Orbital Apex Syndrome: A Clinico-anatomical Diagnosis.

An 8-month-old girl presented with fever, restricted left eye movements and increasing proptosis for 8 days. On examination she had left orbital cellulitis, relative afferent pupillary defect and ophthalmoplegia. Contrast-enhanced magnetic resonance imaging (MRI) brain with orbits revealed orbital apex syndrome (OAS) with cavernous sinus thrombosis. Orbital apex is located posteriorly in the orbit and characterised by involvement of cranial nerves II, III, IV, VI and ophthalmic division of Vth nerve. The close clinico-anatomical differentials of OAS are cavernous sinus and superior orbital fissure syndrome. The current case was treated successfully with intravenous antibiotics and anticoagulation therapy.