kara gagnon, od, faao director of low vision optometry eastern blind rehabilitation center va...
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Kara Gagnon, OD, FAAODirector of Low Vision Optometry
Eastern Blind Rehabilitation CenterVA Connecticut Healthcare System
950 Campbell AvenueWest Haven CT 06516
51 year old male Registered Nurse/Army Medic 14 months spent in Iraq Team diffused mines and explosives Endured 18 IED Explosions Twice Unconscious Symptoms after Exposure to initial blasts:
Headaches Photosensitivity Double vision Blurred Vision Tinnitus These symptoms were initially transient, after repeated blasts
duration increased
March 2007 severe blast exposure, soldier unconscious for less than 30 minutes. Taken off duty for 2-3 days.
Symptoms: * Headaches Photosensitivity Double vision Blurred Vision Memory Problems Sleep Disturbances Tinnitus All blasts exposed to after this head injury causing
unconsciousness, “recovery time from these symptoms was significantly prolonged.”
August 2007 he was exposed to severe blast, rendered unconscious, for unknown period of time. Taken off duty for 10 days. Chronic Symptoms: * Headaches
Extreme Photosensitivity – had to wear dark sunglasses indoors Poor light and dark adaptation Double vision Blurred Vision “Problems with reading”- would have “ burning sensation of his eyes” and “fatigue” after “10
minutes or so”, “feeling that the right eye was not processing information” Bumping into things on his right side, “Things kept popping –up on my right side.” Significant balance issues Dizziness Tinnitus Impaired hearing in both ears, “right ear can only hear noises can not process words’ Difficulties with “organization of speech” Problems with fine motor skills on left side Memory Problems Sleep Disturbances “I tried, but I could not come back”, “I was in denial”, “I was waiting for things to get better”
Her Husband was “ an avid reader” upon return, “would not read at all”
Extremely light sensitive Easily loses balance, “used to take long walks with
dogs, now takes very short walks” Falling down stairs, bumping into things Poor memory Losing his temper Sleep disturbances His driving was unsafe, did not see things on his
right side
Extremely Light Sensitive Fixated above my head when conversing with me,
occasionally would fixate my eyes in primary gaze Demonstrated Poor balance Intermittently trailing the right side of the wall. Turned head to right to listen to me Searching for words, difficulty with speech Had significant difficulty relaying history…unless I asked
very specific directed questions. Fatigued after a very short period Became nauseous easily during ocular motility testing
Open Head TraumaDirect Invasion through the skull (focal injury)
Closed Head Trauma- most commonBlow to the head that does not cause a direct pathway
(global or diffuse injury)* Accelerated- moving object hits the head or head hits
a stationary object causing a focal wound or trauma * Decelerated- body is restrained, causing soft tissues
of the brain to move within the skull* Percussion- Shock wave from IED causing diffuse axonal
injury similar to the decelerated injury
Stretching and Sheering of axons *Processing Speed- axons ability to neuro-transmit across synapse
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Primary Response Occurs at the moment of injury or insult Lacerations, contusions, fractures, diffuse axonal tearing,
hematomas Secondary Response
Occurs hours to weeks post injury Auto-regulatory physiological mechanisms disrupted Neurotoxins are released Cascade of biochemical reactions Further brain damage Post Concussion Syndrome Post Trauma Vision Syndrome (PTVS)
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Frontal lobe Process visual information needed for motor
planning Integrating voluntary movement of skeletal muscle
and voluntary eye movements Abstract thinking, foresight and judgment
Temporal lobe Combines sensory information associated with
recognition and identification of objects Receives auditory stimuli and produces language
Parietal lobe Involved with integrating information about
“object identification” and “object localization”
Occipital lobe Primary visual association area
Right Brain Simultaneous, Spatial –Big Picture Visual “Forest”
Left Brain Sequential, Temporal –Detail Language “Trees”
