sensory system (eye) part 2 leslie lehmkuhl, rn 2009

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SENSORY SYSTEM (Eye)Part 2

Leslie Lehmkuhl, RN 2009

SECTION II ADULT HEALTH NURSING

UNIT 12 NURSING CARE OF THE CLIENT: MOBILITY, COORDINATION, AND REGULATION

CHAPTER 39


Eye Anatomy The eye is the organ of sight, a

nearly spherical hollow globe filled with fluids (humors).

The outer layer or tunic (sclera, or white, and cornea) is fibrous and protective.

The middle tunic layer (choroid, ciliary body and the iris) is vascular.

The innermost layer (the retina) is nervous or sensory.

The fluids in the eye are divided by the lens into the vitreous humor (behind the lens) and the aqueous humor (in front of the lens). The lens itself is flexible and suspended by ligaments which allow it to change shape to focus light on the retina, which is composed of sensory neurons


Sensory Disorder The Eye

Accessory structures: eyebrows, eyelashes, eyelids, lacrimal apparatus, conjunctiva

• Lacrimal apparatus- manufacture and drains tears, contains lysozyme a bactericidal enzyme

• Conjunctiva- membrane that lines inner aspect of eyelids and anterior surface of the eyeball

Anatomy of the eye 3 layers: sclera, choroid,

and retina• Sclera- outermost layer of

the eye, made of white connective tissue

• cornea• Choroid- dark brown

membrane that lines internal area of the sclera, vascular layer

• pupil• Retina- nervous tissue

membrane that receives images and transmits impulses to the optic nerve

• Cones, rods, optic disk


Sensory Disorder The eye is divided into

two chambers by the crystalline lens Anterior chamber-

contains aqueous humor• Watery fluid• Maintains normal

intraocular pressure Posterior chamber-

contains vitreous humor• Jelly like• Gives shape to the

eyeball

Physiology of vision Light must travel

• Through the cornea• Through the aqueous

humor• Through the pupil• Through the lens• Through the vitreous humor• To the cones and rods of

the retina Processes necessary to

form an image: refraction, accommodation, constriction, convergence


Sensory Disorder Diagnostic eye

examinations Snellen test- screening test

which assesses visual acuity

• Patients stands 20 feet away covering one eye, and then the other

• 20/20 normal vision Color vision charts Amster grid Refraction- determines

refractory errors using retinoscope or lenses

Refractory errors Astigmatism- defect in

curvature of the eyeball surface causing blurred vision

Strabismus- cross eyed vision due to asymmetry

Myopia- inability to see distance (nearsighted)

Hyperopia- inability to see close (farsighted)

Presbyopia- changes in accommodation due to aging (usually in 40s)


Vision Retinal image


Vocabulary Refraction: light rays

are bent as they pass through colorless structures in eye –allowing light to focus on retina

Accommodation: eye can focus on objects at different distances image on retina is changed by curvature of lens


Vocabulary Constriction:size of

pupil controlled by dilator and constrictor muscles of iris

Convergence: convergence medial movement of both eyes allows light rays to hit same point on retinas


Snellen’s test Visual acuity Client 20 feet away from chart Covers one eye Reads line above or below 20/20 Line repeats with other eye


Visual acuity Snellen chart Checks vision at 20 feet from chart

20/20 PERRL pupils equal, round, react to light PERRLA pupils, equal, round, react to

light, accommodate


Visual acuity test

Snellen Chart Visual acuity tests may

be performed in many different ways. It is a quick way to detect vision problems and is frequently used in schools or for mass screening. Driver license bureaus often use a small device that can test the eyes both together and individually.


Slit-lamp exam

slit-lamp, which is a specialized magnifying microscope, is used to examine the structures of the eye (including the cornea, iris, vitreous, and retina). The slit-lamp is used to examine, treat (with a laser), and photograph (with a camera) the eye.


Visual field test


Color Blindness Tests


CATARACTS Disorder that causes the lens

or its capsule to lose its transparency and/or become opaque.. Noninfectious opacity or

clouding of the lens Congenital, exposure to

systemic disease, trauma, toxins, medications as steroids, aging (most common cause)..

As clouding develops, visual impairment occurs

S/S: blurred vision, diplopia, photosensitivity, difficulty driving at night, glare, opacity in center portion of lens, hazy vision, glare, difficulty driving at night.

