Visual Field in Glaucoma
- 1. Visual Fields in Glaucoma Cesar A. Perez Jr MD DPBO Philippine Glaucoma Society
- 2. Definition of Visual Field ■ The visual field is that portion of the external environment of the observer wherein the steadily fixating eye can detect visual stimuli International Perimetric Society (1978)
- 3. Extent of the Visual Field Anderson RA. Automated Static Perimetry
- 4. Temporal fieldNasal field 60° 90° 70° 60° 30° Blind spot Why only the central 30 degrees?
- 5. Visual Field vs Anatomy Anderson RA. Automated Static Perimetry
- 6. Traquair’s Island of Vision
- 7. Definition of Perimetry ■ Measurement of visual functions of the eye at topographically defined loci in the visual field1 ■ Measures differential light sensitivity, or the ability of a subject to distinguish a stimulus light from background illumination2 1. International Perimetric Society (1978) 2. American Academy of Ophthalmology
- 8. Clinical Perimetry ■ Two major perimetry types ➢ Manual kinetic ➢ Automated static (gold standard)
- 9. Automated Static Threshold Perimetry ■ Measures the retina's sensitivity to light at predetermined locations in the visual field ■ While the patient focuses on the point of fixation, stimuli are presented in random order at each of the predetermined locations w/in the visual field
- 10. static achromatic stimulus (Gold Standard)
- 11. Clinical Perimetry Stimulus size Size V Size III (standard) Blind spot
- 12. Apostilbs (Asb) (luminance) Humphrey Decibels (dB) (sensitivity) Octopus Decibels (dB) 0.1 50 40 1 40 30 1000 10 0 10,000 0 - Clinical Perimetry
- 13. Clinical Perimetry ▪ Stimulus intensity is varied but w/ fixed size & duration ➢Determines the minimum intensity at w/c patient responds to 50% of the time (threshold) ▪ Determined by bracketing - stimulus intensities moved above & below the threshold Threshold strategy
- 14. Clinical Perimetry “Bracketing” reveals the threshold Infrathreshold (can’t be seen) Suprathreshold (seen)
- 15. Why test the Visual Field? ■ Defines state of optic nerve function ■ Defines visual impairment1 ■ To detect eye diseases (glaucoma, retinal, neuro-ophtha, etc) ■ To monitor an eye disease/visual impairment 1. Asia Pacific Glaucoma Guidelines (2003-2004)
- 16. What is being tested in Perimetry? ■ Light sensitivity is measured in different retinal areas ➢Foveal/central areas more sensitive than peripheral areas ■ Light sensitivity compared to a normative database derived from multicenter studies
- 17. Interconnecting cells ▪ Bipolar ▪ Horizontal ▪ Amacrine cells Visual Physiology of the Retina Light photoreceptors RPE Transmitting cells ▪ Ganglion cells G G
- 20. Parameters Reliability Age Corrected plots Tests (GHT/Bebie curve) Indices Correlate clinically Evaluate 7 Steps – 5 zones (PRACTICE) HumphreyTM OctopusTM 1) P 2) R 3) AC 4) T 5) I 6) C 7) E
- 21. 3 4 5 12 HumphreyTM • 5 Zones • Counter-clockwise 1) Parameters 2) Reliability 3) Age Corrected 4) Tests 5) Indices 6) Correlate clinically 7) Evaluate
- 22. 1 2 3 4 5 OctopusTM • 5 Zones • Clockwise 1) Parameters 2) Reliability 3) Age Corrected 4) Tests 5) Indices 6) Correlate clinically 7) Evaluate
- 23. ▪ Test strategy ➢ Full threshold, SITA-standard, SITA fast ▪ Region/pattern used ➢ 30-2, 24-2, 10-2 ▪ Patient details ➢date of birth, date of VF, pupil size, test time, VA, correction, eye tested 1.Parameters HumphreyTM
