Abstract
Abstract: :
Purpose: To determine duction ranges in normal subjects using the Goldmann perimeter and compare them to those results attained using a cervical range of motion device (CROM.) Methods: 20 normal subjects were selected to measure monocular ductions. Subjects were asked to follow an I4e target which moved in the vertical and horizontal meridian on the Goldmann perimeter. The end point of pursuit was determined by the examiner and reported by the patient. These same patients wore a CROM device and fixated on a 20/40 Snellen target at 6m while they moved their necks vertically and horizontally. In both cases subjects reported when the target blurred and that was recorded as their duction limit. Results: The average time to complete the exam for duction limits of both eyes was 280 seconds for the Goldmann Perimeter and 218 seconds for the CROM testing. The mean abduction using the Goldmann Perimeter was 53° ± 7.6° (Mean ± SD) and for the CROM 45.7° ± 11.0.° For adduction, the mean measurement on the Goldmann was 48.0° ± 7.03° and for the CROM 32.3 ° ± 11.3.° For supraduction, the Goldmann average was 42.2° ± 7.03° while the CROM averaged 24.4° ± 8.30.° Finally, the infraduction measurements had a mean of 57.2° ± 10.9° for the Goldmann perimeter and 49.7° ± 14.1.° for the CROM. Using a paired t test, there was a significant difference between the mean measurements of ductions on the Goldmann perimeter as compared to the CROM measurements. The Pearson coefficients for the correlation were P= .04 for abduction, P= 0.328 for adduction, P= 0.385 for supraduction, and P= 0.55 for infraduction. The mean duction ranges of our subjects were similar to those results reported by Gerling et al in their investigation of 100 normal subjects using the Goldmann Perimeter (see Table 1.) TABLE 1 Conclusion: In its current design the nose-piece of the CROM devise blocks visualization of targets moving nasally reducing the measurement of adduction. Similarly, the head band causes underestimation of elevation. The CROM device in its current version is poorly suited for duction measurements of patients with normal or nearly normal motility.
Keywords: eye movements • neuro-ophthalmology: diagnosis • ocular motor control