Chapter 16: Eye and Ear Diseases and Disorders.

Angiography

(angio = vessel, graphy = procedure to record) a radiographic study of blood vessels after injection of fluorescein dye.

audiometry

(audio = sound, metry = measure) the basic test used to measure hearing. During the test, sound is delivered in varying levels, or decibels, through a headset to each ear separately. The greater the amount of sound needed for the individual to hear or recognize it, the greater the amount of deafness or hearing loss.

Radial keratotomy (RK)

(kerato = cornea, otomy = incision) a surgical procedure to correct myopia; incisions are made in a radial fashion in the cornea to flatten the cornea, thus shortening the length of the eyeball and correcting the refractive error.

mastoidectomy

(mastoid = shaped like a nipple (referring to mastoid process), ectomy = removal or excision) a procedure used to prevent complications and preserve hearing by removing the bony partitions forming the mastoid cells.

myringotomy

(myringo = eardrum, otomy = incision into) incision into the eardrum to remove fluid.

ophthalmoscope

(ophthalm = eye, scope = instrument used to look) the instrument used for a basic examination of the eye.

otoscope

(oto = ear, scope = instrument to look) the instrument used to examine the ear. Otitis externa and a ruptured tympanic membrane can be diagnosed using the otoscope.

Presbyopia

(presby = old age) is hyperopia that is age-related. It is not due to the shape of the eyeball but, rather, is related to the inability of the aging lens to focus light rays properly. In presbyopia, the lens does not return to the normal shape, causing light rays to fall beyond the retina. Presbyopia usually affects individuals age 40 or older and can be corrected with reading glasses, bifocals, CK, and monovision LASIK.

Diabetic retinopathy

(retino = retina, opathy = disease) is a complication of diabetes and the leading cause of blindness in the United States. This condition can happen to any individual with type 1 or type 2 diabetes. The longer the individual has diabetes, the more likely is the development of diabetic retinopathy.

Tonometry

(tono = tone or pressure, metry = measurement) a procedure to measure the pressure inside the eye. => useful in determining the presence of glaucoma.

tympanostomy

(tympano = eardrum, ostomy = new opening) a procedure in which tubes, commonly called PE tubes or pediatric ear tubes, are placed through the tympanic membrane to prevent the accumulation of fluid.

tympanoplasty

(tympano = eardrum, plasty = surgical correction) surgery to repair the tympanic membrane.

The extraocular structures include:

-Muscles that hold the eyeball in place and facilitate movement of the eyeball: 1. Superior and inferior rectus—move eye up and down 2. Medial and lateral rectus—move eye toward the nose and toward the temple 3. Superior and inferior oblique—move the eye to the right and left vertically. -Cranial nerves that innervate the eye and its structures 1. Optic (II) 2. Oculomotor (III) 3. Trochlear (IV) 4. Trigeminal (V) 5. Abducens (VI) 6. Facial (VII) -Eyelids that cover the anterior portion of the eyeball, regulate light entering the eye, protect the eye, and lubricate the eye -Conjunctivae (clear transparent membranes) to protect the eye from foreign objects -Lacrimal glands (tear glands) to clean and moisten the eye.

symptoms of cataracts

. The main symptom is a decrease in visual acuity or a complaint about not being able to see clearly. Other symptoms include blurred vision, glare, and a decrease in color perception. In advanced cases, the cataract can be seen through the pupil, giving the pupil a white, cloudy appearance.

Symptoms of Stye

A tender, painful, red bump, often resembling a pimple, is located at the base of an eyelash or inside the eyelid. Often there is swelling or edema along the entire lid. Purulent drainage can come from the eyelash line or on the conjunctival surface of the eye.

Symptoms of conjunctivitis

Affected individuals might complain of excessive tearing, itching, burning, and pain. An acute, contagious bacterial infection of the conjunctiva is called pinkeye, which can become epidemic among school-aged children.

