anterior segment trauma 2

What are the initial assessments for trauma to the globe

1. Determine the nature of the injury

2. History of the injury = timing and likely object

3. Thorough examinations of the eye and globe

What is blunt trauma and what happens to the eye?

Anterior - posterior compression of the globe with equatorial expansion

• severe increase in IOP as aqueous is forced into peripheral anterior chamber

• Impact often absorbed by iris and lens but damage can occur at distant site (posterior pole)

• If severe enough, globe may rupture at weakest point

• Typical globe rupture is posterior to recti muscle insertions.

What are the signs of blunt trauma?

1. Traumatic mydriasis

2. Accommodative (ciliary) spasm

3. Traumatic iritis

4. Iridodialysis

5. Cyclodialysis

6. Angle recession

7. Hyphaema

8. Vossius ring

What is traumatic mydriasis (sign of blunt trauma)

1. Initially a transient meiosis followed by partial mydriasis with poor pupillary reaction to light and near

2. D shaped pupil

3. Vossius ring: imprint of miotics pupil on anterior lens capsule

4. Iris sphincter tears

5. Iridodialysis

6. Angle recession

7. Hyphaema

Accommodative (ciliary) spasm (sign of blunt trauma)

1. Dull aching pain and photophobia

Traumatic iritis (sign of blunt trauma)

1. Initially vasospasm of anterior uveal vessels followed by hyperpermeability

2. Maybe 3-4 days after initial injury

Iris sphincter tears (sign of blunt trauma)

• glare, change in pupil shape, monocularly diplopia, light sensitivity

Iridodialysis (sign of blunt trauma)

• shearing of iris from ciliary body at iris root

• Rarely needs treatment, unless px has uniocular diplopia, debilitating glare

What can angle recession predispose to?

Glaucoma. Uncommon if recession is less than 180 degrees, however up to 10% can develop glaucoma if recession is more than 180 degreees.

• Avoid gonioscopy for 4-6 weeks following acute trauma.

What is hyphaema?

Common sign of blunt trauma, is a haemorrhage to the anterior chamber = red blood cells sediment inferiorly with resultant ‘fluid level’

What is the treatment and management of hyphaema?

1. In most cases only observation if required.

2. Risk of secondary haemorrhage where it is larger than original hyphaema and occurs at anytime up to a week (first 24hr is most common).

• critical period is 3-5 days after initial hyphaema.

• treat with atropine to keep pupil immobilised and dilated = prevents further haemorrhage

Hospital admission especially if child (running around a lot) or px with hyphaema larger than 50%, to monitor IOP

What is cyclodialysis?

When a portion is ciliary body is detached from sclera.

What are the effects of a cyclodialysis?

1. causes eye pain, tenderness, decreased VA

2. Severe hypotony (abnormally low IOP)

3. Blurred vision with a myopic shift

4. Ciliary body may have ciliary shock = reduction in aqueous production

What are the results of a lens trauma?

1. Vossius ring

2. Lens subluxation or luxation

3. Cataract formation

Usually unilateral and commonly caused by sports, vehicle accidents

Lens subluxation or luxation due to lens trauma

• subluxation can cause change in astigmatism

• Iridodonesis = lack of support to iris causing lens to become tremulous (quiver/shake)

Cataract formation due to lens trauma

• posterior subcapsular cataract along posterior Y sutures

• Traumatic rosette cataract

When can the signs of lens trauma be seen?

• usually has an early appearance, within hours to months after trauma

• Can be delayed by more than 6 months.

How does radiation (type of lens trauma) affect lens?

• affects the epithelial cells

• Posterior subcapsular cataracts where there are opacification along posterior pole.

What are the affects of FB (another type of lens trauma) to lens?

Iron deposits embedded in tissues and bathed by aqueous can cause Siderosis bulbi.

What is siderosis bulbi?

Gives rust coloured anterior subcapsular deposits.

• can cause heterochromia (affected side is darker) and pupillary mydriasis

• If goes in posterior segment = depressed electroretinogram (ERG) amplitudes.

• Other potential consequences: pigmentary retinopathy, retinal microangiopathy + open angle glaucoma.

If cataract + FB removed, no macular trauma = visual prognosis is good.

What occurs due to penetrating injury (another type of lens trauma) to the lens?

