chapter 51ukiahadultschool.net/uploads/6/6/8/4/66842831/eye_and... · · 2015-12-04elsevier items...

1Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.

Chapter 51

Eye and Vision Disorders


Figure 51-1


Figure 51-2


Figure 51-3


Visual Pathway• Light enters eye, passes through transparent cornea, aqueous

humor, lens, and vitreous humor • These structures are called refractive media • Refract (bend) horizontal and vertical light rays so that the light rays

focus on the retina • On retina, light rays are reversed and upside down • Images carried as impulses through the optic nerve • At optic chiasm, fibers from the left field from each eye join to form

the left optic tract • Fibers from right field of eye join to form right optic tract • Images transmitted to the brain by way of the optic tracts


Figure 51-4


Age-Related Changes in the Eye• Skin around the eye becomes wrinkled and loose • Eyelids usually have some excess tissue; not important unless it

interferes with vision • The amount of fat around the eye decreases, permitting the

eyeball to sink deeper into the orbit • Tear secretion diminishes; cornea less sensitive • Grayish ring may be around the outer margin of the iris• Pupil smaller and responds more slowly to light • Presbyopia: ability to focus is impaired


Health History

• History of present illness • Record changes in vision• If pain, inquire about location and nature• Sensitivity to light (photophobia) • Discharge from the eyes• Complaints that the eyes feel dry and irritated

• Past medical history • Diabetes, neurologic disorders, thyroid disease,

hypertension


Health History

• Family history • Any eye diseases as well as a history of

arteriosclerosis, diabetes, and thyroid disease • Functional assessment

• Patient’s occupation, roles, usual activities


Physical Examination• Inspect the external

eye, assess response of the pupil to light, and evaluate gross visual acuity

• If abnormalities suspected, inform physician or advise patient to seek medical evaluation

• Acuity commonly tested with Snellen chart


Diagnostic Tests and Procedures

• Ophthalmoscopic examination• Refractometry• Visual fields• Tonometry• Fluorescein angiography • Corneal staining• Imaging procedures

• CT, ultrasonography, radioisotope scanning, or MRI


Therapeutic Measures

• Eye irrigation• Topical medications

• Miotics• Mydriatics• Anesthetics• Cycloplegics• Antibiotics• Anti-inflammatory drugs

• Eye surgery• Surgical incisions, lasers, and cryotherapy


Preoperative Nursing Care

• Assessment• Patient’s emotional state, ability to perform self-

care, and knowledge of surgical routines and outcomes

• Be sure the patient understands the preoperative routine

• Interventions• Anxiety • Self-Care Deficit


Postoperative Nursing Care

• Assessment• Vital signs and level of consciousness • Inspect dressing for bleeding or drainage • Patient comfort, including pain and nausea • If vision impaired, inspect environment for safety

hazards • Before discharge, determine patient’s understanding

of and ability to administer prescribed medications by having the patient demonstrate self-medication


Postoperative Nursing Care

• Interventions• Risk for Injury • Disturbed Sensory Perception • Acute Pain • Anxiety • Ineffective Therapeutic Regimen Management


Protection of the Eyes and Vision

• Patient teaching• Adults younger than 40 years of age should have

their eyes examined every 3 to 5 years • After the age of 40, examinations every 2 years and

should include testing for glaucoma • When there are symptoms of eye problems, patients

should seek medical advice



• Prevention of injuries• Teach young children the danger of throwing or

poking objects at the faces of playmates • Assess toys for safety • Adult activities that produce sparks or cause

fragments to be dispersed also cause injuries • Advise protective eyewear for such potentially

dangerous activities



• Basic eye care • Gently cleanse the eyelids each time the face is

washed; use a clean cloth without soap • Wash eye from the inner canthus (near the nose)

toward the outer canthus


Effect of Visual Impairment

• Mild losses may require only some adaptations • Serious losses affect independence, mobility,

employment, and interpersonal relationships • People grieve for the lost function just as they might

grieve after the death of a loved one • Factors that affect a person’s response to this loss

include personality, usual coping style, effect of vision loss on the person’s life, and the circumstances of the loss


Care of the Visually Impaired Patient

• Be aware of visually impaired person’s thoughts and feelings about handicaps

• Assume that people with visual impairments can be independent and productive

• The person needs help with some tasks but should be treated as an adult

• The extent of vision loss determines the types of assistance needed


Care of the Visually Impaired Patient

• Interventions• Disturbed Sensory Perception • Ineffective Coping • Self-Care Deficit • Ineffective Therapeutic Regimen Management


