Comparative Study Between Modified Thorington Test and Von Graefe Phorometry on Near Lateral Phoria Assessment among Emmetropes
Authors: Atuanya GN, Uchendu VC, Musa MJ, Akpalaba RUE
The aim of this study was to compare the modified Thorington test and Von Graefe Phorometry in the assessment of near lateral phoria among emmetropes. A total of one hundred subjects (N=100), consisting of 56 males and 44 females, with a mean age of 22.57±3.26 years participated in the study. The modified Thorington and Von Graefe techniques were performed at near (40 cm) using the Bernell muscle imbalance measure card commonly known as Thorington card and the Phoropter respectively under standard testing procedures. Results showed that the near phoria measurements with the Von Graefe technique ranged from 6Δ esophoria to 12Δ exophoria with a mean of 4.90±3.84Δ exophoria, while that with modified Thorington technique ranged from orthophoria to 12Δ exophoria with a mean of 4.67±2.91Δ exophoria. Although the Von Graefe phorometry showed a broader range of exophoria as compared with the modified Thorington, it was not statistically significant (p<0.05). In conclusion, the Von Graefe technique cannot be replaced by the modified Thorington technique in the measurement of near phoria.
Affiliations: Department of Optometry, Faculty of Life Sciences, University of Benin, PMB 1154, Benin City, Nigeria.
Keywords: Modified Thorington, Von Graefe, Phorometry, Lateral Phoria, Emmetropes
Published date: 2020/12/30