Eye Trauma

Initial Assessment (Any Eye Trauma)

1. Visual acuity - check before any other intervention; this is the vital sign of the eye
2. Anterior chamber depth - if flat, a ruptured globe is certain; stop the exam immediately
3. Globe integrity - look for the Seidel sign (aqueous leaking through a corneal/scleral defect, diluting fluorescein dye)
4. Ocular motility - restricted upgaze or lateral gaze suggests orbital blow-out fracture with entrapment
5. Intraocular pressure - only if no signs of open globe

Key rule: never pressure the globe in a suspected open globe injury. Apply a protective metal shield (or a paper cup bent over the orbit - see below) and refer emergently.

Classification by Mechanism

1. Chemical Burns - TRUE EMERGENCY (Act First, Examine Later)

• Acid burns (e.g., battery acid): cause immediate coagulative necrosis; the eschar limits further penetration
• Alkali burns (e.g., lye, ammonia, cement): far more devastating - saponify cell membranes and continue penetrating long after initial contact. Can cause corneal melting, perforation, and chronic glaucoma. An alkaline substance like lye can cause permanent, irreversible blindness.

• Copious irrigation - up to 1,000 mL normal saline or lactated Ringer's (or water from any available source in the field)
• Continue until conjunctival pH = 7.5-8.0; check pH after irrigation and again 30 minutes later
• Aggressive antibiotic ointment and lubrication post-irrigation
• Immediate ophthalmology consultation

2. Corneal Injuries

• Caused by contact lenses, fingernails, foreign objects, or high-speed machinery
• Symptoms: intense pain (delayed up to several hours), foreign body sensation, photophobia, tearing, blepharospasm
• Diagnosis: fluorescein staining under cobalt blue light; slit lamp exam shows irregular epithelial defect
• Relief of pain with topical anesthetic is virtually diagnostic
• Management:
  • Topical NSAIDs or short course of topical antibiotics (e.g., erythromycin ointment)
  • Patching is generally not recommended
  • Heals in 24-48 hours typically
  • Follow up for abrasions from contact lens wear (risk of Pseudomonas infection)

• History of high-speed machinery (grinder, lawn mower, hammering metal on metal) raises concern for full-thickness penetration
• Metal foreign bodies leave a rust ring within hours; remove with a burr at slit lamp
• After removal, treat as corneal abrasion

• Seidel test: positive streaming of aqueous through the wound (fluorescein washes out in a stream)
• Do not remove any impaled objects
• CT orbit (2-3 mm cuts, axial and coronal) - preferred imaging; MRI contraindicated if metallic foreign body possible
• Ophthalmology emergently; NPO, antiemetics, avoid Valsalva

3. Conjunctival Injuries

• Less symptomatic than corneal injuries due to lower innervation
• Subconjunctival hemorrhage: bright red, well-demarcated; usually benign and resolves in 1-2 weeks. However, 360-degree hemorrhage after trauma should raise suspicion for globe rupture
• Conjunctival laceration: check with Seidel test to rule out globe perforation; most do not require suturing
• Management: erythromycin ointment 0.5% QID x 2-3 days; refer if globe laceration suspected

4. Blunt Trauma - Specific Injuries

• Graded by percentage of anterior chamber filled (Grade I < 1/3, Grade II 1/3-1/2, Grade III > 1/2, Grade IV = "8-ball" total)
• If supine, blood distributes uniformly over iris simulating heterochromia
• Complications: secondary glaucoma, corneal blood staining (especially with IOP > 25 mmHg), rebleeding (peak at day 3-5)
• Requires prompt ophthalmology evaluation; management includes head elevation 30-45°, cycloplegics, aminocaproic acid to prevent rebleeding, and monitoring IOP

• Most common rupture site: the limbus (junction of cornea and sclera) - a pigmented mass there may be a blood clot or prolapsed uveal tissue (iris)
• Signs: 360° subconjunctival hemorrhage, peaked/irregular pupil pointing toward rupture, flat anterior chamber, decreased IOP (paradoxically may be normal), poor view of fundus due to vitreous hemorrhage
• Any manipulation may extrude intraocular contents - stop the exam, shield, and refer emergently for surgical repair

• Common after blunt trauma; cells and flare on slit lamp
• Pupil may be constricted or dilated
• Treat with cycloplegics and topical steroids; ophthalmology follow-up

• Blunt trauma can rupture zonular fibers
• Slit lamp shows asymmetric lens position, iridodonesis (trembling iris)
• Urgent ophthalmology referral

• Floaters, cobwebs, painless visual loss
• Fundus view obscured; ultrasound is the key imaging tool to rule out retinal detachment
• Urgent ophthalmology

5. Orbital Injuries

• Mechanism: blunt force raises intraorbital pressure, fracturing the weak floor (or medial wall) into the maxillary/ethmoid sinus
• Clinical features:
  • Restricted upgaze (inferior rectus entrapment)
  • Enophthalmos (sunken globe - may be masked early by edema)
  • Infraorbital numbness (inferior orbital nerve)
  • Diplopia
• Imaging: CT facial bones
• Avoid nose-blowing (forces air into orbit causing emphysema)
• Ophthalmology + ENT/plastics referral; surgery if significant enophthalmos or persistent diplopia

• Postseptal hemorrhage can cause orbital compartment syndrome - a true emergency
• Clinical: eye pain, proptosis, impaired EOM, decreased vision, afferent pupillary defect, elevated IOP
• IOP > 40 mmHg - indication for emergency lateral canthotomy and cantholysis
• Lateral canthotomy procedure: local anesthetic at lateral canthus, clamp horizontally for 1 minute, then incise to release lateral canthal tendon

6. Eyelid Injuries

• Lacerations involving the lid margin (> 1 mm) require repair by an oculoplastic specialist
• Full-thickness lid lacerations need layered repair: tarsus with absorbable 6-0 suture (not through conjunctiva - would abrade cornea); lid margin with 6-0 silk using meibomian gland orifices as landmarks; skin with 7-0 nylon
• Medial canthal lacerations: risk damage to lacrimal canaliculi - probe before repair

7. Intraocular Foreign Body (IOFB)

• High suspicion with: hammering metal on metal, grinding, weed whacking
• May present with surprisingly mild symptoms
• CT orbit (NOT MRI if metallic) essential
• Urgent surgical removal; risk of endophthalmitis and siderosis/chalcosis over time

8. Radiation / UV Injury (Photokeratitis)

• Caused by welding arc, sun lamps, UV reflection off snow
• Delayed onset 6-12 hours after exposure
• Bilateral pain, photophobia, foreign body sensation
• Punctate corneal staining on fluorescein
• Treatment: cycloplegics, topical NSAIDs, lubricants; resolves in 24-48 hours

Summary - Urgency Classification

• Tintinalli's Emergency Medicine: A Comprehensive Study Guide - Chapter 241, "Eye Trauma" (pp. 1586-1600)
• Goldman-Cecil Medicine, "Major Ocular Trauma" (p. 4128)
• Textbook of Family Medicine 9e, "Eye Trauma" and "Chemical Burns" (pp. 354-355)