Internal Orbital Injury: Fractured Orbital Wall Floor fractures cause: hypotropia; hypertropia; diplopia Medial fractures cause: orbital emphysema- blood or air from nasal
sinuses, secondary orbital cellulitis External Injury
Extraocular muscle movement- comitancy Hypoesthesia Enopthalmos Proptosis Corneal Abrasions Corneal lesions Lid Injuries
Post Trauma Vision Syndrome (PTVS) Oculomotor Imbalance: Strabismus Oculomotor Dysfunction: Ocular Fixation and Ocular
Motor Difficulties, pursuits and saccades Accommodative Abnormalities: amplitude and facility Convergence Insufficiency Visual Field Loss and Inattention Vestibular and Disequilibrium- inability to match visual
information with kinesthetic proprioceptive and vestibular experiences
Lagopthalmous Pupillary Defects : Anisocoria
Double vision Problems with depth perception Blurred near vision Perceived movement of print Asthenopia Loss of place when reading Reduced reading speed Inability to read despite the ability to write Avoidance of near tasks Headaches Photosensitivity Dry Eye Symptoms -decreased blink rate
Visual Memory Deficits Visual perceptual processing deficits: inability to perceive spatial
relationships between and among objects Difficulty locating/fixating on an object and pursuing the object
visually as it moves Objects appear to move when they are not actually moving Bumping into objects/exhibits abnormal posture Poor concentration and attention Inability to perceive the entire picture or to integrate it’s parts Inability to distinguish colors Inability to visually guide their arms, legs, hands and feet Inability to recognize objects with their vision alone
Ocular motor Ocular motor dysfunctiondysfunction
Most commonMost common
Vergence (56.3%)Vergence (56.3%)11 Convergence insufficiencyConvergence insufficiency
Accommodation Accommodation (41.1%)(41.1%)11
Accommodative insufficiencyAccommodative insufficiency
Version (51.3%)Version (51.3%)11 Saccadic deficiencySaccadic deficiency
Cranial nerve palsy Cranial nerve palsy (6.9%)(6.9%)11
Cranial nerve III palsyCranial nerve III palsy
Strabismus (25.6%)Strabismus (25.6%)11 Strabismus at nearStrabismus at near
Visual field defects 38.75%6 Most common:
Scattered defects (58.06%)
Photosensitivity Associated with elevated dark adaptation
threshold7
Vestibular and balance problems Results from mismatch of visual information Associated with:
Fixation disparity Accommodative Vergence problems Blurred vision Ocular motor dysfunction
Ocular disease Most common:
Corneal abrasion, blepharitis, chalazion/hordeolum, dry eye, traumatic cataract, vitreal prolapse and optic atrophy8
Disturbances in Body Image Disturbances in Spatial Relationships
Right-left discrimination problems Laterality - directionality
Visual Agnosia/difficulties in object recognition Visual Form Constancy Visual Figure Ground Visual Discrimination
Visual Memory Losses Visual Sequential Memory Visual Motor Skills
Apraxia – difficulty in manipulation of objects
Detailed case history and ocular inventory
Description of incident Any loss of consciousness Localization of injury or Diffuse Axonal Injury (DAI)
Detailed ocular inventory including: Missing part of visual field Bumping into objects or walls Asthenopia Light sensitivity Decreased night vision Dry eye symptoms Headaches Dizziness Reading symptoms
Visual acuity Distance and near Utilize different charts
Snellen, ETDRS, Feinbloom, broken wheel, and Lea symbols
May need to isolate lines and/or letters
Contrast sensitivity Pelli Robson chart
Contrast SensitivityContrast Sensitivity
• Subjectively: Illumination History
• Objectively: Vistek/ Pelli Robinson Charts
Visual field screening Confrontation visual fields FDT perimetry screening
If defects noted on screening, then Humphrey or Goldmann visual field testing should be performed
Cover test Distance and near Steady or unsteady fixation
Color vision
Stereopsis
Ocular motility EOMs Pursuits and saccades
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Refraction with binocular balance
Phoria testing Von Graefe (in-phoropter) Modified Thorington (out-of-phoropter) Maddox Rod in 9 diagnostic action fields Park’s 3 step (if vertical deviation in primary gaze)
Vergence testing Risley prism (in-phoropter) Prism bar (out-of-phoropter)
Accommodation Amplitudes
Minus lens (in-phoropter) Push up or pull away (out-of-phoropter)
