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Nursing of Adults with Medical & Surgical Conditons. Eyes, Ears, and Special Senses. Layers of the Eyeball. Outer Layer Sclera Tough, white fibrous, protective layer Anterior portion is the cornea transparent “Eye’s Window” lies over the colored part (iris) of the eye
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Nursing of AdultswithMedical & Surgical Conditons Eyes, Ears, and Special Senses
Layers of the Eyeball • Outer Layer • Sclera • Tough, white fibrous, protective layer • Anterior portion is the cornea • transparent • “Eye’s Window” • lies over the colored part (iris) of the eye • Remainder is white, and is commonly known as the “white of the eye”.
Layers of the Eyeball • Middle Layer • Choroid coat • Contains the blood vessels that supply the eye • Anterior portion has three separate structures • Iris • the colored part of the eye • shaped like a donut • attaches to the ciliary body • opening in the middle is called the pupil • Ciliary Body • muscular ring that alters the shape of the iris • Suspensory Ligament • structure that holds the lens in place
Layers of the Eyeball • Inner Layer • Retina • “The camera of the eye” • receives image formed by the lens • Only in the posterior portion of the eye • consists of specialized nerve tissue for the reception of light • Structure upon which light rays come to focus • Contains tiny receptors • rods - night vision • cones - day vision • Optic Nerve • conducts impulses from the receptors to the brain
Humors of the Eyeball • Aqueous Humor • Watery, transparent liquid that circulates through the anterior cavity of the eye. • Maintains intraocular pressure • Vitreous Humor • Clear, jelly-like fluid in the posterior cavity • Fills the vitreous body to give shape to the eye
Eye Muscles • Extrinsic Eye Muscles • Attach to the outside of the eyeball and to the bones of the orbit • Voluntary muscles • Move the eyeball in any desired direction • Four are straight muscles • superior rectus, inferior rectus, medial rectus, lateral rectus • Two are oblique muscles • superior oblique, inferior oblique
Eye Muscles • Intrinsic Eye Muscles • Located inside the eyeball • Two involuntary muscles • Iris • donut shaped sphincter muscle • regulates the size of the pupil; amount of light entering eye • Ciliary Body • flattened ring the size of the iris • alters the shape of the iris • changes the focus of the lens; adjusts the eye for distant and close-up vision
Accessory Structures of the Eye • Eyebrows and Eyelashes • Protect against foreign objects entering the eye • Eyelids • Located in front of the eyeball • Blink as a result of sensory stimuli • Consist of voluntary muscle and skin • Conjunctiva • mucous membrane lining eyelids • transparent and is continuous over the surface of the eye • Palpebral Fissure • Opening between the eyelids • Inner and Outer Canthus • angles at the ends of the eyelids
Accessory Structures of the Eye • Lacrimal Glands and Ducts • Secrete tears • keep anterior surface moist and free from irritating particles • Size of small almonds • Located in the upper, outer portion of each orbit • Nasolacrimal Ducts • small tubes extending from the lacrimal sacs into the nose to drain tears from the eye to the nose
Parts of the Ear • External Ear • Pinna (auricle) • The outer, extended portion • Composed of cartilage and covered with skin • External Auditory Canal • About 1 inch in length • Contains cerumenous glands • Tympanic Membrane (eardrum) • Stretches across the end of the auditory canal • Separates the external ear from the middle ear
Parts of the Ear • Middle Ear • Small air cavity located in the temporal bone • Contains three ossicles • Malleus (hammer) • attached to tympanic membrane • Incus (anvil) • attached to the head of the malleus • Stapes (stirrup) • fits in the oval window • Allows transmission of sound by the vibrations of the ossicles • Eustachian Tube • Connects the middle ear with the nasopharynx • Allows equalization of air pressure on both sides of the eardrum
Parts of the Ear • Internal Ear • Contains essential organs for hearing and equilibrium • Sends equilibrium and hearing sensations to the auditory nerve • Membranous Labyrinth • Lies within the bony labyrinth • Filled with fluid (endolymph) • Contains receptors for • equilibrium • sense of position • sense of head movement • hearing
Parts of the Ear • Bony Labyrinth • Cochlea • resembles the shape of a snail • filled with fluid (perilymph) • contains receptors for hearing • Organ of Corti • hearing sense organ • sends sensations to the cochlear nerve • Semi-circular Canals • Three canals placed at right angles to each other • Filled with fluid (endolymph) • Contain receptors for equilibrium • Movement of fluid stimulates the receptors; send the message to the brain • Vestibule • Between the cochlea and the semi-circular canals • Maintain a sense of “up and down”.
