Vision and Hearing Flashcards
what is the leading cause of blindness in people over 50yo
age-related macular degeneration (AMD)
what is the process of light entering the eye
light enters cornea –> thru back of cornea –> thru aqueous humor (fluid filling the lens) –> thru the lens
cornea and lens focus light on macula (central foveal are of reina) –> in retina light converted to chemical and electrical impulses–> sent down optic nerve to brain
how does the eye change w age
it is an elastic organ that over time begins to collagenize in certain areas as well as undergo certain microvascular changes
what is considered low vision
visual acuity of 20/50 or worse that can’t be corrected w prescription lens or medical interventions, AND/OR loss that limits physical performance
what is visual acuity
capacity of eye to discriminate details of objects in visual field
what is the visual field
central or peripheral vision related to dec pupil size which limits amt of light that can reach retina
- extends laterally, inf, sup
what is depth perception
ability to perceive relative distance of objects in the visual field
what does it mean to be legally blind
visual acuity 20/200 or less, or visual field of 20deg or less in better eye
what is conductive hearing loss
dysfunction of external or middle ear that results in dec transmission of sound wave vibration
what is sensorineural hearing loss
damage to cochlea, organ of corti or 8th CN
what sensory changes are seen in the eye w aging
dec # of rods (light and dark)
dec pupil size & reactivity
flattened cornea
lens changes shape
thickening of retina
dec nuclei in outer layer of retina
loss of protein homeostasis, cell death and mitochondrial dysfunction
what sensory changes inc susceptibility of retina detaching
dec nuclei in outer layer of retina
loss of protein homeostasis, cell death and mitochondrial dysfunction
ciliary bodies become more collagenized
what sensory changes are seen in the ears with aging
atrophy of organ of Corti
loss of hair cells
loss of afferent neurons
what sensory changes in the ears leads to sounds of all frequencies becoming more muffled
atrophy of cochlear lateral wall
- decline in cochlear endolymphatic potentials –> dysfunction of cochlear amplifier
visual contrast sensitivity: what is it, how does it change w aging, functionality/implications
structural changes in lens and pupil relating to adapting to changes in light
light/dark adaptation slows with age
dec ability to drive at night
difficulty exiting movie theater in broad daylight
how does color perception change w age, why, and what is the functionality/implications
dec color perception and difficulty distinguishing b/w colors w shorter wavelengths (blues, greens, violets)
d/t changes in retinal cones and ganglion cells
difficulty discriminating dark furniture from dark rooms
what is presbyopia and what does this lead to
dec lens elasticity and ciliary ms strength –> causing eye strain esp w reading and dark conditions
leads to inability to focus on near objects (need for reading glasses)
what is presbycusis and what does this lead to
progressive, (B), and age related sensorineural hearing loss, primarily observed in high frequency range d/t cochlear degen
leads to dec speech comprehension w fast speech or when background noise present
what are 4 common age related eye diseases (pathological, not normal part of aging)
cataracts
age related macular degen
glaucoma
diabetic retinopathy
what are cataracts d/t
lens (which is normally high in protein) undergoes proteostasis (loss of protein homeostasis) causing lens to become stiff and unable to properly filter light
what is age related macular degen d/t
altered intercellular communciation
what is glaucoma d/t
mitochondrial dysfunction
what is diabetic retinopathy d/t
dysfunction of insulin signaling pathways that leads to dysregulation of nutrients
what are cataracts
clouding of lens that affects vision
what are risk factors for developing cataracts
cigarette smoking
UV light exposure
DM
high body mass index
clinical s/sx of cataracts
clouded, dim, low vision
how are cataracts treated
surgery
opaque lens removed and replaced by artificial intraocular lens
what is the leading cause of curable blindness worldwide
cataracts
what is glaucoma and its pathophysiology
visual impairments and pathological changes of optic nerve caused by loss of retinal ganglion cells –> retinal ganglion cells project axons via optic nerve from eye to brain and vulnerable to age related changes
can develop slowly or quickly
what are risk factors for glaucoma
age
genetics
African and Asian origin
