Table_1_The effects of blurred visual inputs with different levels on the cerebral activity during free level walking.docx

ObjectiveThe aim of this study was to evaluate the effects of blurred vision on electrocortical activities at different levels during walking.Materials and methodsA total of 22 healthy volunteers (all men; mean age: 24.4 ± 3.9 years) underwent an electroencephalography (EEG) test synchronous with free level walking. Visual status was simulated by goggles covered by the occlusion foil targeted at a Snellen visual acuity of 20/60 (V0.3), 20/200 (V0.1), and light perception (V0). At each of these conditions, the participants completed barefoot walking for five blocks of 10 m. The EEG signals were recorded by a wireless EEG system with electrodes of interest, namely, Cz, Pz, Oz, O1, and O2. The gait performances were assessed by the Vicon system.ResultsDuring walking with normal vision (V1.0), there were cerebral activities related to visual processing, characterized as higher spectral power of delta (Oz and O2 vs. Cz, Pz, and O1, p ≤ 0.033) and theta (Oz vs. Cz and O1, p = 0.044) bands in occipital regions. Moderately blurred vision (V0.3) would attenuate the predominance of delta- and theta-band activities at Oz and O2, respectively. At the statuses of V0.1 and V0, the higher power of delta (at V0.1 and V0, Oz, and O2 vs. Cz, Pz, and O1, p ≤ 0.047) and theta bands (at V0.1, Oz vs. Cz, p = 0.010; at V0, Oz vs. Cz, Pz, and O1, p ≤ 0.016) emerged again. The cautious gait pattern, characterized by a decrease in gait speed (p ConclusionMildly blurred visual inputs would elicit generalization of low-frequency band activity during walking. In circumstance to no effective visual input, locomotor navigation would rely on cerebral activity related to visual working memory. The threshold to trigger the shift might be the visual status that is as blurred as the level of Snellen visual acuity of 20/200.</p

Effects of optotype speed on dynamic visual acuity (DVA).

<p>The resolution of dynamic optotypes in the control group and in the patient group was adversely affected by increasing speed. During the preoperative phase, the patient group showed worse DVA performance than the control group at all the four speed levels (p<0.001) (A). Postoperatively, DVA performance in the patient group improved significantly (p<0.001) (B) and recovered to levels comparable to the control group (C). SVA was treated as visual acuity at 0 dps. Error bars depict standard errors of the means (SEMs). LogMAR, logarithm of the minimum angle of resolution; dps, degree per second; pre, preoperative; post, postoperative.</p

Significant Improvement in Dynamic Visual Acuity after Cataract Surgery: A Promising Potential Parameter for Functional Vision

<div><p>Purpose</p><p>Dynamic visual acuity (DVA) is a relatively independent parameter for evaluating the ability to distinguish details of a moving target. The present study has been designed to discuss the extent to which age-related cataract impacts DVA in elderly individuals and to determine whether it could be restored after bilateral phacoemulsification combined with intraocular lens implantation surgery.</p><p>Methods</p><p>Twenty-six elderly cataract patients scheduled for binocular cataract surgery and 30 elderly volunteers without cataract were enrolled in the study. DVA at 15, 30, 60 and 90 degree per second (dps) was assessed, and velocity-dependent visual acuity decreases between consecutive speed levels were calculated.</p><p>Results</p><p>Compared with the control group, the patient group exhibited significantly worse DVA performance at all speed levels (p<0.001), and the decreases in velocity-dependent visual acuity were more serious in the patient group at the intervals of 0–15 dps (p<0.001), 15–30 dps (p = 0.007) and 30–60 dps (p = 0.008). Postoperatively, DVA performance at every speed level in the patient group clearly improved (p<0.001) and recovered to levels compatible to the control group. The decrease in visual acuity with increasing speed was less pronounced than during the preoperative phase (p_{0–15 dps} = 0.001, p_{15–30 dps}<0.001 and p_{30–60 dps} = 0.001) and became similar to that of the control group. The postoperative visual benefit regarding DVA was more pronounced than the improvement in static visual acuity (p_{15 dps} = 0.001 and p<0.001 at 30 dps, 60 dps and 90 dps).</p><p>Conclusions</p><p>The impact of age-related cataract on DVA was more severe than its effects on static visual acuity. After cataract surgery, not only static vision of the patients was restored markedly, but also the dynamic vision. DVA could be an important adjunct to the current evaluation system of functional vision, thereby meriting additional attention in clinical assessment.</p></div

Comparison of postoperative visual benefit between static and dynamic setting.

<p>Postoperative improvement in dynamic visual acuity (DVA) at every speed level was more statistically significant than the improvement of binocular static visual acuity (SVA) (p≤0.001). The static condition was treated as a speed level of 0 dps. Error bars represent standard errors of the mean values (SEMs). LogMAR, logarithm of the minimum angle of resolution; dps, degree per second.</p

Binocular static visual acuity and dynamic visual acuity.

<p>Note. SVA, static visual acuity; DVA, dynamic visual acuity; logMAR, logarithm of the minimum angle of resolution; dps, degree per second; pre, preoperative; post, postoperative.</p><p>Values are presented as means ± standard errors of the means (SEMs).</p><p>*indicates statistical significance when comparing the control group and the patient group during the preoperative phase.</p>#<p>indicates statistical significance when comparing the pre- and postoperative phases in the patient group.</p><p>Binocular static visual acuity and dynamic visual acuity.</p