Aios 2010 presentation 1

1,374 views

Published on

Published in: Health & Medicine
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
1,374
On SlideShare
0
From Embeds
0
Number of Embeds
34
Actions
Shares
0
Downloads
65
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide
  • Usually the first field done.
  • The picture shows advanced glaucomatous cupping in RE and “normal” disc in LE
  • Aios 2010 presentation 1

    1. 1. 2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />1<br />Single field analysisbyDr.AnandSudhalkar<br />AIOS 2010, Kolkatta. Instruction course no. 82 [IC76] <br />GLAUCOMA –Basic Sunday, 24-1-2010<br />
    2. 2. Situations demanding Field Test <br />Glaucoma Diagnostic Triad with IOP and Disc changes.<br /> IOP > 21mm Hg.<br />Significant Cupping with/without high IOP<br />Strong Family History, Myopia, Diabetes<br />Narrow Angles/Int. IOP<br />Normal “Other” Eye of the glaucoma patient<br />2/20/2010<br />
    3. 3. What are we testing?<br />Actual visual field<br />Tested visual field<br />60°<br />Fixation<br />Blind spot<br />90°<br />60°<br />30°<br />Temporal field<br />Nasal field<br />70°<br />The central 30° field represents 66% of the ganglion cells and 83% of the visual cortex<br />Nearly all pathologies can be associated with loss of retinal sensitivity in the 30° visual field<br />If in doubt, it is recommended to repeat the central field rather than test the periphery<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />3<br />
    4. 4. How is the field tested? Static Perimetry<br />In static perimetry every location is tested in a “vertical direction“ by making the stimulus dimmer and brighter <br />Only psychophysical documentation with Quantification of visual loss in glaucoma<br />Comparison with age matched normative data<br /> Statistical, glaucoma specific analysis.<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />4<br />Normal field<br />Pathologicalfield<br />2/20/2010<br />
    5. 5. What are we looking for?<br />Is the visual field reliable?<br />Pattern of defects<br />Significance of defects<br />Normal or Glaucoma<br />Clinical correlation<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />5<br />2/20/2010<br />
    6. 6. Reading the chart<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />6<br />Patient and examination data<br />Measured values and greyscale<br />GHT<br />Defect Curve<br />Comparison values<br />VF Indices<br />Probability plots<br />Eye fixation<br />
    7. 7. Patient and examination data<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />7<br />Pupil size<br />Program and strategy<br />Date of birth<br />Questions, repetitions and catch trials<br />Refraction<br />
    8. 8. VA grey-scale degradation with age<br />2/20/2010<br />8<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />
    9. 9. Reliability check by:<br />Fixation losses<br />catch trials<br />2/20/2010<br />9<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />
    10. 10. Reliability check by catch trials Positive Catch Trials<br />With the positive catch trials, the perimeter produces a stimulus sound although NO light is projected - the patient should not respond.<br />With many positive mistakes, the patient is a “happy trigger” patient. <br />2/20/2010<br />10<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />
    11. 11. Reliability check by catch trials Negative Catch Trials<br />With the negative catch trials, the perimeter projects its brightest spot where a less intense stimulus was seen before - the patient must respond!<br />With severely depressed fields, the patient usually makes more mistakes. This is normal.<br />2/20/2010<br />11<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />
    12. 12. Reliability check by catch trialsEvaluation<br />The Reliability Factor is the number in percent of the positive and negative catch trial mistakes.<br />Whenever this factor exceeds 15-20% the results must be evaluated with caution.<br />2/20/2010<br />12<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />
    13. 13. 2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />13<br />Value table and VA grey-scale<br />The VA grey-scale presents a comprehensive summary of the visual field<br />The measured values are the base for all further calculations and graphics<br />Foveal Threshold<br />
    14. 14. Octopus Humphrey comparisonsMeasuring range in Decibel (dB)<br />d.l. sensitivity luminance inDecibel(dB) in Apostilb (asb)<br /> Perimeter models 101 300 HFA<br /> 40 dB - 0.1 asb 0.4 asb 1 asb<br /> 30 - 1.0 4.0 10<br /> 20 - 10 40 100 10 - 100 400 1’000 0 - 1’000 4’000 10’000<br /> Background (asb) 4 31.5 31.5<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />14<br />
    15. 15. Basic perimeter parameters<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />15<br />Parameter OCTOPUS 101 OCTOPUS 300 HFA<br />Bowl type Spherical bowl Direct projection A-spherical bowl 42.5 cm 18-30 cm<br />Background - Luminance 4 asb 31.4 asb 31.5 asb (1.27 cd/m²) (10 cd/m²) (10 cd/m²)<br />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 <br />Measuring range 0 - 40 dB 0 - 40 dB 0 - 40 dB<br />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<br />Normal values Age correction per year of age<br />
    16. 16. Comparison table and CO grey-scale:(difference (comparison) between the age-corrected normal data and the actual measured results)<br />Actual Value table<br />Age matched comparison<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />16<br />
