Ординатура / Офтальмология / Английские материалы / A Visual Field Evaluation with Automated Devices 2nd edition_Reddy_2006
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VISUAL FIELD LOSS IN GLAUCOMA 111
SINGLE FIELD ANALYSIS PRINTOUT OF EARLY GLAUCOMA
A case of localized field defect :
1. The total deviation probability plot and pattern deviation probability plot look identical.
2. PSD 3.82 dB P < 0.5%
3. MD -2.4 dB P < 5%
Patient data: |
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Name of the patient : K. Ekkiah |
Age: 50 |
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Visual acuity |
: 6/6 (+0.25DSph) |
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Refractive error correction for N V :+2.75DSph |
Pupil size: 3 mm |
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Indication for field: Glaucoma suspect |
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Selection of the test: 24-2 SITA Standard |
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Step 1: Patient data was correctly entered in the printout
Step 2: Selection of the test is proper (it is always better to select central 30-2 with full threshold strategy
in glaucoma suspect cases) |
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Visual acuity: 6/6 |
Foveal threshold: 35 dB |
112 A VISUAL FIELD EVALUATION WITH AUTOMATED DEVICES
Comment: The near vision refractive error correction is proper.
Reliability Indices :
Fixation losses : 0/14 |
False (+) ve error: 0% |
False (-)ve error:0% |
Comment : Excellent reliability
Interpretation: ——
Total deviation probability plot Localized scotomas in the lower quadrant if seen
Pattern deviation probability plot
Global indices MD : -2.40 dB P value less than 5%
PSD : 3.82dB P value less than 0.5%
G.H.T : Outside normal limits.
Anderson criteria: All the above findings are fulfilling the Anderson’s minimum criteria to label as early focal depression due to glaucoma.
Final interpretation report: Early glaucoma field defect present. In the form of early lower arcuate scotoma starting from blind spot.
VISUAL FIELD LOSS IN GLAUCOMA 113
SINGLE FIELD ANALYSIS PRINTOUT OF
KNOWN PATIENT OF GLAUCOMA
A case of localized field defect:
1. The total deviation probability plot and pattern deviation probability plot look identical.
2. PSD: 14.44 dB P < 0.5%
3. MD: -11.1118 dB P < 0.5%
Patient data: |
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Name of the patient :M. Sujatha |
Age:42 |
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Visual acuity |
:6/6 |
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Refractive error correction for NV : +2.50DSph |
Pupil size: 3 mm |
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Indication for field: Chronic angle closure glaucoma with 0.6 cup. |
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Selection of the test : 24-2 SITA Standard |
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Step 1: Patient data correctly entered. |
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Step 2: Selection of the test is proper |
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Visual acuity : 6/6 |
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Foveal threshold: 32dB |
Comment : Refractive error correction for NV is proper.
114 A VISUAL FIELD EVALUATION WITH AUTOMATED DEVICES
Reliability Indices
Fixation losses : 0/18 |
False (+) ve error: 0% |
False (-)ve error:0% |
Comment: Excellent reliability |
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Interpretation: |
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The total deviation probability plot |
Localized deep scotomas in the lower nasal |
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The pattern deviation probability plot |
quadrant in arcuate pattern is seen. |
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Global indices
MD : -11.18dB P value less than 0.5 %
PSD : 14.44 dB P value less than 0.5%
G.H.T: outside normal limits
Anderson criteria : Non-edge scotomas, MD, PSD and GHT are fulfilling the criteria to label as focal visual field defect due to glaucoma.
Final interpretation report: Visual field defect in lower arcuate area is present due to glaucoma.
VISUAL FIELD LOSS IN GLAUCOMA 115
SINGLE FIELD ANALYSIS PRINTOUT IN ADVANCED GLAUCOMA
Patient data:
Name of the patient : S. Rama Reddy
Age: 50
Visual acuity : Not recorded Refractive error correction for NV : Not recorded
Pupil size: 3 mm
Indication for field: Advanced glaucoma with 0.8 cup Selection of the test : 24-2 threshold test - SITA standard
Step 1: Patient data is correctly entered (visual acuity and refractive error correction were not entered)
Step 2: Selection of the test is proper. But 10-2 Full Threshold strategy or 10-2 SITA Standard is more appropriate test in advanced glaucoma, as this test will give better information regarding macular split.
Test reliability : Unreliable test: Fixation |
loses 8/20xx |
Visual acuity : Not recorded |
Foveal threshold: 30dB |
Comment: As foveal threshold is 30dB we presume that refractive error correction for near vision is proper
Reliability indices :
Fixation losses : 8/20xx |
False (+) ve error:3% |
False (–)ve error:0% |
Comment: High fixation loses. Test is unreliable |
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Interpretation: Advise to repeat the test. Sometimes in advanced glaucoma cases, we will get high fixation losses.
