Eye, Vision, Hearing, and Balance Disorders: Study Notes

Chapter 58: Eye and Vision Disorders

Assessment of Low Vision

  • History Examination:

    • Distance and near visual acuity.

    • Visual field.

    • Contrast sensitivity.

    • Glare.

    • Color perception.

    • Refraction.

  • Tools:

    • Snellen and Rosenbaum eye charts.

    • Ophthalmoscope.

Management of Low Vision

  • Support:

    • Coping strategies.

    • Grief processes.

    • Acceptance of visual loss.

  • Strategies for Environmental Adaptation:

    • Placement of items in room (e.g., the "Clock method" for trays).

  • Communication Strategies:

    • Collaboration with low-vision specialist, occupational therapist, or other resources.

    • Braille or other methods for reading and communication.

    • Service animals.

Ocular Medication Administration

  • Aseptic Technique is crucial.

  • Client Positioning: Lie supine or tilt head back.

  • Dropper Technique:

    • Rest dominant hand on the client's forehead.

    • Hold dropper 1 to 2 cm above the conjunctival sac.

    • Drop medication into the sac, avoiding direct placement on the cornea.

    • Client should close eye gently.

    • If the client blinks during instillation, repeat the procedure.

  • Preventing Systemic Absorption:

    • Apply gentle pressure with a finger and a clean facial tissue on the nasolacrimal duct for 30 to 60 seconds.

  • Multiple Medications: If instilling more than one medication in the same eye, wait at least 5 minutes between them.

  • Eye Ointment Application: Apply a thin ribbon to the edge of the lower eyelid from the inner to the outer canthus.

Ophthalmic Medications

  • Topical Anesthetics.

  • Mydriatics (dilate) and Cycloplegics (paralyze):

    • Example: Atropine.

    • Contraindications: Narrow angles or shallow anterior chambers, and impatients on monoamine oxidase inhibitors (MAOIs) or tricyclic antidepressants (TCAs).

    • Side Effects: May cause central nervous system (CNS) symptoms and increased blood pressure (BP), especially in children or older adults.

  • Anti-infective Medications: Include antibiotic, antifungal, or antiviral products.

  • Glaucoma Medications:

    • Mechanism: Increase aqueous outflow or decrease aqueous production.

    • Effects on Vision: May constrict the pupil and may affect the ability to focus the lens, thereby affecting vision.

    • Systemic Effects: Can also produce systemic effects.

  • Anti-inflammatory Drugs; Corticosteroid Suspensions:

    • Side Effects of Long-Term Topical Steroids: Glaucoma, cataracts, and increased risk of infection.

    • Alternative: Oral NSAID (Nonsteroidal Anti-Inflammatory Drug) therapy may be used to avoid steroid side effects.

Macular Degeneration (AMD)

  • Description: Central loss of vision that affects the macula; no cure.

  • Prevalence: Common cause of blindness.

  • Types:

    • Dry (Nonexudative): Most common (85% to 90%). Gradual blockage in retinal capillary arteries. Characterized by slow breakdown of the layers of the retina with the appearance of drusen.

    • Wet (Exudative): Less common, but may have abrupt onset. New growth of abnormal blood vessels with thin walls that leak blood and fluid (choroidal revascularization) under the retina.

  • Expected Findings:

    • Lack of depth perception.

    • Objects appear distorted.

    • Blurred vision.

    • Loss of central vision.

    • Blindness.

  • Age-Related Macular Degeneration (AMD): Leading cause of irreversible blindness and visual impairment worldwide.

Nursing Management of AMD

  • Patient Education.

  • Supportive Care.

  • Promote Safety.

  • Recommendations: Improve lighting, use magnification devices, and referral to vision center to improve or promote function.

Cataracts

  • Description: Opacity in the lens of an eye that impairs vision.

  • Causes/Types:

    • Age-related: Drying of the lens due to water loss.

    • Traumatic: Blunt or penetrating injury.

