1. 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 1 Single field analysisbyDr.AnandSudhalkar AIOS 2010, Kolkatta. Instruction course no. 82 [IC76] GLAUCOMA –Basic Sunday, 24-1-2010

2. Situations demanding Field Test Glaucoma Diagnostic Triad with IOP and Disc changes. IOP > 21mm Hg. Significant Cupping with/without high IOP Strong Family History, Myopia, Diabetes Narrow Angles/Int. IOP Normal “Other” Eye of the glaucoma patient 2/20/2010

3. What are we testing? Actual visual field Tested visual field 60° Fixation Blind spot 90° 60° 30° Temporal field Nasal field 70° The central 30° field represents 66% of the ganglion cells and 83% of the visual cortex Nearly all pathologies can be associated with loss of retinal sensitivity in the 30° visual field If in doubt, it is recommended to repeat the central field rather than test the periphery 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 3

4. How is the field tested? Static Perimetry In static perimetry every location is tested in a “vertical direction“ by making the stimulus dimmer and brighter Only psychophysical documentation with Quantification of visual loss in glaucoma Comparison with age matched normative data Statistical, glaucoma specific analysis. Sudhalkar Eye Hospital, Baroda, Gujarat 4 Normal field Pathologicalfield 2/20/2010

5. What are we looking for? Is the visual field reliable? Pattern of defects Significance of defects Normal or Glaucoma Clinical correlation Sudhalkar Eye Hospital, Baroda, Gujarat 5 2/20/2010

6. Reading the chart 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 6 Patient and examination data Measured values and greyscale GHT Defect Curve Comparison values VF Indices Probability plots Eye fixation

7. Patient and examination data 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 7 Pupil size Program and strategy Date of birth Questions, repetitions and catch trials Refraction

8. VA grey-scale degradation with age 2/20/2010 8 Sudhalkar Eye Hospital, Baroda, Gujarat

9. Reliability check by: Fixation losses catch trials 2/20/2010 9 Sudhalkar Eye Hospital, Baroda, Gujarat

10. Reliability check by catch trials Positive Catch Trials With the positive catch trials, the perimeter produces a stimulus sound although NO light is projected - the patient should not respond. With many positive mistakes, the patient is a “happy trigger” patient. 2/20/2010 10 Sudhalkar Eye Hospital, Baroda, Gujarat

11. Reliability check by catch trials Negative Catch Trials With the negative catch trials, the perimeter projects its brightest spot where a less intense stimulus was seen before - the patient must respond! With severely depressed fields, the patient usually makes more mistakes. This is normal. 2/20/2010 11 Sudhalkar Eye Hospital, Baroda, Gujarat

12. Reliability check by catch trialsEvaluation The Reliability Factor is the number in percent of the positive and negative catch trial mistakes. Whenever this factor exceeds 15-20% the results must be evaluated with caution. 2/20/2010 12 Sudhalkar Eye Hospital, Baroda, Gujarat

13. 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 13 Value table and VA grey-scale The VA grey-scale presents a comprehensive summary of the visual field The measured values are the base for all further calculations and graphics Foveal Threshold

14. Octopus Humphrey comparisonsMeasuring range in Decibel (dB) d.l. sensitivity luminance inDecibel(dB) in Apostilb (asb) Perimeter models 101 300 HFA 40 dB - 0.1 asb 0.4 asb 1 asb 30 - 1.0 4.0 10 20 - 10 40 100 10 - 100 400 1’000 0 - 1’000 4’000 10’000 Background (asb) 4 31.5 31.5 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 14

15. Basic perimeter parameters 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 15 Parameter OCTOPUS 101 OCTOPUS 300 HFA Bowl type Spherical bowl Direct projection A-spherical bowl 42.5 cm 18-30 cm Background - Luminance 4 asb 31.4 asb 31.5 asb (1.27 cd/m²) (10 cd/m²) (10 cd/m²) Stimulus - Size Goldmann I - V Goldmann III, V Goldmann I - V- Duration 100 ms 100 ms 200 ms- Luminance 1’000 asb 4’800 asb 10’000 asb for 0 dB Measuring range 0 - 40 dB 0 - 40 dB 0 - 40 dB Test strategies 4-2-1 dB bracketing 4-2-1 dB bracketing 4-2 dB bracketing Dynamic strategy Dynamic strategy SITA Normal TOP TOP SITA Fast Normal values Age correction per year of age

