(7) Eyes & Visual Pathway Flashcards
1
Q
List the 7 bones of the orbit:
A
- Frontal
- Sphenoid
- Ethmoid
- Lacrimal
- Maxilla
- Zygomatic
- Palatine
2
Q
List the 3 anatomical structures of the eyelid:
A
- Palpebral fissure (open area b/w eyelids)
- Tarsal plates
- Levator palpebrae muscle
3
Q
What anatomical feature is best described: “connective tissue at each corner with meibomian glands that produce oily lubricant for surface of eye”
A
Tarsal plates
4
Q
What innervates the levator palpebrae muscle and what is its function?
A
CN III (Oculomotor) innervates the levator palpebrae muscle; elevates the eyelid
5
Q
List 3 functions of the eyelid:
A
- Distribute tears across eye surface
- Limit light that enters eye
- Together with eyelashes, protect from FB (blinking mechanism)
6
Q
What are 3 chambers of the eye?
A
- Anterior – between cornea and iris
- Posterior – between iris and lens
- Vitreous – between lens and retina
7
Q
List 5 anatomical structures of the anterior chamber of the eye: “CSCIP”
A
- Conjunctiva
- Sclera
- Cornea
- Iris
- Pupil
8
Q
Define Conjunctiva and its 2 parts:
A
Vascular, clear mucous membrane
2 continuous parts:
Bulbar conjunctiva – covers anterior eye/sclera
Palpebral conjunctiva – lines the eyelids
9
Q
What is the function of the Conjunctiva?
A
Provides protection/lubrication to cornea and sclera; keep things from getting to the back of the eye
10
Q
Define Sclera:
A
White of the eye; Opaque, fibrous, protective, outer layer
11
Q
Define Cornea:
A
- transparent
- avascular
- covers the Iris & Pupil
12
Q
Define Limbus:
A
border between the cornea and the sclera
13
Q
Define Iris and its function:
A
Colored, circular muscle that controls constriction/dilation of the pupil and amount of light entering
14
Q
Dilation with light? Sympathetic or parasympathetic? Drug influence?
A
Dilation occurs with less light, sympathetic innervation. Can be seen with cocaine/ecstasy.
15
Q
Constriction with light? Sympathetic or parasympathetic? Drug influence?
A
Constriction occurs with bright lights, parasympathetic innervation. Can be seen with opiates, fentanyl, heroin.
16
Q
Define Pupil:
A
Eye’s aperture, which allows light to travel through eye to the retina
17
Q
Describe the 3 functions of Tears:
A
- Prevent excessive drying of the surfaces of the conjunctiva & cornea
- Provide nutrition and oxygen to surface structures
- Possess antibacterial properties
18
Q
Describe the 3 layers of Tears and their associated glands:
A
- Mucous layer – Conjunctival cells
- Lipid/oil layer – Meibomian glands
- Watery layer – Lacrimal glands
19
Q
Describe the Lacrimal Apparatus:
A
The lacrimal apparatus is a group of structures responsible for generating, and collecting and draining the Tear fluid
Lacrimal gland → sweeps across eye to two punctum medially → Drain into lacrimal sac, down nasolacrimal duct → into inferior nasal turbinate
20
Q
List 2 anatomical structures of the posterior chamber of the eye:
A
- Lens
- Ciliary body
21
Q
Define Lens:
A
- suspended by ligaments (zonule fibers)
- muscles of the ciliary body control the thickness of the lens
- Allows eye to focus on near/distant objects (accommodation)
22
Q
Define aqueous humor:
A
Ciliary body produce aqueous humor that fills posterior chambers to anterior chamber via pupil → Drains out through canal of Schlemm → controls the intraocular pressure
23
Q
Describe the vitreous body and its function:
A
Gelatinous material posterior to the lens that maintain eye shape
24
Q
Describe the Optic Fundus and its (7) components:
A
The fundus of the eye is the interior surface of the eye includes the Retina, Choroid, Macula, Fovea, Optic disc, Physiologic cup, Retinal vessels
25
Describe the Choroid:
Vascular tissue between sclera and retina, feeds nerves of lateral retina
26
Components of the Retina:
Neural retina contains the visual receptor cells (the rods and cones)
Rods: absorbs a wide bandwidth of light
Cones: absorbs color of light
27
Describe Macula:
Functional center of the retina with high resolution color vision (cones)
28
Describe Fovea:
Center of macula; central vision (has most cones)
29
Describe Optic Disc:
