Visual field print out interpretation and analysis

Visual field analysis

1. Visual field Birhanu Belete(MSc)

2. Course Objectives Upon completion of this section, the student is expected to: Define VF Describe the normal VF Describe and Differentiate between different modalities of Perimetry Correlate VF maps to clinical scenarios 2 3/7/2024

3. VISUAL FIELD (VF) - Introduction The field of vision is that portion of a subject’s surroundings that is visible at any one time. The visual field properly includes central fixation, conventionally measured by visual acuity tests, and extra-foveal (or peripheral) vision Central fixation, or visual acuity, and the visual field are tested in different ways and provide information on different aspects of visual function Visual acuity testing measures resolution, the ability to identify forms Visual field testing measures sensitivity, the ability to detect light thresholds at different locations 3 3/7/2024

4. VISUAL FIELD (VF) - Introduction A perimeter is an instrument that measures the VF by the patient’s subjective responses Perimetry refers to the processes/methods used to measure and document the presence and severity of a visual field defect To quantify or confirm a VF defect discovered or suspected through screening To detect subtle field defects such as those associated with glaucoma To monitor changes in a previously known condition 4 3/7/2024

5. VISUAL FIELD (VF) - Introduction An abnormal visual field can indicate a problem in the retina, optic nerve, or visual pathway Visual field testing is part of a thorough ophthalmic examination The visual field of each eye is tested separately by one or more tests The visual fields are routinely screened with the confrontation fields test If macular disease is suspected to be causing a central visual field defect, a device called an Amsler grid is used to test the central area of each eye’s visual field If a visual field defect is detected by screening, further evaluation is conducted by MANUAL or AUTOMATED procedures known as PERIMETRY 5 3/7/2024

6. VISUAL FIELD (VF) - Introduction The visual field (VF) is an inverted and reversed map of corresponding retinal points Limited by the Ora serrata and any intervening obstructions (e.g. orbital rim and nose); the normal visual field extends (from fixation) about: 50 degrees superiorly 60 degrees nasally 70 degrees inferiorly 90 degrees temporally 6 3/7/2024

7. VISUAL FIELD (VF) - Introduction The visual field can be divided in to CENTRAL , INTERMEDIATE , and PERIPHERAL zones The CENTRAL zone includes an area from the fixation point to a circle 30 degrees away (a 5 mm radius from the fovea) The central zone contains the temporal physiologic blind spot , which corresponds to the optic nerve head centered about 15 degrees from the fovea. The INTERMEDIATE zone, extends from 30 degrees to 50 degrees The PERIPHERAL zone is the area beyond 50 degrees 7 3/7/2024

8. VISUAL FIELD (VF) - Introduction A scotoma , also called a visual field defect, is a place in the visual field where an object cannot be seen Based on its Density a scotoma is labeled as: A Relative scotoma - an area in the visual field where test objects of low luminance cannot be seen, but larger or brighter ones can An Absolute scotoma - an area where no test object can be seen (e.g. the physiologic blind spot or a scotoma in advanced disease) In addition to its density , a scotoma is described by its Shape (e.g. hemianopia, quadrantanopia, etc ) and its Location (e.g. temporal, superonasal, etc ) 8 3/7/2024

9. VF EXAMINATION (PERIMETRY) PERIMETRY is the measurement of the VF during central fixation using either Moving ( Kinetic Perimetry ) or Stationary test stimuli ( Static Perimetry ) In Kinetic perimetry, points along the edge of the VF are determined by finding the weakest light stimulus ( Visual Threshold ) that evokes a visual sensation The line that joins points having the same threshold is called an Isopter In Static perimetry, the use of fixed targets that change in brightness gives a threshold map of different points where the patient has an equal chance of either seeing or not seeing the target 9 3/7/2024

10. VF EXAMINATION (PERIMETRY) The map of the visual field is a topographic plot of neural sensitivity at different locations The clinical record of the normal field of vision varies with The Size, Color, Brightness, and Movement of the test stimulus, or target; The background illumination; A patient’s Alertness and Familiarity with the test 10 3/7/2024

