Visual Failure for Medical Finals (based on Newcastle university learning outcomes)

8/14/2019 Visual Failure for Medical Finals (based on Newcastle university learning outcomes)

1/13

Hospital Based Practice Visual failure & traumaAcute visual failure.

Causes of acute visual failure.

Migraine

Retinal and optic nerve vascular occlusions Inflammation of optic nerve

Haemorrhage (retinal or vitreous)

TIA and stroke

Acute glaucoma

Retinal detachment

Migraine

Can be classic migraine, with headache symptoms.

Migraine aura, without proceeding headache, is common in eye departments.

Aura lasting about 15 minutes.

Management. Investigate to rule out other pathology.

Investigate a diagnosed migraine if there is.

Other neurological symptoms.

No previous history of migraine.

Worsening symptoms and attacks.

Once investigations have ruled out serious pathology, reassure and discharge.

Central retinal artery occlusion.

Clinical picture.

Sudden onset. Painless

Profound visual loss

Drop to about 6/60.

Afferent pupil defect.

Pale retina

Thread like arteries.

Cherry red spot.

Classical sign on fundoscopy.

Red spot is the healthy area, the paleness surrounding it is abnormal.

Fundoscopy showing pale retina with cherry red spot.


2/13

Management.

Have to act within 4 hours to avoid permanent damage.

Try to convert to Branch radial artery occlusion.

Ie. Push embolus further along the artery.

Will still cause retinal infarction, but in a smaller area than if condition was left

untreated.

Reduce intra optic pressure.

Vasodilate.

5% carbon dioxide

Re breath into paper bag.

Prevent further episodes.

Aspirin

Check for risk factors.

Hyperviscosity

Carotid bruits.

Partially treated CRAO, with infracted pale area in middle of image but reperfused pink areas around edges.

Central retinal vein occlusion.

Gradual onset, over hours.

Painless

Variable visual loss.

6/6 6/60

Severe cases show afferent pupil defects.

Fundoscopy

Flame haemorrhages scattered throughout retina

Tortuous vessels

Congested disc.

Milder CRVO with few haemorrhages Severe CRVO, with multiple haemorrhages and congested disc.


3/13

Investigations.

Check BP

Check for hyperviscosity.

Decide if it is ischemic. Multiple deep, round haemorrhages.

APD.

Management.

If ischemic.

Lasar PRP

If non ischemic.

Regularly review to check that it isnt progressing.

Branch retinal vein occlusion.

Clinical picture.

Mild symptoms.

May develop problems in visual fields.

Often found incidentally.

Fundoscopy.

Small area affected

Flame haemorrhages

Vascular tortuosity.

Management.

Discharge.

Macular oedema may need laser treatment.

BRVO showing localised flame haemorrhages.


4/13

Anterior Ischmic Optic Neuropathy.

Clinical picture.

Sudeen onset

Loss of top half, bottom half or total vision. Fundoscopy.

Swollen optic disc.

Haemorrahges around optic disc.

AION with poorly demarcated swollen disc and haemorrhages around disc.

Investigations

Check BP

ESR

Check for hyperviscosity

Fluorescein angiogram.

Will show filling defect on disc.

Management.

Control BP

Aspirin 75 mg OD

Stop smoking.

Optic neuritis.

45 80% of cases are the presenting symptoms of MS.

Clinical picture.

Blurred vision

Colour desaturation

Pain on eye movement. (RBN)

May resolve by the time vision is lost.

Afferent pupil defect.

Swollen disc.

If papilitis

Disc pallor.

Late sign.


5/13

Management.

High dose IV, and then oral, steroids.

May delay onset of full blown MS

|No impact on long term prognosis

Vitreous haemorrhage.

Symptoms. Cobwebs & floaters

Loss of vision.

Signs depend on severity.

Mild Hazy retinal details.

Moderate Dull red reflex

Severe Absent red reflex.