Symptoms of blepharitis

Affected individuals might complain of itching and burning and a feeling of something in the eye. The eyelids appear red, swollen, and crusted.

treatment for motion sickness

Antihistamine medications are generally used to treat and prevent this condition. These medications appear to work by calming the stimulation of the inner ear. Meclizine (Antivert®, Dramamine II®) can treat symptoms. Motion sickness can also be relieved or reduced by lying down and closing the eyes.

considerations that might decrease the effect or prevent the occurrence of motion sickness include:

Avoiding heavy meals prior to a trip. Finding a seat in the most stable area of the boat or plane. During automobile rides, making frequent stops for short walks in the fresh air. Not reading while traveling. Avoiding stuffy areas, especially those with odors such as cigarette smoke. Trying to stay cool with plenty of fresh air when possible. Avoiding too much heat.

Diagnosis of nystagmus

Computerized tomography (CT) scan, magnetic resonance imaging (MRI), myelogram, angiography, and spinal tap might be needed to confirm the cause of the condition.

four common types of refractive errors:

Myopia. Hyperopia. Presbyopia. Astigmatism.

Color Blindness or Color Vision Deficiency

Normal ability to see colors diminishes with age due to the progressive yellowing of the lens. Colors become less intense, and the colors of green and blue often become more difficult to distinguish. Difficulty in distinguishing colors also can occur in young individuals affected with color vision deficiency (CVD). also commonly occurs as an inherited, X-linked disorder that affects approximately 1 in 10 males. It is rarely seen in females.

Common signs and symptoms of ear disease that need medical attention include:

Otalgia (ot = ear, algia = pain; ear pain) Deafness Vertigo (dizziness) Tinnitus (ringing in the ears).

Common signs and symptoms of eye disease that need medical attention include:

Pain or burning in or around the eye Decreased visual acuity or ability to see Any visual disorder such as seeing flashes of light Eye redness.

Symptoms of Diabetic retinopathy

Retinal scarring decreases visual acuity and can ultimately cause permanent blindness. These vascular changes tend to occur in both eyes and are more extensive in uncontrolled diabetes or in individuals whose blood sugar is not controlled. Diabetic retinopathy can be asymptomatic in the early stages, but as the disease progresses, symptoms include blurred vision, poor night vision, floating spots in the visual field, and vision loss.

Otitis Media caused by serous

The fluid is clear and can be due to a Eustachian tube obstruction, allergy, or change in middle-ear pressure. Middle-ear pressure commonly occurs with air flight. Any of these situations may allow clear serous fluid to accumulate in the middle ear. This fluid accumulation causes inflammation of the middle ear, but without infection. Symptoms are usually mild and include a feeling of fullness in the ear and conductive hearing loss.

suppurative otitis media

The fluid is pus due to a bacterial infection in the middle ear. often due to bacteria entering the middle ear, usually from the Eustachian tube during an upper respiratory infection. Blowing the nose forcefully often drives respiratory bacteria through the Eustachian tube into the middle ear. Swimming in contaminated water can be another cause of suppurative infection.

The external ear includes:

The pinna (auricle) and the external auditory canal. -The pinna is mostly cartilaginous tissue with a small amount of adipose tissue in the earlobe. -The external auditory canal is about 1 inch long and contains hair and wax producing glands.

symptoms of macular degeneration

The primary symptom is a loss of central vision. Peripheral vision and color perception are unaffected. The disease generally develops slowly and painlessly, and both eyes are usually affected. As the disease progresses, reading and activities that require fine, detailed vision become impossible. There can be a complete loss of central vision, but generally, blindness does not occur.

Symptoms of color blindness

There are three main kinds of color vision defects. Red-green color vision defects are the most common, occur more often in men, and affect the ability to distinguish between red and green. The other major types are blue-yellow defects and complete absence of color vision.

Diagnosis of Diabetic retinopathy

This condition is best diagnosed with a dilated eye exam to allow the physician to see abnormal blood vessels, blood or fatty deposits in the retina, retinal detachment, and damage to the nerve tissue, all symptoms of diabetic retinopathy.

Treatment of macular degeneration

Vision might be improved in some cases by laser surgery or by taking antioxidant vitamins. There are also several new drugs on the market to treat age-related macular degeneration, and the Food and Drug Administration recently approved an implantable miniature telescope.

