orbit
- to progressive neuropathy causes: - failure to drain aqueous humor - increased intraocular pressure (trauma/ damage/ blood)
glaucoma
oblique muscles
in anatomical movement of EOMs, abducting inactivates
rectus muscles
in anatomical movement of EOMs, adducting inactivates
extorsion
inferior ... EOMs
o: anterior orbital floor i: lateral globe, posterior to lateral rectus insertion a: elevation, extortion, abduction innervation: CN III
inferior oblique origin/ insertion/ action/ innervation
o: common tendiuous ring i: inferior globe a: depression, adduction, extorsion innervation: CN III
inferior rectus origin/ insertion/ action/ innervation
the retina (turns light signals to be integrated)
inner layer of eyeball
central retinal artery
inner retina blood supply
LR6 SO4 AO3 - lateral rectus CN VI - superior oblique CN IV - inferior oblique, medial rectus, superior rectus, and inferior rectus CN III
innervation for EOMs
accomodation - CN III (parasympathetic)
innervation of ciliary muscle and zonular fibers
medially
intorsion
- colored part of eye - Sphincter Pupillae (CN 3 parasympathetic) - Dilator Pupillae (sympathetic from superior cervical ganglion) ("fans out" - big in "fight or flight" bc want lights of light to see)
iris
Parasympathetic innervation from CN VII (facial) = greater petrosal nerve branch
lacrimal apparatus innervation
O: common tendinous ring i: lateral eyeball a: abduction innervation: CN VI
lateral rectus origin/ insertion/ action/ innervation
AVASCULAR no innervation refracts light
lens
elastic = unable to accomodate (lens is more flat) PRESBYOPIA
lens becomes less... with age = ?
o: common tendinous ring i: medial globe a: adduction innervation: CN III
medial rectus origin/ insertion/ action/ innervation
CN VII
motor innervation for closing eyelids
sclera
muscle attachment for EOMs
Choroid/Ciliary Body/Iris
muscular middle layer of eyeball
- Effects most ocular muscles (Levator Palpebrae Superioris & Sphincter Pupillae_ - What you'll see: a) Superior eyelid droop b) dilated/nonreactive pupil (unopposed dilator pupillae/sympathetic) c) Pupil will be down & out - bc trochlear/superior oblique is still intact pulling the eye laterally & down --> III, IV, and VI move eye (III is not intact - IV moves out, VI moves down and out --> that is way eye will move)
oculomotor (CN III) Palsy
levator palpebrae superioris (CN III) and Muller's (superior tarsal) (sympathetic)
opening the eyelid
choroid
outer retinal blood supply
contracts/ dilates
pupil
- CN 2 = afferent - CN 3 = efferent - Often 1st sign of oculomotor nerve compression is ipsilateral slowness of pupillary light response
pupillary light reflex afferent/ efferent/ clinical correlation
- visual retina - nonvisual retina - optic disc - macula and fovea
retina contains
- white part of eyeball - extension of dura mater/ optic sheath functions: - Provides site of attachment for extraocular muscles - Helps shape eyeball
sclera anatomy and function
CN V1 and V2
sensory innervation of orbit
macula and fovea highest amount of cones
sharpest vision
supraorbital (V1?) frontal (V1) CN IV
superficial n suppy to orbit
O: body of sphenoid bone I: tendon passes through trochlea attaching to eyeball lateral to superior rectus Act: depresses, intorsion, adduction Innervation: CN IV
superior oblique origin/ insertion/ action/ innervation
o: common tendinous ring i: superior globe a: elevation, adduction, intorsion innervation: CN III
superior rectus origin/ insertion/ action/ innervation
intorsion
superior... EOMs
- part of eyelid - secretes lipids -- lubrication of the eye - if overactive = eye boogies
tarsal gland
-Acellular viscous gel - 99% water - Fills space between lens & retina (in vitreous chamber of eye) - Helps maintain spherical shape of eyeball
vitreous humor
- separation of inner neural and outer pigmented layers cause: -Build up of pressure or fluids behind the retina & it pushes it off - Build up can be caused by too much produced or a blockage
what is detached retina and cause
optic disc where optic nerves leave
"blind spot"
"out"
... oblique EOMs
"in" (except for medial and lateral rectus)
... rectus EOMs
- brainstem disease/ head injury - diplopia (double vision) - muscles paralysis limits eye movement
EOM and orbital nerve palsies may be from/ result in:
-ptosis and pupil constriction sympathetic NS issue!!!!!!
Horner's syndrome
- Lateral rectus muscle is paralyzed/CANNOT ABDUCT (moves out) - Pupil deviates medially bc unopposed medial rectus muscle (moves in) --> lat rectus is unable to move eye laterally so eye pulled in medially
abducens (CN VI) nerve palsy
curvature of lens is changed to allow for focusing of objects as they approach the eye
accomodation
- Produced by: Ciliary Processes - Drains: Canal of Schlemm into Scleral Venous Plexus - Function: Nourishes cornea & lens
aqueous humor produced by/ drains/ function
-Instant & total blindness that is irreversible (AION) - Unilateral - Seen in older individuals
blockage of central retinal a
- Thrombophlebitis of cavernous sinus - Slow, painless loss of vision - May be reversible
blockage of central retinal v
Frontal Lacrimal Ethmoid Maxilla Zygomatic Sphenoid Palatine
bones of the orbit
- Partial or complete opacity of the lens - Develops from clustering of proteins in lens - Progressive neuropathy - Cause: failure to drain aqueous humor, resulting in increased intraocular pressure
cataracts
Anterior - between cornea & iris Posterior - between iris & lens Vitreous - big boy space behind lens
chambers of the eye
-"red eye" (light bounces off and refracts back) -supplies blood to outer layers of retina - branch of ophthalmic artery
choroid
- Connects choroid with circumference of iris - muscular and vascular functions - attaches to lens via Zonular Fibers - ciliary processes secrete aqueous humor
ciliary body - connects - functions - attaches - processes
zonular fibers relax, lens is spherical
ciliary muscles contracts: zonular fibers and lens...
zonular fibers tense, lens is flat
ciliary muscles relax: zonular fibers and lens...
rounded
close/ near vision = ? lens
orbicularis oris - palpebral part (inferior- gently closes eye) - orbital part (superior- squinting tightly
closing the eyelid
covers sclera and provides nutrients contains: - lateral angle - bulbar conjunctiva (covering schlera) - medial angle - palpebral conjunctiva (covering eyelid)
conjunctiva functions and contains
aids in light refraction innervated by CN 1 AVASCULAR (takes a long time to heal- how cornea is clear)
cornea: function/ inneervation
- use on coma pts - Touch cornea w cotton wisp - Normal Response = blink - Absence of blink may indicate CN V1 (sensation of cornea) or CN 7 lesion (ability to close eye/blink)
corneal reflex
ptosis (the eye is slightly open/ not all the way closed because Muller's muscle is still active)
damage to CN III (eyelids)
CN II CN III CN IV CN V1 (trigeminal) CN VI nasociliary frontal lacrimal
deep n supply to orbit
dim = dilated bright = constricted
dim light = ? pupil bright light = ? pupil
laterally
extorsion
flatter
far/ distant vision = ? lens
sclera and cornea (invisible, aid in light refraction)
fibrous outer layer of eye