Domain 2 Module: Relevant Medical Information (10 test questions) Flashcards
the globe
- Collects and absorbs; light rays so they can form a clear image on the retina
- Outer layer
o Conjunctive
o Sclera
o Cornea
- Inner layer
o Anterior chamber
o Posterior chamber
o vitreous
Orbit
thin, transparent membrane; lines the inside of the eyes/sclera; does not cover cornea
- Protective barrier (alerts for foreign bodies)
- Lubricates front of eye
- Indicates ocular/physical health
Conjunctiva
White part of the eye; dense; provides protection
- Maintains shape of globe
- Provides protection to inner structures
- Provides attachment points for extraocular muscles
Sclera
Highly organized group of cells and proteins; contains no blood vessels; receives nourishment from tears
- Refract and transmit light
- Provides most of the eye’s optical power
- If cornea loses elasticity or is damaged, it won’t be able to function properly and blurred images will be transmitted to the retina
Cornea
Space in front of cornea, but behind the iris; contains iris, trabecular meshwork, canal of schlemm
Anterior Chamber
Small space between back of iris and lens
Posterior Chamber
Clear fluid inside anterior and posterior chamber; provides nourishment and support
Aqueous Humor
Composed of ciliary muscle
- Involved in controlling lens accommodation and IOP
Ciliary Body
Colored part of the eye
- Regulates light entering the eye
Iris
Hole in the middle of the iris
- Constricts in bright light (becomes smaller)
- Dilates in dim light (becomes larger)
Pupil
Extends where iris meets the cornea
- Drains/filters the eye
Trabecular Meshwork
Located between the retina and sclera
- Nourishes retina
- Removes waste
- Contains many blood vessels and capillaries
Choroid
Refracts and focuses light
- Helps create a sharp image on retina
- Can change shape
Lens
Light sensitive nerve tissue
- Breaks down images into brightness, position, color, and movement
- Converts images into electrical signals and sends those signals to the brain
Retina
Peripheral retina; active in low light
- Responsible for night vision
- Poor perception of color and detail
Rods
Light receptor cells
- Active in high light and color
- Detects color and detail
Cones
Central part of the retina
- Responsible for detecting color and fine detail
- Clear visual acuity
Macula
Visual pathway; no photoreceptor cells; cannot process light
Optic Nerve
a. carries impulses for sight from the retina to the brain
b. each nerve fiber corresponds to specific parts of the retina
c. once information gets to the optic nerve, it gets sent to the brain via the Visual Pathway
d. damage in this area: loss of vision in affected eye
optic nerve/ optic pathway
a. where nasal fibers of each optic nerve cross
b. separates information from the right visual field and the left visual field
c. right half of the visual field goes to the left side of the brain
d. left half of the visual field goes to the right side of the brain
e. images projected on the retina are inverted
f. damage in this area: hemianopia: loss of half the visual field (temporal loss)
g. damage AFTER chiasm: temporal loss in one eye, nasal loss in the other
optic chiasm
a. contains visual cortex
b. info from each part of the retina is combined and interpreted
c. organized into layers and columns
d. responsible for vision and visual perceptions
e. damage in this area: temporal loss in one eye, nasal loss in the other
f. “macular sparring”: when the macula is left in tact
occipital lobes
a. the area at the side of each cerebral hemisphere
b. contains major portions of optic radiations
c. complex visual analysis
i. allows for categorization of objects; “memory library” of images
5. posterior parietal lobes
a. upper mid part of each cerebral hemisphere
b. responsible for body sensations
c. responsible for spatial information
i. right parietal lobe – understanding spatial aspects of the world, recognizes shapes, being aware of ones body in space
temporal lobes
What it is:
- Progressive, degenerative damage to the central part of the retina
- Affects the cones
- Wet: abnormal blood vessel grow and leak under the macula
