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ERG and VEP Lecture sept 20, 2015

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ERG and VEP Lecture sept 20, 2015

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ERG and VEP Lecture sept 20, 2015

  1. 1. ERG and VEP for NEURO-VISUAL FUNCTION ASSESSMENT J. Alberto Martinez, M.D.
  2. 2. CURRENT REALITY • BY THE TIME WE DIAGNOSE GLAUCOMA, THE PATIENT HAS HAD IT FOR 5 YEARS! (or more)
  3. 3. “In patients who are glaucoma suspects, PERG signal anticipates an equivalent loss of OCT signal by several years (as many as 8 years).” Invest Ophthalmol Vis Sci. 2013;54:2346–2352) DOI:10.1167/iovs.12-11026 Per NIH and Bascom-Palmer
  4. 4. ASSESSMENT OF NEURO-VISUAL FUNCTION Neuro-visual Pathway Function Review 1. Anatomy at glance 2. Neuro-physiology at glance Electrophysiology 1. Visual Evoked Potential (VEP) concepts 2. VEP hardware and software 3. VEP obtaining and interpreting 4. Other electrophysiological tests Clinical VEP 1. Glaucoma 2. MS 3. Amblyopia 4. Cataract 5. Other Continued
  5. 5. INDEX VEP and Function Tests 1. VA, CS, CV 2. VF VEP and Structure Tests 1. HRT, GDx OCTINDEX PERG 1. Basics 2. Clinical usage of PERG 3. Retino-cortical time. Q & A ASSESSMENT OF NEURO-VISUAL FUNCTION
  6. 6. Eye Optic Nerve Optic Chiasm Optic Tract Lateral Geniculate Nucleus Optic Radiation Visual Cortex ANATOMY ASSESSMENT OF NEURO-VISUAL FUNCTION
  7. 7. ANATOMY Photoreceptor Bipolar Ganglion Ganglion cell axon Relay neuron Relay neurons axon Visual cortex neuron ASSESSMENT OF NEURO-VISUAL FUNCTION
  8. 8. NEURO-PHYSIOLOGY Phototrans duction Conversion of light into electricity ASSESSMENT OF NEURO-VISUAL FUNCTION
  9. 9. VEP Photoreceptor Ganglion cell axon Relay neuron Visual cortex neuron NEURO-PHYSIOLOGY Bipolar Light Phototransduction Electricity Electricity Electricity Electricity ASSESSMENT OF NEURO-VISUAL FUNCTION
  10. 10. ELECTROPHYSIOLOGY • Electrocardiogram • Electromyography • Auditory Evoked Potential • Electroencephalogram ASSESSMENT OF NEURO-VISUAL FUNCTION
  11. 11. Electric signal registered at the occipital region in response to a visual stimulus. ASSESSMENT OF NEURO-VISUAL FUNCTION VEP Electrical activity of V1 occipital cortex
  12. 12. Electric signal registered at the lower lid in response to a visual stimulus. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG Electrical activity of retinal ganglion cells
  13. 13. ASSESSMENT OF NEURO-VISUAL FUNCTION Previous Limitations • Test time was approximately 45 minutes • Required highly trained operators • Limited to large research institutions
  14. 14. ASSESSMENT OF NEURO-VISUAL FUNCTION • Test time is approximately 1 minute • Does not require highly trained operators • Currently installed in about 700 offices worldwide Current Conditions
  15. 15. VEP Stimulus • Diffuse • Pattern Reversal Pattern-onset Transient Steady State ASSESSMENT OF NEURO-VISUAL FUNCTION
  16. 16. • Diffuse Pattern Reversal Pattern-onset Contrast Color ASSESSMENT OF NEURO-VISUAL FUNCTION
  17. 17. ASSESSMENT OF NEURO-VISUAL FUNCTION Why would VEP show a functional change on patients with 20/20? 20/20 20/200 20/100 20/50 20/30 20/70 20/100 20/10020/25
  18. 18. ASSESSMENT OF NEURO-VISUAL FUNCTION N75 N135 P100 VEP Components
  19. 19. ASSESSMENT OF NEURO-VISUAL FUNCTION N75 N135 P100 VEP Components • Amplitude usually translates to the number of axons conducting along the visual pathway • Latency usually translates to the myelin status of the visual pathway
  20. 20. Diopsys® VEP Report ASSESSMENT OF NEURO-VISUAL FUNCTION
  21. 21. Diopsys® VEP Report ASSESSMENT OF NEURO-VISUAL FUNCTION
  22. 22. Diopsys® VEP Report ASSESSMENT OF NEURO-VISUAL FUNCTION
  23. 23. Diopsys® VEP Report ASSESSMENT OF NEURO-VISUAL FUNCTION
  24. 24. Diopsys® VEP Report ASSESSMENT OF NEURO-VISUAL FUNCTION
  25. 25. Diopsys® VEP Report ASSESSMENT OF NEURO-VISUAL FUNCTION
  26. 26. Diopsys® VEP Report ASSESSMENT OF NEURO-VISUAL FUNCTION
  27. 27. Diopsys® VEP Report ASSESSMENT OF NEURO-VISUAL FUNCTION