The only treatment for a cataract is surgical removal of the lens Cataract extraction

• Intracapsular- not common• Extracapsular- removes lens

and anterior capsule with intracapsular lens implant


Cataract - close-up of the eye This photograph shows a

cloudy white lens (cataract) over the pupil. Cataracts are a leading cause of decreased vision in older adults, but children may have congenital cataracts. With surgery, the cataract can be removed, a new lens implanted, and the person can usually return home the same day.


Cataract


Cataract Surgery: Normal The lens of an eye is

normally clear. A cataract is when the lens becomes cloudy as you get older


Indications; Cataract Surgery Surgery is usually

recommended for people who have vision problems or other major problems caused by the cataract.


Cataract surgery - series: Procedure, part 1

Two procedures are used to treat cataracts. In the manual extraction procedure, a small incision is made at the edge of the outer lining of the eye (cornea). The lens is then removed and replaced with an artificial lens.


Cataract surgery - series: Procedure, part 2

Another procedure is called phacoemulsification. This involves inserting a needle through a small incision on the eye. The end of the needle produces sound waves. The sound waves break up the lens, which is then sucked out through the needle. This procedure requires a smaller incision than the manual extraction procedure.


Cataract Surgery-Series: Aftercare Cataract surgery usually works

very well. The operation has few risks, the pain and recovery period are short, and your sight is usually greatly improved. Ninety-five percent or more of all cataract surgeries result in improved vision.

Initially will have difficulty with images and depth perception

Teach to avoid activities that could cause potential injury..

No coughing, sneezing, dark glasses to decrease glare, wear eye patch when sleeping.


Eye surgery Post operative: no

coughing , sneezing, vomiting, bending

No increase in intraocular pressure after surgery

Sleep on unoperative side

Eye patch on at night for several nights


GLAUCOMA Disorder characterized

by an elevated high pressure of fluid inside the eyeball d/t obstruction of outflow of aqueous humor.

Treatment is focused on drug therapy to reduce intraocular pressure.

Surgical intervention to facilitate drainage of aqueous humor is called an iridectomy.


Glaucoma

Glaucoma is a condition of increased fluid pressure inside the eye. The increased pressure causes compression of the retina and the optic nerve which can eventually lead to nerve damage. Glaucoma can cause partial vision loss, with blindness as a possible eventual outcome.


Glacuoma Elevated pressure

within the eye due to obstruction of outflow of aqueous humor

Open angle: no signs or symptoms in early stage… then tunnel vision, eye pain , diffficulty adjusting to darkness, halo around lights, inability to detect colors


Glacuoma Closed angle: severe pain, decreased vision,

nausea, vomiting, sclera erythematous, and pupil enlarged and fixed colored halos around lights

Increased intraocular pressure Open angle—beta blockers, miotics Closed angle—osmotic diuretics, miotics,

surgery….


Glaucoma


Acute glaucoma

http://lh3.google.com/_p163cKQmQ3k/RqBEZuukrGI/AAAAAAAAAX4/RhG8uiYWzBQ/s800/glaucoma.jpg


RETINAL DETACHMENT Separation of the retina from the choroid. This condition is painless and may result

from trauma or from intraocular disorders. Treatment includes procedures that

create an inflammatory reaction that results in retina reattaching to the choroid, or surgery.


Retinal detachment Cryosurgery to freeze borders of retinal

hole Diathermy burn retina for sealing scarring

occurs Cryosurger to freeze border4s of retina hole Scleral buckling Eye patch for 1-2 days after surgery patch

both eyes


Retinal detachment


Retina Diabetic retinopathy Microaneurysms, hemorrhage, exudate Blood vessels in retina begin to widen and small

hemorrhages develop ..Scars form.. Vision decreases

Photocoagulation seals leaking vessels, helps prevent retinal edema


Retinal detachment Separation of retina from choroids in

posterior of eye Hole in retina allows vitreous humor to

leak between choroids and retina Flashes of light, followed by floating spots

and loss of specific field of vision no pain


Detached Retina

As a result of injury, tumors, or disease, the retina can become completely or partially detached causing diminished vision. The retina can be repaired by laser, cryoprobe, or surgery.


Retinal detachment repair - series: Normal anatomy The retina is the

internal layer of the eye that receives and transmits images that have passed through and been focused by the lens and cornea.