    • Toxic: Long-term use of corticosteroids, phenothiazine derivatives, beta-blockers, or miotic medications.

    • Associated: Diabetes mellitus, hypoparathyroidism, Down syndrome, chronic sunlight exposure.

    • Complicated: Intraocular disease.

Surgical Management of Cataracts

  • Indication: Surgery is not needed if reduced vision does not interfere with normal activities.

  • Procedure Details: Performed on an outpatient basis with local anesthesia, usually taking less than 1 hour. Patients are discharged soon afterward.

  • Complications: Rare but can be significant.

Nursing Management of Cataracts

  • Preoperative Care: Usual preoperative care for ambulatory surgery, including dilating eye drops or other medications as ordered.

  • Postoperative Care:

    • Patient Education: Provide written and verbal instructions.

    • Urgent Contact: Instruct patient to call primary provider immediately if vision changes; continuous flashing lights appear; redness, swelling, or pain increases; type and amount of drainage increases; or significant pain is not relieved by acetaminophen.

Glaucoma

  • Description: Disturbance of the functional or structural integrity of the optic nerve causing increased intraocular pressure (IOP).

  • Types:

    • Primary Open-Angle Glaucoma (POAG): More common. Aqueous humor outflow is decreased, causing a slow rise in IOP.

    • Primary Angle-Closure Glaucoma (PACG): IOP rises suddenly.

  • Diagnostic Findings:

    • Tonometry: To assess IOP.

    • Ophthalmoscopy: To inspect the optic nerve disc.

    • Central Visual Field Testing.

Treatment of Glaucoma

  • Goal: Prevent further optic nerve damage and maintain IOP within a range unlikely to cause damage.

  • Pharmacologic Therapy:

    • Miotics (Cholinergic Agents): Carbachol, echothiophate, pilocarpine.

    • Beta-blockers: Timolol.

    • Adrenergic Agonists: Apraclonidine, brimonidine tartrate, dipivefrin hydrochloride.

    • Carbonic Anhydrase Inhibitors: Acetazolamide, dorzolamide, and brinzolamide.

    • Prostaglandins: Bimatoprost, latanoprost.

    • Systemic Effects: Watch for systemic effects of these medications.

  • Glaucoma Surgery: Shunt placement.

Retinal Disorders

  • Retinal Detachment: Rhegmatogenous detachment is the most common type.

  • Retinal Vascular Disorders:

    • Central retinal vein occlusion.

    • Branch retinal vein occlusion.

    • Central retinal artery occlusion.

  • Macular Degeneration.

Retinal Detachment

  • Description: Separation of the sensory retina and the retinal pigment epithelium (RPE).

  • Manifestations: Sensation of a shade or curtain coming across the vision of one eye, bright flashing lights, sudden onset of floaters.

  • Diagnostic Findings:

    • Assess visual acuity.

    • Assessment of retina by indirect ophthalmoscope, slit lamp.

    • Stereo fundus photography, fluorescein angiography.

    • Tomography and ultrasonography may also be used.

Surgical Treatment of Retinal Detachment

  • Scleral Buckle: Compresses the sclera.

  • Vitrectomy: Intraocular procedure where gas bubble, silicone oil, perfluorocarbon, and liquids may be injected into the vitreous cavity.

Nursing Management of Retinal Disorders

  • Patient Education: Eye surgery is often an outpatient procedure, so patient education is vital.

    • Educate on signs and symptoms of complications, especially increased IOP and infection.

  • Promote Comfort: Patient may need to lie in a prone position.

Retinal Vein or Artery Occlusion

  • Manifestation: Loss of vision can occur.

  • Causes: Atherosclerosis, cardiac valvular disease, venous stasis, hypertension, or increased blood viscosity.

  • Associated Risk Factors: Diabetes, glaucoma, and aging.

  • Symptoms: Patient may report decreased visual acuity or sudden loss of vision.

