HAPE Flashcards
Iris
controls the amount of light allowed to enter the eye through the pupil
Cornea
covers both the pupil and the iris and is continuous with the sclera
The upper eyelid
covers a portion of the iris but does not normally overlay the pupil
Palpebral fissure
the opening between the eyelids
Conjunctiva
Covers the surface of the eye and the inner surfaces of the eyelids
Two Components of Conjunctiva
Bulbar conjunctiva covers most of the anterior eyeball
Palpebral conjunctiva lines the eyelids
Tarsal Plates
Contains parallel rows of meibomian glands (also known as tarsal glands)
Provides oily lubrication to the ocular surface
Levator palpebrae superioris
Primary muscle that raises the upper eyelid
Innervated by the oculomotor nerve, cranial nerve (CN) III
Müller’s muscle (superior tarsal)
Innervated by the sympathetic nervous system
Also contributes to lid elevation
Lacrimal Gland
Tears are produced at the lacrimal gland Drain through the lacrimal puncta Then pass through the canaliculi Into the lacrimal sac On into the nose through the nasolacrimal (tear) duct
Tear Film
protects the conjunctiva and cornea from drying
inhibits microbial growth
gives a smooth optical surface to the cornea
Lens
Suspended by ligaments (zonule fibers) - controls thickness of lens
Allows the eye to adjust focus on near or distant objects (accommodation)
Projects clear image on retina, the sensory part of the eye
Presbyobia
farsightedness caused by loss of elasticity of the lens of the eye, aging problem.
Three Chambers of Fluid in Eye
Anterior chamber (between the cornea and iris) Posterior chamber (between the iris and the lens) Both are filled with aqueous humor Vitreous chamber (between the lens and the retina) Filled with vitreous humor, maintains the shape of the eye
Optic Fundus
The posterior portion of the eye that is seen through the ophthalmoscope
Retina
a layer of tissue in the back of your eye that senses light and sends images to your brain
Macula
Part of the retina in the back of the eye. Fovea is in the middle of macula. Macula surrounds the fovea.
Fovea
Point of central vision. Tiny pit in the macula of the retina that provides the clearest vision of all
Optic Disc
entry point of optic nerve. the round spot on the retina formed by the passage of the axons of the retinal ganglion cells, which transfer signals from the photoreceptors of the eye to the optic nerve, allowing us to see
Choroid
the middle layer of tissue in the wall of the eye
Vitreous
the clear gel that fills the space between the lens and the retina of the eyeball
Pupillary constriction.
Sphincter Pupillae and is a parasympathetic response. Miosis
Pupillary dilation
Dilator pupillae. A sympathetic innervation. mydriasis and raising of upper eyelid (mullers muscle).
Light Test Abnormality
There may be a lesion in the optic tract. The eyes should move consensually. The initial sensory pathways are like those described for vision:
Retina, optic nerve (CN II), and optic tract, which diverges in the midbrain
The constrictor muscles of the iris are transmitted through oculomotor nerves (CN III)
Near Reaction
Pupils constrict
When gaze shifts from far to near object
Mediated by the oculomotor nerve (CN III)
Eyes converge
Bilateral medial rectus movement
Accommodation
Increased convexity of the lenses caused by contraction of the ciliary muscles
Pupillary dilation abnormality.
A lesion anywhere along this pathway may impair sympathetic effects that dilate the pupil and will cause miosis
Dilation Pathway
Starts in the hypothalamus
Passes down through the brainstem and cervical cord into the neck
The neurons travel with the brachial plexus at the lung apex
Returns to the superior cervical ganglion near the mandible
Follows the carotid artery or its branches into the orbit
Hyperobia
Farsightedness
Myopia
nearsightedness
diplopia
double vision
What may cause painless unilateral vision loss
Vitreous hemorrhage from diabetes or trauma Macular degeneration Retinal detachment Retinal vein occlusion Central retinal artery occlusion
What may cause PAINFUL unilateral vision loss
Usually in cornea or anterior chamber. Corneal ulcer
Uveitis
Traumatic hyphema
Acute angle closure glaucoma
Optic neuritis from multiple sclerosis
If associated with headache, a thorough neurologic examination is warranted
Immediate referral is warranted
What may cause bilateral and painless vision changes?
Vascular etiologies, stroke, or non-physiologic causes.
What may cause bilateral and PAINFUL vision changes?
Intoxication, trauma, chemical or radiation exposures
What may cause gradual vision loss?
Cataracts, glaucoma, or macular degeneration
What are moving specks or strands
Vitreous floaters.
What do blind spots (scotoma) suggest
lesions in the retina, visual pathway, or brain
Red Painless Eye
Subconjunctival hemorrhage and episcleritis
Red Eye with gritty sensation
Viral conjunctivitis and dry eye
Red painful eye
Corneal abrasions, foreign bodies, corneal ulcers, acute angle closure glaucoma, herpes keratitis, fungal keratitis, hyphema, and uveitis
What may cause diplopia?
