The usefulness of the cervical range of motion device in the ocular motility examination

Objectives: To determine if the cervical range of motion (CROM) device, an instrument designed to assess the range of motion in the cervical spine, ma y be suited for accurately quantifying the magnitude of a patient's abnorma l head posture, limitation of ductions, or range of single binocular vision at distance fixation. Methods: The CROM device was used to measure abnormal head postures in 10 s ubjects and limitations of ductions in 12 patients by 2 masked observers. I n addition, it was used to test the diplopia field in 17 patients at one th ird of a meter and 6 m. These findings were compared with a standard diplop ia field performed on a Goldmann perimeter. Results: For 10 subjects with abnormal head postures, the findings of the 2 observers had a mean+/-SD difference of 1.0 degrees+/-0.7 degrees (P=.15, paired t test). For the assessment of limitations of ductions, the findings of the 2 observers had a mean+/-SD difference of 1.1 degrees+/-12.6 degree s (P=.17, paired t test). For the 17 patients undergoing diplopia field tes ting, the results obtained on the Goldmann perimeter and with CROM device a t the same test distance were essentially identical (mean+/-SD difference o f 1.3 degrees+/-0.95 degrees; P=.88, paired t test); however, there was a s ignificant difference between een the results at one third of a meter and 6 m (mean+/-SD difference of 6.0 degrees+/-1.1 degrees for esotropic patient s [P=.001]; mean+/-SD difference of 6.0 degrees+/-2.6 degrees for exotropic patients [P=.002]). Conclusion: The CROM device seems to be suitable for testing abnormal head postures, limitations of ductions, and the range of single binocular vision .