Trauma Prevention and Emergency Treatment

  • Prevention: Patient and public education on eye injury prevention.

  • Emergency Treatment:

    • Flush chemical injuries.

    • Do not remove foreign objects.

    • Protect the eye using a metal shield or paper cup.

  • Complication: Potential for sympathetic ophthalmia causing blindness in the uninjured eye with some injuries.

Safety Measures and Education

  • Patient Education: A vital nursing intervention for patients with eye and vision disorders.

    • Prevention of eye injuries.

    • Safety strategies for patients with low vision in the hospital and home setting.

    • Patient education after eye surgery or trauma.

  • Potential Complications:

    • Loss of binocular vision with a patch or vision impairment of one eye; impacts safety.

    • Proper use of an eye patch and shield.

Infectious and Inflammatory Disorders of the Eye

  • Dry Eyes.

  • Conjunctivitis ("Pink Eye"):

    • Classification by Cause: Bacterial, viral, fungal, parasitic, allergic, toxic.

    • Viral conjunctivitis is highly contagious.

    • Hyperemia (redness) is a common symptom in viral conjunctivitis.

  • Uveitis.

  • Orbital Cellulitis.

Ocular Consequences of Systemic Disease

  • Diabetic Retinopathy: One of the most common causes of blindness in adults 40 years and older.

  • Ophthalmic Complications Associated with AIDS.

  • Eye Changes Associated with Hypertension.

Chapter 59: Hearing and Balance Disorders

Inner Ear Disorders

  • Vertigo: Sensation of the "room spinning."

  • Meniere's Disease: Triad of symptoms: episodic vertigo, tinnitus, and fluctuating sensorineural hearing loss.

  • Labyrinthitis: Inflammation of the labyrinth, often due to otitis media, causing severe vertigo, nausea, vomiting, tinnitus, and hearing loss. Treated with meclizine and antibiotics.

Assessment of Hearing and Balance

  • Inspection of the external ear.

  • Otoscopic examination.

  • Gross auditory acuity.

  • Tests:

    • Whisper test.

    • Weber test.

    • Rinne test.

Diagnostic Evaluation for Hearing and Balance

  • Audiometry.

  • Tympanogram.

  • Auditory brainstem response.

  • Electronystagmography.

  • Platform posturography.

  • Sinusoidal harmonic acceleration.

  • Middle ear endoscopy.

Hearing Loss

  • Prevalence: Increases with age; 50% over the age of 70 experience hearing loss (Table 59-2).

  • Presbycusis: Increased incidence of hearing loss with age.

  • Risk Factors: Exposure to excessive noise levels.

  • Types:

    • Conductive: Caused by external or middle ear problems.

    • Sensorineural: Caused by damage to the cochlea or vestibulocochlear nerve.

    • Mixed: Both conductive and sensorineural components.

    • Functional (Psychogenic): Caused by emotional problems.

Manifestations of Hearing Loss

  • Early Symptoms:

    • Tinnitus: Perception of sound; often described as "ringing in the ears."

    • Increased inability to hear in a group setting.

    • Turning up the volume on the TV.

  • Progression: Impairment may be gradual and not recognized initially by the individual.

  • Advanced Symptoms: As hearing loss increases, the person may experience deterioration of speech, fatigue, indifference, social isolation or withdrawal, and other symptoms.

Guidelines for Communicating with Hearing-Impaired Persons

  • Determine how the person prefers to communicate.

  • Use a low-tone, normal voice.

  • Speak slowly and distinctly.

  • Reduce background noise and distractions.

  • Face the person and get their attention.

  • Speak into the less impaired ear.

  • Use gestures and facial expressions.

  • If necessary, write out information or obtain a sign language translator.

Conditions of the External Ear

  • Cerumen Impaction (Earwax):

    • Removal Methods: Irrigation, suction, or instrumentation.

    • Gentle Irrigation: Use lowest pressure, directing stream behind the obstruction.

