MEDSURG 6 Chapter 21: Nursing Assessment: Visual and Auditory SystemsSTRUCTURES AND FUNCTIONS The visual system includes external tissues and structures surrounding the eye. o External structures include the eyebrows, eyelids, eyelashes, lacrimal system, conjunctiva, cornea, sclera, and extraocular muscles. o Internal structures include the iris, lens, ciliary body, choroid, and retina. The cornea, aqueous humor, lens, and vitreous must all remain clear for light to reach the retina and stimulate the photoreceptor cells. Refraction is the ability of the eye to bend light rays so that they fall on the retina. When light does not focus properly, it is called refractive error. Types of refractive errors are myopia (nearsightedness) and hyperopia (farsightedness). Astigmatism is caused by corneal unevenness resulting in visual distortion. Presbyopia is a type of hyperopia due to aging. The auditory system consists of peripheral and central systems. o Peripheral system includes the external, middle, and inner ear and is involved with sound reception and perception. o The central system (brain and its pathways) integrates and assigns meaning to what is heard. Presbycusis can result from aging or insults from a variety of sources. Tinnitus, or ringing in the ears, may accompany the hearing loss that results from the aging process. External and middle ear portions conduct and amplify sound waves from the environment. Problems located in these areas cause conductive hearing loss with changes in sound perception/sensitivity. The inner ear functions in hearing and balance. Problems located in this area or along the nerve pathway from the brain cause sensorineural hearing loss with changes in tone perception/sensitivity. Central auditory system problems cause central hearing loss with difficulty in understanding the meaning of words.

ASSESSMENT AND DIAGNOSTIC STUDIES Patient information obtained should include past eye/ear health and family history. History also should include specific diseases and medications known to cause vision and hearing problems. Past history of visual and auditory tests and eye/ear trauma is also noted. Visual assessment determines visual acuity, ability to judge closeness and distance, extraocular muscle function, evaluating visual fields and pupil function, and measuring intraocular pressure.

Auditory assessment notes head posturing and appropriateness of responses when speaking to the patient and balance. Problems with balance may present as nystagmus or vertigo. Visual and auditory external structures are assessed by inspection for symmetry and deformity. Some eye structures must be visualized with an ophthalmoscope; an otoscope is used for further assessment of certain ear structures. Visual assessment can include color vision and stereopsis with auditory assessment often including whisper/spoken word testing, audiometry, and tuning fork tests.

****Chapter 22: Nursing Management: Visual and Auditory ProblemsPROBLEMS OF THE EYE REFRACTIVE ERRORS Refractive errors are the most common visual problems. They occur when light rays do not converge into a single focus on the retina.

Myopia, or nearsightedness, is the most prevalent refractive error. Hyperopia refers to farsightedness. Presbyopia is farsightedness due to decreased accommodative ability of the aging eye. Most refractive errors are corrected by lenses (eyeglasses or contact lenses), refractive surgery, or surgical implantation of an artificial lens.

EXTRAOCULAR DISORDERS A hordeolum (sty) is an infection of sebaceous glands in the lid margin.

A chalazion is a chronic inflammatory granuloma of meibomian (sebaceous) glands in the lid. Blepharitis is a common chronic bilateral inflammation of the lid margins. Conjunctivitis is infection or inflammation of the conjunctiva. o Acute bacterial conjunctivitis (pinkeye) is common. o It occurs initially in one eye and can spread rapidly to the unaffected eye. o It is usually self-limiting, but antibiotic drops shorten the course of the disorder. Trachoma is a chronic conjunctivitis caused by Chlamydia trachomatis. o It is a global cause of blindness. o It is preventable and transmitted mainly by hands and flies.

Keratitis is corneal inflammation or infection. o The cornea can become infected by bacteria, viruses, or fungi.

o Topical antibiotics are generally effective, but eradicating infection may require antibiotics administered by subconjunctival injection or IV. o Other causes are chemical damage, contact lens wear, and contaminated products (e.g., lens care solutions, cosmetics). o Tissue loss due to infection produces corneal ulcers. o Treatment is aggressive to avoid permanent loss of vision. An untreated ulcer can result in corneal scarring and perforation. CATARACT A cataract is an opacity within the lens. Symptoms of cataracts are decreased vision, abnormal color perception, and glare. Removal of the cataract is the most common surgery for older adults. Most patients undergoing cataract removal have an intraocular lens implanted during surgery. After cataract surgery, the eyes are temporarily covered with a patch and protective shield. Postoperative nursing goals include teaching about eye care, activity restrictions, medications, follow-up visit schedule, and signs/symptoms of possible complications. Healing is complete around 6 to 8 weeks postoperatively.

RETINOPATHY Retinopathy is microvascular damage to the retina that can lead to blurred and progressive vision loss. It is often associated with diabetes mellitus and hypertension.