116 A VISUAL FIELD EVALUATION WITH AUTOMATED DEVICES
SINGLE FIELD ANALYSIS PRINTOUT WITH WEDGE SCOTOMA
(TEMPORAL WEDGE IN EARLY GLAUCOMA)
GHT within normal limits
Name of the patient |
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XXXX |
Reliability |
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Good |
Total deviation probability plot |
: Scotomas in the upper temporal field. |
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Pattern deviation probability plot |
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Similar type of depth defects as in TDPP. |
MD value |
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- 6.12 P<1% |
PSD value |
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7. 34 P< 2% |
Glaucoma Hemifield test: within normal limits
This is the field of known patient of POAG, the disk showing nasal pallor, intraocular tension more than 26 mm of Hg.
Still glaucoma hemifield test is within normal limits - How it is possible?
Please note that in GHT test, the area temporal to the blind spot was not included for comparative analysis. So, any scotoma temporal to blind spot will not be analyzed by the GHT test.
VISUAL FIELD LOSS IN GLAUCOMA 117
THE IMPORTANCE OF SELECTION OF THE TEST 10-2
IN ADVANCED CASES OF GLAUCOMA
Because of the following reasons, central 10-2 field should be selected in all advanced cases of glaucoma.
Whereas in 10-2 Central Field
Only one degree of bare area is left surrounding the fixation spot. From this we understand, most of the central space surrounding the fixation spot is tested in 10-2 field. If the field defect is progressing towards the fixation center upto 1° from the fixation spot, the computer presumes that the untested 1° bare area is also affected and hence we get a printout as if the central untested 1° is also affected. So the most important fact one should notice is to get the macular split the field defect should extend at least upto 1° from the fixation point and hence 10-2 test became the test of choice in advanced cases of glaucoma.
If some central field is preserved, for example, 30- 2 Central field/ 24-2 Central field:
3° bare area around fixation spot is not tested.
If the field defect extends from the periphery upto 3° from the fixation spot, the computer presumes that the untested 3° bare area is also affected and gives a printout as if the central untested 3° is also affected.
3° bare area of 30-2 and
24-2 in 10-2 field.
only 1° bare area is not tested surrounding the fixation spot 10-2 central field.
118 A VISUAL FIELD EVALUATION WITH AUTOMATED DEVICES
24-2 CENTRAL FIELD IN ADVANCED CASES OF
GLAUCOMA—CASE- I (LEFT EYE)
K. Venkata Reddy Left eye field Selection of the test : 24-2 SITA Standard Reliability : Good
A case of irregular generalized field defect 1. Generalized depres-
sion in the total deviation probability plot and localized field defect in the pattern deviation probability plot.
2. PSD : 12.82 dB P < 0.5%
3. MD : -19.53 dB P < 5%
24-2 Central field
Total deviation probability plot |
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Generalized depression in total deviation probability plot and |
Pattern deviation probability plot |
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lower arcuate field defect in the pattern deviation probability plot. |
PSD |
: 12.82 dB P < 0.5% |
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MD |
: –19.53 dB P < 5% |
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GHT |
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Outside normal limits |
Interpretation |
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Glaucoma field defect (advanced). |
VISUAL FIELD LOSS IN GLAUCOMA 119
10-2 CENTRAL FIELD OF THE SAME PATIENT (LEFT EYE)
10-2 Central field of the same patient
Because there is macular split in 24-2 field, 10-2 field was advised to know exactly the status of the macular split
The single field analysis printout with 10-2 is showing very good 5° field without macular split which was shown in 24-2 central field.
How important is the selection of 10-2 Central threshold test in advanced cases of glaucoma is shown here.
120 A VISUAL FIELD EVALUATION WITH AUTOMATED DEVICES
24-2 CENTRAL FIELD IN ADVANCED CASES OF GLAUCOMA
CASE—II (LEFT EYE)
S. Rami Reddy
Left eye field
Selection of the test : 24-2
SITA Standard
Reliability : Good
A case of uniform generalized field defect
1. Generalized depression in the total deviation probability plot and almost normal pattern deviation probability plot.
2. PSD : 6.24 dB P < 0.5%
3. MD : 30.35 P < 0.5%
24-2 Central field
Total deviation probability plot |
: Generalized depression with macular involvement. |
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Pattern deviation probability plot |
: No scotoma indicates gross uniform reduction in the |
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retinal sensitivity. |
PSD |
: 6.24 dB p < 0.5% |
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MD |
: 30.35 P < 0.5% |
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GHT |
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Outside normal limits |
Interpretation |
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Advanced glaucoma field defect. |