what is the hallmark sign of glaucoma and what does it indicate
redness of eye
- indicates inc intraocular pressure
how is glaucoma treated
w med that lowers intra-ocular pressure (IOP) given the correlation b/w IOP and retinal ganglion loss
what is the leading cause of incurable blindness
glaucoma
is glaucoma treatable and what happens if untreated
effective if dz dx in early stage
- thru treatment sight may be maintained
if untreated progression leads to severe dec of visual field and irreversible blindness
clinical s/sx of glaucoma
peripheral vision loss
what optic pathology is most closely related to aging
AMD
- cataracts and glaucoma can be seen in younger pts w predisposing factors
what is the pathophysio of AMD
degen of photoreceptors causing degenerative lesions in retina
(circulatory insufficiency plays a part)
what 2 optic pathologies is smoking cessation important in prevention
cataracts
AMD
what are risk factors for AMD
aging
tobacco
genetics
degree of pigmentation
- light eyes at inc risk
arterial HTN
UV rays
consumption of non-balanced diet
how is AMD treated
intravitreous drugs
lasers
dynamic phototherapy
surgery
these slow the progression of dz
clinical s/sx of AMD
loss of central vision in the fovea
dry vs wet AMD
DRY
- majority of cases
- characterized by lipid deposits beneath retina
WET
- progression of dry AMD as lipid deposits cause leaky vessels and eventual hemorrhaging
- clinical presentation: acute, sudden, irreversible vision loss
what is diabetic retinopathy characterized by
micro aneurysms
hemorrhaging of retinal vessels
what are risk factors for diabetic retinopathy
duration of diabetes
level of glycemia
presence of high bp
dependence on insulin
elevated serum lipid levels
genetics
what visual pathologies does diabetic neuropathy inc the risk of
cataracts
2x risk for glaucoma
what is key in decreasing the progression of diabetic retinopathy
improving glycemic control
clinical s/sx of diabetic retinopathy
damage to many parts of eye
vision loss
blindness
what is onchocerciasis
river blindness
infectious dz caused by parasitic filaria, deposition of larva in subQ tissue
s/sx of onchocerciasis
infectious larvae deposits in subQ tissue leading to:
- acute dermatitis -> severe itching
- eye inflammation, bleeding, other complications –> blindness
clinical s/sx of onchocerciasis
“halo vision” (like glaucoma) in early stages
what parasite is responsible for onchocerciasis
blackfly transmits dz in fertile riverside areas that are often uninhabited for fear of infection
- central and sub-Saharan Africa
- Yemen
- Latin America
snellen chart: what does it assess, results
visual acuity
poorer than 20/50 -> affects postural stability
R vs L eye dominance
R dominant in 2/3 of pop
L dominant more common in people w migraines -> can affect balance
what is looked for in a smooth pursuits visual assessment
attention to eye mvmt range
- can detect dec ROM
what is a peripheral vision assessment and what are the norms
when you perceive things in periphery of field of vision relative to nose
- via confrontation method (temp, sup, inf)
90deg periph to central
50 deg sup to nasal
60 deg inf to nasal
what is a depth perception visual assessment dependent on
accurate convergence
what screen should you perform before a depth perception visual assessment
convergence testing
- can look at foot eye coordination, ie kick a ball
what is a functional example of how altered depth perception may present in an older adult
turning too soon during a transfer to a chair
when is ocular toxicity seen
meds given in high doses or for long periods of time
- methotrexate (MTX)
- antifolate in CA
- auto-immune dz (RA) - tamoxifen
- blocks estrogen in breast CA - anti-malarials (ex: plaquenil)
what can ocular toxicity cause (2)
toxic retinopathy
optic neuropathy
sensorineural vs conductive hearing loss: what is it, pronounced w which sounds, causes/risk factors, clinical presentation
SENSORINEURAL
- dysfunction of inner ear
- more pronounced w high pitched frequencies (F,S,T)
- gradual or sudden loss
- genetic, noise pollution, meniere’s, aging, ototoxicity, DM
- present w dec speech comprehension w fast speech or when background noise present
CONDUCTIVE
- dysfunction of outer or middle ear
- across all frequencies
- mechanical cause: impacted cerumen, foreign bodies, benign tumors, fluid
- soft voice and dec hearing
treatment for conductive hearing loss and why
hearing aid
- mechanical global amplification
parts to general hearing assessment
observation
- signs of inflammation (redness, colored fluid)
whispered voice and have them repeat back
rub hands together
