To evaluate portable methods for documenting ocular muscle limitationthat might be used at multiple sites in a clinical trial.
In a prospective consecutive case series, 2 examiners independentlyevaluated 3 methods of ocular muscle duction testing: a grading scale of 0to −5 that is in clinical use, the Kestenbaum limbus test using a rulerto measure the millimeters of ocular movement, and an adapted cervical rangeof motion (CROM) device that measures ocular movement in degrees. Twenty consentingpatients (mean age, 55 years) with diplopia, 8 with ocular myasthenia gravis,11 with a cranial nerve III or VI palsy, and 1 with dysthyroid ophthalmopathywere studied.
For Kestenbaum measures, between examiners the standard deviation ofthe difference for all ductions was 1.9 mm (r = 0.75, P = .01); 95% of differences were 4 mm or less. For theCROM device, the standard deviation of the difference was 7.1°; 95% ofdifferences were 15° or less (r = 0.73, P = .01). For each examiner, the CROM standard deviationof the difference was less than 2° (r = 0.98, P = .01). For the grading scale, the 2 examiners had thesame score in 85% of ductions (r = 0.92, P = .01).
The Kestenbaum test and the CROM device gave similar interexaminer repeatability.The repeatability for CROM measures for each examiner was high but was considerablyless between examiners. The grading scale gave similar results between examiners.