Where optic nerve exits & retinal vessels enters the eye
30
Describe Physiologic Cup:
White, cup-like area in center of optic disc;
*in glaucoma, when there is damage to the optic nerve, the cupping increases*
31
List the 5 Extra-ocular Muscles and its associated innervation: "(LR6 SO4) AO3"
Superior Rectus (CN III; oculomotor)
Inferior Rectus (CN III; oculomotor)
Medial Rectus (CN III; oculomotor)
Lateral Rectus (CN VI; abducens)
Superior Oblique (CN IV; trochlear)
Inferior Oblique (CN III; oculomotor)
32
List the (17) ROS for the eyes:
1. Last eye exam and results
2. Vision changes
3. Glasses or contacts
4. Prior surgery or injury
5. Eye medications such as drops
6. Eye pain
7. Redness
8. Excessive tearing or dryness
9. Discharge
10. Double vision (diplopia)
11. Blurred vision
12. Scotomata (spots/specks)
13. Photophobia
14. Flashing lights
15. Glaucoma
16. Cataracts
17. Icterus
33
"The entire area seen by an eye when it looks at a central point"
Visual Field Center
-has the greatest visual acuity and color sensitivity
-photopic "light-adapted"
34
"15 degrees temporal to line of gaze"
"sits in the part of your retina where the optic nerve exits the eye, and there are no photoreceptors (rods or cones) in the optic disk, and, therefore, there is no image in this area"
Blind Spot
35
"Overlap of both fields of vision; producing a single image from the two disparate monocular images"
Binocular vision
-The images of the corresponding (binocular) space are slightly different in each eye. The nervous system fuses these disparate binocular images to produce a single image (e.g., of the pencil located an arm’s length away).
36
List the (6) anatomic structures of the eye through which reflected light must pass in order to strike upon the retina (optic pathway).
Reflected light travels from Cornea → Anterior Chamber → Pupil → Lens → Vitreous body → be focused on photoreceptors in the Retina → the projected image on the Retina is upside down and reversed right to left
37
What are (2) reasons pupillary size changes?
1. In response to light
2. To focus on near object
38
What are (2) types of light reaction? What nerves are stimulated (sensory and motor nerve)?
1. Direct reaction; pupillary constriction of stimulated eye
2. Consensual reaction; constriction of opposite pupil
Sensory - afferent - Optic (CN II)
Motor - efferent - Oculomotor (CN III)
39
Define Near Reaction and its associated nerve:
Pupil constriction when shifting gaze from far object to near object
Mediated by oculomotor nerve (CN III)
40
What are (2) reactions that occur coincidentally when testing near vision:
1. Convergence – medial rectus movement
2. Accommodation – increased convexity of the lenses due to contraction of ciliary muscles; change in lens shape brings near objects into focus
41
List (3) vision abnormalities:
1. Myopia
2. Hyperopia
3. Presbyopia
42
Define Myopia:
Nearsightedness (difficulty seeing distant objects clearly)
Most common cause of impaired vision <40
43
Define Hyperopia:
Farsightedness (difficulty seeing close objects clearly)
44
Describe the expected age-related physical changes for the eyes, including 3 conditions age-related eye changes:
In middle age, the lens of the eye becomes less flexible and less able to thicken and thus less able to focus on nearby objects, a condition called presbyopia.
-senile ptosis
-cataract
-dry macular degeneration
45
Describe the visual field 'Horizontal Defect' resulting from lesions:
Occlusion of the central retinal artery may cause a horizontal (altitudinal) defect. Ischemia of the optic nerve can produce a similar defect.
46
Describe the visual field 'Blind Right Eye Defect' (Right Optic Nerve) resulting from lesions:
A lesion of the right optic nerve and the right eye itself, which produces unilateral monocular blindness
47
Describe the visual field 'Bitemporal Hemianopsia' (Optic Chiasm) resulting from lesions:
A lesion (pituitary tumor) at the optic chiasm. May involve only fibers crossing over to the opposite side; since fibers originate in the nasal half of each retina, visual loss involves the temporal half of each field.
