Sensory Disorders

DISORDERS OF THE EYE

 CATARACTS

GLAUCOMA

1. CATARACTS:(Opacity of the Lens):

A. Incidence and Etiology:

Age-related cataracts(senile cataracts) are found in some degree in anyone >70; also related to trauma, long term drug therapy such as steroids or miotics, systemic diseases such as DM and as result of other ocular disorders such as glaucoma or retinal detachment.

B. Pathophysiology:

With aging, lens loses water and increases in density due to compression of older lens fibers in the center as new ones are produced in the outer layers. This compaction of lens fibers causes proteins to precipitate in the lens.

C. Early Signs & Symptoms:

Include blurred vision and decreased color perception(blue, green, and purple) and later ones include diplopia and absence of red reflexes.

D. Physical Assessment Findings:

Objective: Decreased visual acuity on Snellen testing--acuity of 20/50 is usually considered an indication for surgery; dark defects in the red reflex best seen with diopters set at +10, and eventually absence of a red reflex(mature cataract).

Subjective: Patient reports significant degree of functional impairment. No pain should be reported with cataracts.

E. Nursing Diagnoses:

1. Sensory Perceptual Alteration r/t gradual loss of vision

2. Fear r/t possible blindness

3. Knowledge Deficit r/t surgical procedure and self-care

F. Management:

1. Non surgical: In earlier stages of cataract formation, when visual acuity is less than 20/50 and does not seriously impair ADLs, use of corrective distance lenses, strong bifocals, magnification and improved lighting can often compensate.

2. Surgical treatment is only "cure"--cataract extraction if the most common procedure in the U.S. for persons over 65, and is usually done on an outpatient basis when there is adequate support available to help the patient. Nursing responsibilities relate to many areas, such as orienting a patient with decreased vision to his/her surroundings before the surgery, pre-op teaching,immediate post-op care and planning and implementing continuity of care in the home environment.

a. Preoperative:(Patient must be "cleared medically" for surgery)

(1) Principle: only do one eye at a time(do the worst first)

(2) Teach patient about what to expect on day of surgery(local anesthesia most commonly done) and type of surgery

• (a) Extracapsular cataract extraction(ECCE)--page 1329, text--more common than ICCE--Why? Advantages(page 1328).
• Can be done with conventional incision into eye or with smaller incision used with an ultrasonic probe that uses high frequency sound vibrations to break up the lens which is then suctioned out("Phacoemulsification"--IMAGE #1 BELOW) 
• (b) Intracapsular cataract extraction(ICCE)--technically easier to do, but more potential complications(IMAGE #2 BELOW)
• (c) It is most common to use an IOL(intraocular lens implant--IMAGE #3 BELOW) to replace the missing lens and this is implanted after the extraction of the patient's own lens.

(3) Complete pre-op check list

(4) Administer Medications:

• Sedatives such as Valium
• Diamox or Neptazane may be given to reduce intraocular pressure
• Sympathomimetic eye drops such as Neo-Synephrine to achieve mydriasis and vasoconstriction
• Parasympatholytic drops such as Cyclogyl to induce paralysis of the ciliary muscle
• There is usually a specific sequence and timing of the eye drops and make sure they are given in the correct eye.

b. Postoperatively:

(1) Monitor recovery: Take V.S., position on non-operative side in semi-fowler's, check dressing for drainage and make sure protective shield is in place; have eye tray or equivalent on hand for surgeon

(2) Administer Medications:

• Antibiotics such as Gentamycin ointment or eye drops or Steroid-antibiotic combination ointments or eye drops such as TobraDex(Tobramycin and Dexamethasone). The patient must be taught to give these meds correctly, also.
• Percocet or Tylenol for pain(no ASA); pain should be mild--if sharp or severe, notify surgeon IMMEDIATELY as this may indicate hemorrhage or increased intraocular pressure
• Antiemetics such as Tigan

(3) Observe for and prevent complications and teach patient same:

• (1) Increased Intraocular Pressure--Teach activity restrictions(table on page 1329, text); monitor pain level
• (2)Infection--Observe for purulent drainage or increased redness of the eye;report reduction of visual acuity stat
• (3) Hemorrhage--Teach to wear protective shield at night and during the day if glasses not worn; avoid rubbing eye

(4) Discharge Planning:(must meet criteria for discharge)

Home health care--certain number of visits provided by Medicare; teaching of good handwashing techniques before touching eye, med administration, activity restrictions, identification and immediate reporting of complications is emphasized; home health aide is made available to help with personal hygiene; meals on wheels may be ordered for a short period; many eye care centers provide pickup and delivery for follow up eye checks, usually the day after surgery, one week following, 3 weeks and finally, 6-8 weeks.

