Visual Efficiency Tx Flashcards
What is visual efficiency?
the ways in which various ocular systems operate over time and under various viewing conditions
What does visual efficiency include?
amplitude (amount/sufficiency), facility (flexibility), accuracy and stamina
What does visual efficiency determine?
how clear, comfortable and efficient a person’s vision will be throughout the day and throughout various tasks/activities of daily living
What abilities is visual efficiency composed of?
oculomotor, accommodative, vergence, sensory fusion abilities
What are other names for visual efficiency?
computer vision syndrome, learning related visual problems, visual perceptual difficulty (technically different)
What are treatment options for visual efficiency?
optical correction of ametropia, added lens power, prism, occlusion, vision therapy, surgery
Other order of treatment typically is not a hierarchy, what must come first?
optical correction
What can uncorrected refractive error cause?
under or over accommodation, high phoria or unusual vergence demand, imbalance between the eyes, decreased fusional ability
What does under or over accommodation lead to?
accommodative fatigue or spasm
What does an imbalance between the eyes lead to?
sensory fusion disturbance
What does decreased fusional ability lead to?
blurred retinal images
What magnitude of hyperopia should be prescribed?
greater than 1.50 DS (unless toddler or younger, then hold off)
What magnitude of myopia should be prescribed at any age?
-5.00D
What magnitude of myopia should be prescribed between 1-3 years old?
-3.00D
What magnitude of myopia should be prescribed if older than 3 years old?
-1.00D
What magnitude of astigmatism should be prescribed if older than 3 years old and the cyl appears stable?
-1.00, may need to check patient several times to ensure stability
At what age do you prescribe -1.00 D of cylinder?
3 and older
If there is low ATR cylinder what should you consider?
accommodative problem, maybe don’t Rx
What should you always do before prescribing on kids?
trial frame!! check the reflexes with the potential Rx
What is an added lens power for?
used to alter the accommodative or binocular demand, either plus or minus lenses
What are plus and minus added lens powers used for?
+ is for a bifocal or SV near only, - is SV for a specific purpose
What is one reason you might Rx a SV - lens?
for a divergence excess to wear for the distance
What is the relationship between high AC/A and added lens power?
good return on investment! large change in binocular posture with a small change in refraction
What does a plus lens do?
reducing accommodation and relaxes BV posture aka more exo or less eso at near
What does a minus lens do?
increases accommodation and results in more converged posture aka less exo at distance which is good for DE
What is the relationship between a normal AC/A and added lens power?
a lesser effect on phoric posture, but still there, added lens power can be used for basic exo/eso cases but is probably used FTW which can cause problems
What is a potential problem with added plus FTW?
distance blur
What is a potential problem with added minus FTW?
at near may overwhelm the accomodative system
What is the relationship between a low AC/A and added lens power?
added lenses have a very small effect on the phoria, probably won’t try a bifocal unless the patient also has an accommodative issue like a presbyope
What are 3 purposes of prescribing added lenses?
allow the patient to see clearly at near, enhance the accommodative system, normalize the phoric posture
What are the two options to utilize to determine how much to rx?
data driven options and behavioral options
What are data-driven options?
balance NRA/PRA, creating a normal lag, and gradient AC/A
What are behavioral options?
book ret, just look, visual comfort
What is book retinoscopy?
give lenses to put patient at the “instructional” level, reflex should be bright with slight with to slight against motion
What is just look retinoscopy?
obtain improved attention to a near target, reflex should appear brighter if more engaged
What is visual comfort?
have a patient wear a trial frame while performing a near task, judge the amount based on comfort and ease of completing the task
How is prism used?
to alter fusional vergence demand
When is prism helpful?
horizontal or vertical relieving prism, prism to aid VT, prism when VT is not possible, prism to maintain VT when it is finished, brain injury, cosmetics
T/F you typically need less prism than the math tells you
true
What is occlusion?
used to isolate an eye during therapy, older standard of care
What circumstances is occlusion used in?
treatment of amblyopia, strabismus, suppression
What are opaque occlusion methods?
scotch tape, translucent specs of CLs, bangerter foils
T/F occlusion can be full lens or sectoral
true, sectoral would be binasal, center only, etc
When is surgery unlikely to be used?
as a treatment for non-strab cases
When might surgery be used?
with constant tropias, horizontal phorias greater than 30 prism diopters at all distance or vertical phorias
Explain surgery for a vertical phoria…
hard to use prism to correct, bilateral transposition or obliques which are tricky!
