1. Eyes
By Orest Kornetsky

2. Eye Anatomy – Why Study It?

3. 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?

4. History Vision difficulty? Eye pain? Childhood strabismus?
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,
Eye pain?
Photophobia – inability to tolerate light
Childhood strabismus?
A history of crossed eyes? AKA “lazy eye”
Redness or swelling?
Infections?

5. History cont. Excessive or lack of tearing?
May 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?

6. Anatomy of Eyelid
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
Caruncle physiology?

7. Inspecting External Ocular Structures
General
Note if facial expression is relax or tense
Eyebrows
Note if movement is symmetrical
Eyelids and lashes
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)

8. Abnormalities in Eyelids
Ectropion
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
The lower lid rolls in
Foreign body sensation

9. 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

10. Lesions on the Eyelids Blepharitis Chalazion Hordeolum (Stye)
Inflammation of eyelids
Staph or dermatitis
Burning, itching, tearing, foreign body sensation, pain
Chalazion
A cyst in or an infection of meibomian gland
Nontender, firm, overlying skin freely movable
Hordeolum (Stye)
Localized Staph infection of hair follicle at lid margin
Painful, red, swollen, purulent

11. Anatomy of the Eye
Lacrimal apparatus provides irrigation of conjunctiva
Lacrimal 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

12. Inspecting the Lacrimal Apparatus
Inspect for bulges or pressure near canaliculi
Dacryocystitis
Inflammation of the lacrimal sac and/or nasolacrimal duct
Dacryoadenitis
Infection of lacrimal gland
Dacryoadenitis
Dacryocystitis

13. Anatomy of Extraocular Muscles
4 rectus (straight)
2 oblique
Innervations
SO4 – Superior oblique m.
CN IV (trochlear n.)
LR6 – Lateral rectus m.
CN VI (abducens n.)
AO3 – All other muscles
CN III ( Trigeminal n.)

14. Extraocular muscle movement

15. Extraocular Muscle Dysfunction

16. Anatomy of the Eyeball – Outer Layer
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)

17. Inspection Conjunctiva Sclera
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

18. Vascular Disorders of Eye
Conjunctivitis
“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
Red halo around the iris and cornea
Pupils may be irregular due to swelling
Symptoms: photophobia, blurred vision, throbbing pain

19. Inspecting Cornea and Lens
Corneal abrasion
Assess by shining a light and observing from the side
Pupillary light reflex
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

20. Anatomy of the Eyeball – Middle Layer
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

21. 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
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
Excessive cup-disc ratio of optic disc

22. Disorders of Opacity of Lens
Cataract

23. Anatomy of the Eyeball – Inner Layer
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

24. Inspecting the Ocular Fundus
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

25. 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
Scleral crescent or pigment crescent pic?

26. Visual pathways

28. Testing Visual Reflexes
Pupillary light reflex
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
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

29. Testing Visual Accuity
Snellen Eye Chart
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

30. Testing Visual Fields Confrontation test
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

31. Testing Ocular Muscle Function
Cover Test
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
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
Nystagmus
Fine oscillating movements around the iris
Normal at extreme lateral gaze

32. 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
Color vision – due to inherited X-linked 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

33. Developmental Considerations – Aging
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

34. Developmental Considerations - Aging
Arcus senilis – gray-white arc seen around the cornea. Due to deposition of lipids. No effect on vision
Xanthelasma – raised yellow plaques. Normal

35. EYE HOPE YOU HAVE A GREAT DAY!!!
THE END
EYE HOPE YOU HAVE A GREAT DAY!!!