- Dry: degeneration of retina
Causes:
- Age
- Genetics
Functional implications
- Central acuity loss
- Blind spot
- Photophobia
- Pool color vision
- Normal peripheral vision
Adaptations:
- Eccentric viewing
- Magnification
- Large print
- Diffused less intense light
- Direct light
- Telescopes
- Tinted lenses
- CCVT
- Adjustable lighting
- Reduce/eliminate glare
- High contrast
Treatments:
- Wet: shots in the eye to stop the bleeding
Considerations for older adults with ARMD:
- Rehab interventions can affect coping mechanisms related to psychological adjustment
- Age related visual impairment can be linked to functional impairments, specifically in instrumental activities in daily living (getting dressed, eating, appearance)
- Successful adaptations to visual impairments may affect perception of older adults’ functional disabilities
functional implications
o Central acuity loss
o Blind spot
o Photophobia
o Pool color vision
o Normal peripheral vision
ARMD
What it is:
- Progressive: night blindness peripheral loss tunnel vision complete blindness
- Degeneration of rods (light sensitive cells in retinal periphery)
- Can be found in: Ushers and Lebers
Causes:
- Genetics
Risk Factors:
- Age (teens/young adults)
- Gender (more common in males)
Functional implications
- Loss of peripheral vision
- Night blindness
- Tunnel vision
- Decreased acuity and depth perception
- Retinal scarring (causes spotty vision)
- Cataracts possible
- May be accompanied with myopia, cataracts, keratoconus
Adaptations:
- High illumination
- Reduce glare
- Absorptive lenses
- Prism glasses
- CCVT
- High contrast
- Teach organized search patterns
Treatments:
- None – take precautions to prevent retinal detachment
Functional implications:
o Loss of peripheral vision
o Night blindness
o Tunnel vision
o Decreased acuity and depth perception
o Retinal scarring (causes spotty vision)
o Cataracts possible
o May be accompanied with myopia, cataracts, keratoconus
RP
What it is:
- Decrease in retinal blood vessel development in preemie babies
- Leads to bleeding, scarring, and detachment
- Can range from minimal damage to complete blindness
Causes:
- Low birthweight
- Born before 31 weeks
- High duration and administration of oxygen
Risk Factors:
- Low birthweight
- Born before 31 weeks
- Overall health of infant
Functional implications
- Decreased visual acuity
- Severe myopia
- Possible retinal detachment
- Spotty vision
- Strabismus
- Retinal scarring
- Field loss
- Possible glaucoma
o Decreased visual acuity
o Severe myopia
o Possible retinal detachment
o Spotty vision
o Strabismus
o Retinal scarring
o Field loss
o Possible glaucoma
Adaptations
- high illumination
- magnification
- telescopes
- CCTV
Treatments:
- Vitamin E therapy
- Cryotherapy
- Vitrectomy
- Some cases resolve themselves
ROP
What it is:
• Collection of Eye disease that causes increased pressure in the eye because of blockage in the normal flow of fluid in the aqueous humor
• Damages optic nerve
Caused by:
• Changes in the uveal tract
• Trauma
• Medication reaction
• Surgery
• Genetics
Risk factors:
• 55+
• family history
• diabetes
• Race (higher prevalence in African American or native American)
Functional Implications:
• Fluctuating vision – can lead to stress and fatigue
• Tunnel vision
• Peripheral field loss
• Poor night vision
• Photophobia
• Difficulty seeing large objects in close range
• Decreased sensitivity to contrast
• Pain/headaches
• Eye redness
• Hazy cornea
• Wide open pupil
• Degeneration of optic disc
• Poor spatial awareness
o Fluctuating vision – can lead to stress and fatigue
o Tunnel vision
o Peripheral field loss
o Poor night vision
o Photophobia
o Difficulty seeing large objects in close range
o Decreased sensitivity to contrast
o Pain/headaches
o Eye redness
o Hazy cornea
o Wide open pupil
o Degeneration of optic disc
o Poor spatial awareness
Adaptations:
• Sunglasses, eye shades
• Lamps with adjustable lighting
• Reduce glare
• Increase contrast
• Magnifiers
• CCVT
Treatment:
• Eye drops
• Surgery
o Trabeculectomy – removing portion of trabecular meshwork to improve drainage
o Iridotomy – laser creates hole in iris
Glaucoma
