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The EYE and the EAR

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The conjunctiva is clear and colorless except when blood vessels are dilated. ... A normal fluoresein angiogram. Detached Retina ... – PowerPoint PPT presentation

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Title: The EYE and the EAR


1
The EYE and the EAR
  • The eye the ear are sense organs, like the
    skin, taste buds, and olfactory centers in the
    nose.

2
Outer Eye
  • The conjunctiva is clear and colorless except
    when blood vessels are dilated. Dust and smoke
    will cause this and give the eye the bloodshot
    eye appearance.

Lacrimal caruncle
Conjunctiva
3
EYE
  • A normal, healthy cornea is avascular (with no
    blood vessels) receives nourishment form blood
    vessels near its junction with the sclera. The
    function of the cornea is to bend or refract the
    rays of light.

4
The Inside of the Eye
Macula- yellowish region slightly near the optic
disk, contains the fovea.
The choroid is the middle, vascular dark membrane
of the eye, between the retina the sclera.
Is not constantly reformed, gives shape to eyeball
x
Aqueous Humor
Fovea- small cup-like depressed region is the
center point of clearest vision contains only
cone receptors
  • The x shows where the blind spot called the
    optic disc is. It is where the nerve meets the
    retina. Contains only nerve fibers, no rods or
    cones.

5
Optic Chiasm
  • Chiasm means crossing.
  • Point at which fibers of the optic nerve cross in
    the brain.
  • Notice that half of the visual field is projected
    to the other side of the brain.
  • In the occipital lobe the images are fused to
    form a single image.



Fibers Cross over
Synapse in the Thalamus

6
Hemianopsia- Loss of vision in the contralateral
visual field.
  • Contralateral means opposite.
  • Damage to nerve cells in the right cerebral
    cortex such as in a stroke, will cause a loss of
    vision in the left visual field.
  • Similarly, damage in the left cerebral cortex
    will cause a loss in the right visual field.

7
Sections of the Retina
  • Cones- photoreceptor cells in the retina that are
    responsible for color central vision. 6.5
    million
  • Three types of cones Red, Green Blue
  • Rods -Photoreceptor cells of the retina that are
    essential for vision in dim light and peripheral
    vision. 120 million
  • These cells relay info to the bipolar
    neurons, next to ganglion cells, and at last to
    the fibers of the optic nerve.

8
Normal Retina
  • Intravenous injection of fluorescein (dye) to
    take photographs of the retina through the
    patients dilated pupils.
  • Test shows blood flow in the retina, detects
    vascular changes for HBP and diabetes, and
    identifies lesions of the macular area.
  • A normal fluoresein angiogram.

9
Detached Retina
  • The two layers of the retina separate from each
    other.
  • Trauma, head injuries, bleeding, infection, and
    shrinking of the vitreous humor can produce tears
    or holes result in separation of the retina.
  • Treatment used might be photocoagulation to seal
    a hole, cryotherapy to burn a scar, and use of a
    scleral buckle.
  • Patients often see bright flashes of light-
    (called photopsia) or black spots called floaters.

10
Scleral Buckling
  • A procedure to repair retina detachment.
  • A strip of sclera is resected, or a fold is made
    in the sclera.
  • An implant is inserted with sutures to hold and
    buckle the sclera.
  • A suture of silicon band pushes the two parts
    against each other to bring together the parts of
    the detached retina.

11
Nyctalopia- Retinitus Pigmentosa
  • This is a genetic disorder where pigmented scars
    form on the retina and destroys retinal rods.
    Decreased vision and night blindness occurs.

12
Macular Degeneration
  • Picture seen on left has normal vision. Picture
    on the right as it would appear to someone with
    macular degeneration.
  • Progressive damage to the macula of the retina.
  • Leading cause of blindness in the elderly.

13
Anisocoria
  • Condition of uneven pupils.
  • Indication of neurological injury or disease.

14
Lacrimal Tear Gland Ducts
  • Dacryocystitis-inflammation of the tear sac
  • Drainage of eye goes into the nose.

15
Blepharitis
  • Inflammation of the eyelid
  • Thickened lids with crusts around the lashes.

16
Hordeolum- stye, sty
  • Localized, purulent, inflammatory staphylococcal
    infection of a sebaceous gland in the eyelid.
  • Warm compress to the eye may help open up the
    gland.

