Visual Field in Glaucoma

Testing Methods

Standard Automated Perimetry (SAP)

1. Humphrey Field Analyzer

- 24-2 SITA Standard

- 24-2 SITA Fast

- 10-2 for central field

- 30-2 for wider field assessment

2. Octopus Perimeter

- G1/G2 programs

- Dynamic strategy

- TOP strategy

- Custom testing patterns

Testing Parameters

Standard Protocols

1. 24-2 Protocol

- 54 test points

- Central 24 degrees

- 6-degree spacing

- Enhanced central testing

2. 10-2 Protocol

- Central 10 degrees

- 2-degree spacing

- Macular assessment

- Early damage detection

Testing Specifications

1. Stimulus Parameters

- Size III Goldman stimulus

- 200ms duration

- Background illumination: 31.5 asb

- White-on-white testing

Result Analysis

Key Indices

1. Global Indices

- Mean Deviation (MD)

- Pattern Standard Deviation (PSD)

- Visual Field Index (VFI)

- Global Loss Score (GLS)

2. Reliability Indices

- Fixation losses

- False positives

- False negatives

- Test duration

Pattern Recognition

1. Early Glaucoma

- Nasal step

- Paracentral scotoma

- Isolated points

- Superior arcuate defects

2. Moderate Glaucoma

- Arcuate defects

- Nasalization

- Deepening scotomas

- Expanding defects

3. Advanced Glaucoma

- Ring scotoma

- Central island

- Temporal island

- End-stage tunnel vision

Progression Analysis

Assessment Tools

1. Guided Progression Analysis (GPA)

- Baseline comparison

- Event analysis

- Trend analysis

- Rate of progression

2. Visual Field Index (VFI)

- Percentage scale

- Age-corrected

- Progression rate

- Long-term monitoring

Progression Patterns

1. Focal Deterioration

- Existing defect expansion

- New scotoma formation

- Depth increase

- Pattern changes

2. Diffuse Loss

- General sensitivity decrease

- Increased MD

- Decreased VFI

- Enhanced PSD

Clinical Management

Testing Frequency

1. Early Disease

- 6 tests first 2 years

- Baseline establishment

- Progression rate determination

2. Stable Disease

- Every 6-12 months

- Risk factor dependent

- Treatment response monitoring

3. Progressive Disease

- Every 3-4 months

- Treatment adjustment

- Close monitoring

Special Considerations

Patient Factors

1. Reliability Issues

- Age considerations

- Fatigue effects

- Learning curve

- Physical limitations

2. Testing Modifications

- Rest breaks

- Split testing

- Enhanced instructions

- Comfort adjustments

Technical Factors

1. Testing Conditions

- Proper correction

- Pupil size

- Lens clarity

- Media opacity

2. Quality Control

- Regular calibration

- Environmental conditions

- Staff training

- Standard procedures

Documentation Requirements

Essential Elements

1. Test Parameters

- Strategy used

- Reliability indices

- Testing conditions

- Patient factors

2. Result Analysis

- Global indices

- Pattern analysis

- Progression data

- Clinical interpretation

Conclusion

Visual field assessment remains fundamental in glaucoma management, providing crucial information about functional vision loss and disease progression. Understanding proper testing procedures, interpretation, and clinical applications is essential for optimal patient care.

Note : This document serves educational purposes exclusively and does not constitute medical advice or treatment guidelines