What is vision therapy?
a sequence of neurosensory and neuromuscular activities individually prescribed and monitored by the doctor to develop, rehabilitate, and enhance visual skills and processing
What is vision therapy the treatment of choice for?
most BV, accommodative and oculomotor disorders
What do you need to evaluate about the patient before VT?
motivational level (brain injury and athletes have highest motivation), level of attention (age level considered), and ability to complete the tasks
What are long-term effects of VT?
normal motor and sensory fusion, accommodative skills, and oculomotor control
What are the benefits of VT?
reduces symptoms, eliminates accommodative spasm, eliminates suppression, increases accommodative amp/flexibility
What does VT improve?
NPC, fusional vergence amplitude and facility, stereopsis, accuracy of saccades and pursuits, stability of fixation
Where should you start VT?
where the patient can succeed, then move to where the patient struggles
T/F you should work through the order and build from one phase to the next
true, motor example: gross motor, fine motor, oculomotor
What might you need to treat at the very beginning?
amblyopia
What are the 7 phases of the basic overall sequence?
1)optimal lens prescription 2) gross motor 3) monocular 4) bi-ocular/anti-suppression 5) binocular 6) binocular with loading (automaticity) 7) vip
Where does the majority of your VT program fall?
3-5 aka monocular, bi-ocular/anti-supression and binocular
What is phase 1 (optimal lens prescription)?
encourages optimal acuity, accommodation, binocularity; may need to prescribe prism to encourage fusion
What is the temporary prism?
fresnel press-on prism
What is phase 2 (gross motor)?
many patients have difficulty with visually guided learning like writing, motor coordination and eye-hand coordination
T/F you may need to collaborate with OT/PT for the patient’s gross motor ability
true
When is it especially important to work on gross motor?
in strabismus!
We are b_, b_ b_
bilateral, binocular beings
What is phase 3 (monocular)?
work to match the skills between R and L eyes, emphasis on accommodation, fixation and tracking, one in all CT programs for visual efficiency diagnosis
What are possible monocular procedures?
near/far Hart chart, letter tracking, pegboard rotator, wayne saccadic fixator/binovi system, monocular accommodative rock
What is phase 4 (bi-ocular)?
achieving simultaneous perception, both eyes are open but seeing something different, appreciate physiological diplopia, works on breaking supression
How is bi-ocular work similar to and different from monocular fixation in a binocular field?
biocular= both eyes open but different views, MFBF=background seen for both eyes simultaneously fused but each eye has something individual to focus on
What is MFBF?
monocular fixation in binocular field
What are possible procedures for bi-ocular phase?
R/G TV trainer, R/G Hart chart, Robbin’s rock, Brock string, MFBF matching game
What is phase 5 (binocular)?
work peripheral to central stereopsis, should be done in all VT programs for visual efficiency diagnosis
When do you not work peripheral to central stereopsis?
with ET, start centrally where their visual axes cross then move peripherally
What are the degrees of fusion?
1st simultaneous perception, 2nd luster/flat fusion, 3rd stereopsis
What are possible procedures for binocular phase?
vectograms, tranaglyphs (Keystone basic binocular), computer vergence therapy (virtual reality)
APPROXIMATELY how much time is spent between monocular, bi-ocular, and binocular?
1/3 for each
Why is peripheral stereo easier?
because the eyes are not distracted by VA/focus
What is phase 5 (binocular- advanced)?
additional procedures with higher difficulty
What are possible procedures for binocular– advanced?
single oblique-mirror stereoscope, cheiroscope, brock string, aperture rule, eccentric circles, barrel card, life saver cards
What is phase 6 (binocular with loading)?
builds automaticity of visual skills, builds flexibility– accommodative, vergence, and their interaction
What are possible ways to “load” procedures?
cognitive loading, balance board, yoked prism, +/- lenses
