Orbit Stephens Flashcards
What is the difference between partial and complete ptosis?
Complete ptosis is complete closure of the eye due to paralysis of levator palpbrae superioris.
Partial ptosis is paralysis of tarsal muscle which inserts on upper lid.
What structures drain tears from surface of the eye?
Lacrimal portion of orbicularis oculi sucks tears out of the eye. Upper lid moves tears across cornea and go to lacrimal punctum to drain to lacrimal canaliculi which drains to lacrimal sac to nasolacrimal duct which opens into the inferior meatus of nasal cavity.
How does a blow out fracture of the face occur and what is it?
Fracture of the floor of the orbit due to fracture of zygomatic. Cant look up and will have anesthesia on the face. It will trap the infraorbital nerve in the inferior orbital fissure.
Rare occurrence, but the optic canal is compressed compressing optic nerve and artery and it is called traumatic optic neuropathy vision can be lost transiently or permanently
Describe the shape of Le Fort I
Le Forte I: transverse fracture of the maxilla and you can move the upper dental arch
What are the cardinal signs of gaze?
have patient focus on finger and follow laterally and medially up to left and right down to left and right, back to horizontal. Also bring the finger out and into their face to watch pupil constrict.
H pattern! Both eyes at the same time!
What is Horner’s syndrome?
paralysis of the tarsal muscle resulting in slight ptosis and Miosis(pupil constriction) due to paralysis of dilator pupillae, enophthalamos (due to paralysis of orbitalis muscle of muller), Anhidrosis and blushing of face also present
How do autonomics get to the lacrimal gland?
Zygomatic nerve communicates between maxillary and lacrimal
sphenopalatine ganglion distributes autonomics to what structures?
posterior 2/3 of nasal cavity, nasopharynx, palate
How does the sphenopalatine ganglion get its autonomic fibers?
The greater superficial petrosal nerve, a branch from facial supplies pregang parasymp fibers to the ganglion, the post gang parasymp fibers from it go to maxillary to zygomatic and then lacrimal gland.
Deep petrosal comes is post ganglionic sympathetic fibers and merge with greater superficial petrosal forming nerve to pterygoid canal (Vidian nerve)
Le Forte II
Pyrimidal fracture including orbital marginn
Le Forte III:
Craniofacial dysjunction with a panda bear appearance. Two black eyes. Severe fractures, concern for brain damage, as face is literally broke from the head.
Blood from nose need to be concerned about CSF coming out as well due to dural tears.
What is the periorbita facsia?
Continuous with the endosteal dura
Inability to abduct the eye, what nerve and muscle is damaged?
LR and abducens nerve
Can be caused by intracranial pressure
“sundown gaze”
What does the frontal nerve split into and where is it from?
Supratrochlear and Supraorbital
From the opthalmic branch of the trigeminal
What does trochelar nerve do in the eye?
Innervate superior oblique and sits on top of the muscle
What vessels are associated with the cavernous sinus?
Oculomotor 3 Trochlear 4 Abducens 6 Trigeminal 5.1 5.2 ICA
A patient has external strabismus, complete ptosis and their pupils are dilated and unreactive. What nerve is damaged?
Oculomotor
Inability to adduct and depress the eye, what nerve and muscle is damged?
Patient will tend to tilt their head away from the affected eye.
Superior oblique and trochlear nerve
Inability to abduct eye and diplopia due to internal strabismus, what muscle and nerve?
Lateral rectus and Abducens
Describe corneal/blink reflex.
affects afferent by nasociliary nerve (V)
and efferent by zygomatic branch of 7
Touching the eye should induce blinking of both eyes
Are pupillary constriction and thickening of lens parasympathetic or sympathetic responses?
Parasympathetic
What is Hyphema?
Presencce of blood in the anterior chamber of the eye due to trauma and rupture of the great arterial circle of the iris. Medical emergency
What is a subconjunctival hemorrhage?
rupture of the deep pericorneal plexus and bleeding is restricted to subconjunctival tissue or bulbar fascia
Direct light reflex?
Optic nerve, optic tract to the brachium of superior coliliculus to the superior coliculus. Then to Pretectum and constriction is mediated by edinger-westphal nucleus of the occulomotor nerve which goes to ciliary ganglion and then the pupil constricts
Dilator reflex?
Retia optic nerve superior colliculus pretectum reticular formation lateral reticulospinal tract and preganglionic symp neurons
Horner’s syndrome
What is accommodation?
cortically mediated response.
Triad of accommodating is convergence of gaze and pupillary constriction and thickening of lens
What is argyll robertson pupil
accommodating but un reactive
What is holmes adie pupil?
tonic pupil that slowly converges parasympathomimetic drugs constrict the tonic pupil and has no effect on normal pupil
Papilledema?
pressure on the optic nerve- increased crainial pressure is cause
What nerves do the corneal reflex test?
V1 and VII
What does the central artery supply?
four quadrants of the retina through upper and lower temporal branches and upper and lower nasal branches.
Also supplies anterior optic nerve NOT posterior optic nerve
What arteries supply the optic nerve?
posterior ciliary and central retinal arteries which come from the opthalmic artery
Where do all extraocular muscles attach except one and what is the one?
All attach to the annulus tendinius except for the inferior oblique
What is the thickest wall of the orbit and what bones form it?
Lateral wall formed by the frontal maxilla, zygomatic lacrimal, sphenoid ethmoid and palatine. The first four were bolded in lecture.
