the orbit dan topping, md clinical asst professor january 14th, 2008

The Orbit

Dan Topping, MD

Clinical Asst Professor

January 14th, 2008

The Orbits

• Eyelids and associated structures

• Bones that create it

• Lacrimal apparatus

• Skeletal muscles

• Nerves

• Blood vessels

External view of the eye

Sagittal Upper Eyelid

Orbicularis Oculi

External View of the Eye

Parasagittal Orbit

Lacrimal Apparatus

Skeletal Muscles

Nerves

Autonomic and Afferents

Arteries

Veins

Case 1

• 53 yowf was playing racquetball without eye protection and was hit in the right eye.

• She complains of pain, double vision and numbness of the skin of her lower eyelid.

• What injury could account for these findings?

Orbital Blowout Fracture

• Results from blunt trauma to the eye.• Increased intraorbital pressure is transmitted to

the weakest point (inferior orbital wall)• Can result in entrapment of inferior orbital

structures.– Inferior rectus (can’t look up and impairs conjugate

gaze)– Infraorbital nerve (numbness of the cheek and upper

gum)

Case 2

• 55 year old male had carotid surgery on the left for a blockage, no complications.

• He complains of a sagging eyelid on the same side.

• This is what he looks like…

Horner’s Syndrome

• Results from disruption of the sympathetic outflow to the orbit.

• There is a triad of:– Miosis – constriction (opposite is mydriasis –

dilation) – unopposed parasympathetics– Ptosis – drooping of the upper lid– Anhidrosis – absence of sweating

Case 3

• 13 yowf suffered a closed head injury and numerous other injuries.

• She recovered after losing consciousness for 2 hours.

• She complains of double vision and when asked to look to the left…

Abducens Nerve Palsy (CN VI)

• Causes an inward deviation of the eye and paresis of abduction.

• Numerous causes – infarction, aneurysm, tumor, trauma, leptomeningitis, multiple sclerosis and often times is idiopathic (who knows why?)

Case 4

• 64 yowf with sudden severe headache complains of double vision.

• She has an MRI that shows an intracranial hemorrhage (source unknown)

• You examine her extraocular muscles…

Oculomotor (CN III) Nerve Palsy

• Causes ptosis, and inability to turn the eye inward, downward or upward.

• May involve the pupil (in our patient’s case, mydriasis as the sympathetic tone is intact)

• Causes are numerous (same as with CN VI palsies