Chapter 30 - Assisting in Ophthalmology & Otolaryngology PDF

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Eyes & Ears...

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Chapter 30: Assisting in Ophthalmology & Otolaryngology

Examination of the Eye  

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Ophthalmology o Science of the eye and its disorders and diseases Ophthalmologist o Physician who specializes in the diagnosis and treatment of disorders and diseases of the eye Optometrist o Not a medical doctor, but can perform eye examinations, diagnose vision problems and eye diseases, and treat visual defects through corrective lenses and eye exercises Opticians o Trained to fill prescriptions written by ophthalmologists and optometrists for corrective lenses by grinding the lenses and dispensing eyewear. Not a medical doctor The medical assistant must be familiar with the normal anatomy and physiology of the eyes, ears, nose, and throat.

Anatomy of the eye  

Figure 30-1 shows the anatomy of the eye. The eyeball consists of three layers.

Functions of the Major Parts of the Eye 

What are the three layers of the eye? (The outermost layer is made up of the white sclera [protects the eyeball] and cornea [allows light to enter the eye]. The choroid is the posterior portion of the middle layer of the eye, and it contains many blood vessels that supply nutrients to the outer layers of the retina. The inner layer of the eye includes the retina in the posterior portion and the lens in the anterior portion.)

Process of Vision 

Visual impulse begins with light passing through the cornea

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Cornea refracts the light and passes it through the aqueous humor and pupil into the lens Ciliary muscle adjusts the curvature of lens to again refract light rays Rays pass into the retina, trigger photo-receptor cells of rods and cones Light energy converts into an electrical impulse and is sent through the optic nerve to the brain What occurs in the brain when an electrical impulse is received? (The impulse is received in the visual cortex of the occipital lobe of the brain and is interpreted, and a picture is created.)

Refractive Errors 

Figure 30-2 shows myopia (A) and hyperopia (B), along with how they are corrected.

Other Errors 

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Refractive

Presbyopia o Changing the point of focus from distance to near becomes difficult, due to age o Difficulty seeing at reading level o Treatment involves corrective lens- laser procedures Astigmatism o Occurs when light rays entering the eye are focused irregularly o Occurs because the cornea or the lens is not a smooth sphere, but has an irregular shape o Corrected with glasses, contacts, or surgery How is presbyopia treated? (A combination corrective lens, known as a bifocal lens or a progressive lens correction, is used to focus both distal and proximal

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objects directly on the retina. Conductive keratoplasty is a laser procedure used to treat presbyopia.) How does astigmatism affect vision? (It is like attempting to focus on objects seen through a wavy piece of window glass.) Surgical correction of astigmatism attempts to reshape the cornea into a more spherical or uniformly curved surface.

Refractive Error   

Hyperopia (Farsightedness)- eyeball is too short and this makes it difficult to see up close. Corrective lens or laser Myopia (Nearsightedness)- Light focus in the front of the retina, causing the objects to be blurry- unable to see at a distance. Corrective lens or laser Signs and symptoms- squinting, rubbing of the eyes, and headaches

Disorders of the Eye 

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Strabismus o Eyes do not track together (do not look in same direction) o In children, caused by weakness in eye muscles o Treatment- child can wear a patch over unaffected eye to build muscle in affected eye (lazy eye) wear patch up to 6 hours a day Adults can develop strabismus because of a condition or disease elsewhere in the body, such as diabetes mellitus, muscular dystrophy, or hypertension, or as the result of a head injury; it is caused by muscle weakness in children. A patient with signs and symptoms of nystagmus first should undergo neurologic evaluation to determine the cause of the disorder, with treatment based on those findings. Eyeglasses and contact lenses are the traditional treatments for visual acuity problems caused by refractive errors. Problems with the shape of the lens can be corrected surgically, on an outpatient basis.

Eye Disorders     

Nystagmus Constant, involuntary movement of one/both eyes- can be a sign of drinking & drugs Accompanied by blurred vision Caused by an abnormal function in part of the brain that controls eye movements Typically patient does not realize the eye movement. Can cause decreased visual acuity, can be corrected with surgery or lenses.

