Download CH-15 Lecture Eyes - Horizon Medical Institute

Lecture Notes
15
Special Senses:
Eyes
Classroom Activity to
Accompany Medical
Terminology Systems, Sixth
Edition
Barbara A. Gylys ∙ Mary Ellen Wedding
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SPECIAL SENSES: EYES
Structure
• Globe-shaped, 2.5 cm in
diameter
• Three layers
• Fibrous outer tunic
• Vascular middle tunic
• Sensory inner tunic
• Spaces within the eye are
filled with fluids to
support internal
structures
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SPECIAL SENSES: EYES
Function
• Eyes and accessory structures
• Receptor organs provide vision.
• Refraction system focuses light rays on
receptors in the retina.
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SPECIAL SENSES: EYES
Structure and Function Exercise
Q: What is the composition of the outer layer of the
eyeball?
A: Sclera, white of eye, is the outer layer and is made
of fibrous connective tissue.
Q: What does the middle layer of the eyeball consist
of?
A: The middle layer is the vascular layer. It includes
choroid, ciliary body, and iris.
Q: What does the inner layer consist of?
A: The inner tunic consists of the retina, which
contains the visual receptor cells (photoreceptors).
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SPECIAL SENSES: EYES
Cataract
Signs and Symptoms
• Opacity or cloudiness of lens or its surrounding
membrane.
• Develops slowly, most frequently due to aging and
can be familial.
• May occur after eye injury or surgery, or with
diabetes.
• Gradual loss or blurring of vision, but painless.
• As cataract matures, pupil of the eye may appear
white.
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SPECIAL SENSES: EYES
Cataract
Treatment
• Depends on degree of visual
impairment.
• Depends on age, general health, and
occupation of the individual.
• Glasses for mild cases. Surgery when
vision is impaired.
• Surgical extraction of defective lens.
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SPECIAL SENSES: EYES
Cataract
Treatment (continued)
• Lens extraction followed by use of
eyeglasses, contact lenses, or
surgically implanted lenses called
intraocular lenses (IOLs).
• Two most common surgical methods
to remove cataracts:
phacoemulsification and intracapsular
and extracapsular extraction.
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SPECIAL SENSES: EYES
Clinically Related Exercise
Q: An 80-year-old woman presents for an annual check up and asks
the ophthalmologist what causes cataracts.
A: The doctor explains it is a change in chemical composition of the
lens with loss of lens transparency. Also, it is attributed to aging
(senile cataracts), eye injuries (traumatic cataracts), certain
diseases (secondary cataracts), and heredity or birth defects
(congenital cataracts).
Q: Mary presents to OP surgery for cataract repair. The surgeon will
use ultrasonic vibrations to break the lens into tiny particles and
then suction it out of the eye. This surgical procedure is called
(keratectomy, laser iridectomy, phacoemulsification).
A: phacoemulsification
Q: Fred is having cataract surgery followed by a surgically implanted
lens. The abbreviation for intraocular lenses is _________________.
A: IOL
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SPECIAL SENSES: EYES
Strabismus
Signs and Symptoms
• Eyes cannot be
directed to focus on
the same object.
• Esotropia, also
called cross-eye
• Exotropia, also
called wall-eye
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SPECIAL SENSES: EYES
Strabismus
Treatment
• Depends on the cause.
• Often consists of covering the normal eye,
forcing the child to use the deviating one.
• Exercises and corrective lenses may be
ordered.
• Surgical correction may be necessary.
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SPECIAL SENSES: EYES
Clinically Related Exercise
Q: When eyes deviate from the normal position toward various
directions, the diagnosis is _____________________.
A: strabismus
Q: A 5-year-old girl is diagnosed with strabismus. She has a deviation
of one eye toward the other eye. This is often referred to as crosseye. The medical term for this type of strabismus is
__________________.
A: esotropia
Q: A 7-year-old boy displays deviation of the visual axis of one eye
toward the other and complains of double vision. The MA charts
the symptom of double vision as _________________.
A: diplopia
Q: Tom’s right eye intermittently deviates away from the other eye.
The medical term for this type of strabismus is __________________.
A: exotropia
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SPECIAL SENSES: EYES
Glaucoma
Signs and Symptoms
• Accumulated fluid
pressure within the
eye damages the
retina and optic
nerve, often causing
blindness.
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SPECIAL SENSES: EYES
Glaucoma
Signs and Symptoms (continued)
• Common forms develop asymptomatically.