17
Chalazion
  • Small, hard, cystic mass on the eyelid
    (granuloma) Require incision and drainage.
  • Formed as a result of chronic inflammation of a
    sebaceous gland along the margin of the eyelid.

18
Conjunctivitis
  • Commonly called pinkeye.
  • Inflammation of the conjunctiva which is the
    delicate membrane lining the eyelids and covering
    the anterior eyeball.
  • Discharge of pus characteristic of highly
    contagious condition.

19
Blepharoptosis
  • Drooping of the eyelid

20
Farsightedness- Hyperopia
  • The eyeball shape is too short in the adult eye
    compared to normal or the lens is too weak.
  • Convex lens used to correct.

21
Nearsightedness- Myopia
  • The shape of the eyeball is too long for the
    adult eye compared to a normal eyeball or the
    lens is too strong.
  • Corrected with a concave lens.

22
Astigmatism
  • This causes light rays to be uneven and not
    sharply focused on the retina so that the image
    is distorted.
  • The correction is with a cylindrical lens.
  • Abnormal curvature of corneal surface or shape of
    the lens.

23
Radial Keratotomy (RK)
  • Surgery in which spoke-like incisions are made to
    reshape the cornea, thus correcting
    nearsightedness.
  • The first surgery was performed in Russia in
    1972. Introduced in U.S. in 1978.
  • Shows location of the incisions.

24
Appearance of the Eye After Keratoplasty
  • Also known as a Corneal Transplant.
  • Surgical repair of the cornea results in this
    clinical appearance.
  • This donor cornea is sutured into place after
    removal of the original cornea.

25
PKR- Photorefractive Keratectomy
  • LASIK shapes the tissue below the surface of the
    cornea to reshape or flatten the corneal surface
    using an Excimer laser.
  • The PKR removes tissue from the surface of the
    cornea.

26
LASIK
  • Acronym for laser in situ keratomileusis (shaping
    the cornea)
  • Performed as an outpatient under local
    anesthesia.
  • The surgeon lifts the top of the layer of the
    cornea and uses a laser to sculpt the cornea.
  • The the corneal flap is repositioned.
  • Use of an Eximer Laser to correct refraction
    (myopia, hyperopia, and astigmatism) and lamellar
    keratoplasty.
  • Differs from PKR because it shapes the corneal
    tissue beneath the surface as well as on the
    surface like in PKR.

27
Corneal Stem Transplants
  • Can restore and maintain the clear covering of
    the cornea membrane that may have been destroyed
    by injury or disease.
  • Stem cells are harvested from cadavers and
    transplanted into and around the edges of a blind
    recipient.
  • This technique is in the research stages and has
    some problems with rejection the immune system.

28
Glaucoma
  • Diagnosed by tonometry applied externally to the
    eye with a local anesthetic,
  • Acute glaucoma has extreme ocular pain, blurred
    vision, redness of the eye, and dilation of the
    pupil. May cause blindness.
  • Chronic glaucoma has no symptoms, only a gradual
    loss of vision.

Fluid leaves at the angle where cornea iris
meet.
  • Glaucoma occurs when the circulation in the
    anterior chamber builds up and pressure builds.
  • Treatment may be with drugs or with laser surgery.

29
Slit Lamp Microscopy
  • Examination of anterior ocular structures under
    microscopic magnification.
  • Devices attached to a slit lamp expand the scope
    of examination,
  • Measuring intraocular pressure by tonometry to
    detect glaucoma.

30
Cataract
  • A cataract is a type of degenerative eye disease.
  • The protein in the lens clots clouds the
    vision.
  • It is a gradual development of cloudiness within
    the lenses, not a film that covers the eye.
  • The lens appear cloudy. Often can be seen by the
    naked eye.

31
Cataract Examples
  • Snowflake cataracts are present at birth or
    others occur with complications from diabetes
    mellitus or from trauma.
  • Senile cataracts are linked to the process of
    aging.