2. GLAUCOMA:

A. Incidence:

Aged and black population more at risk(at younger ages)

B. Etiology:

Primary(95% of patients in U.S.):

Two types: Open Angle Glaucoma(POAG) and Angle Closure Glaucoma

Secondary: Complication of infection or trauma

C. Pathophysiology:

1. POAG--Most common type of Primary glaucoma(risk factors on page 1332 in book; pressure rises in eye because there is a resistance to outflow of aqueous humor through the normal pathways in front of the eye(trabecular network or canal of Schlemm); nothing is wrong with the angle between the cornea and the iris; gradual progression of visual defects that are painless and affect the peripheral vision first; patient may not be aware of any changes for a long time; later changes include halos around lights.

2. Angle Closure(acute)--less common; there is a narrowed angle between the iris and cornea and anteriorly displaced iris; this causes an obstruction to the outflow of aqueous humor and may happen suddenly, without warning; this is treated as an emergency as vision may be lost within hours to days. Signs and Symptoms include: acute pain, redness and congestion of eye, visual loss and headache(intraocular pressure may be four times normal).

POAG(OPEN ANGLE) COMPARED TO ANGLE CLOSURE(ACUTE)GLAUCOMA:

D. Physical Assessment Findings:

• VERY FIRM TO HARD EYEBALL ON PALPATION
• VISUAL FIELD DEFECTS, DIMINISHED ACCOMMODATION
• OPTIC DISCS MAY BE PALE, CUPPED, ASYMMETRICAL, ENLARGED WITH SPLINTER HEMORRHAGES ON THE SURFACE OF THE DISC
• CLOUDY ANTERIOR CHAMBER, INCREASED VASCULARITY WITH ACUTE GLAUCOMA
• INCREASED IOP (INTRAOCULAR PRESSURE) MEASURED BY TONOMETRY(ABOVE 10-21 mmHG)
• EXAM WITH GONIOSCOPE REVEALS POSITIVE FINDINGS

E. Management(can be controlled, not cured):

1. Non surgical Management--Goal is to reduce IOP:

a. Drug Therapy:

(1) To constrict pupil so that the ciliary muscle is pulled away from the absorptive network:

Miotics: Pilocarpine, Carbachol, and Phospholine Iodide

(2) To inhibit the formation of aqueous humor:

Beta Blockers: Timoptic and Betagan

Carbonic Anhydrase Inhibitor: Diamox

(3) In emergencies, use systemic agents such as Osmotic Diuretics(Mannitol or Osmoglyn) to reduce IOP rapidly

2. Surgical Management when Medical treatment fails:

(a) Techniques:

(1) Trabeculoplasty--opening clogged network with lasers

(2) Trabeculectomy--during conventional surgery, a new drain is made in the eye so that fluid has a new escape route(through a scleral flap)

ANGLE CLOSURE:

(1) Iridotomy--making a tiny hole in the iris with a laser so that fluid can drain freely; pupil may look "keyholed"

(2) Even after surgeries, may have to return to meds for continued control of pressure

b. Teaching and Followup:

In general, people with glaucoma should avoid drugs that dilate pupil(anticholinergics such as Atropine and Sympathomimetics like Epinephrine).

3. Macular Degeneration(refer to text)

DISORDERS OF THE EAR

HEARING LOSS

MENIERE'S DISEASE

1. Hearing Loss

A. Incidence: 10% of U.S. population; increases with aging; estimates of 30% of people over 60 have some degree of hearing loss

B. Conductive or Sensorineural(SNHL)--define difference?

(1) Conductive: Etiologies: obsturction, infections like otitis media, otosclerosis

Signs & Symptoms: decreased ability to detect low tones and vowels

(2) SNHL: Etiologies: presbycusis; trauma, drug toxicity, Meniere's syndrome, acoustic neuroma, chronic noise exposure