Retinal detachment repair - series: Indications

Retinal detachments are associated with a tear or hole in the retina through which the internal fluids of the eye may leak, causing separation of the retina from the underlying tissues. This is most often caused by trauma, and the risk of retinal detachment after minor trauma, such a blow to the head, is increased in the elderly, and in patients with tumors or inflammation near the retina. In some cases, retinal detachment occurs in the absence of trauma. Symptoms of retinal detachment include bright flashes, "floaters", or loss of part of the visual field. Emergency retinal detachment surgery is necessary to prevent vision loss.


Retinal detachment repair - series: Procedure, part 1

The most common technique used to repair retinal detachment is called a scleral buckle. Prior to performing a scleral buckle procedure, breaks and tears in the retina are closed. There are two major methods used to close breaks and tears in the retina. Cryopexy, uses an intensely cold probe (cryoprobe). This produces an inflammation that leads to formation of a scar which holds the retina to the underlying tissue.



A laser treatment (photocoagulation) can also be used to seals holes in the retina. The choice of cryopexy or photocoagulation is usually determined by the preference of the surgeon-both procedures are equally effective in most cases.



After sealing breaks and tears in the retina with either laser or cryoporbe treatment, the scleral buckle is applied. This consists of a silicone patch wrapped around the eye, compressing the globe and elongating it slightly, thus pushing the retina up against the posterior aspect of the eye, and sealing the detachment. The silicone patch is usually left in place permanently, unless it causes problems later, such as infection.


Retinal detachment repair - series: Aftercare

Scleral buckling for detachment may require a few days in the hospital. Keep the head elevated at all times. Patients should not bend over or strain with lifting or bowel movements. Vigorous exercise should be avoided for 3 to 4 weeks


KERATITIS Inflammation of the

cornea. Contact lens

Infection, irritation, injury, or allergies.

Symptoms include severe eye pain, red, watering eye, photophobia, reduced vision, and sometimes rash.

Treatment includes optical anesthetics, mydriatics, and antibiotic solutions. Topical antibiotics Keratoplasty- corneal

transplant


Before and after corneal surgery


Corneal Transplant Series


Corneal transplant - series: Indications

Indications Corneal transplantation

is recommended for: severe corneal

infection, injury, damage, or scarring

corneas that no longer allow light to pass through (opaque), often secondary to lens surgery (see cataract surgery), infections, and inherited diseases of the cornea.


Corneal Transplant-Series: Incision Corneal transplant is

done with the patient awake and pain-free (local anesthesia). An incision is made around the outer edge of the cornea.


Cornea Transplant- Procedure The damaged

cornea is removed and the corneal graft is stitched in place. The corneal graft is a transplant from a brain dead donor maintained on life support.


Cornea Transplant-Aftercare Transplanted

corneas have a long life expectancy. The benefits of corneal transplant are significant, and include significant improvement in vision.


STYE (HORDEOLUM) Hordeolum “Stye” Acute infection of

eyelid margin or sebacious gland of the eyelashes

Caused by staphylococcal organisms.

Symptoms are pain, redness, and pustule, abscess, and edema and swelling

Treatment includes warm compresses and topical antibiotics.


A stye is a relatively

common infection. Styes are often caused by staphylococcus and occur in the glands that open onto the lid margin. They are red, swollen, and painful.


CHALAZION Chalazion-

inflammatory cyst of the meibomian gland at the eyelid margin

The inherent feature of a chalazion is painless localized swelling that develops over a period of weeks.

Treatment includes surgical excision.


Blepharitis

Inflammation of eyelid margins Eyelids may adhere

Blepharitis is an inflammation of the lash follicles at the eyelid margins due to excess growth in lash follicles of bacteria normally present on the skin.


CONJUNCTIVITIS (PINK EYE) Inflammation of the

conjunctiva with exudate. Bacterial (staph, strep,

gonococcal) viral (herpes I), or allergens, or irritants.

Erythema of lid, crusting, drainage on lids, untreated can cause loss of vision, burning, itchiong, swelling, pain, contagious

Treatment consists of warm

compresses and appropriate medications.

antibiotic ointment, eye irrigation with ns do not cross contaminate

other eye Not spread to others No injury to eye


Bloodshot Eyes

The white portion of the eye (sclera) can appear red when the vessels on the surface become enlarged. This may result from mechanical irritation, environmental irritants (such as extremely dry air, excess sun exposure), allergic reactions, infection, and other medical conditions.

