Comparing ocular muscle limitation tests for clinical trial use

Area of Science:

• Ophthalmology
• Clinical Trials
• Neurology

Background:

• Ocular muscle limitation assessment is crucial for diagnosing and monitoring various neurological and ophthalmological conditions.
• Standardized and portable methods are needed for multi-site clinical trials to ensure consistent data collection.
• Existing methods for documenting ocular muscle limitation vary in precision and portability.

Purpose of the Study:

• To evaluate the reliability and repeatability of portable methods for documenting ocular muscle limitation in a clinical trial setting.
• To compare a clinical grading scale, the Kestenbaum limbus test, and an adapted cervical range of motion (CROM) device for ocular duction testing.

Main Methods:

• A prospective case series involving 2 independent examiners evaluating 20 patients with diplopia.
• Methods assessed included a 0 to -5 grading scale, Kestenbaum test (measuring in millimeters), and CROM device (measuring in degrees).
• Patients had conditions such as ocular myasthenia gravis, cranial nerve palsies, and dysthyroid ophthalmopathy.

Main Results:

• The Kestenbaum test showed good inter-examiner repeatability with 95% of differences within 4 mm.
• The CROM device demonstrated high intra-examiner repeatability (differences < 2 degrees) but moderate inter-examiner repeatability (95% within 15 degrees).
• The clinical grading scale achieved identical scores between examiners in 85% of ductions.

Conclusions:

• The Kestenbaum test and CROM device offer comparable inter-examiner repeatability for ocular muscle limitation.
• While CROM device measurements are highly consistent within an examiner, inter-examiner consistency is less robust.
• The clinical grading scale provides reliable and consistent results between examiners, making it a viable option for multi-site trials.