16. Comparison table and CO grey-scale:(difference (comparison) between the age-corrected normal data and the actual measured results) Actual Value table Age matched comparison 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 16

17. Corrected comparisons table: depicts local defects relative to the mean diffuse depression In the “corrected” comparisons table the deviation value is taken into account to highlight pathological changes without the effect of any preretinalinterferences(mean diffuse depression of 8db) 2/20/2010 This table displays comparisons minus deviation 18

18. CO values Ranking The cumulative defect (Bebie) curve 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 18 The CO values are sorted in size and displayed in order (ranking) from the smallest to the largest defect

20. cataract

21. early glaucomaNormal visual field Focal defect e.g. Early glaucoma

22. Visual Field Indices 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 20

23. Visual field indices For a quick assessment of the visual field it is helpful to average all values in a few (global) indices 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 21

24. Index - mean sensitivity (MS) 2/20/2010 Measured values Normal values Mean sensitivity MS Average of all measured values Sudhalkar Eye Hospital, Baroda, Gujarat 22

25. 2/20/2010 Measured values Mean defect (MD) Normal values Mean sensitivity MS Mean defect (MD)difference between average normal and MS Sudhalkar Eye Hospital, Baroda, Gujarat 23

26. Normal range of MD = -2 to +2 dB The Mean Defect MD represents the average defect of the entire visual field MD reacts strongly on diffuse (homogeneous) depression Localized (topical) defects have practically no influence on MD MD is the index for uniform loss of sensitivity 2/20/2010 24 Sudhalkar Eye Hospital, Baroda, Gujarat

27. Loss variance (LV) 2/20/2010 MD Measured values Normal values MS Loss variance (LV) Spread of measured values from MS 25 Sudhalkar Eye Hospital, Baroda, Gujarat

28. Normal range of LV = 0 to 6 dB2 The index Loss variance (LV) is sensitive to the irregularity of the visual field Normal visual fields have an LV of 0 .. 6 dB2 LV (or sLV) = standard deviation (sd) Normal visual fields have an sLV of 0 .. 2.5 dB An elevated LV (or sLV) is an indication that the field has localized defects exceeding the normal local variability 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 26

29. Probability of defects Probability plots helpful to signal the significance of a local defect 2/20/2010 P<0.5 means that less than 0.5% of the normal population shows a defect of this size at this location – Therefore this defect is a significant defect 28

30. What are we looking at?Established glaucomatous damage Nasal and upper hemifield defects Classic arcuateBjerrumscotoma Nasal Step respecting the horizontal raphe Differentiate between generalized or diffuse against localized deep defects. Increased fluctuations in retinal sensitivity in those specific areas. 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 28

31. Diagnostic field defects in glaucoma Locations on chart The visual field below demonstrates a cecocentralscotoma and superior nasal step and inferior nasal step with some extension into the acruate bundle. 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 29

32. Criteria for glaucomatous loss Early Stage MD > 3 < 6dB Fewer than 15 points affected with p < 5% and fewer than 8 points below p < 1% level 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 30

33. Criteria for glaucomatous loss Moderate Stage MD > 6 < 12dB Fewer than 30 points affected with p < 5% and fewer than 15 points below p < 1% level 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 31

34. Criteria for glaucomatous lossAdvanced Stage MD > 12dB More than 30 points affected with p < 5% and more than 15 points below p < 1% level 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 32

35. Same Patient comparison 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 33 Early Field Loss

36. 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 34 Moderate Field Loss

37. 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 35 Severe Field Loss

38. Pearls Check field for reliability Look for glaucoma specific losses/neurological Correlate with disc cupping, NFL loss and IOP, complete fundus examination. Repeat fields : 1. If in doubt 2. Follow-up 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 36

39. Thank You 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 37

40. 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 38 55 yr Male, LE DV post op 6 months

41. 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 39 Field RE LE

42. 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 40

43. RELE 2/20/2010 Sudhalkar Eye Hospital, Baroda, Gujarat 41