A patient presents after blunt trauma with facial swelling, diplopia, and epistaxis; you suspect a blowout fracture of the orbital floor. Which finding would indicate entrapment of the inferior rectus muscle requiring urgent surgery?

• A. Diplopia with restriction of upward gaze
• B. Ptosis with mydriasis
• C. Conjunctival injection only
• D. Blurred vision with central scotoma

Answer: (A)

When the orbital floor is fractured, the inferior rectus can become entrapped in the fracture site. This creates a mechanical restriction to upward eye movement, so the patient experiences diplopia that worsens with attempts to look up and a limited upward gaze. That combination—vertical diplopia with restricted elevation—points to muscle entrapment and is why urgent surgical release is needed to free the muscle and prevent ischemia or ongoing motility problems.

Other signs described would point to different issues: ptosis with mydriasis suggests cranial nerve III palsy rather than entrapment; conjunctival injection alone is a nonspecific trauma sign; blurred vision with a central scotoma points to retinal or optic nerve injury rather than orbital floor entrapment.