Infections of the Eye 

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Hordeolum (sty) o Localized purulent infection of sebaceous gland of eyelid (caused by staph-warm compress & antibiotics) Chalazion

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o Small cyst from blockage of meibomian gland Keratitis o Inflammation of cornea, results in superficial ulcerations o Eye drops, eye patch (photophobia) Conjunctivitis o Inflammation of conjunctiva caused by irritation, allergy, or bacterial infection Blepharitis o Inflammation of glands and lash follicles along eyelids Bacterial infections are treated with antibiotic ophthalmic preparations.

Disorders of the Eyeball 

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Corneal abrasion o Caused by foreign body or direct trauma  Diagnosis is confirmed by fluorescein stain, highlighted by cobalt blue light  Foreign bodies are removed first, then treated with antibiotic ointment and nonsteroidal anti-inflammatory ophthalmic ointments  Pain, inflammation, tearing and photophobia Cataract o Cloudy area blocks passage of light into retina  Condition may result from eye injury, exposure to extreme heat or radiation, or inherited factors, but is usually due to aging  Blurred, dimmed vision  Effective treatment is surgical removal of the lens  Develop slowly & progressively- typical in age after 60 Symptoms of corneal abrasion include pain, inflammation, tearing, and photophobia. Most cataracts develop slowly and progressively as a result of the natural aging deterioration of the lens of the eye and typically occur after age 60.

Corneal Abrasion  

Figure 30-3 (top) shows corneal abrasion stained with fluorescein. Figure 30-4 (bottom) shows corneal abrasion stained with fluorescein and highlighted by cobalt blue light.

Disorders of the Eyeball 

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Glaucoma o Common and serious, increased intraocular pressure (IOP)  Damages the optic nerve and causes blindness if untreated  Tonometer and gonioscopy used to diagnose  Miotic and beta-blocker eye drops or surgery for treatment Macular degeneration o Progressive deterioration of the macula lutea  Causes severe vision loss and blindness  No cure, but antioxidants may prevent or slow progression  Two forms: dry (90% of cases) and wet What are the two types of glaucoma? (The two types are chronic open-angle glaucoma and acute closed-angle glaucoma. Chronic can be experienced for a long time without noticing symptoms, whereas acute has more obvious symptoms, such as severe pain, headache, and inflammation.) How do physicians screen for glaucoma? (The ophthalmologist first uses a tonometer with a slit lamp to measure increased intraocular pressure. Gonioscopy also can be used to examine the aqueous fluid drainage system and to determine whether the glaucoma is the open- or closed-angle type.)

Glaucoma 

Figure 30-5, A shows open-angle glaucoma; B shows closed-angle glaucoma.

Diagnostic Procedures      

Ophthalmoscope projects light to view interior parts of eye and retina Eyelids examined for edema Pupils examined for shape, symmetry, reactivity to light, and movement coordination Slit lamp biomicroscope to view details of eye, requires mydriatic eye drops Exophthalmometer measures how far eye protrudes beyond edge of socket What is PERRLA? (PERRLA stands for Pupils, Equal, Round, Reactive to Light, and Accommodation. It is charted by the physician if the pupils are reacting normally.)

Distance Visual Acuity     

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Best single test for vision screening, used with the Snellen alphabetical chart Patients must be able to view the chart at eye level, from a distance, and the chart should be illuminated with maximum light Because this is a gross screening of visual acuity, patients are usually allowed to use glasses or contacts Document use of corrective lenses, result of each eye separately and as fractions, outcomes of each test with appropriate abbreviations How do you record the results of this test? (The numerator [top number] is the distance of the patient from the chart [always 20 feet], and the denominator [bottom number] is the lowest line read satisfactorily by the patient. For example, if the patient reads the 20 line at 20 feet, the fraction 20/20 is recorded for that eye. The last line the patient can read without squinting or straining and with no more than two mistakes is the line recorded in the patient’s chart for that eye.) Figure 30-9 shows different types of Snellen charts. Procedure 30-1 outlines the procedure for measuring distance visual acuity with the Snellen chart.