11. VF EXAMINATION (PERIMETRY) Visual fields are conventionally recorded on charts that represent the field as the patient sees it The Temporal field of the right eye is to the right The field of the right eye is always placed to the right when comparing the visual field maps of both eyes The VF is a THREE-DIMENTIONAL concept that is presented in TWO-DIMENTIONS 11 3/7/2024

12. VF EXAMINATION (PERIMETRY) Different types of perimetry give maps with different appearances A VF performed by Kinetic perimetry (e.g. with the Goldmann perimeter) Is plotted on polar graph paper with: Radial meridians ( measured counterclockwise from 0 degree at the right-hand horizontal ) Circles of eccentricity ( concentric rings every 10 degrees out from fixation ) With a map obtained by kinetic perimetry, the examiner looks down onto the “hill of vision” with its contours represented by isopters 12 3/7/2024

13. VF EXAMINATION (PERIMETRY) In older maps of static perimetry, the examiner looked across the VF landscape and focuses on a certain cross-section. Most maps produced by Automated Static perimetry present an array of sensitivity values These values can also be pictured by an associated program in gray tones in a “map” resembling an isoptric plot 13 3/7/2024

14. VF EXAMINATION (PERIMETRY) 14 3/7/2024

15. VF – Screening Tests Visual field screening is routinely done at a patient’s initial eye examination The CONFRONTATION field test can screen for an unsuspected VF defect caused by a lesion of the central nervous system But confrontation testing is often unreliable for detecting subtle visual field loss, as in glaucoma The Amsler grid , used when the patient has symptoms of central distortion or loss, helps evaluate macular function 15 3/7/2024

16. VF Testing – CONFRONTATION Confrontation testing of a patient’s VF is done in face-to-face position at a distance of about 1 meter (3 feet) By convention, the right eye is examined first, although if there is a marked difference in visual acuity it is advisable to begin with whichever the better eye is The eye not being tested must be completely occluded by: Using a handheld or press-on occluder putting a folded facial tissue under an elastic eye occluder asking the patient to cover the eye with the palm of the hand 16 3/7/2024

17. VF Testing – CONFRONTATION When the patient’s left eye is covered, the examiner’s right eye should be closed, and vice versa, to permit comparison Then present fingers midway between yourself and the patient, testing all four quadrants To assess the patient’s VF, compare the patient’s responses to your own normal field (E.G. +-, # of fingers…) Testing the edges of the central VF is more rewarding than testing the extreme periphery The hand is about the size of the 6/120 optotype, which is the visual level 30 degrees from the fovea ( Finger/ 6/60 = foveal periphery ) Useful to know how your hand compares in size to the Snellen chart To outline the VF slowly bring your hand inward from different directions, testing each of the patient’s meridians 17 3/7/2024

18. VF Testing – CONFRONTATION Special Situations Confrontation testing to screen for VF defects may not be possible in infants , obtunded patients and patients with optic nerve disease Alternative screening methods for such patients include: Reflex eye movement test for infants Test the VF of infants and toddlers by making use of their involuntary fixational reflexes First get the child’s attention in a frontal gaze While the child is watching your face, silently bring an interesting toy or other object from the periphery to elicit fixational head and eye movements 18 3/7/2024

19. VF Testing – CONFRONTATION Special Situations Blink reflex test for obtunded patients Quickly flicking your hand toward a sighted patient’s open eye normally elicits a blink reflex This test can help find a dense hemianopia or quadrantanopia 19 3/7/2024

20. VF Testing – CONFRONTATION Special Situations If you suspect optic neuropathy, ask the patient to subjectively compare the brightness of a light between the two eyes Shine a penlight directly into the patient’s open eye, first into one and then into the other By assigning a 100% score to the brighter eye, have the patient estimate the relative reduction in light intensity perceived by the dimmer eye The color desaturation test requires the use of a bright red object to compare the two eyes Neutral Density Filters can be used to help quantify the difference in brightness 20 3/7/2024

21. VF – Screening Tests – AMSLER GRID The Amsler grid is used to test the central 10 degrees to 20 degrees of each eye’s VF It helps test for suspected macular disease that produces a central scotoma The Amsler grid is a white or red pattern of lines with a central spot printed on a black background 21 3/7/2024