- 24. Perimetry Programs ■ Full Threshold 30-2 ■ Standard ■ 18-20 minutes per eye ■ 4-2-1 staircase with double crossover for Octopus; 4-2 staircase for Humphrey ■ Light stimulus size is standard (Goldmann Size III)
- 26. SITA Standard ▪ Diagnostic sensitivity similar to full threshold (both 95%)1 ▪ Sensitivity, specificity, characterization, & reliability of determining VF properties > vs other threshold tests2-4 ▪ 50% reduction in testing times ➢ 4 minutes for a normal field ➢ 8 minutes for a glaucoma field 1. Delgado, et al, Ophthalmology Dec 2002 2. Bengtsson B, et al. Acta Ophthalmol Scand. 1998 3. Bengtsson, B, Heijl. A. Acta Ophthalmol Scand. 1998 4. Budenz DL, et al. Ophthalmology. 2002
- 28. ■ 2-6 minutes ➢ 3 minutes normal field ➢ 5.5 minutes glaucoma field ■ 93% sensitivity vs 95% for SITA standard1 For patients : Younger ➢ Restless ➢ “Learning” 1. Delgado, et al, Ophthalmology Dec 2002 SITA Fast
- 29. • 24-2 tests 54 points • 30-2 tests 76 points 24-2 or 30-2? HumphreyTM 10-2? • For advanced glaucoma • Tests 68 points in the central 10 degrees
- 30. HumphreyTM
- 33. Is the field reliable? ▪ false (+): pressing button even w/o visual stimulus ▪ false (-): failure to respond to a threshold stimulus previously seen at the same point ▪ if > 33% FP or FN, then unreliable ▪ if > 20% fixation losses then unreliable
- 34. 3 12 HumphreyTM 1) Parameters 2) Reliability 3) Age Corrected
- 35. Compare total & pattern deviation 3.Age Corrected plots HumphreyTM Zero in on the probability plots
- 36. Compare total deviation (TD) & pattern deviation (PD) probability plots HumphreyTM ▪ If defect in TD & PD plots look similar ➢ Focal field defect ▪ Depressed TD w/ a normal PD ➢ Diffuse or generalized field defect
- 37. Focal defect Compare total & pattern deviation HumphreyTM
- 38. HumphreyTM Generalized defect Compare total & pattern deviation
- 39. 3 4 12 HumphreyTM 1) Parameters 2) Reliability 3) Age Corrected 4) Tests
- 40. ■ Outside normal limits ➢if sensitivities in > 1 of the 5 zones in upper half of the field are different (p<0.01) from those in the corresponding lower half zones 4.Tests: glaucoma hemifield test (GHT) HumphreyTM
- 41. 3 4 5 12 HumphreyTM 1) Parameters 2) Reliability 3) Age Corrected 4) Tests 5) Indices
- 42. 5.Indices (global) ▪ MD: mean deviation ▪ PSD: pattern standard deviation ▪ SF: short-term fluctuation ▪ CPSD: corrected PSD HumphreyTM
- 43. Mean deviation (MD) ▪ Average difference between overall sensitivity of patient and age-matched controls ▪ Indication of generalized defects or elevation (+ or - 2 dB normal) ▪ Good measure of diffuse defects
- 44. 5.Indices (global) HumphreyTM Mean deviation (MD) 40 0 30 20 10 90 60 30 0 30 60 90 Normal hill of vision (age corrected) dB
- 45. Pattern standard deviation (PSD) shape of VF departs from normal age- corrected field ▪ Focal / localized defects ▪ Single most useful analysis ▪ Beginning VF loss appear earlier in probability plots vs grayscale ▪ Normal value : 0 to 6 dB
- 46. Short term fluctuations (SF) ▪ 0-2dB normal ▪ Average between 2 determinations should be: ➢ < 2dB in normal field ➢ < 3dB in early damage ➢ < 4dB in moderate damage • Increased fluctuation
- 47. ▪ Pattern Standard Deviation (PSD) corrected for the SF ▪ Better measure of localized field loss (0-4 dB normal) Corrected Pattern Standard deviation (CPSD) HumphreyTM 5.Indices (global)