Conduction • Air Conduction • Occurs in the external ear • Sound waves come through the external auditory meatus and set the tympanic membrane in vibration • Bone Conduction • Occurs in the middle ear • The chain of ossicles transmits the vibration of the tympanic membrane to the inner ear • Fluid Conduction • Occurs in the inner ear • Vibration of the ossicles sets the fluid system into motion • Movement of fluid in the cochlea stimulates the Organ of Corti; to the auditory nerve; to the brain
Special Senses • Smell • Olfactory sense • Organ of Smell • Nose • Receptors for the olfactory nerve lie in the mucosa of the upper part of the nasal cavity • Adaptation to odors is very rapid • receptors become fatigued
Special Senses • Taste • Gustatory Sense • Organ of taste • Tongue • Receptors are the taste buds located in the papillae of the tongue • Four fundamental taste sensations • Salty - tip of the tongue • Sweet - tip of the tongue • Sour - sides of the tongue • Bitter - back of the tongue
Special Senses • Touch • Tactile receptors • Located throughout the integumentary system • Respond to touch, pressure, and vibration • Pain • Pain receptors • Located in the skin and viscera • Gives warning of potentially harmful environmental changes
Diagnostic Tests • Snellen’s Test • Purpose • Assessment of visual aculity • Used as screening test • Procedure • Pt stands 20 ft from chart • Covers one eye • Reads above or below the 20/20 line
Color Vision • Purpose • Assess ability to see color • Prerequisite for driver’s license • Procedure • Color dots are reflected on a background of mixed colors. • Pt identifies color patterns on the test field
Refraction • Purpose • Measure visual acuity to determine refractory errors such as: myopia, hyperopia, presbyopia, and astigmatism • Procedure • Ophthalmologist asks pt to indicate clear/blurred vision with each lens change in the retinoscope.
Ophtalmoscopy • Purpose • Evaluation of underlying structures of the eye • Routine screening • Procedure • Mydriatic drops are applied • Dilates pupils • Room is darkened • Pt is asked to focus on stationary object • Examiner uses ophthalmoscope to view internal eye structure
Tonometry • Purpose • Measurement of intraocular pressure • Determine tumors and glaucoma • Procedure • Examiner places tonometer on cornea • Pressure readings are obtained • Normal intraocular pressure ranges from 10 to 22 mm Hg
Amster Grid Test • Purpose • Diagnose and monitor macular problems • Procedure • Patient fixates on center dot and records any abnormalities of the grid lines, such as wavy, missing, or distorted areas.
Schimirmer Tear Test • Purpose • Measures tear volume produced throughout fixed time period • Procedure • One end of lacrimal filter paper is placed in lower cul-de-sac • Area of tear saturation is measured after 5 minutes
Blindness and Near Blindness • Etiology/Pathophysiology • Loss of visual acuity • Congenital or acquired • Legal blindness • 20/200 with corrective eyewear (normal 20/20) • visual field less than 20 degrees (normal 180)
Blindness and Near Blindness • Signs & Symptoms • Diplopia • double vision • Pain • Floaters and light flashes • Pruritus • Burning of the eyes • Loss of peripheral vision • Halos • Orbital pressure • Bulging of the eyes
Blindness and Near Blindness • Treatment • Corrective eyewear • Canes • Seeing eye dogs • Magnifying systems • Surgical procedures
Refractory Errors • Astigmatism • Strabismus • Myopia • Hyperopia
Refractory Errors • Etiology/Pathophysiology • Astigmatism -unequal curve in the shape of the cornea or lens
Refractory Errors • Strabismus -inability of the eyes to focus in one direction -cross-eyed
Refractory Errors • Myopia • Nearsightedness • Eyeball is too long
Refractory Errors • Hyperopia • Farsightedness • Eyeball is too short
Refractory Errors • Signs & Symptoms • Diminished or blurred vision • Treatment • Corrective lenses • Surgical correction
Conjunctivitis • Etiology/Pathophysiology • Inflammation of the conjunctiva • Bacterial or viral infection • Allergy • Environmental factors • Commonly called “pink eye”
Conjunctivitis • Signs & Symptoms • Erythema of the conjunctiva • Edema of the eyelid • Crusting discharge • Pruritus • Burning • Excessive tearing
Conjunctivitis • Treatment • Warm compresses • Eye irrigations with normal saline • Antibiotic drops or ointment • Keep free of exudate
Keratitis • Etiology/Pathophysiology • Inflammation of the cornea • Injury, irritants, allergies, viral infection, or diseases • Pneumoccoucs, staphylococcus, streptococcus and Pseudomonas are most common types of bacterial causes. • Herpes simplex is most common viral cause.
Keratitis • Signs & Symptoms • Severe eye pain • Photophobia • Tearing • Edema • Visual disturbances
Keratitis • Treatment • Topical antibiotic therapy • Systemic antibiotics • Analgesics • Pressure dressings • relax eye muscle and decrease discomfort • Warm or cold compresses • Epithelial debridement • Keratoplasty • corneal transplant
Cataracts • Etiology/Pathophysiology • Noninfectious opacity or clouding of the lens • Congenital • Acquired • Senile • associated with older adults • most common