Blepharitis

• Inflammation of hair follicles along eyelid margin • Caused by bacteria, most often by staphylococci • Symptoms include itching, burning, and photophobia;

scales or crusts on the lid margins• Physician may prescribe an antibiotic ointment • Be certain that any medication applied to the eye is an

ophthalmic preparation • Eyelids can be gently cleansed with baby shampoo

solution


Hordeolum

• Commonly called a stye • Common acute staphylococcal infection of the eyelid

margin that originates in a lash follicle• Affected area of lid is red, swollen, and tender • Apply warm, moist compresses several times a day• Repeated infections may be related to staphylococcal

infections at some other location on the body • Physician may treat with ophthalmic antibiotics


Chalazion

• Inflammation of the glands in the eyelids • Swelling prevents fluid from leaving the glands,

causing tenderness • Warm compresses may bring some relief • Physician may order antibiotics if infection • Surgical removal of the gland necessary if

condition persists


Conjunctivitis

• Inflammation of the conjunctiva caused by microorganisms, allergy, or chemical irritants

• Bacterial conjunctivitis commonly called pinkeye • Red conjunctiva, mild irritation, drainage • Warm/cool compresses, topical vasoconstrictors• Infected people should practice good hand washing

and should avoid sharing washcloths


Conjunctivitis

• Viral conjunctivitis caused by herpes simplex virus type 1, herpes zoster virus, or adenoviruses • Characterized by redness and drainage • Round, raised white or gray areas on the

conjunctiva • Infections caused by herpes simplex virus type 1

are treated with ointments or other topical medications


Keratitis

• Inflammation or infection, or both, of the cornea • From bacteria, viruses, fungi; chemical or mechanical

injuries cause inflammation that may be followed by infection

• No noticeable drainage, but considerable pain • Topical antibiotics and topical corticosteroids • Systemic antibiotics after culture and sensitivity • Sometimes physician injects antibiotics directly into the

conjunctiva


Entropion

• The lower lid turns inward • Eyelashes rub against the eye, causing pain

and possibly scratching the cornea • Surgical correction usually recommended


Ectropion

• The lower lid droops and turns outward • The eye does not close completely, causing it

to become dry and irritated • The dry cornea is easily injured • Requires surgical correction


Foreign Body

• Blinking/tearing wash small irritants from eye • If foreign body remains, evert the upper and lower lids • If object is clearly visible and does not appear to be

embedded, you may attempt to remove it • Use sterile cotton swab to touch object gently • If object not embedded, it usually clings to swab and

can be removed • If object is embedded, it should be removed only by a

physician


Corneal Opacity

• Inflammation and infection• When cornea injured by infection or trauma, scar tissue may

form • If scar tissue prevents light from entering the eye, varying

degrees of vision impairment occur • Only treatment is keratoplasty (removal of the scarred cornea

and replacement with a healthy cornea) • During keratoplasty, damaged cornea removed first

• An identically sized graft then taken from the donor eye and secured to the recipient’s eye with very fine suture


Care of the Patient Having Keratoplasty

• After surgery, the keratoplasty patient has an eye pad and a metal shield over the operative eye

• Corticosteroid eye drops may be ordered to reduce inflammation


Care of the Patient Having Keratoplasty

• Assessment• Inspect dressing for drainage and ask if patient has pain or

nausea • After dressing is removed, inspect for corneal opacity• Also evaluate the patient’s visual acuity

• Interventions• Risk for Injury • Pain • Impaired Sensory Perception • Ineffective Therapeutic Regimen Management


Myopia

• The medical term for nearsightedness • The lens is situated too far from the retina • Light rays come together to focus in front of the

retina • People with myopia have difficulty seeing

distant images clearly • New glasses needed approximately every 2

years


Hyperopia

• Commonly known as farsightedness• The lens is too close to the retina• Light rays come together behind the retina • The hyperopic person sees clearly in the

distance but has difficulty focusing on close objects

• Convex corrective lenses needed


Figure 51-16


Astigmatism

• Irregularities in the cornea or lens• If condition is mild, the natural lens can correct

for the abnormality • If severe, vision is distorted, and corrective

lenses are needed


Presbyopia

• Poor accommodation due to loss of elasticity of the ciliary muscles • Accommodation: adjustment of the lens for near and

distant vision• Contraction or relaxation of the ciliary muscles,

which causes the lens to change shape • It most often develops after age 40 years • Corrective lenses are needed


Medical Treatment

• Corrective lenses for errors of refraction • Eyeglasses • Contact lenses

• Surgical treatment • Photorefractive keratectomy (PRK) • Laser in situ keratomileusis (LASIK)

• Nursing care• Encourage periodic examinations and know if the

patient uses corrective lenses


Cataract

• Lens opaque (cloudy); no longer transparent• Causes: congenital, traumatic, degenerative • Pathophysiology