22. VF – Screening Tests – AMSLER GRID When viewed at a distance of 30 cm (12 to 14 inches) using near correction, the lines are 1 degrees apart A patient with no abnormalities perceives the lines as straight and complete Patients with abnormalities report distorted or missing lines, which they can record themselves on a preprinted Black-on-white version of the grid 22 3/7/2024

23. Assignment/Exercise 1. Construct an Amsler Grid with 10 grid lines (vertical & Horizontal) from the center, that are 1 degree apart when viewed at a distance of 30 cm Describe, mathematically, how to determine the separation in mm between the grid lines What is the approximate separation of the grid lines to the nearest 0.1mm? 23 3/7/2024

24. KINETIC Manual Perimetry The Tangent screen and Goldmann perimeter are two forms of kinetic perimetry that are performed manually The Tangent screen (at a distance of 1 m and with a white test stimulus or target that is 1 to 2 mm in diameter) tests the central 30 degrees of the VF Tangent screen testing is principally used: to assess the size of the blind spot to detect a central or ceccocentral scotoma and to evaluate functional or factitious defects 24 3/7/2024

25. KINETIC Manual Perimetry The Goldmann perimeter tests the entire VF, using different target sizes and intensities The patient’s corrective lenses are used when testing the central 30 degrees Testing outside the central 30 degrees zone is done without correction The tangent screen and the Goldmann perimeter plot the VF in Degrees of Arc Exploring the VF with different target sizes is known as Quantitative Perimetry 25 3/7/2024

26. KINETIC Manual Perimetry The use of colored targets is called Qualitative Perimetry and can help distinguish between: a retinal disturbance, in which there is a relatively greater loss for blue a visual pathway defect, which has a greater loss for red Before beginning manual perimetry describe the test to the patient explain how the test object is going to be presented and how to respond 26 3/7/2024

27. KINETIC Manual Perimetry Display the test object and then tell the patient to fixate on the central target Before mapping the blind spot, relieve the patient’s anxiety by explaining that it is normal to be unable to see the test object in central areas Throughout the entire test, watch the patient vigilantly to ensure continued fixation 27 3/7/2024

28. KINETIC Manual Perimetry – Tangent Screen The tangent screen is a square black cloth , usually made of felt, which hangs on a wall Some tangent screens have concentric circles and radiating meridians sewn into the fabric The concentric circles represent the angle in Degrees from the center The radiating meridians represent Degrees of the circle, at 30 degrees interval , around the fixation point The tangent screen test examines the central 30 degrees of the VF, no matter how far the patient is from the tangent screen 28 3/7/2024

29. KINETIC Manual Perimetry – Tangent Screen Four blind spots are faintly indicated on the screen The smaller pair of right and left ovals is for testing at 1 m (the usual testing distance) The larger pair is for testing at 2 m distance A white disk is positioned at the center of the screen as a fixation target For a patient with decreased vision, this fixation target can be larger, or a cross made of two pieces of white adhesive tape can be used The examiner presents the test object against the screen 29 3/7/2024

30. KINETIC Manual Perimetry – Tangent Screen The choice of test objects depends on the patient’s visual acuity and mental alertness The central field is normally tested by holding a 2 mm white disc or sphere on a black wand against the tangent screen For patients who are familiar with the test, a 1 mm white test object may be more effective for revealing a subtle defect Tangent screen testing generally consists of plotting the blind spots and checking for scotomas Patients with suspected non-organic (Functional/Fictitious) VF loss may be tested at both 1 m and 2 m (Funnel – Normal VS. Tunnel – Functional) 30 3/7/2024

31. KINETIC Manual Perimetry – Tangent Screen Test results are recorded by outlining the limits of the patient’s VF on a standard preprinted record form For a bedridden patient who cannot come to the office, a type of tangent screen perimetry might be possible by using a laser pointer to test the VF on a hospital wall or ceiling 31 3/7/2024

