Visual Field Changes in Idiopathic Intracranial Hypertension

Clinical Presentation

Characteristic Visual Field Defects

- Enlarged blind spot (most common initial finding)

- Nasal step defects

- Arcuate defects

- Concentric constriction

- Central scotoma (in advanced cases)

Pattern of Progression

1. Early Stage:

- Enlarged blind spot

- Subtle peripheral nasal defects

2. Intermediate Stage:

- Inferior nasal quadrant defects

- Progressive arcuate defects

3. Advanced Stage:

- Severe constriction

- Central vision involvement

- Potential total field loss

Assessment Protocol

Initial Evaluation

Essential components include:

- Baseline visual field testing (24-2 and 30-2 SITA Standard)

- Careful blind spot mapping

- Central threshold testing

- Reliability indices documentation

Testing Strategies

Recommended approaches:

1. Static Perimetry:

- Humphrey Visual Field Analyzer

- 24-2 SITA Standard as primary test

- 30-2 for peripheral involvement

2. Kinetic Perimetry:

- Goldmann perimetry for severe cases

- Useful for peripheral field assessment

3. Special Considerations:

- Blue-on-yellow perimetry for early detection

- Frequency doubling technology

- OCT correlation for structure-function analysis

Monitoring and Management

Follow-up Protocol

Frequency based on disease severity:

- Acute phase: Weekly to bi-weekly

- Stable phase: Monthly to quarterly

- Remission: Every 6 months

Critical Measures

Key parameters to monitor:

- Mean deviation (MD)

- Pattern standard deviation (PSD)

- Visual field index (VFI)

- Point-by-point analysis

- GHT (Glaucoma Hemifield Test) results

Clinical Interpretation

Key Patterns

Important features to identify:

1. Spatial Pattern:

- Location of defects

- Symmetry between eyes

- Progression pattern

2. Temporal Changes:

- Rate of progression

- Response to treatment

- Recovery patterns

Red Flags

Critical findings requiring immediate attention:

- Rapid progression of field defects

- New central field involvement

- Sudden asymmetric changes

- Decreased reliability indices

Treatment Monitoring

Visual Field Response

Indicators of treatment effectiveness:

- Improvement in MD values

- Reduction in blind spot size

- Resolution of nasal steps

- Stabilization of field defects

Recovery Patterns

Typical progression of improvement:

1. Early Phase:

- Reduction in blind spot size

- Improvement in peripheral sensitivity

2. Late Phase:

- Resolution of arcuate defects

- Recovery of central sensitivity

Documentation and Reporting

Essential Elements

Required documentation:

- Quantitative measures (MD, PSD, VFI)

- Qualitative description of defects

- Comparison with previous tests

- Reliability indices

- Treatment correlation

Communication

Important aspects to report:

- Changes requiring medical intervention

- Treatment effectiveness

- Compliance issues

- Quality of life impact

Clinical Recommendations

Best Practices

For optimal assessment:

1. Standardized Testing:

- Consistent testing strategy

- Same time of day when possible

- Regular calibration checks

2. Patient Factors:

- Proper patient instruction

- Fatigue consideration

- Optimal correction

- Pupil size documentation

Conclusion

Visual field assessment in IIH requires systematic approach, careful interpretation, and regular monitoring. Understanding the patterns and progression of field defects is crucial for effective management and preservation of vision.

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