Date of Award
Master of Science in Vision Science
Scott C. Cooper
Near dissociated phoria measurements are effected by a variety of variables including accommodation, testing conditions, and procedures. Several studies have compared various techniques and repeatability of near phoria measurements. However, previous studies have not assessed target manipulation to determine how the phorias may be affected. The intention of this study was to evaluate if a change in card design has any influence on the outcome of near dissociated phoria measurements. Forty volunteers between the ages of 20 and 40 years were used to assess near point phorias using the von Graefe method. Phorias were measured with a standard near point card and an experimental near point card which eliminated most "white space" on the card. Two near phoria measurements per card per subject were performed independently by three examiners. The results showed a mean near phoria using the standard card was 3.730A exophoric and the mean phoria using the experimental card was 4.607A exophoric. Based on these values alone a statistical difference does exist. However, when interexaminer variability was taken into account a statistical difference does not exist between the standard and experimental near phoria targets. This was due to the large range of measurements between examiners.
Anderson, Traci; Fischer, Beth; and Wurst, Sandy S., "Differential near phoria measurements between standard and experimental targets" (2001). College of Optometry. 1360.