- 48. 3 4 5 12 HumphreyTM 1) Parameters 2) Reliability 3) Age Corrected 4) Tests 5) Indices 6) Correlate clinically 6
- 49. 3 4 5 12 HumphreyTM 1) Parameters 2) Reliability 3) Age Corrected 4) Tests 5) Indices 6) Correlate clinically 7) Evaluate6 7
- 51. ▪ Test strategy ➢ Normal, Dynamic, TOP ▪ Pattern/region used ➢ G1, 32, M2, LVC ▪ Patient details ➢ Date of birth, date of VF, pupil size, test time, VA, correction, eye tested OctopusTM 1.Parameters
- 52. ▪ Points positioned in areas of concern in glaucoma ➢Accentuates nasal step ➢Higher resolution in paracentral area G1 program OS OctopusTM 1.Parameters - pattern
- 54. OctopusTM ➢excellent correlation w/ normal strategy ▪ Dynamic ▪ TOP Shorter strategies:
- 55. Perimetry Programs ■ Dynamic Program 30-2 (Octopus) ■ ~ 7 minutes per eye ■ Stimulus presentation adapted to measured threshold value ■ Higher sensitivity ! smaller steps (2 dB) ■ Lower sensitivity ! larger steps (6-10 dB) ■ Single crossover ■ Light stimulus size is standard (Goldmann Size III)
- 56. Perimetry Programs ■ Tendency Oriented Perimetry (TOP) Program 30-2 ■ ~ 2-3 minutes per eye ■ Screening ■ Only 1 test question per location ■ Single answer influences the value of 8 neighboring points ■ Light stimulus size is standard (Goldmann Size III) ■ Phase 1 only ■ No SF (short term fluctuation)
- 58. G1 vs 32 pattern OctopusTM
- 59. ▪ For detection and/or f/up of defects in the central 100 ➢ Neurological ➢ Macular ➢ Peri-macular M2 program 00 100 OctopusTM 1.Parameters - pattern
- 61. ▪ Tests sensitivity in central foveal area ➢ Same grid as 32 program ➢ End stage glaucoma ➢ Goldmann stimulus V LVC program 00 300 1.Parameters - pattern OctopusTM
- 63. 2. Reliability Factor ▪ Ideally < 15 ▪ Lower the better OctopusTM
- 64. 1 2 3 OctopusTM 1) Parameters 2) Reliability 3) Age Corrected
- 65. Zero in on the probability plots OctopusTM Compare C & CC probability plots 3.Age Corrected plots
- 67. ▪ Quickly assesses defect characteristics & depth ▪ Diffuse vs focal defect ➢ Diffuse: curve below & parallel to the normal curve ➢ Focal: steep fall-offs on the right side of the curve OctopusTM 4.Tests: Bebie curve
- 68. Diffuse defect: curve below & parallel to normal curve OctopusTM 4.Tests: Bebie curve
- 69. Focal defect: steep fall-offs 4.Tests: Bebie curve OctopusTM
- 71. mean sensitivity (MS) mean deviation (MD) mean defect (MD) pattern std deviation (PSD) loss variance (LV) short term fluctuations (SF) short term fluctuations (SF) corrected pattern standard deviation (CPSD) corrected loss variance (CLV) OctopusTMHumphreyTM 5.Indices (global)
- 72. Visual Field Indices Normal Values ■ Mean Defect ( -2.0 to +2.0 db ) ■ Loss Variance ( 0 to 6.0 db ) ■ Short-term Fluctuation ( 0 to 2.0 db ) ■ Corrected Loss Variance ( 0 to 4.0 db )
- 73. 1 2 3 4 56 OctopusTM 1) Parameters 2) Reliability 3) Age Corrected 4) Tests 5) Indices 6) Correlate clinically
- 74. 1 2 3 4 567 OctopusTM 1) Parameters 2) Reliability 3) Age Corrected 4) Tests 5) Indices 6) Correlate clinically 7) Evaluate
- 75. Is the field defect glaucomatous? • Is the defect focal? • Is the defect diffuse? STEP 1
- 76. Glaucoma defects are Focal in nature Diffuse Focal
- 77. What kind of a defect is this? diffuse or focal? combined diffuse & focal defect
- 78. If the defect is Focal STEP 2: Is the focal defect glaucomatous?
