Ocular first aid - Introductory ocular disease Flashcards
Mechanical injury types:
• corneal abrasions
• recurrent corneal erosion
• foreign bodies (superficial & penetrating/perforating)
• blunt trauma
• Non-mechanical injuries:
• radiation: non-ionising
• radiation: ionising
• chemical burns
Corneal anatomy
Anterior
• Epithelium
• Bowman’s membrane
• Stroma
• Descemet’s membrane
• Endothelium
Posterior
Corneal Abrasion - Symptoms
• Previous trauma (not alwavs)
• Foreign body sensation
• Pain
• Photophobia
• Tearing
•Blepharospasm
• Reduced vision
Corneal Abrasion - Examination
• Check Visual acuity
• Rule out chemical injury and penetrating injury
• Assess the extent of the abrasion using NaFl
• Ensure you evert lids and check cornea to exclude any sub-tarsal or corneal foreign bodies
• Evaluate to determine if there is an inflammatory response in the anterior chamber
Corneal Abrasion - How are signs investigated?
Slit lamp investigation:
• White light
• Normal routine plus:
• anterior chamber (conical beam)
• evert lid (check for foreign body)
• Fluorescein staining:
• size
• depth
• section beam,shape, colour
Corneal Abrasion - Signs
• Varies depending on severity
• Lid oedema and hyperaemia
• Corneal epithelial defect with or without underlying stromal oedema)
• Visual loss
• Possible secondary anterior uveitis
Corneal Abrasion - Management; Healing time frame
Healing:
• 6hrs: epithelial cells have started to migrate across defect
24-48hrs: defect filled with epithelial plug (no staining remains)
• 72-96hrs: cells start attaching to deeper layers
•3/12: attachment fully formed
Corneal Abrasion - Management; General
• Nothing?
• Artificial tears
• Antibiotics?
• Pain relief; Systemic analgesia (paracetamol, or ibuprofen; dosage as for headaches)
- Cyclopentolate 1% b.d. for relief of ciliary spasm
• Bandage contact lens
• Advice
• Follow-up
Describe Recurrent Corneal Erosion
• Poor adherence of epithelium to basement membrane
• Can occur within 3/12 of corneal trauma
• Lids stick to epithelium at night
• Epithelium torn away from basement membrane when eyes are opened
Recurrent corneal erosion - symptoms
• pain
• photophobia
• lacrimation on waking
Recurrent corneal erosion - Examination
• Check visual acuity
• Assess the extent of the abrasion using NaFI - pay particular attention to the edges of the lesion
• (evert lids and check cornea to exclude any sub-tarsal or corneal foreign bodies)
• Evaluate if there is inflammatory response in the anterior chamber
Recurrent corneal erosion - Signs
• Epithelial disturbance
• Fluorescein staining
• Maybe a grey area around epithelial defect
• Microcysts at the healing edge of the defect
Recurrent corneal erosion - Management
• Lubrication during the day and at night (minimum 3/12)
• Bandage contact lens
• Cycloplegic and antibiotic?
• Referral
Recurrent corneal erosion - Management
• Lubrication during the day and at night (minimum 3/12)
• Bandage contact lens
• Cycloplegic and antibiotic?
• Referral
Describe foreign bodies
Common ways a FB enters the eye - blown in by wind, high velocity (hammering/grinding), during DIY and gardening.
• Particles can eyelashes, dust, organic matter, metal
• When doing DIY without eye protection
• On presentation the foreign body could be:
- washed away (producing corneal abrasion)
- around eye (in tear film or under lid)
- embedded in cornea
Corneal/sub-tarsal foreign body; Symptoms and Signs
Symptoms:
• pain
• foreign body sensation
• photophobia
• tearing
Signs:
• corneal defect (like corneal abrasion)
• foreign body may be visible
Corneal/sub-tarsal foreign body; Treatment
• Locate foreign body
- look under lids, cannot go behind eye, be sure it has not penetrated the eye
- assess the depth of a foreign body
• Removal of foreign body
- irrigate, anaesthetise and remove with instrument, Removal method depends on location
- Corneal: needle and alger burr
- Sub-tarsal: cotton bud, nylon loop or needle
• Treat pain?
• Prophylaxis against infection with antibiotics?
Penetrating and perforating foreign bodies:
Symptoms, signs and treatment
• Symptoms & Signs
- Similar to corneal foreign bodies
- Seidel test can determine if wound is leaking (1% fluorescein)
• Treatment:
- Do not attempt to move the FB or put pressure on the eye
- Emergency (same day) referral to ophthalmologist
Describe Blunt Trauma:
• Can affect any of ocular structures
• Blow to the eye - accidental (RTA, Industrial, domestic, sports or non accidental e.g. fist
Blunt Trauma: Symptoms
• Pain varies from mild to severe
• Epiphora
• Visual loss
• Photophobia
• Possible diplopia
Blunt Trauma: Signs
• Lid edema and ecchymosis
• corneal damage: abrasion, edema
• haemorrhage:
- subconjunctival haemorrhage
- uvea
- hyphema
• Increased or decreased IOP
• Retinal detachment
Photo keratitis: Symptoms
• Usually caused by UV light (welding, sunbed, snow)
• Pain
• Photophobia
•Blepharospasm
• Foreign body sensation
• Tearing
• Occur ~8hrs after exposure
Photo keratitis: Signs
• Widespread punctate staining
• Bilateral
• Lid chemosis and redness
• Conjunctival hyperaemia
• Epiphora
• Punctate staining of corneal epithelium with fluorescein (may be coalescent)
• Mild transitory visual loss
• Associated skin burns from UV exposure
Photo keratitis: Management
• Reassurance and advice
• Cold compresses
• Artificial tears and un-medicated ointment
• Systemic analgesia
Describe Chemical Burns
• History of chemical in eye
• Acids and alkalis penetrate deeply into eye
• Acid
- e.g. sulphuric acid (car battery), hydrochloric acid (many industrial compounds)
• Alkali (any ‘hydroxide’ compound)
- e.g. lime, cement, fireworks
Chemical Burns: Treatment
• Irrigate!!
- ASAP and for at least 15-30min
• Sterile saline, if not tap water
• Refer on emergency basis to repair any damage