32
Cataract Surgery
  • Phacoemulsification- technique of cataract
    extraction using ultrasonic vibrations to
    fragment (emulsify) the lens and aspirate it from
    the eye by use of an ultrasonic probe.
  • The surgeon uses a small, self-sealing
    scleral-tunnel incision..
  • In most patients, an intraocular lens is
    implanted at the same time.

33
Ophthalmoscopy
  • Visual examination of the interior of the eye.
    The pupil is dilated and the physician shines the
    light into the back of the eye.
  • Ophthalmoscope

34
Visual Acuity Vision Field Tests
  • The Snellen chart assesses vision by reading a
    chart at a distance of 20 feet.
  • Expressed as a ratio, such as 20/20 (1st tells
    distance, 2nd normal person could have read)
  • Visual fields are examined by measuring the area
    within which objects are seen when the eyes are
    fixed, looking straight ahead without turning
    head.

35
Color Blindness
  • People with normal vision will see the number 74.
    People with red-green color blindness cannot.
  • Used to classify red-green if they see the 2
    only, the red sensitive cones are abnormal if
    they see the 4 only, the green sensitive cones
    are abnormal.

36
Anatomy of the EAR
  • The two functions of the ear are to hear and to
    provide the sense of balance.

37
Inner Ear Middle Outer Ear
The eustachian tube or auditory tube leads to the
pharynx opens upon swallowing to reduce pressure
in the middle ear and keeps the eardrum from
bulging outward.
38
Eardrum- Tympanic Membrane
  • A. Healthy tympanic membrane
  • B. Tympanic membrane with a cholesteatoma (tumor
    of skin cells cholesterol).

Tympanic membrane is derived from the Greek word
for drum.
39
Eardrum- Tympanic Membrane
  • D. Myringotomy with tympanostomy tube
  • C. Acute Otitis Media (severe ear ache)

Placing tubes reduces the pressure.
40
Ossicles
  • The tiny three bones of the middle ear pick up
    the vibrations of the eardrum and transfer the
    vibrations onto the inner ear through the oval
    window.
  • Stapes is Latin for stirrup.
  • The middle ear region.

41
Stapedectomy
  • A prosthetic device (wire, Teflon, or metal) is
    placed into the incus and attached to a hole in
    the oval window.
  • Using a microsurgical technique and a laser, the
    stapes bone is removed.

Malleus Incus
New device
Oval window
42
Inside the Cochlea
  • This movement stimulates the hair cells on the
    organ of Corti to generate a nerve impulse.
  • The vibrations of the oval window cause the
    perilymph in the bony labyrinth of the cochlea to
    move.

43
Cochlear Transplant
  • If the hairs of the organ of Corti are damaged,
    nerve deafness occurs.
  • A new surgically implanted device can improve
    this form of hearing loss.
  • A transmitter outside the scalp sends sound info
    to a receiver behind the auricle which translates
    into an electrical code relayed to directly the
    cochlea and its nerve..

44
Acoustic Neuroma
  • Benign tumor arising from the acoustic
    vestibulocochlear nerve (8th cranial nerve) in
    the brain.
  • Causes tinnitus (ringing in the ears), vertigo
    (dizziness), and decreased hearing.

45
Meniere Disease
  • Disorder of the labyrinth of the inner ear marked
    by elevated endolymph pressure within the cochlea
    and semicircular canals.
  • Symptoms include, tinnitus, vertigo, nausea, and
    headaches. Attacks last for minutes or for hours.
  • Cause is unknown an treatment is rest and drugs.

46
Audiometry
  • Pure-tone audiometer
  • lt One earphone emits a test sound while the
    other emits a masking noise.

47
Otoscopy- Visual examination of the ear with an
otoscope.
  • The auricle (pinna) is pulled up and back. The
    hand holding the scope is placed against the face
    for stabilization.
  • Ear thermometry using a tympanic membrane
    thermometer within 2 seconds.

48
The end
  • Glaucoma- is Greek glaukos for blue-gray or sea
    green, means a morbid condition.
  • Cataract- is derived from the Greek word for
    waterfall, as you would see things through a
    watery veil of mist or waterfall.
  • Iris- special messenger of the Queen of Heaven
    according to Greek mythology. She passed from
    heaven to earth over the rainbow while dressed in
    rainbow hues.
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