  28. 28. Main Indications • Glaucoma • Multiple Sclerosis • Ischemic Optic Neuropathy • Traumatic Brain Injury • Amblyopia • Other Neuropathies ASSESSMENT OF NEURO-VISUAL FUNCTION VEP
  29. 29. VEP and other Ophthalmic Diagnostic Tests • Psychophysics • VF • GDx • HRT • OCT ASSESSMENT OF NEURO-VISUAL FUNCTION
  30. 30. Psychophysics of vision Visual Acuity Test ASSESSMENT OF NEURO-VISUAL FUNCTION
  31. 31. Psychophysics of vision Contrast Sensitivity Test ASSESSMENT OF NEURO-VISUAL FUNCTION
  32. 32. Psychophysics of vision Color Vision Test ASSESSMENT OF NEURO-VISUAL FUNCTION
  33. 33. Psychophysics of vision Visual Field Test ASSESSMENT OF NEURO-VISUAL FUNCTION
  34. 34. ERG mERG pERG mVEP EOG Electroretinogram Multifocal Electroretinogram Pattern Electroretinogram Multifocal Visual Evoked Potential Electrooculogram Electrophysiological tests ASSESSMENT OF NEURO-VISUAL FUNCTION
  35. 35. ASSESSMENT OF NEURO-VISUAL FUNCTION N35 N95 P50 PERG GENERAL Concept Pattern Electroretinography is the electrical signal registered at the eye because of a pattern stimulation of the retina.
  36. 36. ASSESSMENT OF NEURO-VISUAL FUNCTION Stimulus (Monitor) Recording (Sensors) Eye stimulation by a checkerboard pattern elicits a ganglion cell response known as PERG. PERG is an accurate and objective indicator of ganglion cell and macular function. (ISCEV) PERG can detect retinal dysfunction (OHT) before structural tests. (Parisi et al.) pERG
  37. 37. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG GENERAL ERG PERG Q
  38. 38. 24” 24.1° Stimulation Monitor ASSESSMENT OF NEURO-VISUAL FUNCTION PERG TEST
  39. 39. ASSESSMENT OF NEURO-VISUAL FUNCTION Reproducibility Factors able to affect the PERG results • Refraction errors • IOP • Diabetes M • Patient Attention • Technique PERG TEST
  40. 40. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG TEST MonofocalMultifocal PERG should be done with refractive correction for 24” Uncorrected
  41. 41. Diopsys® pERG Electrodes Comfort Convenience Quality ASSESSMENT OF NEURO-VISUAL FUNCTION
  42. 42. ASSESSMENT OF NEURO-VISUAL FUNCTION Active for OS Reference for OD Active for OD Reference for OS Ground Sensors Position PERG TEST
  43. 43. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG TEST Active Skin Sensor Placement Step 1. Sensor positioning. Eyelashes Eyelid Skin
  44. 44. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG TEST Active Skin Sensor Placement Step 2. Sensor positioning. Eyelashes Eyelid Skin
  45. 45. ASSESSMENT OF NEURO-VISUAL FUNCTION Electrodes Picture Cost ($) Position Amplitude Repeatability Visual Axis Disturbance Overall Discomfort Usage DTL 13 Conjunctiva (invasive) ***** Sensitive to eye movements (noise) ** *** Disposable HK Loop 35 Conjunctiva (invasive) ***** Sensitive to eye movements (noise) ** *** Reusable Gold Foil 10 Conjunctiva (invasive) ***** Sensitive to eye movements (noise) ** *** Disposable Gold Cup 13 Skin *** Good ** ** Reusable Diopsys 11 Skin *** Good * * Disposable ELECTRODES COMPARISON
  46. 46. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG TEST Q Protocols 1. VEP TR 2. VEP LX 3. PERG Manual 4. PERG Auto
  47. 47. ASSESSMENT OF NEURO-VISUAL FUNCTION Concentric Fields 24° and 16° PERG TEST
  48. 48. ASSESSMENT OF NEURO-VISUAL FUNCTION Contrast Sensitivity (higher and lower contrast) PERG TEST
  49. 49. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG Main Indications • Glaucoma • Maculopathies
  50. 50. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG CLINIC Vision problem of unknown cause VEP PERG Differentiating between optic nerve and retinal disorders Manual TR
  51. 51. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG Report
  52. 52. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG Report
  53. 53. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG Report
  54. 54. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG Report
  55. 55. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG Report
  56. 56. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG Report Magnitude DMagnitude D
  57. 57. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG Report Grating Size: 64
