Eye trauma Flashcards
(26 cards)
Main sources of eye trauma
Mechanical: abrasions, lacerations, fb, contusion injuries
Chemical
Radiation
Theraml
Features of conjunctival abrasions
- Minor irritation, discharge/watery
- well defined borders
- underlying tissue intact
- hyperaemia, chemosis
Features of corneal abrasions
- gritty sensation - severe pain
- lacrimation, photophobia, blepharospasm, decrease vision, redness, pseudoptosis
- epithelial or stromal damage, AC reaction
- mx: debride eyes, decrease RCE, topical antibiotic (chloramphenicol 4x a day) - continue 14 days or 3 days after healed, do NOT patch abrasions, oral analgesics
- ocular lubricants, mydriatic/cyclo if severe AC (atropine 1%), BCL if loose tissue, review 24-48 hours (then every 2-3/7), advise risk of recurrent epi erosion
Features of recurrent corneal erosion
- Comes from previous corneal abrasion commonly
- Debride edges –> decrease recurrent risk
- Pain upon wakening
- Mx: lubrication (esp at night), ointment at night, BCL + broad spec antibiotic, ice pack, analgesia (reduce pain)
Features of superficial fb (conj or sclera)
Corneal fb
- marked vascular injection locally
- grey ring of infiltration & oedema (Coat’s white ring)
- Scar after removal
- If unremoved –> secondary infection, corneal ulcer
- Metallic fb –> Rust ring
Removal: irrigation, 25 gauge needle, forceps, burr, anaesthetic, cotton bud (if conj & superficial)
- TX: broad spec antibiotic (chloramphenicol qid), cycloplegic, analgeisc, NSAID, lubricant
- review next day
Features of intraocular fb
- greater pain, more visual impact and oedema
- +ve sidel sign, shallow AC, decreased IOP, AC inflammation, CT scan
- needs sx, no padding
- cataract, iris prolapse, hyphaema, vitreous prolapse, RD, enucleated eye, endophthalmitis
- imaging: OCT, B scan, MRI, X-ray
Anterior segment Contusion injury clinical manifestations
Corneal abrasion: heals 24-48hrs, infection risk
Lid ecchymosis: oedema and haemorrhage common, cold press (decrease swelling), can spread to other eye (subcutaenous supply)
Orbital features: mainly floor and medial wall (thinnest)
- orbital floor fracture (from ‘blow out’ fracture)
–> increased intraorbital pressure, IO/IR trapped (restricted eye elevation), DV, endophthalmos, infraorbital nerve anaesthesia
–> sx: plate over damaged floor
- medial wall fracture: presence of air crepitus (air under skin) –> swelling, infection spread
–> limited adduction and abduction
subconj haemorrhage: definite borders, blood thinners (if idiopathic), warm/cold compress (alternating, cold first), heals in 14 days
Iris: mydriasis, or miosis, paralysis temporary or permanent
- ruptures to sphincter papillae (irregular, semi-dilated pupil, no reaction to light or accomm, glare sensitive, monocular DV)
- iridodialysis - iris torn insertion to CB, hyphaema, pupil distortion
- no gonio for 1 week
- iritis - white BC and flare in AC
- -> peri-limbal injection, traumatic iritis (cycloplegic - no steroid if not abrasion)
Hyphaema = blood in AC, increased IOP, secondary glaucoma, refer all cases (unless trace), no physical activity (5% homatropine qid, acetaminophen for pain)
- -> review daily for 3-7 days
- inflammation >2+ cell: Pred acetate 1% q2h
- increased IOP >28mmHg; >2 days - timolol 0.5% bid, CAIs
Lens -
Dislocation: rx affect - astig, myopic shift, monocular DV, deeper AC, abnormal ret reflex
- partial dislocation: sensory ligaments tear
- total dislocation: 360 deg zonule tear
Vossius ring = circle iris pigment on lens (from iris impact against lens) - younger px
Cataract = direct damage to lens fibres - lens compression, subepithelial opacities
- rosette cataract (contusion or perforation injury), diffuse cataract (associate w torn capsule), zonular cataract (series of concentric opacities)
Posterior segment contusion injury clinical manifestations
- oedema, cysts, holes, necrosis, atrophic retinal changes, commotio retinae, RD, haemorrhage, tears
- commotio retinae = milky white retina = retinal oedema - transient and reversible (4 days)
- -> outer retina layers, decreased vision
- -> If severe –> intraretinal haemorrages
Vascular changes
- retinal, subretinal, preretinal, vitreal –> sudden vision loss
Choroidal tears = trauma + increased IOP – fluid enters suprachoroidal space
- b/w disc and macula or temporal to macula
- if haemorrhage –> absorbed –> yellow-grey choroidal lesion
- crescent, vertical
Retinal detachment = separation of RPE and retina - photopsia, floaters
- if shortly after trauma: supero-temporal peripheral (or supero-nasal)
- tobacco dust (in anterior vitreous = shafer’s sign)
- high risk: high myopia, peripheral retinal degen, aphakia
Nerve damage:
- CN5: decreased sensitivity
- Cn6: horizontal diplopia
- cn4: vertical diplopia
- mydriasis, ptosis, DV, limited adduction and loss of accomm (Cn3)
- traumatic hyperopia
- myopic changes (more common) - due to accomm spasm
Optic nerve damage:
- neuropathy, partial or complete evulsion