48
Describe the visual field 'Left Homonymous Hemianopsia' (Right Optic Tract) resulting from lesions:
A lesion of the right optic tract that interrupts fibers originating on the same side of both eyes. Visual loss in the eye is similar (homonymous) and involves half of each field (hemianopsia).
49
Describe the visual field 'Homonymous Left Superior Quadrantic Defect' (Right Optic Radiation, Partial) resulting from lesions:
A partial lesion of the optic radiation in the temporal lobe, may involve only a portion of the nerve fibers, producing "pie in the sky" homonymous quadrantic.
50
Describe the visual field 'Left Homonymous Hemianopasia' (Right Optic Radiation) resulting from lesions:
A complete interruption of fibers in the optic radiation, which produces a visual defect similar to that produced by a lesion of the optic tract.
51
Describe (2) abnormalities of the eyebrows:
1. Seborrheic dermatitis of eyebrows (scaliness)
2. Absence of lateral 1/3 of eyebrow (due to hypothyroidism)
52
List (8) abnormalities of the eyelids.
1. Exophthalmos
2. Ptosis
3. Blepharitis
4. Xanthelasma
5. Entropion
6. Ectropion
7. Stye (hordeolum)
8. Chalazion
53
Describe Exophthalmos and 'caused by':
Protrusion of the eyeball and lid retraction (rim of sclera visible between upper lid and iris)
Caused by: hyperthyroidism
54
Describe Ptosis and 'caused by':
Drooping of upper eyelid
Caused by: myasthenia gravis, oculomotor nerve palsy/damage, Horner syndrome, senile ptosis (age related change), congenital
55
Define Blepharitis and 'caused by':
Inflammation of eyelids at base of hair follicles; red inflamed lid with crusting
Caused by: most common chronic staphylococcus aureus
56
What condition is best described? Determine the cause:
Benign, raised, yellow, well-circumscribed cholesterol-filled plaque to the eyelids
Xanthelasma
Caused by: Hyperlipidemia and primary biliary cirrhosis
57
Define Entropion:
Inward turning of lid margin, where lashes abrade cornea
58
Define Ectropion:
Outward turning of lid margin, leading to dry eyes
59
What condition is described?
Painful, tender red lump at inner or outer margin of eyelid; Points out (like a pimple)
Stye (hordeolum)
60
What best describe the condition?
Nontender, painless nodule on eyelid; Usually points inside the lid
Determine the cause:
Chalazion
Caused by: blocked Meibomian gland
61
List (2) abnormalities of the External Eye:
1. Dacryocystitis
2. Raccoon Eyes (periorbital ecchymosis)
62
What condition is best described?
Infection or inflammation of the lacrimal sac due to a blockage in the nasolacrimal duct; Painful, red, swollen, tearing
Dacryocystitis
*Pressure applied to lacrimal sac may push thick material through punctum (avoid if inflamed)*
63
What can cause Raccoon Eyes 'Periorbital Ecchymosis':
Fractures of anterior fossa, basilar skull fracture.
*Watch for CSF, rhinorrhea, vision changes*
64
List (4) abnormalities of the Conjunctiva:
1. Conjunctivitis
2. Pinguecula
3. Pterygium
4. Subconjunctival hemorrhage
65
Define Conjunctivitis:
-Redness pattern
-Pain
-Vision
-Discharge
-Pupil
-Cornea
Determine the causes:
Inflammation of conjunctiva
-Redness pattern: diffuse dilatation of conjunctival vessels, redness maximal peripherally
-Pain: mild discomfort rather than pain
-Vision: blurry vision but no lasting damage
-Discharge: watery, mucoid discharge
-Pupil: not affected
-Cornea: clear
Caused by: viral, bacterial, allergic, chemical
66
What best describe the condition?
Benign, yellowish, raised nodule of bulbar conjunctiva
*Often nasal side, can be temporal, does NOT cross limbus*
Determine the cause:
Pinguecula
Caused by: dry eyes, dust, sunlight.