Treatment of Stye

Warm compresses may relieve pain, help localize the infection, and promote drainage. Styes usually form a soft spot, open, and drain and heal without further treatment. In some cases, styes may need to be incised to promote drainage and healing. In chronic conditions, topical (placed on the skin) antibiotic or systemic (taken by mouth or injection) antibiotics may be needed.

cataract

a clouding of the lens of the eye. develop from a change in metabolism and nutrition within the lens, most commonly from aging. Approximately 60% of all individuals 70 years of age or older will have clouding of a lens. Cataracts also can be caused by trauma, birth defects, and other diseases such as diabetes mellitus. Cataracts usually develop very slowly in one or both eyes.

Glaucoma

a common condition characterized by excessive pressure inside the eye from the fluid inside the eye, known as aqueous humor, which is produced constantly by blood. It circulates through the eye and is reabsorbed into the bloodstream. Excessive pressure inside the eye occurs if too much fluid is produced or does not drain properly. There are several forms of glaucoma, including open- angle and closed-angle glaucoma.

Nystagmus

a constant, involuntary movement of the eyes that might be unnoticed by the affected individual. Movement can be vertical, horizontal, circular, or a combination of these. One or both eyes might be affected. might be the result of brain tumors, disease, alcohol abuse, or congenital defects. Diseases that cause nystagmus include Ménière's disease and multiple sclerosis.

amblyopia

a decrease in the vision of the affected eye due to a lack of visual stimuli.

Macular degeneration

a degeneration of the macular area of the retina, which is important in seeing fine detail. The cause of this degeneration can be due to the effects of drugs, but the most common cause is aging. Risk factors include farsightedness, light eye color, and cigarette smoking. This disease is the leading cause of visual impairment in individuals 50 years of age and older.

Strabismus

a disorder in which the eyes fail to look in the same direction at the same time (Figure 16-13). Strabismus is often incorrectly referred to as lazy eye and as crossed eye or cockeye. result of muscle weakness in one or both eyes. The affected eye can deviate upward or downward, but more commonly, it looks inward (convergent strabismus) or outward (divergent strabismus).

Automated lamellar keratoplasty (ALK)

a surgery using a device called a microkeratome to separate and remove a thin disc of cornea. The thickness of the disc removed determines the change in the refractive error.

Otitis externa

also called swimmer's ear or external otitis, is an inflammation of the external ear canal. This disease commonly affects swimmers who spend many hours in the water. Other causes include trauma to the ear canal, such as can occur when attempting to scratch or clean the ear canal, and when swimming in contaminated water. The condition often is due to bacterial or fungal infection. Wearing headphones/earphones/earbuds also creates a favorable environment for the growth of microorganisms.

The middle ear

also called the tympanic cavity, is a small space containing three bones: the malleus (hammer), incus (anvil), and stapes (stirrup). Next to the stapes is the oval window that leads to the inner ear.

Symptoms of otitis externa include

an inflamed ear canal with extreme pain, fever, pruritus (itching), and hearing loss. The ear also might drain clear or purulent (containing pus) fluid.

Conjunctivitis

an inflammation of the conjunctiva, the pink membrane lining the inner eyelids; can be caused by excessive exposure to wind, sun, heat, and cold. The eyelids become red and swollen.

Stye (Hordeolum)

an inflammatory infection of a sebaceous (oil-secreting) gland of the eyelid at the base of a hair follicle or eyelash. Most styes are caused by Staphylococcus bacteria and are often seen in blepharitis. They are also found more frequently in individuals who have diabetes and seborrhea.

Astigmatism

an irregularity in the surface of the cornea, causing light rays to spread over the retina rather than focus properly on part of the retina. This refractive error can lead to blurred or fuzzy vision, often described as seeing halos around objects. Astigmatism can be treated with prescriptive lenses or LASIK.

The semicircular canals

assist the body in adjusting to changes in direction, and the movement of fluid in this area can cause symptoms of dizziness.

Snellen chart

chart containing symbols that is used in the testing of visual acuity. Normal vision is expressed as 20/20 and is considered normal vision for an individual viewing a particular line of the chart from 20 feet away. The first number, 20, expresses the fact that the individual is tested from 20 feet, and the second number expresses the distance from which an individual with normal vision could view those same images. For example, 20/220 means that the tested individual can see at 20 feet what most people can see at 220 feet.

Hyperopia

commonly called farsightedness. Individuals with hyperopia can see objects that are far away but have difficulty seeing close objects. Hyperopia can be treated with prescriptive lenses, conductive keratoplasty (CK), ALK, laser epithelial keratomileusis (H-LASEK), and thermal keratoplasty.