- -> papillitis, optic atrophy - widespread retinal or choroidal damage
Contusion injury - plan
- assess: orbital fracture, EOM entrapment, globe position, globe rupture (seidel test), ant and post seg
- DFE
- Screening
- Refer if ON/ retina damage
- CT scan - bone damage - sinus compromise - crepitus
- Refer for penicillin or cephalosporin po
What injuries do chemicals cause to eye
- Superficial punctate erosion (urgent ocular emergency) - complete epithelial denudation, stromal opacification, melting
Main sources of chemical ocular injuries
- acids - binds tissue protein and coagulates in corneal epithelium (barrier for further penetration) - rarely reaches AC, less damaging than alkali, minimal corneal penetration
- alkalis: penetrates tissue faster than acids (e.g. household cleaners), destroys collagen, disrupts cells, softens tissues, worsens over time –> totally opaque cornea, can penetrate AC CB (cataract, increased IOP)
- aerosols: hyperaemia, swelling, blepharospasm, lacrimation, pain, SPK, corneal and conj sloughing off, corneal oedema
- capsicum spray: total epithelial defect, conj chemosis & necrosis, stromal oedema, symblepharon
Managing chemical ocular injuries
- irrigate immediately with sterile saline or water (30 mins) or until neutral on litmus paper
- refer grade 3-4 - emergency ophthal care
- after irrigation: topical anaesthesia & during irrigation, measure VA, SL, evert lids, NaFl stain, remove particles (soak cotton bud w anaesthesia)
- grade 1-2 (optom mx): prophylaxis - topical broad-spec antibiotic (chloramphenicol or tetracycline qid), cycloplegia (pain + ac reaction - homatropine qid), analgesia (ibuprofen, panadol), artifical tears (q1h), topical steroids (if AC reaction - flarex q2h), mx IOP (accept 30mmHg for 4 hours, otherwise Timolol 0.5% bid)
- grade 3-4: as above and: sodium citrate (decrease degradation and inflammation), sodium ascorbate (increase collagen synthesis, decrease stromal loss), tetracycline/ acetylcysteine (prevent stromal degradation)
Sites of ocular absorption of UV radiation
- UVA: aqueous, lens nucleus and epithelium
UVB: cornea, conj, aqueous, lens nucleus and epi
UVC: tears, conj and cornea
Ocular effects of UV radiation
- corneal epi absorbs most UV radiation
- Photokeratitis = common short term effect
- Long term: pterygium, pingueculum, nodular band keratopathy/ climatic-droplet keratopathy
- cataract (lens epi and nucleus absorb part UVA and UVB)
- retinal effects: pigment change, early AMD, damage to phR and RPE, uveal melanoma, need UV protection and use UV absorbing IOLs
- Solar maculopathy - burn foveal area due to excessive UV light exposure
Features of photokeratitis
= Snow blindness/ Arc eye / welders flash
- symptoms: latent period (6-12hrs), fb sensation, lacrimation, photophobia, blepharospasm, lid oedema, corneal erosion, erythema
- SPK staining, discomfort disappears after 48 hours
- Plan: prevent infection, facilitate healing, help pain
Mx: tear supp (q5-10mins 1st hr, q1h-3h), broad spec antibiotic (optional)
Ocular effects of visible light
- most reaches retina
- damage: photochemical, thermal photocoagulation (retinal burns)
- blue visible light = short wavelength - low contrast, glare, fatigue, eye strain
Ocular effects of infrared radiation
- e.g. sunlight, furnace, electric fires
- cornea: opacification (esp stroma), polymegathism
Lens: cataract
Retina: solar retinopathy, IR lasers, medical laser
–> absorbed by RPE and choroid –> inflammatory response
Ocular absorption of IR
IRA: lens, retina
IRB: lens
IRC: cornea
Microwave radiation
- increases tissue temp
- lens prone to thermal damage –> PSC
Lasers
- 4 main classes: 1, 2, 3R, 3B, 4 (3B,4 = irreversible ocular damage)
ocular effects: - UV lasers: damage epithelium, cataract
- visible and IR lasers: traumatic cataract
retinal effects: visible and IR: absorbed by melanin, RPE, choroid –> thermal damage
Ionising radiation
- v short wavelengths
- x -ray, gamma radiation
- not initially severe, erythema, skin damage, corneal compromise, cataract (ant and PSC)
Thermal injuries
- due to radiation, gases, fluids, hot bodies
- involves: lids, not globe
- oedema, tissue necrosis, pain
- Flame burns: lids, lashes scorched –> epiphora - damaged lacrimal puncta and canaliculi
- Contact burns: due to molten substance, boiling liquid, fireworks –> prompt removal and irrigation (reduce damage), molten metal (low melting pt) –> less damage
Managing thermal burns
- clean site, irrigate w saline
- debride necrotic tissue
- prophylaxis and cold compress
- antibiotic - q2h @1day, then q4h until healed or ointment- e.g. chloramphenicol, 5% homatropine (in office x1)
- artificial tears (e.g. q1h), analgesic (panadol)
Different materials for eye protection
- Low impact: CR39, polycarbonate, trivex
- Med impact: polycarb, trivex
- High impact: no prescription eye protector
- polycarb is used for eye protection bc highest impact resistance