67
What best describe the condition? Determine the cause:
Triangular, fleshy tissue growth of bulbar conjunctiva *can progress to cover part of cornea and affect vision*
Pterygium "Surfer’s Eye”
Caused by: dry eyes, wind, dust, UV light
68
Define Subconjunctival hemorrhage:
-Redness pattern
-Pain
-Vision
-Discharge
-Pupil
-Cornea
Determine the causes:
Sharply demarcated bright red spot covering sclera due to rupture and leaking blood vessels
-Redness pattern: sharply demarcated red area
-Pain: painless
-Vision: none
-Discharge: none
-Pupil: not affected
-Cornea: clear
*Heals on its own (days to weeks)*
Caused by: sneezing, increased venous pressure via cough, trauma, bleeding disorders
69
List (4) abnormalities of the Sclera:
1. Icterus
2. Blue sclera
3. Episcleritis
4. Scleritis
70
Define Icterus 'Jaundice' and 'caused by':
Yellowing of the Sclera
Caused by: hepatitis, other liver disease, hyperbilirubinenemia
71
Blue Sclera can be caused by:
Congenital (osteogenesis imperfecta 'brittle bone disease') or acquired diseases
72
What condition is best described?
Episcleral tissue between conjunctiva and sclera, where localized or diffuse bright red or pink bulbar injection can appear
*vessels appear movable over the scleral surface & can blanch*
*discomfort, no vision changes or discharge*
Determine the cause:
Episcleritis
Caused by: often idiopathic (unknown), but can be autoimmune (RA, Sjogren)
*Typically benign and self limiting*
73
What condition is best described?
Inflammation of episclera and sclera; immovable vessels that do not blanch
*More serious, more painful red eye than episcleritis*
*Loss of vision if not treated promptly – refer!*
Determine the cause:
Scleritis
Caused by: >50% involve underlying systemic disease (RA, Lupus)
74
List 2 abnormalities of the Cornea:
1. Corneal abrasion
2. Corneal ulcer
75
Define Corneal Abrasion:
Scratch of cornea that can be painful with tearing, redness, light sensitivity, FB sensation
76
What condition is best described?
gray to white opaque or translucent area on cornea; open sore on the cornea
Determine the causes:
Corneal Ulcer
Caused by: infection, severe dry eyes, etc.
77
List 2 abnormalities of the Anterior Chamber of the Eye (cornea and iris):
1. Hyphema
2. Acute Angle-Closure Glaucoma (obstructed anterior chamber angle)
78
What condition is best described?
Blood collection in anterior chamber with painful, photophobia, blurry/clouded/blocked vision *Emergent referral!*
Determine the cause:
Hyphema
Caused by: Trauma, blood clotting disorders, vascular abnormalities
79
Define Glaucoma and cupping:
Condition when aqueous humor builds up, and cause increase pressure to the eye and damage to the optic nerve
Cupping: optic nerve fibers begin to die, causing the cup to enlarge in comparison to the optic disc
80
Describe the difference between Acute Angle-Closure Glaucoma vs. Primary Open-Angle Glaucoma:
Acute Angle-Closure Glaucoma:
- acute condition
- increase in pressure is rapid and sudden
- crescent shadow on the medial side of the iris (angle of anterior chamber)
Primary Open-Angle Glaucoma:
- chronic condition
- increase in pressure is small and slow
- 2nd leading cause of blindness in US
81
Acute Angle-Closure Glaucoma:
-Redness pattern
-Pain
-Vision
-Discharge
-Pupil
-Cornea
-Redness pattern: deeper vessels radiating from the limbus are dilated, reddish violet flush (ciliary injection); may be diffuse redness instead
-Pain: severe, aching, deep
-Vision: decreased vision
-Discharge: none
-Pupil: dilated and fixed
-Cornea: steamy and cloudy
82
What condition is an abnormality of the iris?