A bright red, uniformly dense bloody area on the sclera results from a small amount of bleeding (hemorrhage) into the conjunctiva. It is a fairly common occurrence and is usually caused by straining or coughing. It generally clears up on its own after a few days.


REFRACTIVE ERRORS Myopia–

nearsightedness. Hyperopia–

farsightedness.

Astigmatism–asymmetric focus of light rays on the retina.

Presbyopia–inability of the lens to change curvature in order to focus.


Normal, Near, And Farsightedness

Normal vision occurs when light is focused directly on the retina rather than in front or behind it. A person with normal vision can see objects clearly near and faraway.

Nearsightedness results in blurred vision when the visual image is focused in front of the retina, rather than directly on it. It occurs when the physical length of the eye is greater than the optical length. For this reason, nearsightedness often develops in the rapidly growing school-aged child or teenager, and progresses during the growth years, requiring frequent changes in glasses or contact lenses. A nearsighted person sees near objects clearly, while objects in the distance are blurred.

Farsightedness is the result of the visual image being focused behind the retina rather than directly on it. It may be caused by the eyeball being too small or the focusing power being too weak. Farsightedness is often present from birth, but children can often tolerate moderate amounts without difficulty and most outgrow the condition. A farsighted person sees faraway objects clearly, while objects that are near are blurred.


Farsighted

A person who is farsighted has the abillity to see objects clearly far away but not see as clearly closeup. Farsightedness usually occurs naturally with the aging process.


REFRACTIVE ERRORS (continued)

Strabismus–inability of the eyes to focus in the same direction.


Strabismus (Crossed Eyes) People are very sensitive to other

individuals' eye positions. By looking at another person's eye position, one can very effectively gauge where they are looking. People are also sensitive to eyes that are not looking in the same direction, which is referred to as crossed eyes (strabismus). Other more specific medical terms refer to eyes turned either outward or inward, or that are abnormally rotated. Any appearance of crossed eyes in young children should be immediately evaluated, as should recent onset of crossed eyes in an adult.


Eye muscle repair - series: Indications


Before and after strabismus repair


Eye muscle repair - series: Normal anatomy


Eye muscle repair - series: Incision


Eye muscle repair: Procedure


Eye muscles


Eye muscle repair - series: Aftercare


Foreign objects in eye Foreign objects in the eye

usually are flushed out through the natural blinking and tearing action of the eye. If the foreign body can be seen on the inner surface of either the lower or upper lid, try to gently flush it out with water or use a cotton-tipped swab to invert the eyelid and inspect the underside. Seek medical attention if the foreign body cannot be removed, or if there is still discomfort or blurred vision after removal.


Eye injury Penetrating injury Both eyes covered Styrofoam cup or

shield that does not touch object

Do not touch or rub eyes do not attempt to remove object

Object removed by opthamologist


CHEMICAL BURNS Emergency treatment

includes immediate lavage of the eye with tap water.

No attempt should be made to neutralize the chemical because that may cause further injury.

Both eyes should be patched for comfort.


IMPAIRED VISION Blindness- loss of

visual acuity 20/200 legally blind

Those who have visual acuity between

20/70 and 20/200 in the better eye, with glasses, are “partially sighted.”

Many visual aids are available. Talk in normal voice Avoid common phrases Introduce self with each

contact Explain all activities Ambulate patient by

walking 1 foot in front of patient with patient’s hand on your elbow

Don’t pet the dog


Macular degeneration Macular degeneration is a disease of the

retina that affects the macula in the back of the eye. The macula is important for clear central vision, allowing an individual to see fine details. There are two types of macular degeneration, dry and wet. Dry macular degeneration is more common and is characterized by the thinning of the retina and drusen, small yellowish-white deposits that form within the retina. The dry form of macular degeneration is usually mild. Wet macular degeneration can happen more quickly and be more serious. It occurs when vessels under the retinal layer hemorrhage and cause the retinal cells to die creating blind spots or distorted vision in the central vision. The disease becomes increasingly common amongst people in each succeeding decade over 50.

Age-related macular degeneration (ARMD or AMD); Senile macular degeneration (SMD)

Definition: Macular degeneration is a disorder that affects the macula (the central part of the retina of the eye) causing decreased vision and possible loss of central vision.

http://www.nlm.nih.gov/medlineplus/ency/article/002291.htm


MACULAR DEGENERATION Slow progressive loss of

central and near vision Wet-new vessel growth in

macular region that occurs suddenly and scaring develops

Vision loss is permanent Atrophy or deterioration of the

macula. Central vision is lost, but

peripheral vision remains. May be caused by aging,

injury, infection, or inflammation of the macula.

