Eye Trauma

Retrobulbar hemorrhage/ orbital compartment syndrome

Pathology

• Secondary to Trauma
• Hemorrhage into the potential space within the rigid orbit and around the eye transmits pressure onto the optic nerve
• Acute orbital compartment syndrome occurs when this results in a compressive optic neuropathy

DDx

• ruptured globe — proptosis and raised intraocular pressure are not consistent with this
• orbital blowout fracture — raised intraocular pressure, RAPD and decreased visual acuity are not seen in this condition unless there is coexistent retrobulbar hemorrhage.

Examination findings

• Loss of vision/reduced visual acuity
•  inability to open the eyelids due to severe swelling
• There is a relative afferent pupillary defect affecting the right eye.
• Extraocular movements are markedly reduced.
• High intraocular pressure

Management

• Admit to hospital and treat with aggressive decompression.
• Therapy depends on whether there is compressive optic neuropathy or severely raised IOP:
  • Evidence of optic neuropathy or severely raised IOP (>40 mmHg)
    • lateral canthotomy and cantholysis should be performed immediately (ideally by an ophthalmologist)
    • use procedural sedation in the ED if it does not cause a delay
  • No evidence of optic neuropathy but IOP is raised (e.g. >30 mmHg)
    • treat with agents used to lower IOP (e.g. topical timolol, acetazolamide, mannitol; see acute glaucoma).

lateral canthotomy/ cantholysis 

• Primary indications:

• Decreased visual acuity
• Intraocular pressure > 40 mm Hg
• Proptosis

• Secondary indications:

• Afferent pupillary defect
• Cherry red macula
• Ophthalmoplegia
• Nerve head pallor
• Eye pain

• Contraindications:
• Globe rupture

The main steps in emergency ≈/ cantholysis are:

• use local anesthetic but warn the patient that they may feel pain
• Perform the canthotomy:
  • place the scissors across the lateral canthus and incise the canthus full thickness
• Perform cantholysis:
  • Grasp the lateral lower eyelid with toothed forceps
  • Pull the lower eyelid anteriorly
  • Point the scissors toward the patient’s nose, place the blades either side of the lateral canthal tendon, and cut.

Orbitozygomatic fractures/ Orbital blowout fracture  

• Clinical
  • Palpable step at infraorbital margin or lateral brow area
  • Infraorbital nerve parasthesia
  • Depression of malar eminence (cheekbone)
  • Diplopia/ restricted external eye movements
  • Impaired mouth opening/ closure – zygomatic arch is depressed
  • reduced visual acuity, hyphaemia
• Management
  • If visual acuity normal can be managed conservatively
  • Do not blow nose – can increase eyelid swelling

Chemical Burn to eye

• Immediately irrigate the eye
  • Topical aneasthetic drops 
  • Check pH before you start for a baseline 
  • Use a morgan lens and Hartman’s solution one litre run through stat (takes about an hour). 
  • Ensure lying down with LOTS of towels etc (might vasovagal over the sink) 
  • Might need to give antiemetic / oxycodone to tolerate the procedure 
• Once good irrigation has run through check the pH again and if still not neutral do it again, ensure eyelids have been everted and no chrystals under there but unlikely after morgan lens 
• Once the tears are pH neutral you can assess the eye
  • End point of irrigation is pH of the tears have returned to normal (about pH 7.5)
• Check vision both eyes, corrected / pin hole if necessary 
• Look for corneal clouding 
• Use topical anaesthetic and fluorosceine drops and examine under slit lamp looking for defect / extent of defect 

• Potential complications
  • Extensive burns of the cornea 
  • Continued “melting” of the cornea via collagenases 
  • Loss of vision / need for corneal transplant 
  • Ongoing pain 
  • Superinfection (use topical antibiotic drops – chlorsig usually) 
• Further management includes:
  • analgesia (usually oral) and cycloplegics
  • frequent use of preservative-free artifical tears
  • treatment of secondary glaucoma
  • daily review until the corneal defect has healed, after which steroids may be used by an ophthalmologist to reduce inflammation.
  • Severe chemical burns may require more specialised therapies (e.g. debridement, collagenase inhibitors, ascorbate or citrate for alkali burns, even stem cell transplantation from the contralateral eye) and hospitalisation may be required.
• Reason for transfer
  • All should have ophthalmology review – when do they need to be reviewed? 
  • No obvious burn or minor burns review after 24h 
  • Those with burns to >30% epithelium and the corneal edge with any clouding of the cornea need transfer
    • In these cases they use acidic drops and oral vit C high dose 
    • And / or steroid drops 
  • Would talk to closes ophthalmology on call services for all and transfer as per their recommendation