6 Sub retinal layerChoroidal 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 conesDamage may be caused by toxicity, inflammation, infections or heredity.
9 Retinitis pigmentosaA 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 pathologyDamage to cone receptors causing damage to the central 5 degrees.Decreased color and VA will result.
11 Monocular retinal zone Characteristics Retinal layerSubretinal layerRods and conesRetinitis pigmentosaMacular pathologyAll 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 tumorsa= bjerrum areaB=papillomacular bundle causing central and ceccocentral scotomasC=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 defectsBjerrum area defectsAll 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 defectsDamage to nerve fiber layer will show on VF.
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.
23 Binocular chiasmal zone Bi temporal VF loss characteristicsCaused 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.
25 Post chiasmal zoneLateral geniculate bodyOptic Radiations
26 Post chiasmal zoneHomonymous 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?