    17. 17. Corrected comparisons table: depicts local defects relative to the mean diffuse depression <br />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)<br />2/20/2010<br />This table displays comparisons minus deviation<br />18<br />
    18. 18. CO values<br />Ranking<br />The cumulative defect (Bebie) curve<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />18<br />The CO values are sorted in size and displayed in order (ranking) from the smallest to the largest defect<br />
    19. 19. Typical defect curves<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />19<br />Suspect field:<br /><ul><li>incorrect date of birth</li></ul> or trial lens<br /><ul><li>small pupil
    20. 20. cataract
    21. 21. early glaucoma</li></ul>Normal visual field<br />Focal defect<br />e.g. Early glaucoma<br />
    22. 22. Visual Field Indices<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />20<br />
    23. 23. Visual field indices<br />For a quick assessment of the visual field it is helpful to average all values in a few (global) indices<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />21<br />
    24. 24. Index - mean sensitivity (MS)<br />2/20/2010<br />Measured values<br />Normal values<br />Mean sensitivity MS<br />Average of all measured values<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />22<br />
    25. 25. 2/20/2010<br />Measured values<br />Mean defect (MD)<br />Normal values<br />Mean sensitivity MS<br />Mean defect (MD)difference between average normal and MS<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />23<br />
    26. 26. Normal range of MD = -2 to +2 dB<br />The Mean Defect MD represents the average defect of the entire visual field<br />MD reacts strongly on diffuse (homogeneous) depression<br />Localized (topical) defects have practically no influence on MD<br />MD is the index for uniform loss of sensitivity<br />2/20/2010<br />24<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />
    27. 27. Loss variance (LV)<br />2/20/2010<br />MD<br />Measured values<br />Normal values<br />MS<br />Loss variance (LV)<br />Spread of measured values from MS<br />25<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />
    28. 28. Normal range of LV = 0 to 6 dB2<br />The index Loss variance (LV) is sensitive to the irregularity of the visual field<br />Normal visual fields have an LV of 0 .. 6 dB2<br />LV (or sLV) = standard deviation (sd)<br />Normal visual fields have an sLV of 0 .. 2.5 dB<br />An elevated LV (or sLV) is an indication that the field has localized defects exceeding the normal local variability<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />26<br />
    29. 29. Probability of defects<br />Probability plots helpful to signal the significance of a local defect<br />2/20/2010<br />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<br />28<br />
    30. 30. What are we looking at?Established glaucomatous damage<br />Nasal and upper hemifield defects<br />Classic arcuateBjerrumscotoma<br />Nasal Step respecting the horizontal raphe<br />Differentiate between generalized or diffuse against localized deep defects. <br />Increased fluctuations in retinal sensitivity in those specific areas.<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />28<br />
    31. 31. Diagnostic field defects in glaucoma<br />Locations on chart<br />The visual field below demonstrates a cecocentralscotoma and superior nasal step and inferior nasal step with some extension into the acruate bundle.<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />29<br />
    32. 32. Criteria for glaucomatous loss Early Stage<br />MD > 3 < 6dB<br />Fewer than 15 points affected with p < 5% and fewer than 8 points below p < 1% level<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />30<br />
    33. 33. Criteria for glaucomatous loss Moderate Stage<br />MD > 6 < 12dB<br />Fewer than 30 points affected with p < 5% and fewer than 15 points below p < 1% level<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />31<br />
    34. 34. Criteria for glaucomatous lossAdvanced Stage<br />MD > 12dB<br />More than 30 points affected with p < 5% and more than 15 points below p < 1% level<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />32<br />
    35. 35. Same Patient comparison<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />33<br />Early Field Loss<br />
    36. 36. 2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />34<br />Moderate Field Loss<br />
    37. 37. 2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />35<br />Severe Field Loss<br />
    38. 38. Pearls<br />Check field for reliability<br />Look for glaucoma specific losses/neurological<br />Correlate with disc cupping, NFL loss and IOP, complete fundus examination.<br />Repeat fields : 1. If in doubt<br /> 2. Follow-up<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />36<br />
    39. 39. Thank You<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />37<br />
    40. 40. 2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />38<br />55 yr Male, LE DV post op 6 months<br />
    41. 41. 2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />39<br />Field RE<br />LE<br />
    42. 42. 2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />40<br />
    43. 43. RELE<br />2/20/2010<br />Sudhalkar Eye Hospital, Baroda, Gujarat<br />41<br />

    ×