MT2 Material Flashcards
conditions that cause overall field loss (or general constriction)
- glaucoma
- retinitis pigmentosa
- trauma
- proliferative diabetic retinopathy with extensive PRP
- retinopathy of prematurity
describe some characteristics of overall field loss
- only a small central island of vision remains
- pt may not realize until it is 5-10 degrees
- usually a gradual process
- pts will start to show compensatory scanning when field loss is gradual
conditions that cause hemianopic field loss
- aneurysm or stroke (cerebral lesion) most common: think R/L homon. hemi.
- central nervous system tumors: think bitemporal hemi for pituitary tumor
- demyelinating diseases (MS): optic neuritis
- optic neuropathies: think bilateral altitudinal for AION
- head trauma (TBI or ABI)
what does prism therapy help the patient to do?
-prism causes displacement of object in pts blind area to area on retina where there is useful vision (image jump)
prism displaces an image towards the
apex of the prism
one diopter of prism will shift the image ___ degrees towards apex
0.57
what patients are more successful candidates for prism therapy?
- hemianopsias of recent onset
- the better the acuity (macular sparing)
device summary for overall constriction (2 options)
- orientation and mobility
- minification devices (reverse telescopes)
device summary for hemianopic loss
-prism
what is the goal of sector prism for treatment of hemianopic field loss
-to develop scanning skills to provide peripheral information
-to have smaller eye movements needed to see into non-seeing field
an “awareness system” from the diplopic image
what is the downside to Gottlieb prism design?
- due to the alternation between the prism and the rest of the lens, perception can be quite jumpy
- also it is very thick and too far into patient’s visual axis
what are the fitting principles if you do fit Gottleib prism?
- starting point is limbal (if fit is too tight, eye jumps in and out too frequently)
- round (different size segments)
what is the basis behind expansion prism therapy?
how it works, where the prisms are, how much, etc.
- increased field of view with peripheral prism
- 40-57 diopter fresnel
- monocular fit
- superior and inferior
- peripheral diplopia but clear single central vision
describe the fitting process of expansion prism? (steps)
- monocular fit (on side of VF defect)
- upper segment first (demonstrate increased field, training, cleaning and care)
- 2 week adjustment
- lower segment
- 2 week adjustment
- prism ground into lens
when can mirrors be used? (in what type of VF loss)
hemianopic field loss only
but rarely prescribed
how are mirrors (for hemianopic field loss) mounted?
mounted on the top nasal area of the glasses on the eye that has the field loss
(point it towards the field loss)
in a reverse telescope, a patient views through the ___ lens
objective
in what conditions do reverse telescopes work the best
- low powered telescopes (<2.5)
- patients with good VA
- used for sighting
if a patient is using minus lenses for overall field loss, what do they have to do to see the image clearly?
accommodate, use their add, or remove their myopic glasses to see the image clearly
as minus lens is held close to the eye, what happens to accommodation and minification?
- accommodation increases
- minification decreases (tube length decreases)
what are the main categories for Sensory Substitution Devices?
- Audio Substitution
- Relative Size
- Tactile Substitution
what are the 3 types of evaluations we do at clinic for technology?
- 10 minute overview (general overview)
- 20-30 minute technology evaluation (eval of patient’s needs and specific goals, technology only)
- Type one Evaluation (2-3 hours, writing plan for dep. of rehab, life plan on all aspects)
what are some examples of Relative Size devices?
- CCTVs
- Handheld Electronic Magnifiers
what is the proper positioning for a computer or CCTV?
- 20-25 inches from screen
- monitor tilt 10-20 degrees if possible
- test for contrast, magnification, illumination
- watch patient to see if they are looking up, sideways, etc.
what are some features of handheld electronic magnifiers?
- portable, different sized viewing screens
- digital mag from 3.5x - 14x
- freeze frame, several contrast modes
- removable standard battery or charger
- handles, reading stands
- some connect with TVs or monitors for increased screen size and mag
- some can store images
example of a handheld electronic magnifier
Ruby XLHD by Freedom Scientific
examples of portable CCTV’s
- Transformer (computer assisted relative size device)
- Acrobat (stand alone relative size)
- Davinci (stand alone)
- ONYX by freedom scientific
what does an audio substitution devices (standalone) do?
- devices that can be used with Audio only and require no computer interface
- they can be attached to a screen and become a relative size device also
(ex: Clear Reader by Optelec)
what are some Specialty Glasses options?
- Nueyes
- Orcam
- Iris Vision
- AIRE
- Patriot
relative size/ audio substitution computer programs
magnify or read: OCR
- Magic
- Fusion
- Kurzweil
- Open Book
- Dolphin Guide
- Supernova
audio substitution computer programs
- FUSION (Jaws)
- NVDA
- Window Eyes
- Supernova screen reader
- Dolphin guide
sensory substitution programs (voice)
-Dragon Naturally Speaking (dictation software- voice)
list 5 programs you can use:
- FUSION (mag/ OCR)
- Jaws (screen reader)
- Window Eyes (screen reader)
- Magic (magnification/ OCR)
- Dolphin Guide (screen reader)
list 5 programs you can use:
- FUSION (mag/ OCR)
- Jaws (screen reader)
- Window Eyes (screen reader)
- Magic (magnification/ OCR)
- Dolphin Guide (screen reader)
the Light House International sampled older adults seeking vision rehab and what % had depression (both major and subthreshold)
7% had major depression
27% had subthreshold depression
whether a person with vision loss becomes depressed or not seems to depend on:
the impact the vision loss has on a person’s functioning rather than to the actual severity of vision loss
whether a person with vision loss becomes depressed or not seems to depend on:
the impact the vision loss has on a person’s functioning rather than to the actual severity of vision loss
how is Chronic Depression (Dysthymia) described as?
- less severe than major (comes and goes)
- can linger often 2 years or longer
- may be gene/ brain chemical related but majoy life stressors, chronic illness, medications, and relationship/ work problems are often the cause
what are the symptoms and diagnostic criterion for Chronic Depression (Dysthmyia)?
- main symptom: low, dark, or sad mood on most days for at least 2 years (in children for 1 year)
- 2 or more of the following symptoms will be present almost all of the time (feelings of hopelessness, too little or too much sleep, low energy or fatigue, low self-esteem, poor appetite or overeating, poor concentration)
what is Major Depression (Clinical Depression) described as?
- difficult to work, study, sleep, eat, and enjoy friends and activities
- several times in a lifetime
what are the symptoms and diagnostic criterion for Major Depression (Clinical Depression)?
-symptoms that are present every day for at least 2 weeks (fatigue, loss of energy, feelings of worthlessness, guilt, impaired concentration, indecisiveness, insomnia or hypersomnia, diminished interested or pleasure in almost all activities, restlessness, feeling slowed down, recurring thoughts of death/suicide, weight loss or gain)
Generalized Anxiety Disorder (GAD) affects what # and % of the population? how many of those are treated?
6.8 million (3.1% of pop)
only 43.2% are receiving treatment