Maddox Test

Equipment Required

- Maddox rod (red filter typically used)

- Light source (pen torch)

- Prism bar or loose prisms

- Distance fixation target

Test Versions

1. Maddox Rod Test

- Single Maddox rod

- Used for distance and near measurements

- Measures one plane at a time

2. Double Maddox Rod Test

- Uses two Maddox rods

- Specifically for cyclophoria/cyclotropia measurement

- Can detect torsional deviations

Testing Procedure

Basic Setup

1. Position patient at required testing distance

2. Place Maddox rod before one eye (traditionally right eye)

3. Present light source at appropriate distance

4. Ensure proper room illumination (dim lighting preferred)

Horizontal Deviation Assessment

1. Position cylinders vertically to create horizontal streak

2. Ask patient to report streak position relative to light:

- Streak through light = Orthophoria

- Streak right of light = Esophoria/tropia

- Streak left of light = Exophoria/tropia

Vertical Deviation Assessment

1. Position cylinders horizontally to create vertical streak

2. Patient reports streak position:

- Streak through light = Orthophoria

- Streak above light = Right hyperphoria/tropia

- Streak below light = Right hypophoria/tropia

Measurement Process

1. Introduce prisms to align streak with light

2. Note prism power needed for alignment

3. Record direction and magnitude of deviation

Clinical Interpretation

Normal Values

- Distance: 1Δ exophoria to 2Δ esophoria

- Near: 3-5Δ exophoria

- Vertical: 0-2Δ

Abnormal Findings

1. Horizontal Deviations

- Significant esophoria/tropia (>5Δ)

- Large exophoria/tropia (>10Δ)

2. Vertical Deviations

- Any vertical deviation >2Δ

- Pattern deviations in different gazes

Clinical Applications

Primary Uses

1. Screening for phorias/tropias

2. Monitoring stability of deviations

3. Pre/post-operative assessment

4. Vertical deviation measurement

Advantages

- Quick administration

- Good patient understanding

- Reliable for vertical deviations

- Easily quantifiable results

Limitations

- Subject to patient cooperation

- Artificial viewing conditions

- Not suitable for young children

- Limited by patient's fusion ability

Documentation Requirements

1. Record test distance

2. Note deviation direction and magnitude

3. Document testing conditions

4. Report patient symptoms during testing

Tips for Accurate Testing

1. Ensure proper room illumination

2. Maintain consistent testing distance

3. Use standardized instructions

4. Check patient understanding

5. Compare with alternate cover test results

Common Pitfalls

1. Incorrect Maddox rod orientation

2. Poor room illumination

3. Inconsistent testing distance

4. Inadequate patient instructions

5. Failure to note associated symptoms

Modifications for Special Cases

1. Non-verbal patients

- Use pointing methods

- Observe fixation behavior

2. Torsional assessment

- Double Maddox rod technique

- Document in degrees of rotation

Clinical Pearls

1. Always compare with cover test

2. Test at both distance and near

3. Document associated symptoms

4. Consider refractive status

5. Note fusion ability

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