Myopia

commonly called nearsightedness or short-sightedness. Individuals can see nearby objects but have difficulty seeing distant objects. Myopia can be treated with prescriptive lenses, radial keratotomy (RK), automated lamellar keratoplasty (ALK), laser-assisted in-situ keratomileusis (LASIK), and implantable contact lenses (ICL) surgery.

Refractive errors

defects caused by the eye's inability to focus images correctly on the retina. Approximately one-third of the population is affected by refractive errors. The cause of refractive errors is unknown, although some run in families, suggesting an inheritance pattern. Although these disorders affect individuals of all ages, incidence increases with age.

The primary symptoms of strabismus are _______________

diplopia and altered eye movement.

vertigo

dizziness.

diplopia

double vision.

otalgia

ear pain.

cerumen

ear wax

suppurative

formation of pus.

symptoms of glaucoma

glaucoma progresses slowly, might or might not be symptomatic, and rarely affects individuals under age 40. Increased pressure inside the eye for a continued period of time can lead to damage of the optic nerve and blindness, and permanent damage is often done before symptoms occur. For this reason, intraocular pressure should be checked on an annual basis.

Meclizine

helpful in prevention of motion sickness if taken at least one hour prior to travel.

Otitis media

inflammation in the middle ear. It usually affects infants and young children and is commonly called middle-ear infection, but it might not necessarily be an infection. The middle ear is normally filled with air, but when this area fills with fluid, inflammation occurs. For this reason, otitis media is classified by the type of fluid that fills the ear.

Keratitis

inflammation of the cornea, usually unilateral, affecting only one eye. A frequent cause of keratitis is infection by herpes simplex virus secondary to an upper respiratory infection involving cold sores (herpes simplex). Allergies and contact lenses can also lead to this condition.

Blepharitis

inflammation of the edge of the eyelid, including the eyelash follicles and glands; can be caused by bacterial infection and allergic reaction to smoke, dust, or chemicals. Seborrhea, a disorder of the sebaceous gland, or oil-secreting gland, also can cause blepharitis.

Mastoiditis

inflammation of the mastoid bone or process. This bone is porous or honeycombed in appearance and located behind the ear. This condition commonly affects children and is usually the result of a middle-ear infection. Prior to antibiotics, this was a leading cause of death in children. With current diagnosis and treatment regimens, it is less common and rarely dangerous. Acute mastoiditis is usually the result of a middle-ear infection commonly caused by Streptococcus.

The clear fibers enclosed in a membrane that refract and focus light to the retina is (are) called the ________

lens.

The structures in the vestibule

maintain equilibrium during movement of the head.

Cochclea

organ of hearing.

Symptoms of keratitis include

pain, photophobia (photo = light, phobia = fear), and excessive tearing.

Implantable contact lenses (ICL)

permanently implant contact lenses into the eye. An advantage of ICL over surgeries that flatten the cornea is that overcorrection or undercorrection can be remedied by replacing the contact lens with the correct prescription.

The slow but gradual loss of hearing is called _______________

presbycusis.

The mechanism for vision occurs after the impulses leave the __________and travel through the optic nerves to the brain.

retina.

The intraocular structures consist of

some parts of the eye that are visible externally and some parts visible only through an ophthalmoscope. Including: 1. Sclera—white area covering the outside of the eye except over the pupil and iris 2. Cornea—clear tissue covering the pupil and iris 3. Iris—round disk of smooth and radial muscles giving the eye its color 4. Pupil—round opening in the iris that changes size as the iris reacts to light and dark 5. Anterior chamber—space between the cornea and iris/pupil that is filled with clear fluid called aqueous humor 6. Posterior chamber—space between the iris and lens that is filled with aqueous humor 7. Lens—clear fibers enclosed in a membrane that refract and focus light to the retina 8. Posterior cavity—the space in the posterior two-thirds of the eyeball filled with a thick, gelatinous material called vitreous humor 9. Posterior sclera—white opaque layer covering the posterior part of the eyeball 10. Choroid layer—the layer containing blood vessels between the sclera and retina 11. Retina—the inner layer of the posterior part of the eye that receives the light rays (visual stimuli).

Common symptoms of refractive errors include

squinting, blurred vision, headaches, and rubbing of eyes.

