A 12-year-old boy is struck in the orbit by a cricket ball. He develops enophthalmos and diplopia on upward gaze. CT scan shows a 'trapdoor' fracture of the orbital floor with inferior rectus muscle entrapment. What is the MOST URGENT indication for early surgical repair in a paediatric blowout fracture?

• A Cosmetic correction of enophthalmos
• B Prevention of late diplopia
• C Restoration of normal visual acuity
• D Relief of oculocardiac reflex (bradycardia, nausea) from muscle entrapment ✓

Explanation

In paediatric blowout fractures, the 'trapdoor' mechanism traps soft tissue or muscle in the fracture. Traction on the entrapped inferior rectus activates the oculocardiac reflex (trigeminovagal reflex) causing bradycardia, nausea, and sometimes syncope. This constitutes an ophthalmic emergency requiring urgent surgical repair within 24-48 hours to release the entrapped tissue and prevent ischaemic damage to the inferior rectus. Enophthalmos and diplopia are chronic concerns in adults but urgency is dictated by the oculocardiac reflex in children.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.