- 79. Glaucomatous Visual Field Defects (Seagig Glaucoma Guidelines ‘08) ▪ Asymmetrical across horizontal meridian* ▪ Are located in mid-periphery* (5–250 from fixation) ▪ Reproducible ▪ Not attributable to other pathology ▪ Clustered in neighboring test pts (localised) ▪ Correlate with optic disc and RNFL * Applicable to early/moderate cases
- 80. Localized patterns of glaucoma VF defects ▪ Nasal step (earliest) ▪ Paracentral scotoma ▪ Arcuate (Bjerrum) scotoma ➢ Later becoming altitudinal ▪Temporal island ▪ Central island
- 84. Superior altitudinal w/ inferior arcuate scotoma
- 85. Reproducibilty ■ A visual field defect must be real. To be real, it must be confirmed on repeated exams
- 86. 1. Anderson DR, Patella VM. Automated Static Perimetry. 2nd Ed. St Louis: Mosby 1999 2. Hodapp E, Parrish RK, Anderson DR. Clinical decisions in glaucoma. St Louis: Mosby ▪ What is the minimum criteria for a defect to be possibly glaucoma? 1 ▪ When do you classify a glaucoma defects as:2 ➢ Early? ➢ Moderate? ➢ Severe? Identification & Classification of a glaucoma defect
- 87. Minimum Criteria for glaucoma defects (1) ▪ ≥ 3 non-edge points w/ p< 5% ▪One point w/ p< 1% ▪Cluster in arcuate area Anderson DR, Patella VM. Automated Static Perimetry. 2nd Ed. St Louis: Mosby 1999 Pattern deviation plot
- 88. Criteria for glaucoma defects (2) CPSD or PSD depressed, with p < 5% Anderson DR, Patella VM. Automated Static Perimetry. 2nd Ed. St Louis: Mosby,1999
- 89. Criteria for glaucoma defects (3) Abnormal GHT Anderson DR, Patella VM. Automated Static Perimetry. 2nd Ed. St Louis: Mosby 1999
- 90. 3 minimum criteria for glaucoma defects 2) CPSD or PSD depressed w/ p < 5% 3) Abnormal GHT Anderson DR, Patella VM. Automated Static Perimetry. 2nd Ed. St Louis: Mosby 1999 1) PD plot a) ≥ 3 non-edge points w/ p< 5% b) 1 point w/ p < 1% c) Cluster in arcuate area
- 91. Hodapp E, Parrish RK, Anderson DR. Clinical decisions in glaucoma. St Louis: Mosby Criteria for Early Glaucoma Defect ▪ MD < -6 dB ▪ On PD plot, < 25% (18 pts) below 5% level and < 15% (10 pts) below 1% level ▪ No pt w/in central 50 : sensitivity < 15 dB
- 93. ▪ MD > -6 dB but < -12 dB ▪ PD plot, < 50% (37 pts) < 5% level and < 25% (20 pts) < 1% level ▪ No absolute deficit (0 dB) in the central 50 ▪ Only 1 hemi-field has point w/ sensitivity < 15 dB in the central 50 Hodapp E, Parrish RK, Anderson DR. Clinical decisions in glaucoma. St Louis: Mosby Criteria for Moderate Glaucoma Defect
- 95. ▪ MD > -12 dB ▪ On PD plot ➢ > 50% of pts < 5% level ➢ > 25% of pts < 1% level ▪ Absolute deficit (0 dB) in the central 50 ▪ Both hemi-fields w/ pt(s) w/ sensitivity < 15 dB w/in th central 50 Hodapp E, Parrish RK, Anderson DR. Clinical decisions in glaucoma. St Louis: Mosby Criteria for Severe Glaucoma Defect
- 97. Detecting Progression ➢ Widening or deepening of an existing scotoma ➢ Development of a new glaucomatous scotoma ➢ Occasionally generalized field depression (although usually caused by media opacity or miosis) Asia Pacific Glaucoma Guidelines (2003-2004)
- 98. ■ Requires a series of at least 3 or 4 fields ■ Basing judgements on only 1 progressed field is very risky unless the changes encountered are ➢ Very large and/or ➢ Confirmed by other clinical findings, such as changes in optic disc configuration Detecting Progression