weber test: conductive vs sensorineural results
should hear equally
conductive
- hear more in affected ear
sensorineural
- hear more towards unaffected ear
rinne test: conductive vs sensorineural hearing loss results
should hear air longer 2:1 ratio
conductive
- hear better on bone than air
sensorineural
- air better than bone but <2:1 ratio
what does it mean that a medication is ototoxic
harmful SE of drugs/toxins influencing hearing (contributing to and/or exacerbating hearing loss) and balance functions of ear
what are examples of ototoxic meds
**antibiotics
- gentamicin, vanco, streptomycin
loop diuretics - furosemide
chemo - cisplatin
chemicals
- CO, quinine, arsenic, Hg, EtOH, tobacco
what visual paths inc fall risk
low vision
visual impairment
visual loss + NM deficits (dec somatosensation, inc vibration sensation threshold)
how does low vision inc fall risk
greater difficulty reweighting other sensory cues
-> negotiating obstacles, uneven surfaces, stairs
-> diminished protective responses
what does hearing loss inc the risk of
frailty
how could visual or hearing paths impact driving as an ADL
dark adaptation
- difficulty driving at night
color discrimination
- take longer to detect brake light
hearing
- unable to localize horns from other cars
what are strategies to adjust the environment for visual impairments
minimize glare
inc lighting
contrasting surfaces
add a seat at entrance for don/doff garments
large face clocks
contrasting color foods and table settings
colored electrical tape on grab bars
well placed signs and visual cues
what is the most promising strategy for visual impairments
adjusting the environment
what are strategies to adjust the environment for auditory impairments
face to face communication
- in foveal field
more words w vowels
- easier to emphasize
announce changes in subject
drapes & fabric that absorb sound
what is a main strategy to improve balance in someone w visual impairments
uptrain vestib and somatosensory systems
balance and strength treatment activities
yoga (somatosensation)
tai chi (proprioceptive kinesthetic awareness technique)
obstacle course w collision warning device
stair climbing w high contrast edge highlighter on edge of each tread
what are examples of vision based tech
hand held spectacle or telescope
floor lamp
table magnifiers
tactile dots on objects to localize
what is a telescoping lens
hand held or mounted on glasses can be monocular or binocular
what are low vision sunglasses
colors can help vision become less foggy
- yellow and orange can improve contrast sensitivity
what are examples of auditory tech
hearing aids
cochlear implants
amplifiers
hearing aids: indications, limitations
conductive hearing loss
small batteries difficult to manipulate
hard to hear in loud rooms
cochlear implants: indications, how does it work, precautions
severe to profound hearing loss
sound transmitted to impulses sent to cochlea and auditory nerve
- prosthesis - magnetic to skull
caution w modalities and infections
amplifiers: how does it work, limitation
speaker on device amplifies sound thru headphones (or Bluetooth)
- frequency selective (aka higher frequency)
while it is somewhat effective, less than hearing aids or cochlear implants
what is universal environmental design
approach to design that integrates products and building features that are usable by anyone regardless of their ability
- most widely accepted theory for environmental design
what are examples of components to universal environmental design
fluorescent lighting
appropriate draperies
acoustic ceiling tiles
indoor/outdoor carpet
furniture contrasts w floor
colored fixtures in bathroom
how is fluorescent lighting a component of universal environmental design
adequate illumination while minimizing glare
how are appropriate draperies a component of universal environmental design
sheers minimize glare
certain fabrics absorb sound
how is the use of acoustic ceiling tiles a component of universal environmental design
allow for better speech discrimination
how is the use of indoor / outdoor carpet a component of universal environmental design
cushions falls
minimizes friction
vinyl is easier to clean but is a higher risk of injury w falls
how are colored fixtures in the bathroom a component of universal environmental design
minimizes glare and helps minimize the effects of poor depth perception
what are 5 major red flags and what do they likely indicate
CNS:
- blurred/dec vision in one or both eyes
- double vision
- loss of speech or trouble understanding speech
- nystagmus, ptosis, impaired pupillary response
CV disorder:
- severe HA
