Date of Award
Master of Science in Vision Science
Vertical phorias detected in the phoropter using the Von Graefe technique are often regarded as artifactual, while vertical duction (vergence) findings are usually considered valid and reliable indicators of true vertical deviations. Data from twenty-two patient case records showing vertical phorias were used to determine the correlation between the vertical phorias and the midpoints of the opposing duction values. In general, the calculated correlation coefficients were significant, thereby supporting the results of earlier studies. Hence, for these twenty-two patients, the Von Graefe vertical phoria proved to agree fairly well with the vertical imbalance shown by the vertical vergences.
Nelson, Randall K., "How trustworthy are vertical phoria findings in the phoropter?" (1982). College of Optometry. 626.