Abstract
Abstract: :
Purpose: Quantitative assessment of the afferent system has gradually become more detailed from Snellen’s original description of optotypes to a more recent addition of automated static perimetry, FDT, OCT, and nerve fiber layer thickness assessment. Efferent system abnormalities have been far less amenable to quantitation. Hess, Lancaster screens, and binocular single vision fields reveal asymmetry in ocular motility, but there has been little attention to quantitative duction measurements. Recent studies of orthopedic equipment (CROM) has proven less reliable than the gold standard of Goldmann bowl perimeter measurement of ductions. Goldmann bowl are becoming less accessible. We have attempted to adapt the Humphrey’s kinetic system to measure ductions. Methods:A Humphrey’s 750 apparatus with kinetic perimetry option was studied as a pilot means of quantitatively assessing ductions. Results: The custom program on the Humphrey’s kinetic perimetry option allowed a stimulus to move from central fixation eccentrically. While all meridians could be tested, we chose to look at 0, 90, 180, and 270 meridians giving up, down, left, and right gaze. The patient was instructed to follow the stimulus until it blurred. By increasing the stimulus size to the Goldmann V size, the drift off the fovea resulting in blurring could be better appreciated. Conclusions: This pilot study indicates that the Humphrey’s system with kinetic perimetry option can be easily adapted for quantitative duction measurements. Initial results suggest the use of a V size test object gives more accurate readings. Preliminary studies suggest reasonable reproducibility and gross comparison with Goldmann duction measurements. Programming modifications may make this simpler by reducing the number of inputs required. Quantitative duction measurements may be important in following patients with ocular motility disturbances such as ophthalmoplegia, myasthenia gravis, and thyroid restrictive disease.
Keywords: eye movements • eye movements: recording techniques • neuro-ophthalmology: diagnosis