1 / 31

Visual Field Examinations

Visual Field Examinations. Week 3 Visual Pathway and Visual field defects. 4 major visual pathway zones. Monocular retinal zone Nerve fiber/optic nerve zone Binocular chiasmal zone Post chiasmal zone. Monocular retinal zone. Retinal layer.

awells
Download Presentation

Visual Field Examinations

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Visual Field Examinations • Week 3 • Visual Pathway and Visual field defects

  2. 4 major visual pathway zones • Monocular retinal zone • Nerve fiber/optic nerve zone • Binocular chiasmal zone • Post chiasmal zone

  3. Monocular retinal zone

  4. Retinal layer • Field defects are found opposite in the VF to the location of the damages in the eye.

  5. Retinal layer Retinal detachment Visual field

  6. Sub retinal layer • Choroidal lesions care caused by tumors, inflammations, infection, or fluid leaks. • This type of damage does not respect the horizontal or vertical meridian.

  7. Sub retinal layer Epi retinal membrane tear with bleeding hamangioblastoma

  8. Rods and cones • Damage may be caused by toxicity, inflammation, infections or heredity.

  9. Retinitis pigmentosa • A diffuse pattern of field loss ( rod damage) forming a ring a variable scotomas that will expand outward toward the periphery and inward toward the fovea until blindness results.

  10. Macular pathology • Damage to cone receptors causing damage to the central 5 degrees. • Decreased color and VA will result.

  11. Monocular retinal zoneCharacteristics • Retinal layer • Subretinal layer • Rods and cones • Retinitis pigmentosa • Macular pathology • All defects will be monocular. • Most pathology will be visible with a scope. • Lesions temporal to the fovea will present nasal on VF. • Lesions can cross all meridians. • Central scotomas will cause abnormal VA and color vision.

  12. Nerve fiber layer/optic nerve region zones • Nerve fiber layer. • Most common cause is glaucoma. Also may be caused by trauma, blood vessel occlusions, infections, inflammations and tumors

  13. Papilledema • (swelling of the disc) • Produces a field loss by pushing the surrounding retina out from the disc creating an enlarged blind spot. • It will present more concentric than an enlarged blind spot caused by glaucoma.

  14. Nerve fiber defect patterns • Macular and papillomacular defects create central or ceccocentral scotomas

  15. Bjerrum Defects • Bjerrum area of nerve fiber layer. • 15 degrees off fixation. • Defect in this area will cause an arcing VF loss opposite of the damage. • Will start small and increase in size over time.

  16. Nerve fiber layer/optic nerve region characteristics • Nerve fiber layer • Optic nerve (papilledema) • Nerve fiber pattern defects • Bjerrum area defects • All defects are monocular. • Defect will point to the disc since the nerve fibers are traveling toward this point. • All pathology will be visible with a scope

  17. Nerve fiber/optic nerve region Glaucomatous defects Damage to nerve fiber layer will show on VF.

  18. Glaucoma Temporal wedge Nasal step

  19. Nerve fiber/optic nerve region Optic nerve central scotoma Visual field

  20. Optic nerve zone

  21. Nerve fiber/ optic nerve region Characteristics • All will be monocular only effecting the damaged eye. • Damage to the nerve fiber layer will be caused by glaucoma. • The VF will show up opposite of the damaged area. • Specific areas of nerve fibers that have been damaged will respect the horizontal meridian and point in the direction of the disc. • Disc problems will be visible with a scope.

  22. Binocular Chiasmal Zone

  23. Bi temporal VF loss characteristics Binocular chiasmal zone • Caused by pituitary tumors or swelling, • Always bi temporal. • Not visible with a scope. • CT scan or MRI needed to show defect. • Bilateral hemianopia (temporal). • Will respect vertical meridian. • Will start small and gradually increase in size.

  24. Post chiasmal zone

  25. Post chiasmal zone Lateral geniculate body Optic Radiations

  26. Post chiasmal zone • Not visible with a scope. • Problem will be visible with CT or MRI scan. • Homonymous defect will always be present. (Same side) • Will start out small and gradually get larger. • Will be hemianopic and will respect the vertical meridian.

  27. Let’s see what you learned! • Follow the pathway- • Page 22 in your text. • What is this problem?

  28. What is the problem here?

  29. What’s the problem here?

  30. Last two, what’s wrong?

  31. Great job! See you next week for GoldmannPerimetry lecture.

More Related