Learn Connect Succeed. JCAHPO Regional Meetings 2015

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1 Learn Connect Succeed JCAHPO Regional Meetings 2015

2 VISUAL FIELDS No financial conflicks Florida Society of Ophthalmology 2015 Gary Schemmer, MD Definition of Visual Field The area in space perceived by the eye(s) is called the visual field This island of vision in the sea of darkness is called Traquar s Island 1

3 Normal Visual Field Upper and medial limits extend approximately 60 degrees Temporally extends to 100 degrees Inferiorly 75 degrees Prominent brows and noses may limit the superior and nasal visual field Optic nerve creates a blind spot ~15 degrees from the fovea or center of visual field The retina has variable sensitivity and visual fields are plotted to show this Therefore target size, color, movement, distance and contrast with background determine the extent of the visual field 2

4 Anatomy of the Visual Pathway Key to understanding and interpreting visual fields is to understand the anatomy of the visual pathway Images from both eyes and the same visual field will end up being sent to the contralateral side of the visual pathway after the optic chiasm Example: vision to the left is perceived by the right occipital cortex Visual Pathway Retinal Nerve Fiber Layer Beginning of the visual pathway is the retina ( visual receptor cells stimulate the nerve fibers when excited) Nerve Fiber do not cross the horizontal ( an imaginery line that goes thru the optic nerve and the macula) 3

5 Visual Pathway Anatomic Site V.F. Defect Retina Optic Nerve Optic Chiasm Optic Tracks Lateral Geniculate Body Optic Radiation Visual Cortex (occipital lobe) Corresponds to lesion Horizontal defect Bitemporal defect Hemianopic (Defect respects Vertical) More congruous the more posterior lesion is anatomically Kinetic V.F. Testing Techniques KINETIC & STATIC Test object is moved from nonseeing area to seeing area Lines of equal sensitivity, isopters, connect test points of where a target of equal size and brightness are first perceived Goldman visual field is the classic kinetic visual field test Riddick phenomenon refers to a moving target is more readily perceived than the same target that is stationary ( example: shooting star ) 4

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7 Static Visual Field Target is nonmoving Target brightness and/or size is increased until the patient sees it Most automated V.F. instruments do static testing (Humphrey) 6

8 Visual Field Instruments/ Methods Confrontation Tangent Screen Goldman Humphrey and other automated visual field instruments Confrontation Visual Fields Confrontation Visual Fields Advantages Disadvantages Examiner dependant Quick Accuarate Not equipment dependant Can be performed on most patients (bedridden ) Examiner dependant No printout or record for comparision (not good for following minor changes in the visual fields) 7

9 Technique of Confrontation Fields Examiner and patient face each other about 1 meter apart Cover opposite eyes (V.F. congruent) Examiner introduces test target into visual field (from nonseeing to seeing) Defect detected when examiner notes target and patient doesn t Red targets especially good for neurologic Tangent Screen Visual Fields Advantages Disadvantages Low cost / low tech. equipment Relatively quick Examiner dependant Excellent for malinger and hysteric patient Ability to do kinetic and static testing Examiner dependant Transfer of data from field to paper Goldman Visual Fields Goldman Visual Fields Advantages Disadvantages Examiner Dependant Design test for problem Reproducable Kinetic and static capable Simple equipment Examiner Dependant Moderately priced equipment Space requirements Time of exam Patient has to be able to sit at instrument 8

10 Automated Visual Field / Humphrey Advantages Disadvantages Less examiner dependant Reproducable Sensitive Expensive equipment High tech. equipment Patient has to be able to sit at instrument 9

11 Interpeting Visual Fields Why was the field done? Reliability of visual field Determine right and left eyes Is the field normal or abnormal blind spot is in proper position and size isopters are oval and properly concentric Interpreting Visual Fields Does the field defect respect the horizontal or vertical meridian (If both - vertical takes precidence) If it respects the horizontal there is an optic nerve problem If it respects the vertical it is chiasmal or post chiasmal Bitemporal V.F. defect means a chiasmal lesion A homonous V.F. defect means postchiasmal lesion. Lesion is on opposite side of brain from Visual field defect (Right hemianopic defect Left side of brain). Also more congruous more posterior the lesion Interpreting Visual Fields Anatomic Site V.F. Defect Retina V. F. defect corresponds to retinal lesion Optic Nerve Horizontal V.F. Defect Optic Chiasm Bitemporal V.F. Defect Post Chiasmal Hemianopic V.F. Defect Misc. Tunnel & other defects Retina V. F. defect corresponds to retinal lesion and possibly nerve fibers, therefore may cross horizontal and vertical (but may respect horizontal due to nerve fiber layer damage) Optic Nerve Lesion Classic V.F. defect respects the HORIZONTAL, visual field defect is worse above or below the horzontal meridian * nasal steps * arcuate defects * Bjouran defect * Altitudal defects 10

12 Optic Diseases HORIZONTAL VISUAL FIELD DEFECT OPTIC NERVE, OPTIC NERVE, OPTIC NERVE Classic and most common GLAUCOMA Optic neuropathies (Ischemic, inflamatory, toxic) Compressive (tumors, thyroid ophthalmopathy, aneuyrsms) Optic Chiasm Bitemporal Visual Field Defect BITEMPORAL VISUAL DEFECT OPTIC CHIASM, OPTIC CHIASM, OPTIC CHIASM 11

13 Optic Chiasm Diseases Pituitary Tumors (ademonas that may secrete excess hormones: growth hormone, lactation hormone, thyroid stimulating hormone) Meningomas and other tumors Aneurysms Trauma M.S. POSTCHIASMAL LESIONS Visual Field defect respects the vertical, but both eyes have defect to the same side(hemianopic V.F. defect). Lesion is on opposite side of brain than visual field defect 12

14 Postchiasmal Diseases/Lesions Hemianopic Visual Field Defect POSTCHIASMAL LESION POSTCHIASMAL LESION POSTCHIASMAL LESION STROKE (CVA) Tumors Aneurysms Trauma Demyelinating diseases Odds and Ends Those Fields that don t readily fit our system 13

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16 Tunnel Visual Fields Causes of Tunnel Visual Fields Endstage glaucoma optic nerves cupped Functional (malingering or hysteric) Bilateral occipital lobe strokes with macular sparing Rod dystrophy / Retinitis Pigmentosa Post papilledema and secondary optic atrophy 15