• capsule may heal after small penetration but will give localised opacity - capsular and cortical

• Water influx to fibres.

Orbital fractures

1. Blow out orbital floor

2. Blow out medial wall

3. Roof

4. Lateral wall

Blow out orbital floor fracture

A sudden increase in orbital pressure due to an object larger than 5cm striking orbit.

• lateral wall and roof withstand pressure

• Most common

Blow out medial wall fracture

Also common, often associated with floor fractures as medial wall and floor are more fragile.

• isolated is less common

Roof orbital fractures

• least common

• Due to falling on sharp object or blow to forehead - very dangerous as can have leakage of cerebral spinal fluid

Lateral wall orbital fracture

• Least commonly seen, as the lateral wall is the strongest

• Usually associated with extensive facial injury

Signs of a blow out orbital fracture

1. Preorbital ecchymosis (bruising of the lid)

2. Oedema (swelling of the lid)

3. Subcutaneous emphysema

4. Infraorbital nerve anaesthesia

5. Enophthalmos

What is subcutaneous emphysema

• Crackling noise if press around orbital rim indicates there is air that has escaped from sinus

What is infraorbital nerve anaesthesia

• Anaesthesia to cheek, lower lid, side nose, upper lip, upper teeth and gums

• Must check if these locations are feeling numb

What is enophthalmos

• Eye being sucked in, present when blow out fracture is severe

• May be present once oedema has been resolved

• May increase as post traumatic degeneration and fibrosis develop

What are the 2 causes for diplopia from a blow out fracture?

1. Haemorrhage and oedema of orbit causes septa connecting inferior oblique and inferior recuts to tighten = mechanical restriction, resolves and doesn’t require surgery

2. Mechanical entrapment of IR and IO, or adjacent CT and fat in fracture - may improve if entrapment of fat only and persists if muscles are involved. Requires surgery

What is the treatment for a blow out fracture?

Initial treatment with antibiotics to stop infections.

Don’t blow nose! - due to connection to sinuses which can increase swelling or cause movement.

Surgical repair if required, after oedema (swelling) has resolved.

• prevents permanent vertical diplopia

• Cosmetics

Orbital roof fracture

1. Haematoma of upper lid

2. Periocular ecchymosis - developed after a few hours, spreads to opposite side + panda eyes

3. Affected eye is slightly depressed compared to unaffected eye

4. Pulsation of globe due to transmission of CSF pulsation

Signs and symptoms of intraocular FB

1. Subconjunctival and vitreous haemorrhage

2. Iris transillumination defect

3. Hyphaema

4. Focal lens opacity

5. Corneal or scleral laceration

6. Capsular defect

7. Focal corneal oedema

What appearance does high copper content (intraocular FB) give?

Endophthalmitis like appearance

What does the intraocular FB, copper alloy, cause?

Brass, bronze colour.

• Kayser-Fleischer’s ring

• Anterior sunflower cataract

• Plaques of copper in the retina

What is a carotid-cavernous fistula?

Abnormal communication between carotid artery and cavernous sinus

• blood within vein arterialised where venous pressure rises, venous drainage is altered

• Glaucoma from raised pressure

What are the two types of carotid cavernous fistula?

1. Direct

2. Indirect

What is a direct carotid cavernous fistula?

“High flow” trauma.

• when there is a spontaneous rupture of the intracavernous aneurysm or artheroscleric artery (common in menopause women)

• when carotid artery blood flows to cavernous sinus through defect in wall of intracavernous section

What is an indirect carotid cavernous fistula?

Slower blood flow trauma.

More common in older px as developed slowly.

• when arterial blood flows indirectly to cavernous sinus from meningeal branches of external or internal carotids

• Often doesn’t require tx

Sympathetic ophthalmitis

Very rare, typically after a penetrating or perforating trauma. Also after vitrectomy.

• usually occurs months after trauma - 90% after 12 months.

• has ‘exciting’ eye and ‘sympathising’ eye

What is an ‘exciting’ eye?

The eye that shows evidence of initial trauma, red + irritable (had trauma)

What is the ‘sympathising’ eye?

Unaffected eye that becomes photophobic and irritable overtime.

It can develop:

1. Bilateral granulomatous anterior uveitis

2. Vitritis

3. Posterior uveitis - yellow/white lesions, Dalen-Fuchs nodules and swelling of nerve