    • Softening Agents: Glycerin, mineral oil, half-strength H2O2 (hydrogen peroxide), or peroxide in glyceryl may help soften cerumen.

  • Foreign Bodies:

    • Removal Methods: Irrigation, suction, or instrumentation.

    • Caution: Objects that may swell (e.g., vegetables or insects) should not be irrigated.

    • Danger: Foreign body removal can be dangerous and may require extraction in the operating room.

    • Effect: Can cause sudden diminished hearing.

  • External Otitis (Swimmer's Ear):

    • Cause: Inflammation most commonly caused by bacteria (Staphylococcus or Pseudomonas) or fungal infection (Aspergillus spp).

    • Manifestations: Pain and tenderness, discharge, edema, erythema, pruritus, hearing loss, feelings of fullness in the ear.

    • Therapy: Aimed at reducing discomfort, reducing edema, and treating the infection.

    • Wick Insertion: A wick may be inserted in the canal to keep it open and facilitate medication administration.

    • Malignant External Otitis: A rare, progressive infection that affects the external auditory canal, surrounding tissues, and skull.

Conditions of the Middle Ear

  • Tympanic Membrane Perforation.

  • Acute Otitis Media (AOM):

    • Prevalence: Most frequently seen in children.

    • Pathogens: Most commonly bacterial or viral.

    • Manifestations: Otalgia (ear pain), fever, and hearing loss.

    • Treatment: Antibiotic therapy, myringotomy, or tympanotomy.

  • Serous Otitis Media: Fluid in the middle ear without evidence of infection.

  • Chronic Otitis Media:

    • Cause: Result of recurrent acute otitis media.

    • Effect: Chronic infection damages the tympanic membrane, ossicles, and involves the mastoid.

    • Treatment: Prevent by treating acute otitis. Surgical options include tympanoplasty, ossiculoplasty, or mastoidectomy.

Middle Ear Surgical Procedures

  • Tympanoplasty: Reconstruction of the tympanic membrane.

  • Ossiculoplasty: Reconstruction of the bones of the middle ear; prostheses are used to reconnect the ossicles and reestablish sound conduction.

  • Mastoidectomy: Removal of diseased bone, mastoid air cells, and cholesteatoma to create a noninfected, healthy ear.

    • Cholesteatoma: A benign tumor, an ingrowth of skin that causes persistently high pressure in the middle ear, which leads to hearing loss and neurologic disorders and destroys structures.

Conditions of the Inner Ear

  • Vestibular System Disorders: May increase the risk of falls.

    • Dizziness: Any altered sense of orientation in space.

    • Vertigo: The illusion of motion or a spinning sensation.

    • Nystagmus: Involuntary rhythmic movement of the eyes associated with vestibular dysfunction.

  • Other Inner Ear Conditions:

    • Tinnitus.

    • Labyrinthitis.

    • Benign Paroxysmal Positional Vertigo (BPPV).

    • Ototoxicity.

    • Acoustic Neuroma: Tumor of the VIII cranial nerve.

Meniere's Disease

  • Cause: Abnormal inner ear fluid balance caused by malabsorption of the endolymphatic sac or blockage of the endolymphatic duct.

  • Manifestations (Triad of Symptoms):

    • Episodic vertigo.

    • Tinnitus.

    • Fluctuating sensorineural hearing loss.

    • Other symptoms include a feeling of pressure, nausea, and vomiting.

  • Treatment:

    • Dietary: Low-sodium diet (1000 to 1500 mg/day).

    • Pharmacologic: Meclizine (Antivert), tranquilizers (e.g., Valium), antiemetics (e.g., promethazine), and diuretics may be used.

    • Rehabilitation: Vestibular rehabilitation and/or physical therapy for chronic balance issues.

    • Surgical Management: To eliminate attacks of vertigo; includes endolymphatic sac decompression, middle and inner ear perfusion, and vestibular nerve sectioning.