Week 6- Ocular Trauma:- Flashcards
Incidence of ocular trauma:- scotlanc/usa
• Scotland Incidence of trauma: 5million pop/428 admisions 1991-1992
- Incidence 1.96 per 100k
• US: 2.4m eye injuries annually, 1m permanent significant visual impairment, 75% blind in one eye
- Second most common cause of visual impairment after cataract
Ocular trauma classification:-
•Non-mechanical trauma:
- Chemical
- Thermal
- Electrical
- Radiation
• Mechanical Trauma:
- Contusion
- Perforation
Mechanical Injury Clinical classification:-
• Closed Globe
- Contusion
- Lamellar laceration
• Open Globe
- Lacerations
~ Penetrating
~ Perforating
~ IOFB
- Rupture
Eye trauma Glossary definitions:-
• Eyewall
• Closed globe
• Open globe
• Eyewall - Sclera and Cornea
• Closed Globe - No full thickness wound of eyeball
• Open globe - Full thickness wound of eyeball
Eye trauma Glossary definitions:-
• Contusion
• Lamellar laceration
• Rupture
• Contusion: No full thickness wound
• Lamellar laceration: Partial thickness wound of eyewall
• Rupture: full thickness wound of eye-wall, caused by blunt object
Eye trauma Glossary definitions:-
• Laceration
• Penetrating Injury
• Perforating Injury
• Laceration: Full thickness wound of eye-wall, caused by sharp object
• Penetrating Injury:
- Entrance wound
- Retained foreign object/s
• Perforating Injury
- entrance and exit wounds: causes by same agent
Severity can be classified by and factors:-
• Mild to severe
• Risk of blindness
• Risk dependent on number of factors:-
- Type of injury
- Time passed before treatment initiated (e.g chemical)
- ocular structures affected
Chemical Injury:-
• Most destructive
• Occur at work or home
• Severity depends on form of chemical:-
- Liquid, vapour, gas or solid.
• Extent of damage depends on time of exposure
• 2/3 occur at home
- Usually accidental
Chemical injury - Types
- Alkalis - cleaning substances
- Acids - car batteries
- Organic solvents - Units in paints etc
- Surfactants (wetting agents): in soaps and detergents
- Aerosols: powders, or droplets, suspended in a gas
Alkali Burn:-
• Most severe
• Alkalis tend to penetrate tissue deeper than acids
• Alkali injuries twice as common as acid burns
• Alkali commonly used in household cleaning agents
Alkali Injury Grading:-
- Grade I - Clear cornea, no limbal ischemia
- Grade II - Hazy cornea, visible iris, < 1/3 limbal ischemia
- Grade III - Opaque cornea, stromal haze, iris details obscured, 1/3 - 1/2 limbal ischemia
- Grade IV - Opaque cornea, iris details obscured, > 50% limbal ischemia
Acid burns:
• Potentially less severe than alkali
• Do not affect deeper tissue layers
• Clinical features are generally similar to alkali injuries:
- lid oedema (swelling)
- generalised redness
- Small conjunctival haemorrhages
- Conjunctivitis
• Prolonged exposure may cause:
- ulceration and opaqueness of corneal and conjunctival epithelium
- Permanent haze and vascularisation
Organic solvents:-
Do not usually cause permanent damage
May cause:
- Irritation
- Punctate keratitis (epithelial)
- Stromal damage
- Lacrimation
- Pain
- Photophobia
- Stinging
Chemical injury - Management
• emergency treatment
• Irrigation is vital
- Neutralise pH before history, with copious irrigation, using saline 15-30mins, if not tap water. Evert eyelids, remove particles and apply topical anaesthetic for comfort
Chemical Injury - Treatment by medicine (5)
• Topical antibiotics such as Prophylaxis
• Topical steroids to reduce inflammation: but reduces healing
• Topical cycloplegia
• Topical lubricants
• Oral analgesia
All topical treatment should be preservative free if possible
Chemical Injury - Alternative Treatment: (3)
• Elevated IOP : treatment indicated
• Ascorbic acid (topical and systemic) improves wound healing
• Topical citric acid (sodium citrate) - inhibits neutrophil activity, reduces inflammation
• Surgery, e.g penetrating keratoplasty for opaque corneas
Blunt Trauma:-
• Often caused by flying blunt obiects
• Rugby/ football injury - elbow
• Ocular damage may be the result of wave forces travelling through the liquid contents of the eye
• This may cause an explosive force within the globe
• Commonly associated with more complex injuries
Blunt trauma - clinical features: Anterior segment
- Corneal abrasion
- Corneal oedema
- Hyphaema
- Miosis
- Mydriasis
- Cataract
Blunt trauma - clinical features: Posterior segment
- Posterior vitreous detachment
- Retinal oedema
- Retinal breaks
- Macular holes
- Choroidal rupture
- Traumatic optic neuropathy
Traumatic Optic Neuropathy:-
•Caused by transmission of force through the orbital bones due to a trauma to the orbit, forehead, or brow:
- shearing of optic nerve fibres
- haemorrhage
- optic nerve oedema
- vision loss
Fractures of the orbit:-
• Caused by blunt trauma
• Involved broken orbital bones
• Symptoms include:
- Swelling of eyelid
- Bruising around the eye
- Eye pain
- Double vision
- Reduced motility of the affected eye
Fracture of orbit: Blow-out fracture:-
• Specific type: Blow-out fracture:
- Orbital floor or medial wall affected
- Muscle may get trapped in fracture
- Motility problems, esp. when looking up
- Diplopia possible
- Painful
- Patient may have nosebleed
Blunt trauma - management
• Primary repair globe
• Secondary: surgical repair of iris, lens or other affected structures
- All HES
Anterior segment of eye - Damages to cornea, conjunctiva, anterior chamber, iris and lens examples
• Cornea:
- Superficial foreign body (common)
• Conjunctiva:
- Sub conjunctiva haemorrhages can occur, not sight-threatening, referral not essential
• Anterior chamber:
- Hyphaema is potentially more serious
- May cause secondary glaucoma
• Iris:
- Iris damage may give rise to traumatic mydriasis or traumatic miosis (temporary or permanent)
- Patients may experience glare
- Angle recession and glaucoma may develop
• Lens
- Dislocation possible
