Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
VISUAL FIELD ASSESSMENT
STATIC PERIMETRY

BY

DR. ANAND SUDHALKAR


                      Sudhalkar Eye Hospital, Baroda, ...
Situations demanding Field Test
   Glaucoma Diagnostic
       Triad with IOP and
       Disc changes.
       IOP > 21mm ...
What are we testing?

Actual visual field                                 Tested visual field
              60°
 Fixation ...
What are we looking for?

 Is the visual field reliable?
 Pattern of defects
 Significance of defects
 Normal or Glauc...
Reading the chart
  Patient and
  examination data


  Measured values
  and greyscale

  GHT
           Defect Curve

  C...
Patient and examination data
                   Program and strategy                               Pupil size




Date of ...
VA grey-scale degradation
with age




           Sudhalkar Eye Hospital, Baroda, Gujarat   9/22/2010   8
Reliability check by:


     Fixation losses
     catch trials




                        Sudhalkar Eye Hospital, Barod...
Reliability check by catch
trials
Positive Catch Trials
     With the positive catch trials, the perimeter
      produces...
Reliability check by
    catch trials
      Negative Catch Trials
   With the negative catch trials, the
    perimeter pr...
Reliability check by catch
trials
Evaluation
     The Reliability Factor is the number in
      percent of the positive a...
Value table and VA grey-scale
 The measured values are the                     The VA grey-scale presents a
 base for all ...
Octopus Humphrey comparisons
   Measuring range in Decibel (dB)
   d.l. sensitivity       luminance
  in Decibel (dB)     ...
Basic perimeter parameters
Parameter            OCTOPUS 101                     OCTOPUS 300                              H...
Comparison table and CO grey-scale:(difference (comparison) between
the age-corrected normal data and the actual measured
...
Corrected comparisons table: depicts local defects
            relative to the mean diffuse depression

  In the “correcte...
The cumulative defect (Bebie) curve
  The CO values are sorted in size and displayed in order (ranking) from the
  smalles...
Typical defect curves


                                            Suspect field:
                                       ...
Visual Field Indices




          Sudhalkar Eye Hospital, Baroda, Gujarat   9/22/2010   20
Visual field indices
For a quick assessment of the visual field it is helpful to
       average all values in a few (globa...
Index - mean sensitivity
          (MS)
                              
                                                  ...
Mean defect (MD)

                              
                                                      Normal values
    ...
Normal range of MD = -2 to +2 dB

 The Mean Defect MD represents the average
  defect of the entire visual field
 MD rea...
Loss variance (LV)
                              
                                                                   Norm...
Normal range of LV = 0 to 6 dB2

 The index Loss variance (LV) is sensitive to
  the irregularity of the visual field
 N...
Probability of defects

   Probability plots helpful to
   signal the significance of a
                   local defect

 ...
What are we looking at?
     Established glaucomatous damage
 Nasal and upper hemifield defects
 Classic arcuate Bjerrum...
Diagnostic field defects in glaucoma


                                 The visual field below demonstrates a cecocentral
...
Criteria for glaucomatous loss
                         Early Stage


 MD > 3 < 6dB
 Fewer than 15 points affected with ...
Criteria for glaucomatous loss
                     Moderate Stage


 MD > 6 < 12dB
 Fewer than 30 points affected with ...
Criteria for glaucomatous loss
                   Advanced Stage


 MD > 12dB
 More than 30 points affected with p < 5%
...
Early Field Loss

Same Patient comparison




         Sudhalkar Eye Hospital, Baroda, Gujarat   9/22/2010   33
Moderate Field Loss




     Sudhalkar Eye Hospital, Baroda, Gujarat   9/22/2010   34
Severe Field Loss




   Sudhalkar Eye Hospital, Baroda, Gujarat   9/22/2010   35
Pearls

 Check field for reliability
 Look for glaucoma specific
  losses/neurological
 Correlate with disc cupping, NF...
Thank You


   Sudhalkar Eye Hospital, Baroda, Gujarat   9/22/2010   37
55 yr Male, LE DV post op 6 months




                         Sudhalkar Eye Hospital, Baroda, Gujarat   9/22/2010   38
Field RE
                                     LE




           Sudhalkar Eye Hospital, Baroda, Gujarat   9/22/2010   39
Sudhalkar Eye Hospital, Baroda, Gujarat   9/22/2010   40
RE                                    LE