- 99. Octopus ▪ Series Program ➢3 examinations arranged in one printout ▪ PeriTrend® Statistical Software ▪ EyeSuite® Detecting Progression
- 101. ▪ Calculates regression curves of MD (mean defect) and LV (loss variance) ▪ Color-coded curves to show changes: ➢red – depressed ➢green – improved ➢blue – trend isn’t significant/stable Octopus: PeriTrend® Detecting Progression
- 103. Humphrey ■ Overview print-out ■ Glaucoma Progression Analysis® (GPA®) software Detecting Progression
- 106. Structure-Function Correlation ■ Combined w/ other examinations ■ No isolated interpretations ■ Disc features must match visual field defects (clinical picture takes precedence)
- 107. New Perimetry Technologies ■ Short Wavelength Automated Perimetry (SWAP) ➢Blue light stimulus on yellow background (“blue on yellow”) ➢Detects VF loss 3-5 yrs before white on white perimetry1 ➢Utilizes the “K” ganglion cells 1. Racette L et al. Ophthalmol Clin North Am. 2003: 16: 227-236
- 108. Goldmann size V 440 nm, 1.80 > 500 nm yellow background • Except for these differences, SWAP is still a basic threshold perimetry test, in w/c std Goldmann stimuli are presented in the conventional way
- 109. New Perimetry Technologies ■ Frequency Doubling Technology (FDT) perimeter ➢Motion/flicker perimetry ➢FDT can detect VF loss 4 yrs before SAP1 ➢Utilizes the “M” ganglion cells/ Magnocellular pathway 1. Johnson CA et al. J Vision. 2002; 2:100a
- 110. ▪ Functional testing essential: SAP ▪ Know retinal anatomy & its relation to visual function ▪ Know programs/parameters ➢ Stick to a single one for ff-up ▪ Glaucoma defects are focal ▪ Progression is a hallmark of Glaucoma ▪ CLINICAL CORRELATION Summary
- 111. Although sometimes it is not as easy as it seems
- 112. Thank You!
- 113. Perimetry Exercises
- 115. …1 year after
- 116. …1 year after Early defects may show up in probability plots and not in the grayscale
- 118. …1 year after
- 119. … 6 mos. after
- 120. … 6 mos. after progressing cataract
- 121. • elevated false “+” score • GHF – “abnormally high sensitivity” • “white scotoma” on grayscale • larger defects on the pattern deviation plots than in the total deviation probability plots • highly positive mean deviation (MD) “Trigger happy” field
- 124. both a focal and a diffuse defect
- 125. ….a year after
- 132. inferior nasal step extending to blind spot
- 134. …1 month after
- 136. Are the VF defects artifacts? ▪ “Learning effect” ? ▪ Rim effect ? ▪ Ptosis, prominent brows ? ▪ Lack of instructions or supervision ? ▪ Anxiety/fatigue/drowsiness ? ▪ Malingering ?
- 139. Learning effect ▪ Depressed sensitivity in mid-periphery 20-300 ▪ Less common in shorter algorithms ▪ 10-20% of normal patients don’t produce normal VF’s on their first test
- 141. Rim effect
- 143. Lid effect seen on grayscale but not seen on probability plots
- 148. same patient after taping upper lid
- 150. “Cloverleaf” pattern •Initial good responses …..then poor •Test begins centered around 4 primary points • patient misunderstanding, lack of motivation, and/or fatigue • poor instruction/supervision by technician
- 151. • The first visual field IS NOT THE BASELINE. • “LEARNING CURVE”