32. KINETIC Manual Perimetry – Goldmann Perimetry The Goldmann perimeter is a hemispheric dome with a white background that is illuminated near the lower limit of photopic vision A movable Pantographic device permits a light target to be projected within the dome, continuously or intermittently, at various sizes, and brightness levels The examiner directly observes the patient’s visual fixation from behind the dome through a telescope, and the patient responds to stimuli with a buzzer The instrument must be calibrated to give a standard target stimulus and background illumination 32 3/7/2024

33. KINETIC Manual Perimetry – Goldmann Perimetry Corrective lenses are not needed for testing the intermediate or peripheral zones For central VF testing, use the optimal lens correction (spherical equivalent) in a trial lens holder for each eye at a working distance of 33 cm (13 inches) Each eye is tested separately while the other eye is occluded Allow 2 minutes for the patient to adapt to the illuminated perimeter before beginning the test 33 3/7/2024

34. Goldmann perimeter 3/7/2024 34

35. Goldmann perimeter 3/7/2024 35

36. KINETIC Manual Perimetry – Goldmann Perimetry Six different target sizes are available, each four times the size of the previous target: 0 (0.0625 mm 2 ) I (0.25 mm 2 ) II (1 mm 2 ) III (4 mm 2 ) IV (16 mm 2 ) V (64 mm 2 ) Target brightness (intensity) is measured in decibels (dB) Gray filters allow the brightness of the target to be reduced in 0.5 dB steps from 4 to 1 and in 0.1 dB steps from e to a 36 3/7/2024

37. KINETIC Manual Perimetry – Goldmann Perimetry Perimetry almost always begins with target size I and intensity 4e This isopter line would be labeled I4e on the diagram Larger targets ( II to V ) are chosen if this isopter is revealed to be constricted The choice of targets is usually limited to two or three of the following: I2,I4, II4, IV4, and V4 37 3/7/2024

38. STATIC Automated Perimetry A Static Perimeter is an instrument that tests for VF defects using fixed light locations Static perimetry can often detect smaller or shallower defects than kinetic perimetry Because the testing is tedious and time consuming, most modern static perimeters are computerized, and new automated instrumentation continues to be developed Automation also has other advantages, including the ability to compare results: statistically with normal individuals of the same age group and with previous test results for the same patient 38 3/7/2024

39. STATIC Automated Perimetry Also automated perimetry does not require highly skilled operators, and it eliminates certain operator errors Some patients, such as young children and individuals who need vigorous encouragement to maintain fixation, may not be good candidates for automated perimetry 39 3/7/2024

40. STATIC Automated Perimetry –Test Targets and Strategy A Projection Perimeter has the best sensitivity and specificity and offers the most flexibility of test strategies and target presentation patterns The standard target size for automated perimetry is equivalent to a Goldmann size III (4 mm 2 ) white target Brightness is indicated in decibels (dB) For many instruments, a decibel is defined as 10 X log (10,000/ asb ), where an apostilb ( asb ) is a unit of brightness per unit area (and is defined as ∏ -1 candela/m 2 ) In contrast to kinetic perimetry, the higher numbers indicate a logarithmic reduction in test object brightness, and hence greater sensitivity of vision 40 3/7/2024

41. STATIC Automated Perimetry –Test Targets and Strategy Two basic testing strategies are used in automated static perimetry Suprathreshold testing A screening procedure to detect gross defects Uses targets well above the brightness that the patient should be able to see Threshold testing Provides more precise results than suprathreshold testing and is generally preferred It takes more time and The equipment often costs more Because a threshold is the sensitivity of a retinal location at which a stimulus intensity is perceived 50% of the time, many patients feel frustrated when they do not see targets during much of the test 41 3/7/2024

42. STATIC Automated Perimetry – Patient Preparation Most automated perimeters use a Bowl setup similar to the Goldmann perimeter with a white background luminance of 31.5 asb . Adjust the table height and chin rest so that the patient’s forehead rests comfortably against the band Align the patient’s eye in the center of the monitor, and measure the patient’s pupils to the nearest 0.5 mm If the pupil is less than 3 mm in diameter, consider dilation with a 2.5% Phenylepherine eyedrop Occlude the eye not being tested, and use tape to lift a drooping Brow or upper eyelid 42 3/7/2024