     Sudhalkar Eye Hospital, Baroda, Gujarat   9/22/2010   41
Upcoming SlideShare
Loading in …5
×

Visual field assessment

13,658 views

Published on

Published in: Health & Medicine

Visual field assessment

  1. 1. VISUAL FIELD ASSESSMENT STATIC PERIMETRY BY DR. ANAND SUDHALKAR Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 1
  2. 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 9/22/2010
  3. 3. What are we testing? Actual visual field Tested visual field 60° Fixation Blind  The central 30° field spot represents 66% of the ganglion cells and 83% of the visual cortex  Nearly all pathologies can be 60° 30° 90° associated with loss of retinal sensitivity in the 30° visual field Nasal field Temporal field  If in doubt, it is recommended 70° to repeat the central field rather than test the periphery Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 3
  4. 4. 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 9/22/2010 5
  5. 5. Reading the chart Patient and examination data Measured values and greyscale GHT Defect Curve Comparison values VF Indices Probability plots Eye fixation Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 6
  6. 6. Patient and examination data Program and strategy Pupil size Date of birth Questions, repetitions and catch Refraction trials Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 7
  7. 7. VA grey-scale degradation with age Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 8
  8. 8. Reliability check by:  Fixation losses  catch trials Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 9
  9. 9. 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. Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 10
  10. 10. 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. Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 11
  11. 11. Reliability check by catch trials Evaluation  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. Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 12
  12. 12. Value table and VA grey-scale The measured values are the The VA grey-scale presents a base for all further calculations comprehensive summary of and graphics the visual field Foveal Threshold Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 13
  13. 13. Octopus Humphrey comparisons Measuring range in Decibel (dB) d.l. sensitivity luminance in Decibel (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 Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 14
  14. 14. Basic perimeter parameters 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 Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 15
  15. 15. 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 Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 16
  16. 16. 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 preretinal interferences(mean diffuse depression of 8db) This table displays comparisons minus deviation 9/22/2010 18
  17. 17. The cumulative defect (Bebie) curve The CO values are sorted in size and displayed in order (ranking) from the smallest to the largest defect CO values Ranking Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 18
  18. 18. Typical defect curves Suspect field: • incorrect date of birth Normal visual field or trial lens • small pupil • cataract • early glaucoma Focal defect e.g. Early glaucoma Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 19
  19. 19. Visual Field Indices Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 20
  20. 20. Visual field indices For a quick assessment of the visual field it is helpful to average all values in a few (global) indices Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 21
  21. 21. Index - mean sensitivity (MS)  Normal values      Mean sensitivity MS    Average of all measured values  Measured values Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 22
  22. 22. Mean defect (MD)  Normal values      Mean sensitivity MS    Mean defect (MD) difference between average normal and MS  Measured values Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 23
  23. 23. 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 Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 24
  24. 24. Loss variance (LV)  Normal values      MS    MD Loss variance (LV) Spread of measured Measured values values from MS  Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 25
  25. 25. 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 Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 26
  26. 26. Probability of defects Probability plots helpful to signal the significance of a local defect 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 9/22/2010 28
  27. 27. What are we looking at? Established glaucomatous damage  Nasal and upper hemifield defects  Classic arcuate Bjerrum scotoma  Nasal Step respecting the horizontal raphe  Differentiate between generalized or diffuse against localized deep defects.  Increased fluctuations in retinal sensitivity in those specific areas. Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 28
  28. 28. Diagnostic field defects in glaucoma The visual field below demonstrates a cecocentral Locations on chart scotoma and superior nasal step and inferior nasal step with some extension into the acruate bundle. Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 29
  29. 29. 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 Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 30
  30. 30. 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 Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 31
  31. 31. Criteria for glaucomatous loss Advanced Stage  MD > 12dB  More than 30 points affected with p < 5% and more than 15 points below p < 1% level Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 32
  32. 32. Early Field Loss Same Patient comparison Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 33
  33. 33. Moderate Field Loss Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 34
  34. 34. Severe Field Loss Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 35
  35. 35. 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 Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 36
  36. 36. Thank You Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 37
  37. 37. 55 yr Male, LE DV post op 6 months Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 38
  38. 38. Field RE LE Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 39
  39. 39. Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 40
  40. 40. RE LE Sudhalkar Eye Hospital, Baroda, Gujarat 9/22/2010 41

×