Mild haemorrhage Moderate haemorrhage Severe haemorrhage.

Management

Investigate for diabetes.

US scan. Look for underlying detached retina.

Management

Chair rest.

Watching TV

Allows blood to settle

Vitrectomy if not settling.


6/13

Age related maculopathy.

Clinical picture.

Gradual loss of vision.

Main problem with reading distance vision.

Often co exists with cataracts.

Pin hole makes vision much worse.

Can be dry or wet.

Dry.

Drussen

Pigmentary disturbances

Loss of retinal pigment epithelium

Wet.

Haemorrhage

Retinal swelling/ scarring

Distorted vision

Demonstrated using Amsler grid.

Dry macular degeneration, showing Drusen (soft yellow blobs) and Retinal pigment epithelial disturbance

Wet macular degeneration, showing Drusen and Sub retinal new blood vessels giving retinal swelling

Subretinal neo vascular membrane Disciform macular sac, a consequence of untreated Wet ARMD

Management..

Regular screening.

Once drusen start to appear.

Screen each eye separately.

Show patient graph paper, and check that lines appear straight.

Diet.

Zinc and carotene may help.

Eat diet rich in fruit and leafy vegetables.

May require supplements.

If asymptomatic.

Discharge

If symptomatic and dry. Glasses


7/13

Register as partially sighted.

Refer for welfare advice.

New wet ARMD (particularly if distortion).

Laser photocoagulation.

If new vessels dont extend under centre of retina.

Would cause worsned blindness if used on centre of retina, as destroys

photosensitive cells.

Verteporfin.

If new vessels do extend under centre of retina.

Always worth treating vision, even if it only occurs in one eye.

50% chance of developing bilateral disease.

Dont know which eye will eventually end up worse, so treat when either

deteriorates.

Retinal detachment.

The 4 Fs.

Flashes Floaters

Field loss

Fall in acuity.

Symptoms.

Early Flashes and floaters

Later Curtain descending over vision

Later still Loss of vision.

Signs.

Early.

Retinal tear

Mild vitreous bleed.

Later.

Grey, wrinkled retina.

Flashes.

Due to retinal stimulation.

At low levels of light.

Often related to head movements.

Need to exclude retinal holes.

A shower of new floaters indicates a break.

Flashes being replaced by a large floater indicates PVD.


8/13


9/13

Cataract.

Management.

Day surgery.

History in visual loss.

Time taken for evolution and duration of vision loss can suggest pathology.

Obscurations Seconds

Emboli Minutes

Migraine Up to 15 minutes.

TIA Up to 24 hours.

Vitreous haemorrhage Days Months.

Ocular trauma.

Prevention is key.

Wear goggles or plastic glasses when ne\ar small moving objects or using tools.

Always record acuity in both eyes.

If uninjured eye is blind, take injury VERY seriously.

Take a detailed history of the event.

If unable to open eye.

Instill a few drops of tetracaine 1%.

Comfortable opening should be possible within a few minutes.

Examine, and note any pain or discharge.

Lids


10/13

Conjunctiva

Cornea

Sclera

Anterior chamber

Pupil

Irregular pupil may suggest globe rupture. Afferent pupil defect is a poor prognostic sign.

Iris

Lens

Vitreous

Fundus

Eye movements.

Note any squint.

CT may be useful.

Avoid MRI as foreign bodies may be magnetic.

Penetrating trauma.

Refer urgently.

Delay risks ocular extrusion or infection.

Uveal injuries can cause sympathetic opthalmia in the other eye.

If there is a history of flying objects (work with hammers, lathes and chisels).

Careful examination

X ray to exclude foreign body.

Dont try to remove large foreign bodies outside of theatre.

Support the object with padding.

Transport supine.

Pad unaffected eye. Prevent damage from conjugate movements.

Consider skull x- ray to exclude intracranial involvement.

Foreign body.

Have a low threshold for referral.