43. STATIC Automated Perimetry – Patient Preparation Reduce the room lighting to a Moderate level Allow 3 minutes for the patient to adapt to the perimeter’s brightness The patient’s vision must be refracted before testing, and the patient’s fixation must be constantly monitored during the test Assuming a 33 cm test distance ( that is the Radius of the perimeter bowl), the proper lens correction is the distance correction ( including Astigmatic errors of 1.00 D or more) with an appropriate Near add rounding up to the nearest 0.25 D 43 3/7/2024

44. STATIC Automated Perimetry – Patient Preparation Contact lenses are preferred if the Spherical Equivalent needed for the test is more than ±6.00 D When inserting and adjusting the perimeter’s trial lens holder, align the pupil in the center of the lens, and put the lens as close as comfortably possible to the patient’s eye without touching the eyelashes The Test Parameters and the Performance steps differ for each computerized instrument and are explained in the Manufacturer’s Instruction Book 44 3/7/2024

45. STATIC Automated Perimetry – Patient Preparation A demonstration program is run for a patient new to automated perimetry, and the patient is instructed about what to expect and what to do E.g. “Always look straight ahead at the steady fixation light. Other lights will flash One At a Time at other positions around the Center Light . Some may be bright, and others will be dim. Press the button whenever you see one of these flashed. You are not expected to see all of them. The best time to blink is just as you press the button ” 45 3/7/2024

46. STATIC Automated Perimetry – Patient Preparation 46 3/7/2024

47. STATIC Automated Perimetry Test Selection - Number and Distribution of Points The number of points tested determines test time Since automated static perimetry is fatiguing for the patient, you should limit the number of test points as much as possible The most commonly used tests explore 50 to 120 test points The most typical grid of points is an array of 76 points that are 6 degrees apart and blanket the central 30 degrees of the field 47 3/7/2024

48. STATIC Automated Perimetry Test Selection - Number and Distribution of Points Different software programs test different areas of the VF, depending on the specific disorder known or suspected Program selection depends on whether the VF examination is done for diagnostic testing of a suspected defect or for follow up of a progressive condition E.g. Glaucoma test includes extra points to detect such common glaucomatous VF defects as a Nasal step or Arcuate defect Neurologic VF testing emphasizes points along the vertical meridian and within the central field, where many neurologic VF defects may be found 48 3/7/2024

49. STATIC Automated Perimetry Test Selection - Size of the Field to be Tested For most patients with Glaucoma or a Neuro-ophthalmologic condition, a 30 degree or 24 degrees field is appropriate The Central 30-2 test is an example of a program that evaluates the central 30 degrees with 76 points It is commonly used for monitoring glaucoma patients and for detecting neurologic defects The 24-2 test provides a 24 degrees field from fixation with an extension of the nasal field to 30 degrees, using 6 degrees grid The “2” in the designation 24-2 test indicates a grid that straddles the horizontal and vertical meridians 49 3/7/2024

50. STATIC Automated Perimetry Test Selection - Size of the Field to be Tested The 24-2 test is generally preferred testing most patients (instead of a 30-1 or 24-1 test , which align the grid onto the vertical and horizontal meridians ) Deficits less than 6 degrees in diameter or located in the far periphery, may be missed by the 30-2 and 24-2 tests For patients with central VF loss , the central 10-2 test may be appropriate for sequential testing, because it tests the central 10 degrees field with a 2 degrees grid For patients with peripheral VF defects, Goldmann perimetry may be better useful 50 3/7/2024

51. STATIC Automated Perimetry Testing Strategy/Plan Most tests begin by testing the blind spot and then present one point in each quadrant Subsequent point brightness is determined by the threshold levels at adjacent points Missed points can be retested by using different thresholds, but this takes more time than simple screening The Foveal threshold must be requested separately but can be done as a separate portion of the testing procedure Most clinicians prefer a threshold, rather than a suprathreshold, testing strategy 51 3/7/2024

