Eye Flashcards
Cutaneous innervation of eyelid
- V1
- Supraorbital
- Supratochlear
- Infratrochlear
- Lacrimal
- V2
- Infraorbital
Eyelid muscle
- Orbicularis oculi
- Colses eyelid
- CN VII
- Levator palpebrae superioris
- Opens upper eyelid
- CN III
- Superior tarsal (Mullers)muscle
- Elevates eyelid
- Smooth uscle
- Symapathetic control, T1, via superior cervical ganglion
- Ptosis
Orbital Septa
- Extension of periostium
- Upper orbital septum continous with levator palpebrae superioris
- Lower orbital septum continous with tarsal plate (dense CT)

Conjuctiva
- Thin membrane
- Protect eye from pathogens
- Facilitates occular movement
- Covers posterior surface of each eyelid and the eye
- Palpebral layer
- Bulbar or occular layer
- Fornical layer

Lacrimal Apparatus
- Lacrimal gland
- Dividied into 2 parts by the levator palpebrae superioris
- Lacrimal sulcus
- Paired serous gland - produce tears
- Lacrimal puncta-openings
- Lacrimal canals or canaliculi
- Lacrimal sac
- Nasolacrimal duct

Eye Structures
7
- Lens
- Pupil
- Anterior chamber
- Filled with aqueous humor
- Posterior auricular
- Aqueous humor
- Canal of Schlemm
- Drains aqueous humor
- Vitreous chamber
- filled with vitreous humor (gelly goo)
- Optic nerve
Anterior Segment
Post segment
- Ant and post seperated by iris
- Filled with aqueous humor
- Made by cilliary body
- Drains into superior opthalmic vein via the canal of schlemm
- Intraocular pressure is measured here
- Posterior segment
- Called vitreous cavity
- Filled with vitreous humor
3 Layers/tunics
- Fibrous tunic
- Vascular tunic or Uveal tract
- Neural tunic
Fibrous Layer/tunic contents
- Sclera
- Surrounds post surface
- Gives strngth and structure, fibrous
- White along periphery
- Allows for muscle attachment
- Cornea (contact lays on this)
- Anterior surface
- Bends light
- Encases most of anterior chamber
- Sensory innervation by V1
Vascular layer or uveal tract
Contents (attachmeents)
- Choroid
- Highly vascularized
- Extends from optic nerve to ciliary body
- Ciliary body
- Lens accomodation
- Parasympathetic CN III, ciliary ganglion
- Suspensory ligaments
- Attach ciliary body to lens
Vascular layer or uveal tract
Contents
- Lens
- Post to iris
- Focusing/refracting light
- Iris
- Sphincter pupillae m
- Constrict pupil,
- Parasympathetic CN III
- Dilator pupillae
- Dilate pupil
- Sympathetic control
- Sphincter pupillae m
- Pupil
Neural Layer
- Retina
- Innermost layer of eye
- Thin and highly vascularized
- Pigmented
- Neural cells, photoreceptors
- 3 specialized areas
- Optic disc
- Macula lutea
- Fovea centralis
Ametropias
4
- Myopia
- Nearsightedness
- Image focused anterior to retina
- Hyperopia
- Farsightedness
- Image focused post to retina
- Astigmatism
- Nonsperical eye
- Image focus at multiple location
- Presbyopia
- Loss of elasticity in the lens
- Age related, reading glasses
Retina parts
- Pigmented part
- thin outer layer
- Absorbs light to prevent it from bouncing around
- Neural part
- Thick inner layer
- Contains
- Photoreceptors
- Neurons
- Supporting cells
Photoreceptors
- Rods
- Work in dim light
- Dont provide sharp or color vision
- Periphery of retina
- Cones
- Operate best in bright light
- High acuity
- Color vision
- Center of retina
Organization of retina
- Rods and cones
- Horizontal cells
- Bipolar cells
- Amacrine cells
- Ganglion cells
- Converge at optic disc
- Become optic nerve
- Travels throuugh optic canal
Macula lutea
Fovea centralis
- Macula lutea
- Lateral to optic disc
- mainly cones
- Fovea centralis
- Only cones
- Maximal visual activity
Optic disc
- Blind spot, no rods or cones
- Unmyelinated axons
- Where central artery and vein enter and exit
Bleaching
Night blindness
- Bleaching
- Rhodopsin breaks down into retinal and opsin
- Night blindness
- Deficiency of vitamin A
Visual pathway photoreceptors to brain
- Message crosses 2 synapses before heading to brain
- Photoreceptor to bipolar cell
- Bipolar cell to ganglion
- Unmyelinated axons from ganglion converge on optic disc
- Penetrate wall of eye as optic nerve CNII
- Join at optic chiasm
- Travel through optic tract
- Travel to lateral geniculate of thalamus
- arrive at visual cortex of opposite occipital lobe
- Left to r lobe
Walls of orbit
- Superior
- Frontal
- Lesser wing of sphenoid
- Inferior
- Maxilla zygomatic palatine
- Medial
- Maxilla
- Ethmoid
- Lacrimal
- Frontal
- Lateral
- Zygomatic
- greater wing of sphenoid
- Frontal
Orbital margin bone
Frontal
Maxilla
Zygomatic
Periorbital Fascia
- Periosteum of orbit
- Orbit is surrounded in fat
Contents of superior orbital fissure
- SUp and inf branches of CN 3
- CN 4
- Lacrimal n V1
- Frontal V1
- Nasocilliary V1
- CN 6
- Sup opthalmic v
- Sympathetic fibers
Contents of optic canal
- CN 3
- Opthalmic artery
Contents of inferior orbital fissure
- Inf opthalmic v
- Infraorbital V2
- Zygomatic of V2
- Pterygopalatine ganglion branches
- Infraorbital vessels
Common tendinous ring
- CN 2
- Opthalmic a
- CN 3
- Nasociliary V1
- CN 6
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Fascia Bulbi (Tenons Capsule)
- Thin capsule of fibrous CT
- Allows for movement, attachment of extraoccular muscles
Nerve supply to orbit
- Optic 2
- Occulomotor 3
- Trochlear 4
- Opthalmic V1
- Maxillary V2
- Abducens 6
- Autonomics
Arterial orbit
- Opthalmic a
- Branch from ICA, travels through optic foramen, inferior and lateral to optic nerve
- Crosses optic nerve to reach medial orbit
- Lacrimal
- Supratrochleat
- Supraorbital
- Ciliary
- Lacrimal
- Ant/post ethmoid
- Dorsal nasal
- Central retinal (in optic nerve)
Arterial supply of orbit from ECA
- Infraorbital a from Maxillary
- Angular a from facial
- Superficial temporal a from ECA
- Tranverse facial a
Venous drainage
- Supraorbital
- Angular
- Facial
- Superior opthalmic
- Inferior opthalmic
- Infraorbital
- Opthalmic veins drain into cavernous sinus
- Pterygoid plexus