Ophtho On Call Case 10: Diagnosis & Conclusions

Diagnosis: Orbital floor fracture

Orbtial Floor Fractures 

>50% floor fx

Our case was a classic case of right orbital floor fracture with entrapment of the inferior rectus muscle. Trauma can increase pressure within the orbit, rupturing the thin orbital floor at its weakest point that makes up the roof of the maxillary sinus. This may cause the inferior rectus to herniate into the maxillary sinus. Sometimes the bone can trap the muscle in the sinus, causing inability to supraduct the affected eye and diplopia on upgaze. Posterior pressure can lead to enophthalmos, or posterior displacement of the eye, as seen in the second image of the case. In a situation where the inferior rectus may be entrapped, an emergent consult to ophthalmology is necessary to intervene before permanent muscular damage occurs.

Bradycardia, nausea, and vomiting can all be signs of inferior rectus involvement due to the oculocardiac reflex. The afferent limb of this pathway is CN V; these have been found to be associated with stretch receptors in periorbital tissues and muscles. This pathway leads to the CNS, where the efferent limb is CN X, and acts to slow the heart rate via vagal stimulation of the SA node. Nausea and vomiting have been found to be associated with vagal stimulation in patients, and therefore can be a sequelae of this reflex. In patients with facial trauma and bradycardia, consider involvement of the periorbital tissues and muscles.

 

The Inferior orbital neurovascular bundle courses within the thin bony orbital floor. This bundle contains the infraorbital nerve and artery, and is highly susceptible to injury in the case of an orbital floor fracture. Since the infraorbital nerve supplies the skin just below the eye, numbness of this area on physical exam should raise suspicion for involvement of the orbital floor.

 

The structure seen in between the asterisks is air. In orbital floor (and other orbital) fractures, the air from access to sinus can escape to the subcutaneous or orbital spaces. When encountering a patient with subcutaneous or orbital emphysema, your suspicion for sinus involvement and orbital bone fracture should be very high.

 

entrapment urgent 

 Treatment

Initial management of orbital floor fracture requires evaluation to determine severity of the presentation. Findings such as decreased VA, widened intercanthal distance, evidence of orbital compartment syndrome, open globe injury, and severe vagal symptoms all require emergent ophthalmology consultation. In a case such as ours, where the patient does not have any of the above, ophthalmology should be consulted to evaluate the patient within 24 hours. Entrapment of an ocular muscle may cause permanent tissue damage if not addressed within this timeframe. Corticosteroids can be administered in those with swelling and limitation of extraocular movements while prophylactic antibiotics to cover sinus pathogens are recommended; however, clinical evidence for these treatment options is limited. Surgical management consists of a transconjunctival approach to repair the orbital floor.

References and Additional Resources: 

1. Langer P, et alOrbital Floor Fractures.  Syed ZA (Eds). American Academy of Ophthalmology: EyeWiki. March 2021. Available at: https://eyewiki.aao.org/Orbital_Floor_Fractures. 

2. Dunville LM, Sood G, Kramer J. Oculocardiac Reflex. In: StatPearls. StatPearls Publishing; 2021.

3. Long J, Tann T. Orbital trauma. Ophthalmol Clin North Am 2002; 15:2493

4. Brady SM, McMann MA, Mazzoli RA, et al. The diagnosis and management of orbital blowout fractures: update 2001. Am J Emerg Med 2001; 19:147

5. Jatla KK, Enzenauer RW. Orbital fractures: a review of current literature. Curr Surg 2004; 61:25.

Case 9 Index

Ophtho On Call Case 9 Index
Ophtho On Call Case 10: Introduction
Ophtho On Call Case 10: Physical Exam
Ophtho On Call Case 10: Case Continued…