Near Visual Acuity   

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Patient holds card with varying size font 14 to 16 inches from face Test each eye, other eye covered, but open Document number at which the patient stopped reading for each eye, whether corrective lenses were worn, and any signs of eye strain, like squinting This test frequently is given to patients initially to screen for presbyopia or hyperopia. The patient reads the card, starting at the top, until reaching the smallest print that can be read. Figure 30-11 shows the chart for the near vision acuity test.

Ishihara Color Vision     

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Test

Tests for defects in color vision (congenital or acquired) Assess perception of primary colors and shades of colors Polychromatic plates with numbers of one color, and background dots are different color If the score is 10 or higher, the patient is within average range If the score is 7 or lower, the patient is suspected of having a color deficiency, and the ophthalmologist performs additional assessment tests using more precise color vision testing equipment. Procedure 30-2 provides the protocol for assessing color acuity using the Ishihara test.

Treatment Procedures

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Eye irrigation o Use sterile technique and equipment to avoid contamination o Used to relieve inflammation, remove drainage, dilute chemicals, or wash away foreign bodies o Never attempt to remove foreign body with applicator Instillation of medication to treat infection, soothe irritation, anesthetize eye, dilate pupils o Eye drops or ointments are common Aseptic procedures in ophthalmology o Avoid contamination of eye medication applicators o Sterility of medications is critical The eye is irrigated to relieve inflammation, remove drainage, dilute chemicals, or wash away foreign bodies. Newly opened sterile solutions should be used for each patient and should be discarded after instillation or given to the patient for home use. Procedure 30-3 details how to perform eye irrigation, and Procedure 30-4 details how to instill eye medication.

Safety Precautions   

Notify the physician immediately if a patient comes into the office with something in his or her eye. If the physician’s order is for you to remove the foreign body, do so with irrigation only. If this technique is unsuccessful, cover both of the patient’s eyes with a gauze dressing and notify your supervisor immediately.

Anatomy of 

Outer ear

the Ear (external)

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o Auricle, auditory canal Middle ear o Tympanic cavity Inner ear o Called the labyrinth o Organ of Corti The auricle collects sound waves and sends them down the auditory canal. The middle ear contains the auditory ossicles or bones: malleus, incus, and stapes. These three tiny bones are linked by minute ligaments to form a bridge across the space of the tympanic cavity. The inner ear, called the labyrinth, is divided into the cochlea and the semicircular canals, which are joined by the vestibule. The organ of Corti, which contains the receptors for sound, is located within the cochlea. Figure 30-12 shows the anatomy of the ear.

Semicircular 

Figure the canals of the inner ear.

Disorders of the

Canals 30-13 shows semicircular

Ear: Hearing Loss

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Conductive hearing loss (trauma, cerumen impaction, recurrent ear infections) o Caused by a problem that originates in the external or middle ear Sensorineural hearing loss (prolonged exposure to loud noises, medications, viral infections) o Results from an abnormality of the organ of Corti or of the auditory nerve Describe the process of conductive hearing loss. (Conductive hearing loss is caused by a problem that originates in the external or middle ear, which prevents sound vibrations from passing through the external auditory canal, limits the vibration of the tympanic membrane, or interferes with the passage of bone-conducted sound in the middle ear.) If the sensorineural hearing loss cannot be improved by hearing aids, an option is surgical implantation of an artificial cochlea.

Hearing Loss 

Figure 30-14 shows different causes of deafness.

Otitis 

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Otitis externa (swimmer’s ear) o Causes: Dermatologic conditions, trauma, continuous use of earplugs/earphones, swimming Otitis media o Serous or suppurative o Often associated with upper respiratory tract infection or allergic reaction o More common in children What is the difference between otitis externa and otitis media? (Otitis externa affects the external ear canal and is called swimmer’s ear. Otitis media is an inflammation of the normally air-filled middle ear that results in a collection of fluid behind the tympanic membrane.)

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Swimmers frequently have otitis externa because water collects in the ears and mixes with cerumen to form an ideal culture medium for bacteria and fungus. Figure 30-15 shows inflammation and infection of the ear and surrounding canals. How is otitis diagnosed? (An otoscopic examination reveals that the normally pearly gray tympanic membrane is inflamed and bulging. Areas of fluid or pus may be visible through the membrane.)