• Injuries cause opacity rapidly, whereas age-related opacity progresses slowly

• Signs and symptoms: cloudy vision, seeing spots or ghost images, and floaters

• Medical treatment • Cataract extraction


Figure 51-17


Cataract

• Complications • Leakage of vitreous humor, hemorrhage into the

eye, and opening of the incision • Lens replacement

• Cataract eyeglasses • Contact lenses • Intraocular lenses


Care of the Patient with Cataracts

• Preoperative care• Drops used before cataract surgery are mydriatics,

cycloplegics, antibiotics, and nonsteroidal anti-inflammatory agents


Care of the Patient with Cataracts

• Postoperative care• Assessment

• Pain and nausea • Patient is likely to wear a patch and shield over operative

eye • Note any drainage • Also note level of consciousness and orientation

• Interventions• Risk for Injury • Impaired Sensory Perception


Glaucoma

• Pathophysiology • Intraocular pressure is above normal • Caused by interference with outflow of aqueous

humor • Although glaucoma may follow trauma, exact cause

is often unknown • Peripheral vision is lost first • Field of vision gradually narrows until tunnel vision • Complete blindness eventually occurs


Types of Glaucoma

• Open-angle glaucoma • Prevents the normal passage of aqueous humor through the

trabecular meshwork • Usually there are no signs and symptoms at first • Tired eyes, blurred vision, and halos around lights • Need for frequent changes in eyeglass prescriptions• Treated first with drug therapy

• Beta-adrenergic blockers, adrenergics, cholinergics, carbonic anhydrase inhibitors, and hyperosmotic agents

• Surgical procedures: trabeculoplasty, trabeculectomy, and cyclocryotherapy


Glaucoma

• Angle-closure glaucoma• Flow of aqueous humor through the pupil is blocked • Pressure forces iris forward; blocks trabecular meshwork • Rapid rise in intraocular pressure; if not lowered promptly,

permanent blindness can result • Signs and symptoms: sudden, acute pain; blurred vision, halos

around lights, nausea and vomiting, and headache on the affected side

• Drugs for treatment: miotics and oral or intravenous carbonic anhydrase inhibitors

• After pressure lowered, iridotomy or iridectomy usually recommended to prevent recurrence


Glaucoma

• Assessment• Collect data about patient knowledge of the disease

and treatment and patient ability to carry out self-care

• Interventions• Risk for Injury • Fear and Ineffective Therapeutic Regimen

Management • Pain


Retinal Detachment

• Pathophysiology • Separation of sensory layer from pigmented layer

• Begins when a tear in the retina allows fluid to collect between the sensory and the pigmented layers

• The fluid causes the two layers to separate • Separation deprives sensory layers of nutrients and oxygen that

normally are supplied by the blood vessels in the choroid • Leads to damage to the nerve tissue in the sensory layer and

resultant partial or complete loss of vision • Retinal tears may occur spontaneously or as a result of

trauma


Retinal Detachment

• Signs and symptoms • Depend on location and extent of detachment • Patients report seeing light flashes or floaters • Vision may be cloudy • If area of detachment is large, vision may be lost

completely • Some patients say it seems as if a curtain has come

down or across the line of vision


Retinal Detachment

• Medical and surgical treatment • Laser photocoagulation • Cryotherapy • Scleral buckling


Retinal Detachment

• Nursing care• Before corrective measures, the patient usually is placed on

strict bed rest with the head elevated • Postoperative care essentially the same as for other patients

undergoing eye surgery• Positioning orders may be specific for these patients • Surgeon prescribes activity limitations; length of hospitalization

depends on location and severity of the tear, the type of repair, and the surgeon’s routines


Senile Macular Degeneration• Changes in the eye cause the macula to degenerate • Both eyes usually affected • Two types

• Dry (strophic)• Abnormal blood vessels develop in or near the macula resulting in

loss of vision in a specific area • Wet (exudative)

• Central vision gets gradually worse• Special telescopic lenses may be helpful • Laser treatments may offer hope to some patients• Nurse needs to help the patient and family members learn to cope

with declining vision


Enucleation

• Removal of the eye• From injury, infection, sympathetic ophthalmia, and

some glaucomas and malignancies • Postoperative observe for excessive bleeding or

increasing pain • Report any temperature elevation • After pressure dressing removed, physician may order wound

care and topical medications • Approximately 1 month after the enucleation, a prosthesis can

be fitted by an optician

chapter 51ukiahadultschool.net/uploads/6/6/8/4/66842831/eye_and... · · 2015-12-04elsevier items...

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