Diploscope test

What is a Diploscope?

A diploscope is an optical instrument that allows an orthoptist or ophthalmologist to present different images to each eye simultaneously. This controlled visual environment enables precise evaluation of how the eyes work together and helps in identifying issues with binocular vision.

Key Functions of Diploscopes

1. Measuring Heterophoria**: Diploscopes can accurately measure the tendency of the eyes to deviate from their normal position when fusion is disrupted.

2. Assessing Fusion**: These instruments help determine the patient's ability to combine images from both eyes into a single, coherent visual perception.

3. Evaluating Stereopsis**: Some diploscopes incorporate features to test depth perception and three-dimensional vision.

4. Diagnosing Suppression**: They can identify if one eye is being suppressed (ignored by the brain) during binocular viewing.

5. Measuring Cyclophoria**: Advanced diploscopes can assess rotational misalignment of the eyes.

Types of Diploscopes

1. Major Amblyoscope**: A large, table-mounted device offering a wide range of tests and measurements.

2. Synoptophore**: A more modern version of the major amblyoscope, often with digital capabilities

How to Use a Diploscope

The use of a diploscope varies slightly depending on the specific type and model, but here's a general guide using a synoptophore as an example:

1. Patient Positioning:

   • Seat the patient comfortably with their chin resting on the chin rest and forehead against the forehead rest.

   • Adjust the height of the instrument to align with the patient's eyes.

2. Calibration:

   • Adjust the interpupillary distance to match the patient's.

   • Ensure the optical centers align with the patient's pupils.

3. Image Presentation:

   • Select appropriate slides or digital images for each eye.

   • Start with the slides set at the patient's objective angle of deviation (if known).

4. Measurement:

   • For heterophoria measurement: a. Dissociate the images by using different slides for each eye. b. Ask the patient to report when the images align. c. Record the angle at which alignment occurs.

   • For fusion assessment: a. Present fusible images to each eye. b. Gradually increase separation and ask the patient to report when fusion breaks. c. Record the fusional range.

5. Stereopsis Testing:

   • Use specially designed stereo slides.

   • Ask the patient to describe the depth relationships in the images.

6. Suppression Testing:

   • Present different images to each eye.

   • Ask the patient what they see to determine if one image is being suppressed.

7. Documentation:

   • Record all measurements and observations.

   • Compare results to normative data and previous tests if available.

8. Patient Education:

   • Explain the findings to the patient and discuss their implications.

Clinical Applications

Orthoptists use diploscopes in various clinical scenarios:

• Diagnosing and quantifying strabismus (eye misalignment)

• Assessing binocular vision in amblyopia (lazy eye) treatment

• Monitoring progress during vision therapy

• Pre- and post-operative evaluation for eye muscle surgery

• Investigating complaints of diplopia (double vision)

Conclusion

Diploscopes remain indispensable tools in orthoptics, providing valuable insights into binocular vision function. While newer technologies have emerged, the fundamental principles behind diploscopes continue to inform and guide the diagnosis and treatment of a wide range of visual disorders. The proper use of these instruments requires skill and experience, allowing practitioners to gather crucial data for effective patient care.

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