Analysis of Response to Prism Stimulation in Exophoria Patients

Abstract

Purpose: The objective of the present study was to identify the differences in real responses to prism stimulation in patients with exophoria. Methods: The present study involved 25 participants with exophoria who did not have any eye disease and had best correct visual acuity of 20/20 or better. A synoptophore was used to measure the subjective and objective deviation angles, as well as the angle of anomaly. Moreover, responses to prism stimulation were identified using afterimage transfer test with the synoptophore. Results: Among the total of 25 participants, 16(64%) showed anormalous retinal correspondence (ARC), with 5(20%) and 11(44%) having harmonious and unharmonious ARC, respectively. Prevalence of ARC was higher than normal retinal correspondence(NRC) in both groups divided according to amount of deviation angle. However, both NRC and ARC were found to have low correlations with amount of deviation angle(p=0.25, p=0.53, p=0.38). In the afterimage transfer test, position of the initial afterimage had a statistically significant correlation with angle of anomaly(p<0.05). Real fusional movement(RFM) in response to prim stimulation was identified in ARC(p<0.05), and the point at which RFM stopped and angle of anomaly showed statistically significant results(p<0.05). Conclusions: It is concluded that identification of responsive state, including the angle of anomaly, may be helpful as data needed during surgical and/or non-surgical treatment.