52. STATIC Automated Perimetry Testing Strategy/Plan A Full threshold test is appropriate for first time testing of a patient, because it crosses the threshold twice (first with a 4 dB increment, then with a 2 dB increment) Accurately determining threshold values makes subsequent tests easier because it allows the perimetry to begin with the previous threshold values for determining future data points FASTPAC is a more rapid testing strategy where the threshold is crossed only once (in 3 dB increments), but this strategy is often not appropriate for diagnosis or follow up 52 3/7/2024

53. STATIC Automated Perimetry INTERPRETATION OF A COMPUTER PRINTOUT Printed test results include basic patient information such as Age and Pupil diameter The raw data from automated static perimetry are shown as: Reliability measures and Numeric Plot (the actual sensitivity values at each tested point) The computerized printout also presents several Statistical Calculations , showing how the patient varies from the expected normal 53 3/7/2024

54. STATIC Automated Perimetry INTERPRETATION OF A COMPUTER PRINTOUT In reviewing the test results, the examiner must look at: The Reliability measure The Numeric plot The Probability maps and The Global indices   The Reliability measures are the proportion of: Fixation losses False positive errors False negative errors 54 3/7/2024

55. STATIC Automated Perimetry INTERPRETATION OF A COMPUTER PRINTOUT Fixation loss is the proportion of times that the patient responded inappropriately, because of wandering fixation , to a stimulus at the presumed Blind spot The False positive error rate is the proportion of times that the patient responded when no stimulus was presented The False negative error rate is the proportion of times that the patient did not respond when a suprathreshold stimulus (a luminance that had been seen earlier in the test) was presented The printout flags these parameters with XX when low reliability is suspected 55 3/7/2024

56. STATIC Automated Perimetry INTERPRETATION OF A COMPUTER PRINTOUT The VF is considered unreliable if three or more the following parameters occur: Total questions ≥400 Fixation loss ≥20% False positive responses ≥33% False negative responses ≥33% Short term fluctuation ≥4.0 dB 56 3/7/2024

57. STATIC Automated Perimetry INTERPRETATION OF A COMPUTER PRINTOUT The Numeric plot gives the measured threshold values at each test point Recall that a higher number means a dimmer light, and thus a more sensitive visual area Repeated determinations are given in parentheses under the retested value A “˂” symbol indicates that the target was not seen or that the bulb in the perimeter needs to be replaced 57 3/7/2024

58. STATIC Automated Perimetry INTERPRETATION OF A COMPUTER PRINTOUT The Grayscale rendering interpolates the raw data in a graphic format that looks like a topographic map similar to one obtained by kinetic perimetry The darker the area, the greater the loss of sensitivity for a given target size Because data between test points are extrapolated, the grayscale may not be accurate 58 3/7/2024

59. STATIC Automated Perimetry INTERPRETATION OF A COMPUTER PRINTOUT The Probability maps Mathematical deviation results are displayed as integers , showing how the patient deviates above and below normal comparable subjects, and as Probability maps illustrated in graphic format A single VF test will compare the patient’s results on a point-by-point basis with results expected from a healthy population of comparable age A series of tests by a patient are compared to a baseline VF test 59 3/7/2024

60. STATIC Automated Perimetry INTERPRETATION OF A COMPUTER PRINTOUT The Total deviation (TD) shows all defects, whether localized or generalized The Pattern deviation (PD) adjusts for any diffuse change in VF sensitivity and thus shows the localized defects Loci more likely to be abnormal are shown by darker symbols In a reliable test, an abnormal field generally requires a cluster of at least THREE abnormal points, not at the edge, on the pattern probability plot 60 3/7/2024

61. STATIC Automated Perimetry INTERPRETATION OF A COMPUTER PRINTOUT The Global indices are: The MD ( mean deviation from age-corrected normal ) The PSD ( pattern Standard Deviation ) SF ( Short-Term Fluctuation ) and CPSD ( Corrected Pattern Standard Deviation ) 61 3/7/2024