Lesions in the brainstem or cerebellum
Weakness or paralysis of one or more extraocular muscles
horizontal diplopia from palsy of CN III or VI
vertical diplopia from palsy of CN III or IV
what may cause diplopia in one eye
ocular surface, cornea, lens, or macula
what may cause diplopia in one eyes
ocular surface, cornea, lens, or macula
Astigmatism
imperfection of the cornea or lens causing distortion while looking at near and far objects
Visual Acuity Test
Done with a snell test. Cover one eye. Read the lowest row possible. First # is how far in feet the person is standing. second # is distance at which a normal eye can read.
Visual Field Test
Static Finger Wiggle Test. Causes of anterior pathway defects
Glaucoma, optic neuropathy, optic neuritis, and compressive lesions
Posterior pathway
Stroke and chiasmal tumors
Bitemporal Hemianopsia
Lesion at the optic chiasm
Pituitary tumor
May involve only fibers crossing over to the opposite side
Fibers originate in the nasal half of each retina
Visual loss in temporal half of each field
Homonymous Hemianopsia
Left Homonymous Hemianopsia (Right Optic Radiation)
A complete interruption of fibers in the optic radiation
A visual defect like that produced by a lesion of the optic tract
Color Vision issues
Damage to optic nerve
Eye position and alignment
Esotropia (inward deviation) one eye inward other normal
Exotropia (outward deviation)
Hypertropia (upward deviation) one eye up other normal
Hypotropia (downward deviation)
Hyper/hypo-globus
Deviation in the globe position
Congenital abnormalities, lacrimal gland enlargement, mucocele, or ocular tumors. It’s like one eye socket up, another down.
Abnormal protrusion or proptosis
Thyroid eye disease, congenital abnormalities, orbital infections, or ocular tumors
Lagophthalmos
Failure of the eyelids to close
Neuromuscular palsy, trauma, and thyroid eye disease
Exposes the corneas to serious damage
Refer to ophthalmology
Ptosis
Drooping of the upper lid
Causes include senescence, myasthenia gravis, damage to the oculomotor nerve (CN III), and damage to the sympathetic nerve supply (Horner syndrome)
A weakened muscle, relaxed tissues, and the weight of herniated fat may cause senile ptosis
May be congenital
Entropcion
More common in the elderly
Inward turning of the lid margin
Ask the patient to squeeze the lids together and then open them
Ectropion
More common in the elderly
Outward turning of the lid margin
Exposes palpebral conjunctiva
Lid Retraction and Exophthalmos
A wide-eyed stare suggests retracted eyelids
Note the rim of sclera between the upper lid and the iris
Exophthalmos describes protrusion of the eyeball
In unilateral exophthalmos, consider thyroid eye disease (though usually bilateral), trauma, orbital tumor, and granulomatous disorders
Lacrimal Apparatus
Inspect for swelling or tearing Excessive tearing May be due to conjunctival inflammation, corneal irritation, impaired drainage, ectropion and/or nasolacrimal duct obstruction Dryness from impaired secretion Seen in Sjögren syndrome
Nasolacrimal Duct Obstruction
Ask the patient to look up
Press on the lower lid close to the medial canthus to compress the lacrimal sac
Look for fluid regurgitated out of the puncta into the eye
Avoid if area is inflamed and tender
Jaundice
A yellowish discoloration of the sclera or skin
Due to excess of the pigment bilirubin
Typically caused by obstruction of the bile duct, liver disease, or excessive breakdown of red blood cells
Hyphema
Blood in anterior chamber from trauma
Swinging Flashlight Test
Clinical test for functional impairment of the optic nerves
In dim light, note the size of the pupils.
After asking the patient to gaze into the distance, swing the beam of a penlight for 1 to 2 seconds first into one pupil, then into the other
Normally, each illuminated eye constricts promptly
The opposite eye also constricts consensually
Anisocoria
One pupil bigger than the other
Argyll Robertson Pupils
The pupils are small, irregular and usually bilateral
Do not react to light
They constrict with near vision and dilate with far vision (a normal near reaction)
Seen in neurosyphilis and rarely in diabetes
Strabismus
Eyes don’t look the same way at the same time. Cover uncover test.
Which Cranial Nerves are the extraocular muscles innervated by.
3,4,6. LR 6. SO 4. Rest are 3.
What does an absent red reflex mean
Opacity of the lens (cataract) Opacity of the vitreous Detached retina Mass Retinoblastoma
Papilledema
Swelling of the optic disc and blurred margins
Anterior bulging of physiologic cup
Elevated intracranial pressure (ICP)
Meningitis, intracranial mass or lesion, hemorrhage
AV Nicking
When the arterial walls lose their transparency, changes appear in the arteriovenous crossings.
Decreased transparency of the retina
The vein appears to stop abruptly on either side of the artery
Macular Degeneration
Important cause of poor central vision in older adults
Types include dry atrophic (more common but less severe) and wet exudative, or neovascular.
Cellular debris called drusen
“Hard” and sharply defined
“Soft” and confluent with altered pigmentation
Cotton-Wool Spots
Not getting enough blood supply, that’s why it appears more whiteish.
OD OS OU
OD (oculus dexter) right eye
OS (oculus sinister) left eye
OU (oculus uterque) both eyes