• Often not detected until irreparable
damage occurs to the retinas or optic
nerves.
• When symptoms appear late, they may
include aching eyes and visual
disturbances such as seeing halos around
lights or a noticeable loss of peripheral
vision.
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SPECIAL SENSES: EYES
Glaucoma
Treatment
• Standard course of treatment is drug
therapy.
• Certain types of drugs may be applied to
the surface of the eye to decrease
intraocular pressure.
• Other drugs may be prescribed that
decrease production of aqueous humor.
• Severe cases employ laser surgery to
promote drainage of aqueous humor.
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SPECIAL SENSES: EYES
Clinically Related Exercise
Q: The ophthalmologist diagnoses Mrs. J with increased intraocular
pressure. The abbreviation for this diagnosis is _____________.
A: IOP
Q: A 67-year-old is diagnosed with glaucoma. The physician
prescribes eye drops to decrease aqueous humor production in the
eyes. This type of medication is known as an _____________________
agent.
A: antiglaucoma
Q: Mary presents with complaints of aching eyes and seeing halos
around lights. The ophthalmologist finds an increase in intraocular
pressure and charts the diagnosis as ________________________.
A: glaucoma
Q: The patient asks the ophthalmologist about complications of not
treating her glaucoma.
A: He tells her that accumulated fluid produces pressure within the
eye which damages the retina and optic nerve, and leads to total
loss of vision.
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SPECIAL SENSES: EYES
Medical Vocabulary
• achromatopsia
• apnea
• astigmatism
• blepharospasm
• conjunctivitis
• dacryorrhea
• diabetic retinopathy
• diplopia
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SPECIAL SENSES: EYES
Medical Vocabulary
(continued)
• hordoleum
• Purulent
inlammatory
infection of a
sebaceous gland of
the eyelid; also
called sty.
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SPECIAL SENSES: EYES
Medical Vocabulary
(continued)
• iridotomy
• macular
degeneration
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SPECIAL SENSES: EYES
Diagnostic Procedures
• Tonometry
• Detects glaucoma
by measuring
increased
intraocular
pressure
• Visual acuity
test
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SPECIAL SENSES: EYES
Word Building Exercise
Q: Instrument to measure hearing:
A: audiometer
Q: Examination of the pupil:
A: pupilloscopy
Q: Act of measuring tension:
A: tonometry
Q: Inflammation of the retina:
A: retinitis
Q: Fear of light:
A: photophobia
Q: Paralysis of the eye:
A: ophthalmoplegia
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SPECIAL SENSES: EYES
Medical and Surgical Procedures
• Cataract surgery
• Phacoemulsificati
on
• Iridectomy
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SPECIAL SENSES: EYES
Medical and Surgical Procedures
• Laser photocoagulation
• Seals leaking or hemorrhaging
retinal blood vessels associated
with diabetic retinopathy.
• Light from laser creates heat that
coagulates the tissues.
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SPECIAL SENSES: EYES
Clinically Related Exercise
Q: During eye surgery the ophthalmologist asks for the surgical instrument to
incise the cornea. This instrument is called a ____________.
A: keratotome
Q: After undergoing cataract surgery, a patient is unable to see. The
ophthalmologist suggests a surgical procedure that requires an incision into
the colored muscular layer that surrounds the pupil. This portion of the eye is
known as the ____________________.
A: iris
Q: A 62-year-old patient with drooping eyelids that impair her sight requires
surgery. The procedure for a surgical repair of the eyelids is referred to as
___________________________.
A: blepharoplasty
Q: Zia is diagnosed with glaucoma and is scheduled for an excision of a portion of
the iris to relieve intraocular pressure. This excision of the iris is documented
in the medical record as an __________________.
A: iridectomy
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SPECIAL SENSES: EYES
Pharmacology
• Antiglaucoma drugs
• Miotics
• Mydriatics
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SPECIAL SENSES: EYES
Clinically Related Exercise
Q: Prior to an eye examination, the technician administers an agent
to dilate the pupils, which is known as a(n) (antiglaucoma drug,
miotic, mydriatic).
A: mydriatic
Q: The nurse administers drops to constrict the pupils. This
medication is known as a(n) (antiglaucoma drug, miotic,
mydriatic).
A: miotic
Q: To reduce intraocular pressure by lowering the amount of
aqueous humor in the eyeball and increase aqueous humor
outflow, a(n) (antiglaucoma drug, miotic, mydriatic) is
prescribed.
A: antiglaucoma drug
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