floaters

-blurry hazy vision -small bleed

-large bleed may obscure vision

Px examination for those w V haemorrhage

VA

Slit lamp

Eye pressure

Dilate eye

Gonioscopy

B scan ultrasound

Signs of haemorrhage - non dispersed

Non dispersed - so would be pre retinal haemorrhage

Clear red haemorrhage, dense dark red patch

-boat shaped

Image of non dispersed haem

Dispersed haem

Blood dispersed through the vitreous

Prognosis of V haemorrhage

Depends on the cause

-fibrovascular proliferation can result which can lead to scarring and contraction = retinal detachment

How do we manage this

Emergency same day referral

Secondary care to V haem

B scan

Gonioscopy IOP

Treat cause

Monitor or vitrectomy -remove vitreous

Posterior vitreous detachment (will see more frequently)

Separation of vitreous cortex and neurosensory retina

-age changes as vitreous shrinks

Incomplete PVD

Involves posterior region , still some attached

Complete PVD

Mostly detached except ora serrata (not detached from ora serrata)

-common in 80 + years

Onset = 60-70 years

What is complete PVD associated with

Myopia trauma or inflammation

Symptoms of PVD

Floaters - cobwebs , spots (not usually a shower as this indicates retinal problem)

-change position w eye movements

-photopsia = flashes of light esp in dim lights and in temporal VF

-metamorphopsia -less common, happens if vitreo retinal traction at macula

Signs of PVD

Weiss ring - grey black annular ring (vitreous pulled away from optic disc), can sometimes see posterior hyaloid face

-can be complete or incomplete

-visible position hyaloid face seen

-causes peripheral pre retinal and disc margin haemorrhages

Images of weiss ring

Complications of PVD

-strong associations wit retinal tears and detachment which is cause of flashes

(Risk is greatest in first 6-8 weeks)

-shaffer sign - tobacco dust - RPE cells in anterior vitreous 90% have retinal break

-vitreous haemorrhages 70% have retinal break

-macular hole formation -tractional, vitreous pulls away from retina can also pull part of macular

NICE guidelines -Same day referral

With VF loss

-with fundascopic signs of retinal detachment or vitreous haemorrhage

NICE guidelines - urgent referral

If flashes floaters present but NO VF loss, no changes in VA and no ret detachment of haemorrhages in vitreous

=urgent referral only

What advice do you give to px about retinal detachment if suspected

Contact DVLA if VF defect or have had retinal treatment in both eyes

-advice on early warning signs of possible future retinal tear/detatchment and the need for immediate opthalmoscopy assessment

-advice px to wear eye protection when doing risk sports, reduce risk of future eye injury