  58. 58. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG CLINIC Vision problem of unknown cause VEP PERG Differentiating between optic nerve and retinal disorders
  59. 59. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG CLINIC Normal Ischemic Compressive Toxic inflammatory Glaucoma Nutritional Hereditary Q
  60. 60. ASSESSMENT OF NEURO-VISUAL FUNCTION Banitt MR, Ventura LM, Feuer WJ, Savatovsky E, Luna G, Shif O, Bosse B, Porciatti V. Progressive loss of retinal ganglion cell function precedes structural loss by several years in glaucoma suspects. Invest Ophthalmol Vis Sci. 2013;54:2346-52. IOP Genetic Oxidative StressNeurotoxicity Hypoxia
  61. 61. ASSESSMENT OF NEURO-VISUAL FUNCTION Banitt MR, Ventura LM, Feuer WJ, Savatovsky E, Luna G, Shif O, Bosse B, Porciatti V. Progressive loss of retinal ganglion cell function precedes structural loss by several years in glaucoma suspects. Invest Ophthalmol Vis Sci. 2013;54:2346-52. IOP Genetic Oxidative StressNeurotoxicity Hypoxia
  62. 62. ASSESSMENT OF NEURO-VISUAL FUNCTION Banitt MR, Ventura LM, Feuer WJ, Savatovsky E, Luna G, Shif O, Bosse B, Porciatti V. Progressive loss of retinal ganglion cell function precedes structural loss by several years in glaucoma suspects. Invest Ophthalmol Vis Sci. 2013;54:2346-52. IOP Genetic Oxidative StressNeurotoxicity Hypoxia
  63. 63. ASSESSMENT OF NEURO-VISUAL FUNCTION Banitt MR, Ventura LM, Feuer WJ, Savatovsky E, Luna G, Shif O, Bosse B, Porciatti V. Progressive loss of retinal ganglion cell function precedes structural loss by several years in glaucoma suspects. Invest Ophthalmol Vis Sci. 2013;54:2346-52. IOP Genetic Oxidative StressNeurotoxicity Hypoxia
  64. 64. ASSESSMENT OF NEURO-VISUAL FUNCTION Banitt MR, Ventura LM, Feuer WJ, Savatovsky E, Luna G, Shif O, Bosse B, Porciatti V. Progressive loss of retinal ganglion cell function precedes structural loss by several years in glaucoma suspects. Invest Ophthalmol Vis Sci. 2013;54:2346-52. IOP Genetic Oxidative StressNeurotoxicity Hypoxia
  65. 65. /Users/jalbertomartinez/Desktop/Suffering ganglion cells.png
  66. 66. ASSESSMENT OF NEURO-VISUAL FUNCTION Structure Function Fundus Photograph (Subjective) Visual Field (Subjective)
  67. 67. ASSESSMENT OF NEURO-VISUAL FUNCTION Structure Function Optical Coherence Tomography (Objective) Pattern ERG (Objective)
  68. 68. Healthy Asymptomatic Symptomatic VF Glaucoma Ellish NJ, Higginbotham EJ. Evaluating a visual field screening test for glaucoma: how the choice of the gold standard affects the validity of the test. Ophthalmic Epidemiol. 2001 Dec;8(5):297-307. ASSESSMENT OF NEURO-VISUAL FUNCTION
  69. 69. Healthy Asymptomatic Symptomatic VF Glaucoma OCT Documented structural damageNon documented structural damage Schuman JS, Hee MR, Arya AV, Pedut-Kloizman T, Puliafito CA, Fujimoto JG, Swanson EA. Optical coherence tomography: a new tool for glaucoma diagnosis. Curr Opin Ophthalmol. 1995 Apr;6(2):89-95. ASSESSMENT OF NEURO-VISUAL FUNCTION
  70. 70. Healthy VF Glaucoma OCT Documented structural damageNon documented structural damage PERG/VEP Documented functional damageNon documented functional damage Parisi V, Miglior S, Manni G, Centofanti M, Bucci MG. Clinical ability of pattern-electroretinograms and visual evoked potentials in detecting visual dysfunction in ocular hypertension and glaucoma. Ophthalmology. 2006 Feb;113(2):216-28. ASSESSMENT OF NEURO-VISUAL FUNCTION OHT
  71. 71. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG CLINIC Maculopathies
  72. 72. ASSESSMENT OF NEURO-VISUAL FUNCTION pERG CLINIC Glaucoma Detection
  73. 73. ASSESSMENT OF NEURO-VISUAL FUNCTION pERG CLINIC Ganglion Cell Function Recovery
  74. 74. ASSESSMENT OF NEURO-VISUAL FUNCTION pERG CLINIC Macular Function Recovery
  75. 75. ASSESSMENT OF NEURO-VISUAL FUNCTION PERG PERG provides information about the functionality of the ganglion cells in the retina. PERG provides information about reversibility of the ganglion cells functionality. PERG provides the earliest information about ganglion cells dysfunctional.
  76. 76. Thanks Q & A ASSESSMENT OF NEURO-VISUAL FUNCTION

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