Negative Vergence Training and its Effect on the Divergence Range and Heterophoria Size

Abbey Salah, BappSc (Orth)(Hons)
Kathryn Thompson, DipAppSc (Orth) (Cumb) DOBA
GradCertHlthScEd.MSc (Orth) Cumb
Elaine Cornell, DipAppSc (Orth) (Cumb)DOBA. MA (Macq)
Nathan Moss, BSc ( Hons) UQld PhD (UNSW)

School of Applied Vision Sciences,
Faculty of Health Sciences
University of Sydney

This study aimed to investigate the extent to which negative Vergence training can influence the divergence range and the associated Heterophoria size. Forty ocularly healthy participants (11 males & 29 females) with an age range between 17-64 years (mean age=26.6 yrs; SD=12.1yrs) were included in the study. The participants were randomly allocated into four groups (n=10/Gp). The first group was trained using the diploscope treatment only, the second group was trained using the cat-stereograms card with additional modifications applied to it, the third group was trained using a standard cat-stereograms card without any modifications. Participants in these groups underwent training for 5 minutes, 3 times a day for 2 weeks. Lastly the control group did not undergo any training.
Results indicated that there was a significant change in the mean near Heterophoria size post training in all groups. This significant change was attributed to chance occurrence and may not yield any clinical relevance. A close to significant interaction between the groups training the cat-stereograms card with modifications and the group training with the standard cat-stereograms card was also found, signifying a better treatment success with modifications applied to the standard cat-stereograms card. Single case analysis of three esophoric participants, pointed to a possible future study to examine the impact of treatment on this group.