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A tympanogram may be done to determine the air pressure of the middle ear and the mobility of the tympanic membrane. Figure 30-17 (left) shows a normal tymponogram test with a peak at normal pressure.

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Figure 30-18 (right) shows a tympanic membrane with a tympanostomy tube.

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The American Academy of Pediatrics recommends an initial delay of treatment with antibiotics, giving the child’s immune system a chance to fight the infection by itself. If the condition does not improve, antibiotics may be prescribed.

Impacted Cerumen 

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Cerumen: Soft, yellowish, waxy substance that lubricates the external auditory canal o Excessive secretion can cause:  Hearing loss  Tinnitus  Feeling of fullness  Otalgia o Impacted cerumen can cause conductive hearing loss How is impacted cerumen removed? (This can be done by softening the wax with oily drops, such as carbamide peroxide [Debrox], and then irrigating the ear with warm water until the plug is removed.)

Ménière’s Disease   

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Causes swelling and edema in the semicircular canals Triggers episodes of recurring attacks of vertigo, tinnitus, a sensation of pressure in the affected ear, and advancing hearing loss Ménière’s disease is treated during active periods with medications for nausea and vomiting. A salt-restricted diet, diuretics, and antihistamines may be prescribed to control edema in the labyrinth. Surgical destruction of the affected labyrinth is an option. Although this relieves symptoms, it may also result in permanent deafness if the cochlea is damaged.

Diagnostic Procedures  

Figure 30-19 shows instruments used in otoscopic testing. A number of tests are used to assess hearing acuity.

Tuning Fork Testing    

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Measures hearing by air conduction and bone conduction To activate the fork, hold it by the stem and strike the tines softly on the palm of the hand Weber test is used if patient reports better hearing in one ear Rinne test compares air conduction sound with bone conduction sound o In normal hearing, sound is heard twice as long by air as by bone conduction Remember that in bone conduction, the sound vibrates through the cranial bones to the inner ear. Striking the tines too forcefully creates a tone that is too loud for diagnostic use.

Audiometric Testing   

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Measures the lowest intensity of sound an individual can hear Wearing headphones, the patient is exposed to sounds and is asked to signal when a sound is heard If initial screening indicates hearing deficit, an audiologist may be consulted The results are printed on a graph, called an audiogram, or the medical assistant charts the results on a graph sheet. An adult with normal hearing can hear tone frequencies

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below 25 decibels, and children with normal hearing can hear those below 15 decibels. Figure 30-20 shows an audiometer and how to correctly place the headphones. Routine examination instruments should be disinfected or sterilized after each use according to office policy and stored in a clean area. Procedure 30-5 describes the protocol for measuring hearing acuity with an audiometer.

Treatment Procedures 

Ear irrigation o Done to remove excessive or impacted cerumen, to remove a foreign

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body, or to treat inflamed ear with an antiseptic solution Administer irrigating solution with applicator tilted up, toward top of external canal

Always chart the treatment and its results immediately after completion Instilling otic medications o Medication ordered for ear instillation is given to soften impacted cerumen, to relieve pain, or as an antibiotic drop for an infectious pathogen Patients with ear conditions may be in considerable pain and may have difficulty hearing, which makes health teaching a challenge. Wait until after the procedure has been completed and the patient is more comfortable to reinforce health behaviors. Procedure 30-6 outlines how to irrigate a patient’s ear. Procedure 30-7 provides the steps for instilling medicated ear drops. o

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Examination of the Nose and Throat       

Nasal cavity examined to test mucous membrane and nostrils Throat includes the larynx and the pharynx o Seen with mirror tongue depressor/gauze square Collection of throat specimens The physician may use a nasal speculum to visualize the nostrils and examines the nasal sinuses by palpation and transillumination. The physician may spray the patient’s throat with a topical anesthetic before the examination to prevent the gag reflex. Throat cultures are collected by gently swabbing the back of the throat and the surfaces of the tonsils with a sterile swab. Procedure 30-8 describes how to collect a specimen for a throat culture.

Patient Education    

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