Nonproliferative diabetic retinopathy is characterized by capillary microaneuryms, retinal swelling, and hard exudates. o Macular edema represents a worsening as plasma leaks from macular blood vessels. o It may be treated with laser photocoagulation. Hypertensive retinopathy is caused by high blood pressure that creates blockages in retinal blood vessels. o On examination, retinal hemorrhages and macula swelling are noted. o Sustained, severe hypertension can cause sudden visual loss with optic disc and nerve swelling. o Treatment focuses on lowering the blood pressure. RETINAL DETACHMENT Retinal detachment is a separation of the retina and underlying epithelium with fluid accumulation between the two layers. Detachment is caused by a retinal break, which is interruption in the full thickness of retinal tissue. Untreated, symptomatic retinal detachment results in blindness. Breaks are classified as tears or holes.

Symptoms are light flashes, floaters, and/or rings in vision. Once detached, painless loss of peripheral or central vision occurs. Treatment of retinal detachment is to first seal retinal breaks and then relieve inward traction on retina. Several types of surgery used include laser photocoagulation and cryopexy and then scleral buckling. Visual prognosis varies, depending on the extent, length, and area of detachment. Discharge planning and teaching are important, with the nurse beginning this process early as the patient is not hospitalized for long.

AGE-RELATED MACULAR DEGENERATION Age-related macular degeneration (AMD) is the most common cause of irreversible central vision loss in older adults. AMD is related to retinal aging. Family history is another strong predictor of risk. AMD has two forms: dry (nonexudative) and wet (exudative). o Dry AMD is more common, with close vision tasks becoming more difficult. Atrophy of macular cells leads to slow, progressive, and painless vision loss. o Wet AMD is more severe, with rapid onset and development of abnormal blood vessels related to the macula. Symptoms are blurred, distorted, and darkened vision with visual field blind spots. o Wet AMD treatment includes laser photocoagulation, photodynamic therapy, and intravitreous injectable drugs. Vitamin and mineral supplements may be considered.

GLAUCOMA Glaucoma is associated with increased intraocular pressure (IOP), optic nerve atrophy, and peripheral visual field loss.

Glaucoma often occurs with advanced age and is a major cause of permanent blindness. Etiology is due to consequences of elevated IOP. Glaucoma is largely preventable with early detection and treatment. Two types of glaucoma include: primary angle-closure glaucoma (PACG) and primary openangle glaucoma (POAG), which is the more common. o With POAG, few symptoms exist and it is often not noticed until peripheral vision is severely compromised. o Symptoms of PACG include sudden, excruciating eye pain along with nausea and vomiting. o Therapy is to lower IOP to prevent optic nerve damage through drugs, argon laser trabeculoplasty, trabeculectomy, and iridotomy. The nurse should teach about glaucoma risk and the importance of early detection and treatment.

PROBLEMS OF THE EAR

EXTERNAL OTITIS External otitis involves inflammation or infection of the auricle and ear canal epithelium due to infection. Symptoms are pain, ear canal swelling, and drainage. Therapy is analgesics, antibiotics, and compresses.

ACUTE OTITIS MEDIA Untreated or repeated attacks of acute otitis media in early childhood may lead to chronic middle ear infection. Symptoms include purulent exudate and inflammation that can involve the ossicles, eustachian tube, and mastoid bone. It is often painless. Treatment may include antibiotics and surgery.

MNIRES DISEASE Mnires disease is characterized by symptoms of inner ear disease with episodic vertigo, tinnitus, fluctuating sensorineural hearing loss, and aural fullness. The cause is unknown, but results in excessive accumulation of endolymph. Attacks may begin with sense of ear fullness, tinnitus, and decreased hearing acuity. The duration of attacks is hours to days, and attacks occur several times a year. Other symptoms are pallor, sweating, nausea, and vomiting. Hearing loss fluctuates, and with continued attacks, recovery lessens, eventually leading to permanent hearing loss. Drugs are used between and during attacks. If not relieved, surgeries include endolymphatic sac decompression and vestibular nerve resection. Nursing care minimizes vertigo and provides for patient safety with acute attacks.

HEARING DISORDERS Hearing disorders are the primary handicapping disability in the United States. Conductive hearing loss: o Occurs in outer and middle ear and impairs the sound being conducted from outer to inner ear. o It is caused by conditions interfering with air conduction, such as otitis media with effusion, impacted cerumen and foreign bodies, middle ear disease, and otosclerosis.

Sensorineural hearing loss: o Is due to impairment of inner ear or vestibulocochlear nerve (CN VIII). o Causes include congenital and hereditary factors, noise trauma, aging, Mnires disease, and ototoxicity. o The main problems are the ability to hear sound but not to understand speech and lack of understanding of the problem. Signs of hearing loss include asking others to speak up, answering questions inappropriately, not responding when not looking at speaker, straining to hear, and increasing sensitivity to slight increases in noise level. Often the patient is unaware of minimal hearing loss. Assistive devices and techniques include hearing aids, speech reading, and a cochlear implant. Prevention of hearing loss focuses on participation in hearing conservation programs in the work environment, monitoring for side effects and level of ototoxic drugs (e.g., salicylates, diuretics, antineoplastics), and avoidance of both continued exposure to high noise levels (above 85 to 95 decibels) and industrial drugs and chemicals (e.g., toluene, carbon disulfide, mercury). Presbycusis (hearing loss associated with aging) includes loss of peripheral auditory sensitivity, decline in word recognition ability, and associated psychologic and communication issues.