The view through hemianopic eyes: saccadic and anti-saccadic movements in patients with hemianopia

Purpose: The purpose of this study is to investigate the eye movements: saccade, anti saccade and vergence in patients with hemianopia and how they differ from the people with normal vision, also to see the differences in the results of the optometric tests in the selected sample. Participants: 8 patients were assessed, of which three of them had a stroke, the other 5 had different aetiologies, all of them diagnosed with hemianopia and 30 controls with normal vision. Method: The participants completed the saccade - antisaccade task and also they were assessed with optometric tests, more specifically DEM test (Developmental Eye Movement) test, NSUCO (Nova Southeastern University College of Optometry) and NCP (near convergence point) test. Results: The results showed no significant differences between groups for correctness of the saccades and antisaccades, although the delta for anti saccades was significant. Comparisons within the control group showed significant correctness, while delta was significant only with Bayesian analysis. In the patient group, correctness and delta were significant using paired t-test and Bayesian analysis. Mixed ANOVA was performed to see the effects of the task, effect of the group and interaction between them for correctness, delta and reaction time. For the variable correctness the interaction between task and group was not significant, while the significant interactions between the task and group was found for the variables delta and reaction time. Post hoc Bonferroni test showed the control group had larger difference between saccade and anti saccade (faster in saccade), while the patients showed smaller difference which was significant. Post hoc for delta showed in control group saccade and antisaccade is not statistically different, while in patients group delta is positive for antisaccade and negative for saccade. In the optometric tests, only the ratio between control and patient group was significant. Conclusion: The study showed no significant differences in the interaction between task and group for correctness, but for delta and time reaction were marginally significant.