62. STATIC Automated Perimetry INTERPRETATION OF A COMPUTER PRINTOUT MD is the average dB value of the entire TD plot and is flagged if there is substantially depressed sensitivity, whether Generalized or Localized PSD is a measure of the variability across the TD plot SF is a measure of the variability of repeated measurements at 10 standard locations SF of greater than 7.0 dB is considered to be an unreliable examination CPSD is derived from PSD and SF to indicate the variability between adjacent points that may be due to DISEASE rather than test-retest error 62 3/7/2024

63. STATIC Automated Perimetry INTERPRETATION OF A COMPUTER PRINTOUT For each Global index, the Statistical significance is given, which is the probability of finding the obtained value in a healthy person Automated VF tests are not self-explanatory and the examiner must decide what TESTING ARTIFACTS or DISEASE might account for an abnormal test 63 3/7/2024

64. Some common glaucomatous VF defects A Nasal Step is a scotoma that, when plotted, abuts onto the horizontal meridian and appears as a Step-Like loss of vision at the outer limit of the nasal VF An Altitudinal Scotoma is one that causes loss of the upper or lower VF There also may be Generalized Depression (also called Peripheral Constriction in kinetic perimetry) in which retinal sensitivity is diffusely reduced 64 3/7/2024

65. COMMON VF DEFECTS An abnormal VF test result should be described according to: which eye is involved the shape of the field abnormality its location, and its symmetry The attributes, and certain typical perimetric patterns, help to localize a lesion along the visual pathway After a VF defect has been documented, its progression is followed via multiple tests over time 65 3/7/2024

66. COMMON VF DEFECTS Terms Used to Describe VF Defects Monocular Field Defects Binocular Field Defects Localized Defects Wedge-shaped temporal VF defect Arcuate nasal VF defect Central scotoma Ceccocentral scotoma Annular scotoma Homonymous Hemianopias With macular splitting With macular sparing Paramidline-sparing vertical hemianopia With unilateral sparing of temporal crescent Generalized Defects Generalized depression (peripheral constriction) Bitemporal Hemianopias Binasal Hemianopias Altitudinal Field defects Quadrantanopias Bilateral Central Field Defects Bilateral Peripheral Field defects 66 3/7/2024

67. Some common glaucomatous VF defects A Bjerrum scotoma, a monocular isolated Paracentral VF defect, is an example of an arcuate scotoma, so called because it yields an arc-like shape when plotted This crescentic form is caused by the normal course of the retinal ganglion cell nerve fibers Defects in the arcuate zone may connect with the blind spot ( Seidel Scotoma ), appear as one or more scattered paracentral scotomas, or end at the Horizontal Raphe ( Ronne’s Nasal Step ) 67 3/7/2024

68. Some common glaucomatous VF defects A Nasal Step is a scotoma that, when plotted, abuts onto the horizontal meridian and appears as a Step-Like loss of vision at the outer limit of the nasal VF An Altitudinal Scotoma is one that causes loss of the upper or lower VF There also may be Generalized Depression (also called Peripheral Constriction in kinetic perimetry) in which retinal sensitivity is diffusely reduced 68 3/7/2024

69. Some common glaucomatous VF defects 69 3/7/2024

70. Some common glaucomatous VF defects 70 3/7/2024

71. Some common glaucomatous VF defects 71 3/7/2024

72. Binocular VF Defects A binocular VF defect in each eye’s Hemifield is called Hemianopia Incomplete hemianopias are referred to as Quadrantanopias and Sectoral Defects A chiasmal or retrochiasmal lesion produces VF defects that respect the vertical meridian and that remain in one Hemifield of each eye Retinal and optic nerve lesions produce VF defects that can cross the vertical meridian 72 3/7/2024

73. Binocular VF Defects - Location A hemianopia may be Homonymous (i.e., impairing visual function on the same side of each eye), Bitemporal or Binasal Quadrantanopias and altitudinal VF defects are described as being, superior, inferior, or checkerboard 73 3/7/2024

74. Binocular VF Defects 74 3/7/2024

75. Binocular VF Defects 75 3/7/2024

76. Binocular VF Defects 76 3/7/2024

77. Binocular VF Defects 77 3/7/2024

78. COMMON VF DEFECTS 78 3/7/2024