kara gagnon, od, faao director of low vision optometry eastern blind rehabilitation center va...

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.