Signs & Symptoms: high frequency loss with loss of speech discrimination of consonants, female voices, difficulty with background noises

C. Physical Assessment Findings:

• History: What questions should be asked?
• On exam: Ear exam may be normal or may see impacted cerumen, scarred, bulging, or perforated tympanic membrane, or growths or foreign bodies in ears
• On testing hearing acuity: Whisper test normal; Rinne, Weber tests abnormal
• Audiometric testing abnormal--example: a hearing loss of 45 to 50 dB renders the patient unable to hear speech without the use of a hearing aid
• Xrays and CT or MRI scans if indicated to detect mastoid, middle ear, inner ear structure abnormalities or tumors of the acoustic nerve.

 D. Psychosocial Assessment:

Patient may be depressed,in denial, feels isolated and irritable due to hearing loss; evaluate coping and compensatory strategies.

E. Nursing Diagnoses:

(1) Sensory/perceptual Alteration(Auditory) r/t inability to hear clearly

(2) Anxiety r/t inability to communicate

(3) High risk for injury r/t vertigo/falling

F. Management:

(1) Assess for early signs of hearing loss

(2) Perform ear irrigations if necessary to remove cerumen and teach patient correct techniques

(3) Teach about drugs as indicated

(4) Teach correct use and care of hearing aid

(5) Teach measures to prevent ear trauma or infection

(6) Use measures to enhance patient's ability to understand--like facing client directly in good light, using a normal tone of voice while speaking clearly, slowly and in short sentences; have a paper and pencil near at hand

(7) Prepare for surgery as indicated:

Principle: If bilateral hearing loss, surgery is always done on the worst ear first; if not successful, patient must decide whether to have the other ear done or to continue using an amplification device

Preop: Teaching relating to procedure, preventing infection before surgery, prognosis of improvement of hearing abilities, possible complications(infection or cranial nerve damage)

Types of surgery: Tympanoplasty, Stapedectomy, Labyrinthectomy (define each and nursing care required)

Postop: Depending on surgery, instructions as in text; generally--avoid straining, air travel, lifting, bending over, getting head wet and infections

G. Followup: Home health care, followup hearing tests, referral to support groups, evaluate for compliance with health teaching relating to drugs, irrigations, postop restrictions, etc.

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2. Vertigo and Dizziness--difference?

A. Common manifestation of ear dysfunction due to inner ear pathology related to the vestibular system consisting of the cochlea and semicircular canals

B. Associated Symptoms include nausea, vomiting, nystagmus, hearing loss and tinnitus

C. Other causes other than ear pathology must be ruled out relating to cardiovascular or C.N.S. disorder

D. Example of a disorder causing a triad of symptoms: hearing loss(unilateral SNHL), vertigo and tinnitis is:

MENIERE'S SYNDROME

1. Incidence: Mostly men, white, age 20-50

2. Etiology: Unknown, could be related to infection, allergies, biochemical imbalances or chronic stress

3. Patho: Either overproduction or decreased reabsorption of endolymphatic fluid causing increased fluid pressure in the inner ear with resulting damage and progressive hearing loss

4. Course: Severe attacks of vertigo, with symptom free periods; progressive hearing loss as the attacks increase in frequency; associated symptoms include headaches, nystagmus, nausea, vomiting, tinnitus

5. Management:

(a) Nonsurgical-- Low Na diet, possible fluid restriction, smoking cessation, drug therapy consisting of diuretics, nicotinic acid, antivertiginous meds such as Antivert, analgesics, antihistamines(Benadryl and Dramamine), antiemetics and sedatives such as Valium. Teaching relating to safety measures and avoidance of rapid movements of the head during attacks.

(b) Surgical-- if medical treatment fails and patient is incapacitated by disease, hearing in the affected ear must be sacrificed to cure the condition. A total Labyrinthectomy is performed in this case. Sometimes, early surgical intervention(called Endolymphatic Decompression) involving draining the excess endolymph fluid and leaving in a shunt to enhance further drainage can be done; in this case, hearing may be preserved and vertigo relieved. Measures must be taken to relieve vertigo in the postop period, and the nurse must assure the patient that this is related to the procedure, not to the disease process.

 Site for help with eye & ear disorders: http://www.nyee.edu(New York Eye & Ear Infirmary)

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