Ask Well, Listen Well, Be Observant, Go Looking For… Kara Gagnon, OD, FAAO Director of Low Vision Optometry Eastern Blind Rehabilitation Center VA Connecticut Healthcare System 950 Campbell Avenue West Haven CT 06516
The Soldier’s Story 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
The Soldier’s Story… 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. ”
The Soldier’s Story… 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”
Wife’s Observations… 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
Clinician’s Observations… 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
Mechanics of Traumatic Brain Injury Open Head Trauma Direct Invasion through the skull (focal injury) Closed Head Trauma- most common Blow 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
Diffuse Axonal Injury Decelerated Injury Stretching and Sheering of axons *Processing Speed- axons ability to neurotransmit across synapse Above image from: www. uihealthcare. com/topics/medicaldepartments/neu rosurgery/braininjury/03 whattypesbraininjuries. html
Sequence of Response to TBI 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)
Visual Pathway Closed Head Trauma Above image from: camelot. mssm. edu/~ygyu/research. html Above image from: www. mhhe. com/socscience/intro/cafe/prof/image. htm
Hierarchical Visual Processing Brain Mapping Above image from: psychology. wikia. com/wiki/Comparative_anatomy. . .
Areas of the brain affected 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
Areas of the brain affected cont. Parietal lobe Involved with integrating information about “object identification” and “object localization” Occipital lobe Primary visual association area
Lateralization of Brain Function Right Brain Simultaneous, Spatial –Big Picture Visual “Forest” Left Brain Sequential, Temporal –Detail Language “Trees”
Primary Ocular Sequella 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
Secondary Visual Sequella 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
Post Trauma Vision Syndrome Symptoms 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
Post Trauma Vision Syndrome Symptoms, continued 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
Visual disturbances Ocular motor dysfunction Vergence (56. 3%)1 Most common Convergence insufficiency Accommodation (41. 1%)1 Accommodative insufficiency Version (51. 3%)1 Saccadic deficiency Cranial nerve palsy (6. 9%)1 Cranial nerve III palsy Strabismus (25. 6%)1 Strabismus at near
Visual disturbances cont. Visual field defects 38. 75%6 Most common: Scattered defects (58. 06%) Photosensitivity Associated with elevated dark adaptation threshold 7
Visual disturbances cont. 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 atrophy 8
Visual Perceptual Processing Deficits Disturbances in Body Image Disturbances in Spatial Relationships Visual Agnosia/difficulties in object recognition Right-left discrimination problems Laterality - directionality Visual Form Constancy Visual Figure Ground Visual Discrimination Visual Memory Losses Visual Sequential Memory Visual Motor Skills Apraxia – difficulty in manipulation of objects
Examination of a TBI Patient 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
Examination cont. 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 Sensitivity • • Subjectively: Illumination History Objectively: Vistek/ Pelli Robinson Charts
Lighting Evaluation
Examination cont. Visual field screening Confrontation visual fields FDT perimetry screening If defects noted on screening, then Humphrey or Goldmann visual field testing should be performed
Examination cont. Cover test Distance and near Steady or unsteady fixation Color vision Stereopsis Above image from: www. michaelgaigg. com/blog/2009/02 Ocular motility EOMs Pursuits and saccades Above image from: www. good-lite. com/Details. cfm? Prod. ID=313
Examination cont. 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)
Examination cont. 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
Ocular Motility & Accommodation Assessments Versions Saccadic Fixations Ocular Pursuits Near Point of Convergence facility near/far change Accommodative Amplitude binocular & monocular Accommodative facility near/far change
Examination cont. Ocular health evaluation: Pupils Slit lamp exam Dilated fundus exam
Additional Testing Vestibular ocular reflex (VOR): Balance testing Dynamic visual acuity Head thrusts Romberg Tandem walking Auditory Basic hearing test Caloric testing (COWS)
Additional Testing cont. 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 Above image from: www. virtualmedicalcentre. com/healthinvesti gations. asp? sid=52
Treatment Strategy Input of Visual Information Ocular health problems Optical and Refractive problems *lenses, prism, tints, coatings, selective occlusion Neuro-optometric Vision Therapy
Optical Treatment Modalities 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
Simplified vision therapy for most common visual disturbances of TBI Deficits of saccades Vergence dysfunction Patient makes large, oblique saccades into four corners of room x 10 Increase difficulty by decreasing distance between targets 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 10 ft away for 3 seconds, then looks at target 16 in away for 3 seconds x 10 Patient views target thru (-) lens for 10 seconds, then (+) lens for 10 seconds x 10
Treatment cont. 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 Patient uses thumb at arm’s length as target and slowly moves head left and right while fixating thumb Use prisms, lenses, and filters to change input during therapy Can increase speed of head movement as therapy progresses Tints 15% absorption blue
Near Evaluation Continued Closed-Circuit Television (CCTV) CCTV Spectacles: Habitual Working Distance/Appropria te add Occlusion of Nondominant Eye Preferred Tint to maximize contrast
Intermediate Evaluation Telemicroscope Magnifying Mirror
Optometric Management of Visual Field Loss Scanning/Awareness Sectoral Yoked Prism Fresnel prism Tight fit: Noxious Stimulus Full Yoked Prism in reading RX
Goldmann visual field results OD OS
Clinical Pearls Share with Interdisciplinary Team 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
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