# Changes of Gait Patterns after Correction of Refractive Error in the Elderly with Cataracts
## 4 Discussion
In our previous study that included healthy young adult subjects [18; 33], which compared a fully corrected condition to induced myopia of S + 1.00 D for both eyes, and induced hyperopia of S \(-\) 1.00 D for both eyes, step length showed a significant decrease, while cadence increased, with expansion of the area of body sway during the process of walking in both anterior-posterior and left-right directions. Based on these findings, we can confirm that changes in habitual gait patterns can occur regardless of age as a result of uncorrected refractive errors. Step width is related to balance control and increased gait stability, and it can be an important factor in gait analysis. [PERSON] et al. [34] suggest that extreme (either too little or too much) step width variability is associated with falls in elderly people who walk at or near normal gait speed and not in in the elderly who walk slowly. Although the step width increased after the participants wore correction glasses in this study, the degree of change was very small, and so there is a limit when it comes to suggesting clinical significance. An analysis of the correlation between changes in step length and different factors affecting gait patterns was here performed in order to determine the cause of changes in gait patterns resulting from the correction of residual refractive errors in elderly subjects (Figure 2). A correlation was observed between an increase in step length after wearing correction glasses and an increase in stride length (r = 0.779/\(p\) = 0.000, Figure 2a), which resulted in a decrease in cadence (r = \(-\) 0.686/\(p\) = 0.000, Figure 2b). A proportional increase in speed with increasing step length was observed with regard to walking velocity after the participants wore correction glasses (r = 0.416/\(p\) = 0.022, Figure 2d). The degeneration of foot and ankle joint function in the elderly is a major cause of postural instability and the increased risk of falls [35]. As suggested by [PERSON] and [PERSON] [36], the ability to process information from feet and ankle joints might decrease with aging, leading to greater dependence on visual information in order to maintain balance. According to the findings of our previous study [37], elderly subjects showed improved synchronization in the left foot as a whole and for both heels, both forefeet, and the left forefoot and right heel after wearing correction glasses. The improvement of static postural stability through the maintenance of the somatic system and enhancement of the capacity for sensory integration was also observed. Therefore, based on the results of our previous research as well as those of this study, the positive effects of correcting refractive errors in elderly patients are not limited to the ability to maintain posture but also extend to gait patterns for mobility. These findings should be considered important for professionals who perform analysis of balance and gait models or are involved in administration of rehabilitation therapy for the accurate diagnosis and treatment of elderly patients. In particular, the findings of this study, which was not conducted under the same experimental conditions employed in our previous studies (in other words, the participants in this study had not previously worn correction glasses), demonstrated that merely wearing correction glasses can result in a more stable change in gait patterns in the elderly; thus, the clinical implications are significant [18,33]. In addition, we examined changes in the gait patterns of the participants in order to determine the effect of refractive error components and visual improvement after vision corrections (Table 2). According to our findings, the level of spherical equivalent power and astigmatic diopter power had no influence on the subjects' gait patterns.