Foregin bodies often hide, so examine the whole eye.

Include lid eversion.

Foreign bodies cause.

Chemosis

Subconjunctival haemorrhage

Irregular pupils

Iris prolapsed

Hyphaema

Vitreous haemorrhage

Retinal tears.


11/13

If metal foreign body suspected, send for skull x ray.

With high velocity foreign bodies, consider orbital ultrasound.

Sensitivity is 90%.

Compared with sensitivity of 40% for x ray.

Requires skill to perform.

Removal of superficial foreign bodies may be possible with a triangle of clean card. Follow up with gentamicin 0.3% drops to prevent infection.

Corneal abrasion.

Often due to small, fast moving objects.

Eg. Childs finger nail.

May cause intense pain.

Anaesthetise with tetracaine before examination.

Management

Stain with fluorescein to see extent of lesion.

Apply gentamicin eye ointment and pad the eye.

Send home with analgesics and review in 24 hours.

If foreign body persists at 24 hours, restain

If corneal stains, reapply ointment and pad.

Review in a further 24 hours.

If stains again at 48 hours.

Refer.

Burns.

Treat chemical burns promptly.

Instil anaesthetic drops.

Tetracaine

Every 2 minutes until patient is comfortable.

Hold lids open.

Often patient will not want to open eye due to excruciating pain.

Bathe eye in copious clean water.

Apply specific antidote when it becomes available.

All burns may have late, serious sequelae.

Corneal scarring

Opacification

Lid damage.

Alkali burns are much more serious than acid burns.

Arc eye.

Welders and sunbed users who dont wear protection against UV light.

Due to corneal epithelial damage.

Clinical picture.

Foreign body sensation.

Watering

Blepharospasm

Management.

Instil local anaesthetic drops.

Every 2 minutes.


12/13

Excruciatingly painful, so be generous.

Pain can disappear after as little as two applications.

Apply antibiotic ointment and pad eye.

Should recover within 24 hours.

Fat embolism.

|Consider in trauma patients with sudden onset visual problems.

Contusions and intraocular haemorrhage.

Eyes are well protected by bony orbit.

Contusions to the head by large objects may cause some damage to the eye.

Smaller objects can causes more severe damage and local contusion.

Lid bruising

Subconjunctival haemorrhage,

If limits of haemorrhage cant be seen, consider orbital fracture.

All penetrating eye injuries require immediate specialist referral.

Bruising and haemorrhages should resolve within 2 weeks.

Intraoccular haemorrhage.

Usually affects acuity.

Requires specialist attention.

Blood often found in anterior chamber.

Hyphaema

Small haemorrhages will clear spontaneously.

Still need referral.

May signify significant injury.

If anterior chamber totally filled, evacuation may be required.

Late complications. Glaucoma

Suggested by pain

Corneal staining

Re bleeding

Suggested by pain.

Secondary haemorrhage.

May occur within 5 days of injury.

Can cause sight threatening glaucoma.

Can cause traumatic mydriasis.

Iris paralysed and dilated.

Normally recovers within a few days

Can be permanent.

Vitreous haemorrhages.

Loss of red reflex.

Dramatic loss of acuity


13/13

Sequelae are more common if penetrating object was small rather than large.

Lens dislocation

Tearing of iris root

Retinal detachment

Splitting of choroid.

Damage to optic nerve

Blows to orbit.

Blunt injury (eg. Being hit by a football) can cause sudden increase in ocular pressure.

Can cause blowout fractures.

Orbital contents can herniated into maxillary sinus.

Can cause diplopia.

Teathering of inferior rectus and inferior oblique muscles.

Test sensation over lower lid.

Loss of sensation indicates infraorbital nerve injury.

Confirms blowout fracture.

CT may show depressed fracture of posterior orbital floor.

Fracture reduction and muscle release is necessary.

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Visual Failure for Medical Finals (based on Newcastle university learning outcomes)