What it is:
- Diabetes can cause changes in blood vessels of the retina
- Causes hemorrhaging in the retina and vitreous
- Neuropathy in feet and hands
- Retinal detachment and full blindness possible
- Proliferative: formation of new blood vessels
- Non-proliferative: beginning stages, blood vessels become weak
Caused by:
- Diabetes
- Genetics
- Retinal hemorrhage
- Glaucoma
- Cataracts
- Optic neuropathy
Functional Implications:
- Sensitive to glare
- Double vision
- Lack of accommodation
- Fluctuating acuity
- Diminished color vision
- Defective visual fields
- Floaters
- Retinal detachment
- Neuropathy – unable to tactilely discriminate
Adaptations:
- Good lighting
- Good contrast
- Magnification
- Reduce glare
- Pay attention to diet
- Tinted lenses
- Take care of feet to prevent infections
- Wear comfortable well-fitting shoes at all times
- Avoid bending, lifting, straining, rapid movement – can affect DR
Treatment:
- Diet
- Insulin
- Surgery
Diabetic Retinopathy
abnormal/leaky blood vessels sealed/destroyed by light
Vascular photocoagulation
laser used to destroy oxygen starved area of retina creating regressing of abnormal/weak blood vessel growth
Retinal photocoagulation
What it is:
- Damage to the visual cortex (in the brain)
o Problem with how information is transmitted from the eye to the brain and how the brain interprets that information
- Ocular structures remain in tact
- Disorders associated with CVI: CP, epilepsy, hydrocephalus, learning disabilities, deafness
- Common with CVI: optic nerve atrophy, optic nerve hypoplasia, retinal abnormalities
Causes:
- Lack of oxygen (anoxia) at birth
- Head injury
- Infections that affect nervous system
Functional implications (depends on type of CVI)
- Fluctuation in visual functioning
- Loss of ability to understand information the eye is giving you
- Visual neglect
- Eye may look normal
- Inattention to visual stimuli
- Preference of touch over vision
- Difficult with visual clutter or when things are too close together
- Difficult discriminating figure-ground
- May have more central vision, peripheral vision
- Light gazing
- Photophobia
- Slower processing/response time
- May easily become overwhelmed
- Inability to coordinate visual information with other senses
- Visual Midline Shift Syndrome- shift in concept of midline following stroke or TBI
Adaptations:
- High illumination – spotlighting/indirect lighting sources are beneficial for clarity
- Eliminate visual clutter
- Eliminate glare
- Routines
- Repetition
- Bright contrast
- Consistent visual cues
- Combination of reading media
- Determine which sensory system works best
- Prevent visual overload
- Provide simple images and tasks
- Encourage tactile exploration
- Demonstrate via hand-over-hand
- Eliminate distractions
- Yoked Prisms
Treatments:
- None
CVI
optic disc is small, sometimes surrounded with a halo; vision may or may not be reduce
congenital abnormality
Usually results in low visual acuity. Additional cognitive disabilities often present. Frequent in children.
Small optic cup
progressive retinal degeneration in both eyes; night blindness in childhood followed by loss of peripheral vision to finally blindness; hereditary
Rod/Cone
degeneration of retinal receptors results in loss of color and central vision, followed by loss of night vision
Cone/Rod:
malignant Intraocular tumor that develops from retinal & visual cells; hereditary; vision loss can be total or scotomic
Retinoblastoma
Hyperopia
Myopia -
Astigmatism
Refractive Errors
farsightedness
Hyperopia
nearsightedness
Myopia
uneven focus of light between both eyes
Astigmatism
What it is:
- Gradual hardening of the lens elasticity
Causes:
- Age
Functional implications
- Reduced ability to accommodate
Adaptations
- Good lighting
- High contrast
Presbyopia
Both eyes together
OU
Right eye
OD
Left eye
OS
shows the quietest sounds you can just hear. The red circles represent the right ear and the blue crosses represent the left ear. Across the top, there is a measure of frequency (pitch) from the lower pitched sounds on the left going to higher pitched sounds on the right. These sounds are measured in Hertz.
