Superior Orbital Fissure (SOF): Mnemonics

Superior Orbital Fissure (SOF) is a cleft between greater and lesser wing of sphenoid which connects orbit and middle cranial fossa. It is divided into 3 compartments by the tendinous ring (annulus of Zinn).

Superior orbital fissure alone (Lateral compartment):

Mnemonic: LFTS

1. Lacrimal nerve (CN V1)
2. Frontal nerve (CN V1)
3. Trochlear nerve (CN IV)
4. Superior ophthalmic vein

Superior orbital fissure in tendinous ring (Intermediate compartment):

Mnemonic: SANI

1. Superior division of Occulomotor nerve (CN III)
2. Abducens nerve (CN VI)
3. Nasociliary nerve (CN V1)
4. Inferior division of Occulomotor nerve (CN III)

Optic canal also lies within the tendinous ring in the lesser wing of sphenoid and transmits:

1. Optic nerve (CN II)
2. Ophthalmic artery

Medial compartment of superior orbital fissure outside the tendinous ring transmits Inferior ophthalmic vein.

Inferior Orbital Fissure lies between the lateral wall (greater wing of sphenoid) and inferior wall of the orbit (maxilla) inferior to superior orbital fissure and transmits:

Mnemonic: ZIP

1. Zygomatic nerve (CN V2)
2. Infraorbital nerve (CN V2), artery and vein
3. Pterygopalatine ganglion branches

Relevant syndromes

Condition	Cranial nerves involved	Cranial nerves not involved	Vessels involved
Orbital apex syndrome	II, III, IV, VI, V1 +/- V2		Ophthalmic artery, Superior ophthalmic vein
Superior orbital fissure syndrome (Rochon-Duvigneaud syndrome)	III, IV, VI +/- V2	II	Superior ophthalmic vein
Cavernous sinus syndrome	III, IV, VI	II, V2	ICA (Cavernous portion)