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Visual Field Examinations

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Presentation on theme: "Visual Field Examinations"— 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

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 zone Characteristics
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
Most common cause is glaucoma. Also may be caused by trauma, blood vessel occlusions, infections, inflammations and tumors a= bjerrum area B=papillomacular bundle causing central and ceccocentral scotomas C=nasal bundle horazontal raphe wedge defects.

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
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 Binocular chiasmal zone
Bi temporal VF loss characteristics 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 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. Not visible with a scope. Problem will be visible with CT or MRI scan.

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?
Anti epileptic drug therapy, glaucoma

30 Last two, what’s wrong?

31 See you next week for Goldmann Perimetry lecture.
Great job! See you next week for Goldmann Perimetry lecture.

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