Down the side, there is a measure of loudness. At the top of the graph are the very quiet sounds, going down to moderate, and then very loud sounds. This loudness is measured in a scale called decibels (dB). Any points that are heard at 20dB or quieter are considered to be within the normal range
Audiogram
a. strength of sound
b. amplitude
c. measured in decibels
d. measure of sound pressure level
e. relative strength of sound waves (transmitted vibrations), which we perceive as loudness or volume
intensity:
a. pitch
b. the rate of particle vibration measured in cycles per second
c. measured in Hertz
d. For sound, this means the number of pressure waves per second that would move past a fixed point. It is also the same as the number of vibrations per second the particles are making as they transmit the sound.
Frequency
portion of a particle in its vibrating cycle
phase:
a. sensation of frequency
b. high pitch = high frequency
c. Pitch relates to the frequency, or how many times a second the particles vibrate. The distance between one wave and the next gives the wavelength. For sounds all travelling at the same speed, high-frequency (high-pitched) sounds have waves very close together. Low-frequency sounds have a greater distance between each wave.
pitch:
a. unit used to measure the intensity of a sound or power level of electrical signal by comparing it with a given level on a logarithmic scale
b. not linear
Decibel:
Air conduction test unmasked left ear
The symbol “X”
Air conduction test unmasked right ear
the symbol “O”
Bone conduction test right ear
the symbol “<”:
Bone conduction test left ear
the symbol “>”:
Affecting both sides
bilateral
o dysfunction of the outer/middle ear
o usually treated with medication/surgery
o loudness deficit
o functional implications
soft speaking voice (they hear their voice louder than normal)
excellent speech discrimination when speech is loud enough
lower frequencies tend to be affected
temporary
conductive hearing loss:
o dysfunction of the inner ear/auditory nerve
o usually permanent
o untreatable
o loudness deficit
o distorted hearing – nerve endings in the cochlea/nerve pathways damaged; messages do not effectively reach the brain
o middle ear structures in tact
o functional implications
inappropriately loud voice
tinnitus
frequency loss – high frequency (most common)
speech sounds distorted
background noise makes listening more difficult
hearing aids may help
sensorineural hearing loss
notorious for distorting, changing, and generally making sounds unusable for orientation and mobility tasks. Many are designed and set to enhance the human voice for communication, not to retrieve environmental sounds. In fact, they may be intentionally blocking distal environmental input. Also, no can reach far into the environment (such as hearing a car 300 feet away).
vertigo
gradual deterioration
difficulty distinguishing near vs. far (location acuity loss)
specific sounds seem unnaturally loud
difficulty understanding speech patterns
Hearing aids, cochlear implants, and other listening devices
o combo of conductive and sensorineural hearing loss
o treatment may be available for the conductive loss
o both high and low frequency losses
mixed hearing loss
o help people with communication disorders to express themselves. These devices can range from a simple picture board to a computer program that synthesizes speech from text.
augmented communication (def.):
a. If the bone conduction hearing thresholds are normal, but there is a loss of hearing for air conduction sounds, this is called a
conductive hearing loss:
a. When there is no difference between the air conduction and the bone conduction thresholds it indicates that the hearing loss is due to a problem in the cochlea.
sensorineural hearing loss:
a. gap between the air conduction and the bone conduction thresholds, however the bone conduction thresholds still indicate a hearing loss as they are not within normal limits. This would suggest that there is a problem in both the cochlear and the middle ear
mixed hearing loss:
-10 to 15 dB HL
normal hearing
16 to 25 dB HL
slight hearing loss
26 to 40 dB HL
mild hearing loss
41 to 55 dB HL
moderate hearing loss
56 to 70 dB HL
moderately severe hearing loss
71 to 90 dB HL
severe hearing loss
> 90
profound hearing loss
a. Diabetic Retinopathy
b. Glaucoma
c. Cataracts
Diabetes
a. Monitor blood sugar and note instances of low/high
b. Lethargy
c. Neuropathy
i. Hands- make it difficult to get feedback from cane
ii. Feet – make it difficult to detect drop offs
d. Rapid changes in vision likely
i. Bad vision days make indicate low blood sugar
e. Pressure sores common
i. Wear comfortable sneakers
ii. Monitor for pain, swelling, bruising, blistering, tenderness, discoloration of the skin
f. Keep a diabetic information sheet
i. Student name, address, phone number
ii. School/agency name, address phone number
iii. Doctor name and phone number
iv. Emergency contact
v. Type of insulin, amount taken, time of day given
vi. Typical symptoms of student and how student wants to handle them
vii. Time of day likely to have reaction
considerations when developing an O&M instruction program for persons with diabetes?
