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Eyes
By Orest Kornetsky
Eye Anatomy – Why Study It?
Why should you care?
Optometrist – Doctor of optometry, 4 year
undergrad + 4 year optometry school
 Ophthalmologists – Medical doctors
 In general, optometrists practice primary
and preventive eye care, while
ophthalmologists perform eye surgery
 What do nurses do?

History
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Vision difficulty?
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Eye pain?
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Photophobia – inability to tolerate light
Childhood strabismus?
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Halos around lights – in glaucoma
Scotoma – blind spot in visual field – in
glaucoma, optic nerve, and visual pathway
disorder
Night blindness – Vit A deficiency, glaucoma,
A history of crossed eyes? AKA “lazy eye”
Redness or swelling?

Infections?
History cont.
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Excessive or lack of tearing?
 May
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be due to irritants or obstruction in drainage
Past history of ocular problems?
Glaucoma? Family history?
Use of glasses or contact lenses?
When tested last?
Any medications?
Anatomy of
Eyelid
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Eyelids (L. palpebrae) protect the
cornea and eyeball from injury
Canthi (sing. canthus) are corners of
the eye, also called angles of eye
Caruncle is located near medial
canthus and contains sebaceous
glands
Tarsal plates are made of connective
tissue and strengthen eyelid. They
contain meibomian (tarsal) glands
which secrete lipid to create airtight
seal when closed and also prevent
eyelids from sticking together
Inspecting External Ocular
Structures

General
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Eyebrows
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Note if facial expression is relax or
tense
Note if movement is symmetrical
Eyelids and lashes
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Note if any redness, swelling,
discharge or lesions
Note if eyelid closes completely and if
drooping


Pallor of lower lid is good indicator of
anemia
For upper eyelid, use applicator stick
to fold the eyelid over (Fig 14-17)
Abnormalities in Eyelids
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Ectropion
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Lower lid rolls out, causing an
increase in tearing
The eyes feel dry and itchy due to
inappropriate itching
Increase risk for inflammation
Occurs mostly in elderly due to
atrophy of elastic tissue
Entropion
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The lower lid rolls in
Foreign body sensation
Abnormalities in Eyelids

Periorbital edema
 May
occur with local
infection of systemic
condition (CHF)

Ptosis
 Occurs
with
neuromuscular
weakness (myasthenia
gravis) or CN III
damage
Lesions on the
Eyelids

Blepharitis
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Chalazion
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Inflammation of eyelids
Staph or dermatitis
Burning, itching, tearing,
foreign body sensation, pain
A cyst in or an infection of
meibomian gland
Nontender, firm, overlying
skin freely movable
Hordeolum (Stye)
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
Localized Staph infection of
hair follicle at lid margin
Painful, red, swollen, purulent
Anatomy of the Eye

Lacrimal apparatus
provides irrigation of
conjunctiva
glands – secrete
lacrimal fluid (tears)
 Lacrimal ducts – lacrimal
fluid to conjunctiva
 Lacrimal canaliculi
(puncti) – drain fluid into
 Nasolacrimal duct –
conveys lacrimal fluid to
nasal cavity
 Lacrimal
Inspecting the Lacrimal Apparatus
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
Inspect for bulges
or pressure near
canaliculi
Dacryocystitis
 Inflammation
of the
lacrimal sac and/or
nasolacrimal duct

Dacryoadenitis
 Infection
of lacrimal
gland
Dacryoadenitis
Dacryocystitis
Anatomy of Extraocular Muscles
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4 rectus (straight)
2 oblique
Innervations
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SO4 – Superior oblique m.
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LR6 – Lateral rectus m.
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CN IV (trochlear n.)
CN VI (abducens n.)
AO3 – All other muscles

CN III ( Trigeminal n.)
Extraocular muscle movement
Extraocular Muscle Dysfunction
Anatomy of the Eyeball – Outer Layer
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Sclera – tough
protective white
covering (posterior
5/6)
Cornea –
transparent part of
the fibrous coat
covering the anterior
of the eyeball
(anterior 1/5)
Conjunctiva –
transparent
protective covering
of exposed part of
eye (palpebral
conjunctiva covers
inside of eyelash)
iris
Corneal reflex – lightly touching the eye with cotton
stimulates a blink.
Trigeminal n. (afferent)
Facial n. (efferent)
Inspection

Conjunctiva
 Sliding
the lower lids down, observe
for redness on conjunctiva and if
eyeball looks moist and glossy
 Reddening may be pathogenic

Sclera
 Should
be white, although may
have gray-blue hue
 Might contain yellowish fatty
deposits beneath the lids

Yellowing of sclera indicates jaundice
Vascular Disorders of Eye
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Conjunctivitis
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“Pink eye”
Due to bacterial, viral, allergic, or chemical
irritation
Redness throughout the conjunctiva, but
usually clear around the iris
Purulent discharge usually common
Symptoms: itching, burning, foreign body
sensation
Iritis
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Red halo around the iris and cornea
Pupils may be irregular due to swelling
Symptoms: photophobia, blurred vision,
throbbing pain
Inspecting Cornea and Lens