Dry-lipid deposits occur with slow atrophy of macular region

color perception altered, distorted vision, loss of ability to see clearly


MACULAR DEGENERATION


TASTE

Serves as a protector and provides delightful sensations.

Taste can be altered secondary to neurological disorders or trauma.

The sense of taste works very closely with the sense of smell.


SPECIAL SENSE ORGANS The taste receptors

Receptors are chemoreceptors called taste buds Cranial nerves VII and IX

carry gustatory impulses Most pathologists list four

kinds of “primary” taste sensations—sweet, sour, bitter, and salty


SMELL Serves as a guardian

from danger. Disorders of the

olfactory sense often go unnoticed.

The body cannot regenerate the olfactory cells.


TOUCH The sense of touch

(tactile) includes sensations pertaining to the skin.

The tactile receptors are located throughout the integumentary system.

Clients with reduced or loss of tactile sensation risk injury when their condition confines them to bed.


Communication and Ambulation with Blind Talk in normal voice tone Do not try to aviod

common phrases see what i mean…

Introduce self with each contact

Explain any activity in room

Explain tray by using the clock

Announce when you are leaving

Blind or near blind Clear pathway Walk ahead of individual

and patient holds the elbow of the nurse

Explain individual for steps, incline, decline


Ambulation


Terms Refraction= light rays are bent as they

pass through the eye allowing light to focus on the retina

Accommodation= eye unable to focus on objects at various distances

Presbyopia= decreased ability to accommodate for near vision


Visual acuity test

Snellen Chart


Walleyes


Lasik eye surgery - series: Normal anatomy


Lasik eye surgery - series: Procedure, part 1


Lasik eye surgery - series: Procedure, part 2


Lasik Eye Surgery - Series: Procedure, part 3


Lasik Eye Surgery - Series: Aftercare


Eyelid eversion

To help find an object that is in the eye, grasp the lower eyelid and gently pull down on it to look under the lower eyelid. To look under the upper lid, place a cotton-tipped swab on the outside of the upper lid and gently flip the lid over the cotton swab.


Head and eye Echoencephalogram


Retinal dye injection


Periorbital cellulitis


Blepharoplasty - series: Indications


Blepharoplasty - series: Incisions


Blepharoplasty - series: Aftercare


Sensory Disorder Keratoconjunctivitis sicca

Lacrimal gland dysfunction due to autoimmune

Dry, sandy or gritty feeling Schirmer’s test Artificial tears

Sjogren’s syndrome Keratoconjunctivitis with dry

mouth Maybe primary or secondary Dx and Tx same as

keratoconjunctivitis


Sensory Disorder Ectropion

Outward turning of the eyelid margin

Topical medications to relieve inflammation and dryness

Surgery preferred Entropion

Inward turning of the eyelid Tx same as Ectropion


Sensory Disorder Cataract surgery

Instill eye medications as ordered

No sudden head movements

No lifting or bending No coughing or sneezing No vomiting or straining

with elimination• Report nausea

Eye patch or eye shield• Eye safety at night

Elevate head of bed 30 degrees

Diabetic retinopathy Characterized by capillary

microaneurysms, hemorrhage, exudates and formation of new vessels

Progressive vision loss and “floaters”

Ophthalmoscopy Photocoagulation- small

laser seals leakage, destroys offending tissue and removes new vessels that contribute to scar formation

Vitrectomy- removal of excess vitreous fluid


Sensory Disorder Macular degeneration

Gradual, variable bilateral loss of central vision due to new vessel growth in the macula (wet type) or lipid deposits (dry type)

• Amster grid test- card with grid lines (like graph paper), if lines appear wavy or distorted is positive for macular degeneration

Photocoagulation maybe used (preventative, not curative)

Retinal detachment Separation of the retina

from the choroid allowing leakage of vitreous humor resulting in progressive loss of vision and eventual blindness

Sudden or gradual development of flashes of light, floating spots, and vision loss

Cryosurgery, diathermy, photocoagulation, scleral buckling

sensory system (eye) part 2 leslie lehmkuhl, rn 2009

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