Monovision

surgery adjusts or fits one eye to see at a distance, leaving the other eye unadjusted for seeing close up, such as is needed for reading. (Normally, the eyes work equally to look at an object, a process called binocular vision.) The monovision idea is easy to achieve also with contact lenses in that one lens can be left out, allowing one eye to be corrected while the other is not.

Laser epithelial keratomileusis (H-LASEK)

surgery loosens the surface area of the cornea and pushes it to the side; a laser reshapes the inner layer of the cornea, and then the outer surface is replaced.

Conductive keratoplasty (CK)

surgery uses mild heat from radio waves to shrink connective tissue (collagen) around the edge of the cornea. This circular pattern acts like a belt that tightens around the cornea, causing it to bulge or steepen the center of the cornea, thus lengthening the too-short eyeball.

Cataracts are commonly treated with ______________

surgery, which involves removing the cloudy lens and replacing it with a clear artificial lens. => commonly called cataract extraction with placement of intraocular lens, is routinely performed as outpatient surgery.

Diagnosis of mastoiditis is made on

the basis of examination and otoscopy (oto = ear, scopy = procedure to look into), X-ray of the mastoid bone, CT scan, and bacterial cultures.

Diagnosis of otitis media is made on

the basis of otoscopy revealing a bulging tympanic membrane or eardrum. The normally pearly colored tympanic membrane is red and swollen. If the tympanic membrane is ruptured, a culture of the fluid can be performed; otherwise, cultures are not obtainable. An elevated white blood cell count is also indicative of infection.

During an otoscopy (oto = ear, scopy = procedure to look), or otoscopic examination,__________________.

the external canal and tympanic membrane can be visualized easily.

During an ophthalmoscopy (ophthalm = eye, oscopy = procedure to look), _________________

the fundus, or interior aspect of the eye, is examined.

Scopolamine

the most commonly prescribed preventive medication. It is available in a skin patch (Transderm Scop®) that is applied behind the ear; the medication is then slowly absorbed into the skin. To be most effective, this patch should be placed at least four hours in advance of the motion activity. Effects of the patch last up to three days.

inner ear

the most sophisticated part of the ear and is responsible for both hearing and equilibrium (balance). It consists of a fluid-filled space housing the vestibule, the semicircular canals, the round window, and the cochlea.

Motion sickness

the nauseated feeling some individuals experience when traveling by automobile, boat, or airplane. The cause of motion sickness is abnormal movement of the organs of balance—the semicircular canals—that are located in the inner ear. These semicircular canals are accustomed to traveling in a horizontal plane, but movement in a vertical plane, as in a boat or bumpy airplane ride, produces an abnormal sensation in these organs, leading to motion sickness. Watching motion on a widescreen picture also can cause motion sickness, even though the individual is not actually moving.

Laser-assisted in-situ keratomileusis (LASIK)

the newest form of RK and is rapidly becoming the procedure of choice. This process uses a precisely controlled, intense beam of ultraviolet laser light to vaporize selected cells and flatten the curvature of the cornea. With this procedure, the tissue around and underneath the tissue that is removed is not affected.

eyeball

the sensory organ of sight located in the bony orbit of the skull. It is about one inch in diameter and consists of extraocular and intraocular structures

The external ear and middle ear are separated by ________________

the tympanic membrane (eardrum).

Symptoms of mastoiditis include

tinnitus (ringing in the ears), otalgia (ot = ear, algia = pain), fever, and headache. The mastoid also can become swollen and painful, and ear drainage can be present.

slit-lamp examination (SLE)

uses a microscope to magnify the surface of the eye by directing a beam of light, narrowed to a slit, at the cornea. Instilling fluorescein dye in the eye prior to the examination can improve visualization of eye disorders. => helpful in determining corneal abrasions, keratitis, and cataracts.

Thermal keratoplasty (TK)

uses heat to change the shape of the cornea by shrinking collagen fibers.

Symptoms of motion sickness include

varying degrees of nausea, vomiting, diaphoresis, and vertigo. Fortunately, motion sickness usually subsides when movement stops.

Photorefractive keratotomy (PRK)

very similar to LASIK. In this process the very top epithelial layer of the cornea is moved aside before the excimer laser sculpts the cornea.