Corneal abrasion


Assess by shining a light
and observing from the
side
Pupillary light reflex
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Charted according to size
of pupil
Charted as a ratio of before
light/after light (3/1)
A sluggish response may
be caused by increased
ICP
No response may indicate
neurological damage
How to chart
pupillary light reflex?
PERRLA:
Pupils Equal, Round,
React to Light and
Accommodation
Anatomy of the Eyeball –
Middle Layer
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Canal of Schlemm
Choroid – provides vascularity to
retina
Pupil – variable-sized, black circular
or slit shaped opening in the center
of the iris that regulates the amount
of light that enters the eye. Appears
black because most of the light
entering the pupil is absorbed by the
tissues inside the eye.
Lens – biconvex disc controlled by
the ciliary muscle to produce far
vision when flat
Anterior chamber

Aqueous humor is produced by the
ciliary body and secreted into
posterior chamber of eye.
 From there, aqueous humor travels
to the anterior chamber where it
exits through the Canal of Schlemm
 Determines intraocular pressure
Increase leads to
Glaucoma
Vascular Disorders of Eye
Physiology review:
Aqueous humor is produced by the ciliary body
and secreted into posterior chamber of eye. From
there, aqueous humor travels to the anterior
chamber where it exits through the Canal of Schlemm

Glaucoma
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Excessive pressure in eye
due to blockage of outflow
from anterior chamber
This puts pressure on optic
nerve
Redness around the iris,
dilated pupils
Symptoms: sudden
clouding of vision, sudden
eye pain, and halos around
lights
Disorders of Opacity of Lens

Cataract
Anatomy of the Eyeball –
Inner Layer
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Retina – visually
receptive layer where
light waves are changed
to nerve impulses
Optic disc – area where
the optic nerve enters the
eyeball
Fovea centralis – area of
most acute vision
Inspecting the Ocular Fundus
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Using an ophthalmoscope to inspect
the internal surface of the retina,
anterior chamber, lens, and vitreous.
Darken the room to dilate the pupils
Remove eye glasses, contacts may
stay in
Ask person to stare at distant object
Hold ophthalmoscope close to your
eye and move to within a few inches
of the person’s face
A red glow filling the pupil is called
the red reflex and is caused by light
reflecting off the retina

Cataracts appear as opaque black
areas against the red reflex
Inspecting the Optic Disc and Retina

Normal optic disc is:
 Yellow-orange
to pink
 Round
or oval
 Distinct margins

Normal retina is:
 Arteries
in each
quadrant
 Arteries are bright red
Visual pathways
Testing Visual Reflexes
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Pupillary light reflex
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Constriction of pupils when bright light shines on the retina
Direct light reflex – constriction of same sided pupil
Consensual light reflex – simultaneous constriction of both
pupils
The impulse is carried afferently by CN II and efferently by CN III
Accommodation
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Adaptation of eye for near vision
Ask person to focus on distant object (dilates the pupils). Then
ask person to shift gaze to near object few inches away. A
normal response is pupillary constriction and convergence of
axes of the eyes
Testing Visual Accuity
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Snellen Eye Chart
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Standing 20 feet from the
chart
Test one eye at a time by
covering the other eye
Leave contact lenses and
glasses on, unless the
glasses are reading
glasses
Normal vision is 20/20
Near vision

Use Jaeger card (smaller
version of Snellen chart) or
just read newspaper
Testing Visual Fields
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Confrontation test
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Measures peripheral vision
compared to examiner
(assuming examiner’s vision is
normal)
Both examiner and pt cover
one eye with a card, stand
about 2 feet away, and
maintain eye contact
Advance finger, starting from
periphery, and ask patient to
say “now” when the finger is
first visible
Inability to see when the
examiner sees suggests
peripheral field loss
Testing Ocular Muscle
Function
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Cover Test
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Detects deviated alignment of eyes
Ask pt. to stare straight at your nose and
cover one of the pt.’s eyes with a card
While noting the uncovered eye, move
away the card
A normal response is a steady fixed gaze
Diagnostic Position Test
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Ask pt. to hold head straight and move
finger in all positions, holding it about 12
inches away
A normal response is parallel tracking of
the objects with both eyes
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Nystagmus
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Fine oscillating movements around the iris
Normal at extreme lateral gaze
Developmental Considerations –
Infants and Children

Strabismus – must be detected
and treated early to prevent
permanent disability
Esotropia – inward turning of eye
 Exotropia – outward turning of eye
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Color vision – due to inherited Xlinked recessive trait, occurs more
often in boys
External eye structures – an
upward lateral slope together with
epicanthal folds occurs in Down
syndrome
Ophthalmia neonatum –
conjunctivitis due to bacteria, virus,
or chemical irritation
Developmental Considerations –
Aging
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Decrease in visual
acuity, diminished
peripheral vision
Ectropion (drooping of
lower lid) or entropion
(eyelids turning in)
Pinguecula – yellow
nodules due to
thickening of
conjunctiva as a result
of prolonged exposure
to sun, wind, and dust
Developmental Considerations Aging
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Arcus senilis – graywhite arc seen around
the cornea. Due to
deposition of lipids.
No effect on vision
Xanthelasma – raised
yellow plaques.
Normal
THE END
EYE HOPE YOU HAVE
A GREAT DAY!!!