Basic approach on HVF

Basic to HVF

1. BASIC APPROACH ON HVF

2. HUMPHREY VISUAL FIELD STANDARD AUTOMATED PERIMETRY STATIC PERIMETRY MEASUREMENT OF THRESHOLD VALUES STATPAC (HFA)- comparison to normative data Inbuilt program for analysis- diagnosis and progression

3. WHITE ON WHITE BACKGROUND ILLUMINATION – 31.5 asb Stimulus size- Goldmann III DURATION OF SPOT EXPOSURE 0.2s

4. PROGRAMS/PATTERNS 30-2 – gold standard 24-2 10-2 MACULA C40 SCREENING Estermann test – for binocular 120 deg field

5. BEFORE RUNNING THE TEST: Selection of adequate test VA Proper environment Comfortable sitting position Adequate size of pupil >3mm Adequate Near correction Proper explanation – running of demonstration Reassurance – not all points will be seen - test can be paused by keeping the response button pressed

6. WANDER W hat was done? A ccuracy (Reliability) N ormal or abnormal D efect pattern E valuate compatible disease R eview

7. ZONE 1 : REPRODUCIBILITY

8. ZONE 2: RELIABILITY Fixation monitor Fixation target – central, small diamond, large diamond, bottom LED Test duration Reliability indices Fixation losses ( Heijl Krakau ) <20 % Gaze tracking False positives < 33% (trigger happy) False negatives < 33 %

9. ZONE 3 : GREY SCALE Based on actual threshold values at each location General identification Patient information

10. ZONE 4: TOTAL DEVIATION PLOT Numerical plot – indicates by how much decibels is each point depressed compared to mean value in normal population of similar age Probability plot- grey scale indicates the probability of occurrence of the deviation in normal population Generalized depression due to media opacities, refractive error, miosis may hamper appearance of a pattern

11. ZONE 5 : PATTERN DEVIATION PLOT Numerical - calculated by adjustment for generalized depression or elevation of visual field Thus brings out pattern Probability plot Significance - ANDERSON’S CRITERIA

12. ZONE 6 : GLOBAL INDICES MEAN DEVIATION : average loss of sensitivity from normal age matched population along with probability calculated from total deviation plot PATTERN STANDARD DEVIATION : range over which change of sensitivity at all the points has occurred, along with probability compensates for effect of generalized depression or elevation of field on mean deviation value local defects affect PSD > MD SHORT TERM FLUCTUATIONS CORRECTED PATTERN STANDARD DEVIATION

13. GLOBAL INDICES -2 (<-6dB) MILD GENERALISED DEPRESSION -7 (<-12dB) MODERATE GENERALISED DEPRESSION -13 (>-12dB) SEVERE GENERALISED DEPRESSION

14. ZONE 7 : GLAUCOMA HEMIFIELD TEST Comparison of 5 clusters of points in superior hemifield with mirror images in inferior hemifield

15. ANDERSON CRITERIA 3 or more congrous ‘non edge points’ in typical arcuate area on 30-2 program depressed @ p< 5 % with at least one point @ p<1 % PSD / CPSD @ p< 5% GHT – outside normal limits  Must be demonstrated on 2 field tests

16. QUALITY OF VF Good eye-hand coordination -not suitable for pt with nystagmus , parkinson , Corrected rx Poor result lead to misdiagnosis Bad day

17. VF ARTIFACTS OBSTRUCTION RIM ARTEFACTS PTOSIS MEDIA OPACITIES MIOSIS REFRACTION ARTEFACTS High power plus and minus lenses

18. VISUAL FIELD DEFECT

19. MONITORING VF PROGRESSION New case/glaucoma suspect : 2 VF IN FIRST 6 MONTH. 2 MORE VF IN NEXT 18 MONTH 4 VF in 2 years MD ≥-2DB/ year : 6 VF in the first 2 year After first 2 years  stable / slow risk : once a year Low mod risk – once yearly High risk – 6 month

20. Excellence is not being the best. It is doing the best. Thank you.