a. CMV (cytomegalovirus):
i. lesions on retina,
ii. varying amount of hemorrhage,
iii. swelling of optic nerve
iv. blurry vision or field loss may occur
b. Kaposi’s sarcoma
i. Vascular tumor
ii. Purple/red growth on eyelid
iii. May block visual field
c. Toxoplasmosis
i. Infection
ii. Retinal inflammation
iii. Retinal destruction due to cysts
d. Cryptococcal meningitis
i. Damages optic nerve and brain
e. Central nervous system infections
i. Second most common cause of blindness
ii. Can lead to diplopia, blurred vision, difficulties in eye movements
f. HIV retinopathy
i. Microvascular disorder
ii. “cotton wool spots”
iii. microanuerysms
iv. retinal hemorrhaging
v. field loss
vi. retinal detachment
eye diseases are associated with AIDS?
a. Decreased functioning of immune system can lead to neurological complications
i. Neuropathy
ii. Can make walking difficult
iii. Brain damage can lead to strokes, dementia, headaches, and behavioral changes
iv. Confusion, seizures, vision loss, and memory and cognitive defects may also be seen
b. Prevent yourself from becoming infected
c. Practice good hygiene
d. Reschedule if you are sick
e. Practice “universal health precautions”
f. Students willingness and ability to participate may vary from day to day or even hour to hour
g. Confirm all meetings several hours before appointment
h. Goals may need to be reassessed and modified as students physical condition changes
i. Because of privacy las, you may not know if a student has HIV/AIDS and it might be difficult to accurately plan lessons and goals
j. Vision impairment comes in the later stages
i. Students may be facing their own mortality
ii. Can greatly impact motivation
the implications of AIDS for O&M instruction?
- nature of seizures depends on location and duration
- changes in consciousness, motor activity, sensory phenomena, inappropriate behavior
- internal stimuli
o stress
o fatigue
o lack of sleep
o fever
o electrolyte imbalance
o excess fluid/salt intake
o not taking medications - external stimuli
o bright/flashing lights
o visual patterns
o fire alarms
o vestibular
o olfactory
o cognitive, emotional, or decision making tasks - partial
o can last several minutes
o student may experience confusion
o guide student to safe place
o stay close until seizure ends and wait until student can respond normally
o during seizure, student may last out if restrained - generalized
o if grand mal
loosen clothing
get a pillow
do not insert anything into mouth
lay student on side when finished to keep airway open
o if petite mal
wait until episode is finished
eyes may stare ahead or roll back
• can’t wake them up
seizure disorder
- Inflammatory disease that affects joints and surrounding areas
- Can be unpredictable
- Can be a result of wear and tear on body
Vision implications - Dry eye
- Scleritis – inflammation/redness of white part of eye
- Uveitis/iritis – can cause severe pain, blurred vision, photophobia
Adaptations - Build up diameter of cane grip
- Lightweight cane
- Wrap joints in warm towels for 7-10 minutes to reduce pain
- Avoid overexertion or fatigue
- Symptoms mat increase in cold weather
- Tinted lenses
- Organize home to minimize impact on joints
- Most frequent items at easy reach
- Plan rest breaks during work
- Use tools that eliminate bending (for cooking – microwave, stove)
- Avoid lifting or carrying heavy items
- Use something with wheels to move items from room to room
- Avoid doing labor in the morning when symptoms are worse
- Warm bath/shower can reduce joint pain
Treatments: - Medications (prescription/non-prescription)
Arthritis:
What it is:
- Involves both heart and blood vessels
- Heart not pumping blood efficiently
Risk Factors:
- High blood pressure
- High cholesterol
- Smoking
- Inactivity
- Diabetes
- stress
Symptoms:
- blood circulation impaired
- fluid may gather in body tissues
- swollen feet and ankles
- shortness of breath
Vision implications:
- Hypertensive retinopathy – changes in retina caused by high blood pressure, can damage optic nerve and cause retinal blood vessels to harden and swell, can range from blurred vision to total blindness
- Retinal artery blockage – “stroke in the eye”
- Retinal vein blockage – bleeding of blood vessels
Adaptations
- Talk with doctor and eye doctor before physical activity
o Some conditions can be affected by bending, lifting, straining, rapid movement
- Simplify everyday tasks to conserve energy
- Plan rest when working