-Redness pattern
-Pain
-Vision
-Discharge
-Pupil
-Cornea
Determine the cause:
Acute Iritis
-Redness pattern: deeper vessels radiating from the limbus are dilated, reddish violet flush (ciliary injection); may be diffuse redness instead
-Pain: moderate, aching, deep, pain
-Vision: decreased vision, photophobia
-Discharge: none
-Pupil: small and irregular
-Cornea: clear or slightly cloudy, ciliary injection around limbus
Caused by: eye injury or systemic infection (herpes zoster, TB, autoimmune diseases)
83
Corneal abrasion/ulcer:
-Redness pattern
-Pain
-Vision
-Discharge
-Pupil
-Cornea
-Redness pattern: deeper vessels radiating from the limbus are dilated, reddish violet flush (ciliary injection); may be diffuse redness instead
-Pain: moderate (abrasion) to severe (ulcer) pain, FB sensation
-Vision: decreased vision, photophobia
-Discharge: teary, watery or purulent discharge
-Pupil: not affected
-Cornea: depends (ulcer; gray to white opaque or translucent area on cornea)
84
List 4 pupillary abnormalities:
1. Adie Pupil (Tonic Pupil)
2. Horner Syndrome
3. Argyll Robertson Pupils
4. Marcuss-Gunn Pupil
85
Define Adie Pupil 'Tonic Pupil':
-Vision:
-Pupil:
-Light Reaction:
-Accommodation:
-Denervation:
-Vision: blurry
-Pupil: dilated, regular, unilateral
-Light reaction: slow or absent
-Accommodation: slow constriction with near vision
-Denervation: parasympathetic
*Female predominance*
86
Define Horner Syndrome:
-Pupil:
-Light Reaction:
-Denervation:
-Pupil: constricted, unilateral
-Light Reaction: react briskly to light and near effort, dilate slowly especially in dim light, Anisocoria (unequal pupils) >1mm
-Denervation: sympathetic nerves to face and eye one side of body *Ipsilateral ptosis of upper eyelid, often loss of sweating on forehead (anhidrosis)*
87
Define Argyll Robertson Pupils
-Pupil
-Light Reaction
-Accommodation
Determine the cause:
-Pupil: small, irregular, bilateral pupils
-Light Reaction: no reaction to light
-Accommodation: normal near reaction
Caused by: Neurosyphilis and diabetic neuropathy
88
Define Marcuss-Gunn Pupil:
- Light Reaction
Determine the cause:
light in normal eye causes constriction to both eyes, BUT light to the affected eye will cause incorrect response to both eyes
Caused by: optic nerve damage
89
List and define an abnormality of the Lens:
Determine the cause and treatment:
Cataracts: clouding of the lens and prevent clear vision
*Common with age, treated with surgery*
90
List and describe 2 abnormalities of extra-ocular muscles:
1. Strabismus: misalignment of the eyes
2. Nystagmus: patho/physio rhythmic abnormal eye movements with a slow pull away and then back to target, can be normal when the eyes are moved really far laterally
91
List 4 abnormalities of the Retina:
1. Diabetic Retinopathy
2. Hypertensive Retinopathy
3. Macular Degeneration
4. Retinal Detachment
92
Describe non-proliferative vs proliferative diabetic retinopathy:
Non-proliferative: tiny blood vessels leak (microaneurysms) causing swelling of the retina
- Ring of hard exudates (white spots) located superotemporally, indicating retinal hemorrhage & cotton wool spots
- Common reason diabetics lose vision
Proliferative: More advance stage, where new vessels grow out of the retina (neovascularization), and can bleed into the vitreous.
- High risk for visual loss
93
What can Hypertensive Retinopathy cause?
Chronic elevated blood pressure can cause:
- Arteriovenous (A/V) nicking
- Flame-shaped hemorrhage
- Cotton wool spots
- Optic disc edema
94
Define Macular degeneration: 'Dry vs Wet'
Dry: thinning macula due to AGE and clumps of protein (drusen) form.
- Slow loss of central vision
- More common; less severe
Wet: scarring of the macula when new abnormal blood vessels grow under the retina and may leak blood/fluids.
- Faster vision loss
- More serious; less common
95
Define Retinal detachment:
Retina becomes separated from underlying supportive tissue, and forms a “curtain” descending from the top of eye or across from the side
*If not reattached soon, permanent vision loss may occur*
96
Describe (3) abnormalities of the retinal vessels:
1. Focal or generalized narrowing of lumen and light reflex
2. Copper Wiring: Thickening of retinal arterioles and increase light reflex, appear orange/yellow instead of red
-w/ chronic HTN
3: AV nicking: arterial wall looses transparency, veins appears to top abruptly on either side
-w/ HTN retinopathy
97
List and define an abnormality of the optic disc:
Determine the cause:
Papilledema:
-pink, hyperemic optic disc
-appears swollen
-blurred margins
-physiologic cup not visualized
Caused by: meningitis, mass, lesions, hemorrhage
98
Define Peripheral Visual Field:
-more sensitive to dim light; scotopic (dark-adapted)
-operates under low illumination.
-has little color sensitivity and poor spatial acuity