Facility/Flexibility NRA and PRA Flippers
Monocular and binocular Posture/Accuracy
MEM Fused or Unfused Cross-Cylinder
Versions Saccadic Fixations Ocular Pursuits Near Point of
Convergence Convergence facility
near/far change
Accommodative Amplitude binocular & monocular
Accommodative facility near/far change
Ocular health evaluation: Pupils Slit lamp exam Dilated fundus exam
Vestibular ocular reflex (VOR): Dynamic visual acuity Head thrusts
Balance testing Romberg Tandem walking
Auditory Basic hearing test Caloric testing (COWS)
Visually evoked potential (VEP) An objective test used to assess
the function of the visual system beyond the retina
Measures the response of the visual cortex to continuous stimulation and the conduction of signal from the optic nerve to the occipital cortex
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Input of Visual Information Ocular health problems Optical and Refractive problems
*lenses, prism, tints, coatings,
selective occlusion Neuro-optometric Vision Therapy
Prescription of appropriate lenses for distance and near
Anti-reflective coatings, tints to reduce glare and photosensitivity
Correcting Prism Convergence Insufficiency Vertical Deviations Fixation Disparities
Deficits of saccades Patient makes large, oblique saccades into four corners of room x 10 Increase difficulty by decreasing distance between targets
Vergence dysfunction Increase vergence demand slowly and gradually until diplopia reported,
then decrease demand until single vision reported
Accommodation dysfunction Target is brought from arm’s length slowly and smoothly toward the patient
until it blurs, then the target is slowly and smoothly moved back to arm’s length x 10
Patient looks at target 10ft away for 3 seconds, then looks at target 16in away for 3 seconds x 10
Patient views target thru (-) lens for 10 seconds, then (+) lens for 10 seconds x 10
Vestibulo-Ocular reflex (VOR) therapy Responsible for stabilizing visual world while head is in
motion Dynamic fusion facility:
Multiple Brock String with balance Wayne Fixator with balance
Use prisms, lenses, and filters to change input during therapy Patient uses thumb at arm’s length as target and slowly moves
head left and right while fixating thumb Can increase speed of head movement as therapy progresses
Tints 15% absorption blue
Closed-Circuit Television (CCTV)CCTV Spectacles: Habitual Working
Distance/Appropriate add
Occlusion of Non-dominant Eye
Preferred Tint to maximize contrast
Telemicroscope
Magnifying Mirror
Scanning/Awareness
Sectoral Yoked Prism Fresnel prism Tight fit: Noxious Stimulus
Full Yoked Prism in reading RX
OD OS
Eye signs may be subtle Eye signs may be intermittent Symptoms may be masked Symptoms may be interpreted differently
based on discipline Patients may not attribute complaints to an
eye problem
1. Ciuffreda KJ, Kapoor N, Rutner D, et al. Occurrence of oculomotor dysfunctions in acquired brain injury: A retrospective analysis. Optometry 2007;78:155-161.
2. Hoge CW, McGurk D, Thomas JL, et al. Mild traumatic brain injury in U.S. soldiers returning from Iraq. The New England Journal of Medicine 2008;358(5):453-463.
3. Cohen AH and Rein LD. The effect of head trauma on the visual system: The doctor of optometry as a member of the rehabilitation team. Journal of the American Optometric Association 1992;63:530-536.
4. Ciuffreda KJ, Rutner D, Kapoor N, et al. Vision therapy for oculomotor dysfunctions in acquired brain injury: A retrospective analysis. Optometry 2008;79:18-22.
5. Kapoor N and Ciuffreda KJ. Vision disturbances following traumatic brain injury. Current Treatment Options in Neurology 2002;4:271-280.
6. Suchoff IB, Kapoor N, Cuiffreda KJ, et al. The frequency of occurrence, types, and characteristics of visual field defects in acquired brain injury: A retrospective analysis. Optometry 2008; 79:259-265.
7. Du T, Cuiffreda KJ, Kapoor N. Elevated dark adaptation thresholds in traumatic brain injury. Brain injury 2005;19(13):1125-1138.
8. Rutner D, Kapoor N, Cuiffreda KJ, et al. Occurrence of ocular disease in traumatic brain injury in a selected sample: A retrospective analysis. Brain Injury 2006;20(10):1079-1086.
9. Newcombe VFJ, Williams GB, Nortje J, et al. Analysis of acute traumatic axonal injury using diffusion tensore imaging. British Journal of Neurosurgery 2007;21(4):340-348.