II. Pathophysiology
- Trauma to eye results in infraorbital artery distribution Hemorrhage
- Orbit is a closed space
- Surrounded by bone in all planes except anteriorly
- Anterior margin is blocked by the medial and lateral canthal tendons which hold the globe in the orbit
- Hemorrhage results in increased orbital pressures
-
Compartment Syndrome results if these pressures are not decompressed
- Compression of artery and Optic Nerve
- Retinal inschemia results when Intraocular Pressure increases above central Retinal artery pressure
III. Imaging
- CT Head
- Bedside Orbital Ultrasound
IV. Management: Lateral Canthotomy Indications
- Retrobulbar Hematoma and
- Primary indications
- Secondary indications
- Afferent Pupillary Defect (see Orbital Ultrasound)
- Eye Pain
- Funduscopic changes
- Cherry red Macula
- Pallor of the nerve head
V. References
- Peak in O'Connor (2012) Medscape: EMedicine
- Wu in Majoewsky (2012) EM:Rap 12(11):11-12
