Transcript CVI - OIT News and Announcements | SFASU

CVI
Cortical Visual Impairment
• The current leading cause of visual
impairment among children is not a disease or
condition of the eyes, but cortical visual
impairment (CVI)—also known as cerebral
visual impairment—in which visual
dysfunction is caused by damage or injury to
the brain.
Medical definition
• Cortical visual impairment (CVI) may be
defined as bilaterally diminished visual acuity
caused by damage to the occipital lobes and
or to the geniculostriate visual pathway. CVI is
almost invariably associated with an
inefficient, disturbed visual sense because of
the widespread brain damage
•
Educational definition
• Cortical visual impairment (CVI) is a
neurological disorder, which results in unique
visual responses to people, educational
materials, and to the environment. When
students with these visual/behavioral
characteristics are shown to have loss of
acuity or judged by their performance to be
visually impaired, they are considered to have
CVI.
• During the last several decades, our
understanding of vision has markedly
improved. It is now realized that vision is not a
single sense but a combination of complex
senses which have evolved over millions of
years. Almost the entire brain is involved in
the process of seeing. In different locations
there are specialized areas for distance vision,
recognition of faces, objects, colors, contrast,
and movement
• CVI is caused by widespread damage to the
brain, which affects most of the specialized
visual centers, resulting in a damaged,
inefficient visual sense.
• The medical definition of CVI is not well
understood by non-medical professionals.
While acuity testing is difficult in the young
and disabled for physicians, it is even more
difficult for teachers. Also, there are many
children with visual problems similar to CVI,
except they have normal acuity. This visual
condition is called "cortical visual dysfunction"
(CVD). The educational management of
children with CVI and CVD is similar.
• CVI is suspected by:
• a normal or close to normal eye examination;
• a medical history which includes neurological
problems; and
• the presence of unique visual/behavioral
characteristics.
Unique visual/behavioral
characteristics
• Normal or minimally abnormal eye exam (CVI may co-exist
with optic nerve atrophy, hypoplasia or dysplasia and ROP.)
• Difficulty with visual novelty (The individual prefers to look
at old objects, not new, and lacks visual curiosity.)
• Visually attends in near space only
• Difficulties with visual complexity/crowding (Individual
performs best when one sensory input is presented at a
time, when the surrounding environment lacks clutter, and
the object being presented is simple.)
• Non-purposeful gaze/light gazing behaviors
• Distinct color preference (Preferences are predominantly
red and yellow, but could be any color.)
• Visual field deficits (It is not so much the severity of the
field loss, but where the field loss is located.)
• Visual latency (The individual's visual responses are
slow, often delayed.)
• Attraction to movement, especially rapid movements.
• Absent or atypical visual reflexive responses (The
individual fails to blink at threatening motions.)
• Atypical visual motor behaviors (Look and touch occur
as separate functions, e.g., child looks, turns head away
from item, then reaches for it.)
• Inefficient, highly variable visual sense
Strategies
Slow down. Allow time for student to
respond.
Simplify the task.
Schedule visual experiences for the time
of day when the student demonstrates
optimal visual functioning.
• Be specific about what you want the student
to see and to do.
• Sequence the task.
• Provide structure and sameness in each
presentation.
Environment
• Provide an environment that is free from
visual clutter.
• Work surface: be sure that the work surface
does not have a pattern.
• Background surfaces and spaces: be sure that
the learning environment has only essential
visual information
Materials
• Enhance the visual targets.
• Keep visual information simple, constant, and
predictable.
• Use real objects in natural sequences to aid in
the understanding of the real visual
environment;
• CORTICAL VISUAL IMPAIRMENT
Cortical Visual Impairment (CVI) is a temporary or
permanent visual impairment caused by the disturbance of
the posterior visual pathways and/or the occipital lobes of
the brain. The degree of vision impairment can range from
severe visual impairment to total blindness. The degree of
neurological damage and visual impairment depends upon
the time of onset, as well as the location and intensity of
the insult. It is a condition that indicates that the visual
systems of the brain do not consistently understand or
interpret what the eyes see. The presence of CVI is not an
indicator of the child's cognitive ability.
•
•
CVI/Functional Vision Evaluation Kit
September 1, 2008 — dianesheline CVI FUNCTIONAL VISION EVALUATION KIT
• Penlight/flashlight with different colored caps/filters
• Flashlight with different colored filters
• Mylar Pom Poms (preferably red and yellow)
• Cereal and other real or simulated food items (Fruit Loops, red licorice, banana,
Cake Decors and Cheerios)
• Mylar paper or wrapping paper (preferably red and yellow)
• Soap bubbles, for blowing
• Measuring tape
• Slinky (solid colors and plastic)
• Hidden pictures or I Spy book
• Variety of different colored balls in a variety of sizes
• A black, light-absorbing background (2 yards of black fabric, Invisiboard, or
other similar material/board )
• 2 yards of white fabric
• Variety of flashing lights (including bikers safety light, snap-on-spoke light clips,
etc.)
• Supplementary light (such as an Ott Lite, or a clamp on directional light)
• Variety of yellow and red toys such as Elmo, Big Bird, reflective mirror, balls,
etc. (or “sets of red and/or yellow objects to be sorted into same colored
containers)
• Black and white toys
• Mirrors
•
• Eye patch or occluder
• Suspended or moving objects (windsock, ball on elastic cord, etc.)
• Reflective materials – mylar balloons, pom poms, shakers, etc.
• Slap bracelets in reflective red and yellow
• Blinking “ice cubes” attached to elastic “ring” band (or any blinking lights that can be
thoroughly cleaned/washed)
• Personal “Laser Light Show” fan
• Spinning Pinwheel on long stick (yellow or red)
• Variety of sunglasses (BabyBanz, yellow clip-ons, overglasses sunglasses, etc), and
croakies (adjustable straps to hold glasses in place)
• Visors or brimmed caps
• Items from everyday routines in solid colors (cups, spoons, toothbrushes, etc.)
• Container of Lysol wipes
• Notebook of variety of CVI articles for parents
• Rolling suitcase to hold it all in
• Extension cord(s)
• Extra Batteries (AA and AAA)
• Selected equipment and materials from APH including;
o Regular or Mini Light Box with clear and colored overlays and colored acrylic objects
o ToAD: Tools for Assessment and Development of Visual Skills
o Invisiboard
o ISAVE Visual Field/Acuity Grid
o Sensory Learning Kit
***Make sure to have the parent bring in the child’s favorite toy
Created by Diane Sheline, CTVI, CLVT, [email protected] updated 09/18/2008
• What will cause the use of the
vision?
“rut” in the snow
• http://www.aph.org/cvi/advo.html
• http://www.aph.org/cvi/index.html
• http://dianesheline.wordpress.com/toolbox/t
echniques-and-strategies-to-use-withstudents-with-cortical-visual-impairment/