high blood pressure/ Cardiovascular disease
o congestive heart failure
generally, people have poor endurance, shortness of breath, and chest pain
be alert to signs of stress
assess exercise tolerance
keep a list of medications and be aware of side effects and precautions
minimize stress
remember
• cardiac status may change from day to day
• extreme hot or cold can affect condition
5. asthma
- factors that can trigger asthma
o inhaled allergens
o dust, wool, feathers
o drastic weather changes
o extreme hot/cold
o strenuous exercise
o respiratory infections
o medications
- when teaching
o minimize potential for triggered attacks
o have the following information available in case of an attack
brief history of student’s asthma and symptoms of an attack
factors that make asthma worse
list of medications
contact info of doctor and emergency contact
description of treatment plan, including recommended actions
heart condition
low blood sugar (treat with fruit drink or sugar)
o Symptoms: can occur suddenly; inappropriate responses, confusion and inattention, drowsiness, pale complexion, perspiration, headache, crankiness, lack of coordination, loss of judgement, sudden hunger, rapid pulse, nausea, vomiting, dizziness
Hypoglycemia
high blood sugar (treat with insulin)
o Symptoms: dry, hot skin, excessive urination, excessive thirst, drowsiness, lethargy, deep/labored breathing, fruity smelling breath, blurry vision
Hyperglycemia:
What should an O&M specialist do if a client has a hypoglycemic reaction or a hyperglycemic reaction during an O&M lesson?
Hypoglycemic: give fruit drink/sugar
Hyperglycemic: insulin
be prepared
obtain as much baseline information as possible
• type of seizure common for student
• description of what it looks like
• typical frequency or duration
• known triggers
• typical behavior following a seizure
have info on medications and their side effects
seizures
- record keeping,
- determine cause if possible,
- administer treatment if given permission & available,
- call EMT for severe reactions
allergic reactions
- document any behavioral incidents that occur in an attempt to better anticipate or reduce behaviors
- seek support from behavior specialist
- employ recommended behavioral strategies
- Know the signs of increasing agitation or instability.
- Know effective ways to deflate the situation.
- Know effective behavior management strategies.
- Avoid confrontation.
- Position yourself so that you can watch for cues.
- Use a teamwork situation, remain in good communication with the individual and team, implement good planning, good backup systems, maintain good records, consider time and length of lessons, use task analysis, sequenced instruction, consider environment, use motivation, be aware of prompting, implement choice making.
- Document all behavior incidents.
frequent aggressive behavior
be prepared
obtain as much baseline information as possible
• type of seizure common for student
• description of what it looks like
• typical frequency or duration
• known triggers
• typical behavior following a seizure
have info on medications and their side effects
record a detailed description of seizure
• include: time, length, if aura occurred, if student lost consciousness, student behavior following seizure, injuries, and if first aid was given
get help if
• seizure lasts more than 5 minutes
• another seizure starts immediately after first one ends
• student can’t be woken up
• student has several seizures in a row and does not regain conscious throughout any of them
• student is pregnant or has another health condition
seizures:
o ABCs:
o Assess the faller and the situation (look for danger).
o Begin care measures, stop the bleeding, don’t move potentially injured body parts.
o Call for help (enlist onlookers to provide help)
o Assess the risk for falls.
o Teach the traveler how to respond after a fall (yell for help, listen to environment and orient toward pedestrians, request and allow help to get up or out of the way of danger.
falls
o document any behavioral incidents that occur in an attempt to better anticipate or reduce behaviors
o seek support from behavior specialist
o employ recommended behavioral strategies
o avoid confrontation
o know effective ways to deflate the situation
emotional/behavioral incidents:
be aware of student’s allergies
look for symptoms of an allergic reaction
administer epi pen in thigh and call 911
allergic reactions
