Blunt Trauma

Introduction & Mechanisms - Impact Zone Insights

• Blunt Ocular Trauma: Injury from non-penetrating force (e.g., fist, ball, airbag).
• Mechanisms:
  • Coup: Direct impact site injury.
  • Contrecoup: Injury opposite impact site due to shockwaves.
  • Equatorial Expansion: Globe compression (AP axis) causes circumferential scleral stretch, damaging zonules, ciliary body.
  • Shearing Forces: Between tissues of different densities.

⭐ Globe rupture is most common at the limbus or behind rectus muscle insertions due to scleral thinning (thinnest points).

Anterior Segment Injuries - Frontline Damage Report

• Cornea:
  • Abrasion: Pain, photophobia. Fluorescein+.
  • Edema: Hazy, ↓VA. Descemet's folds.
• Hyphema: Blood in AC.
  • Grading:

    Grade	AC Filled	Prognosis
    Micro	RBCs only	Good
    Grade I	< 1/3	Good
    Grade II	1/3 to 1/2	Guarded
    Grade III	> 1/2	Guarded to Poor
    Grade IV	Total ("8-ball")	Poor (risk ↑↑)

  • Complications: Rebleed (Day 3-5), corneal blood staining, glaucoma (IOP > 21 mmHg).

    ⭐ Secondary glaucoma is a common complication of significant hyphema.

• Iris:
  • Iridodialysis: Iris root tear. D-shaped pupil.
  • Traumatic mydriasis/miosis.
• Lens:
  • Vossius Ring: Iris pigment on lens.
  • Subluxation/Dislocation.
  • Traumatic Cataract (rosette).
• Angle Recession: Ciliary muscle tear. Risk of late glaucoma (10% over 10 yrs).
• Ciliary Body: Cyclodialysis (disinsertion), hypotony.

Posterior Segment Injuries - Deep Impact Echoes

• Commotio Retinae (Berlin's Edema):
  • Retinal opacification (photoreceptor OS damage); macular cherry-red spot.
  • Usually transient; good prognosis.
• Choroidal Rupture:
  • Crescentic, yellowish-white subretinal lesion, concentric to optic disc.
  • Tears in choroid, Bruch's membrane, RPE.
  • Risk: Late CNVM.
• Vitreous Hemorrhage:
  • Sudden ↓vision, floaters, "cobwebs"; ↓red reflex.
  • B-scan if fundus obscured.
• Retinal Detachment (RD):
  • Flashes, floaters, progressive field loss ("curtain").
  • Requires urgent surgery.
• Traumatic Optic Neuropathy (TON):
  • Acute severe vision loss, RAPD. Disc pallor is a late sign.
• Globe Rupture (Posterior):
  • Often occult. Suspect with: ↓IOP (variable), deep AC, marked chemosis, ↓VA.

⭐ In suspected globe rupture, avoid any pressure on the eye; shield and refer immediately. A 360° bullous subconjunctival hemorrhage is a classic sign.

Evaluation & Management - Trauma Triage Tactics

• Initial Assessment & Triage:

  • History: Mechanism, prior eye conditions, 📌 AMPLE.
  • Visual Acuity (VA): Essential baseline; document for each eye.
  • Pupils: Check for RAPD, shape, reactivity.
  • IOP: Measure carefully (⚠️ Defer if open globe suspected).
  • Slit-lamp exam & Dilated Fundoscopy (if safe).

• Key Investigations:

  • CT Orbit (axial & coronal, thin cuts 1-2mm): Preferred for fractures, intraocular/orbital foreign bodies.
  • B-scan Ultrasonography: If media opacity (e.g., dense hyphema) obscures posterior view.

• General Management Principles:

  • Protect the globe: Rigid eye shield.
  • Control pain & nausea: Analgesia, antiemetics (prevents Valsalva, ↑IOP).
  • Tetanus prophylaxis.
  • Prompt ophthalmology referral for definitive care.

⭐ Always rule out open globe injury first. A missed rupture has devastating consequences for vision.

High‑Yield Points - ⚡ Biggest Takeaways

• Hyphema (blood in anterior chamber) is common; Grade 1 <1/3, Grade 4 is total (8-ball).
• Orbital blowout fractures most commonly involve the inferior wall, causing diplopia and enophthalmos.
• Commotio retinae (Berlin's edema) appears as retinal whitening post-trauma.
• Vossius ring: iris pigment imprint on the anterior lens capsule.
• Angle recession is a major risk for late-onset glaucoma.
• Traumatic optic neuropathy can cause sudden vision loss; consider high-dose steroids.
• Suspect lens subluxation/dislocation with phacodonesis or monocular diplopia.