The most prevalent type of exotropia is intermittent exotropia, which affects around 3 % of Chinese youths. Intermittent exotropia is treated with a combination of patching, prism, overminus lens, vision therapy, and surgery. Currently, there is no consensus on which therapy modality is the most effective for this condition. There have been a number of randomized clinical investigations of occlusion and over the minus lens that support their usage. Surgery is a common therapeutic option for patients with intermittent exotropia, although there is little evidence to back it up. There is a scarcity of data from randomized clinical trials comparing the effects of surgical treatment versus observation alone. Furthermore, it is frequently noted that following surgery, the ailment has a high tendency to return, and a substantial percentage of patients require reoperation.
Unlike surgery, which tries to minimize the size of the deviation, vision therapy is primarily concerned with increasing exodeviation control. Visual skills that may aid in the regulation of exodeviation are developed by vision therapy. There have been a lot of studies that show vision treatment is effective for intermittent exotropia, but none of them used approved methods to assess exodeviation control.
Participants with intermittent exotropia
This was a chart review that was done in the past. From 2017/01 to 2018/12, all patients who received office-based vision therapy for intermittent exotropia in a private optometric clinic were evaluated. Patients who got vision therapy were reevaluated every 5 therapy sessions, and only those who had had at least 5 sessions were studied. Visual acuity in each eye had to be correctable to 20/25 or better in all cases. Intermittent exotropia patients with and without strabismus surgery were both included in the study.
Results
The results of this study suggest that in a private practice setting, office-based vergence/accommodative therapy was beneficial in improving the control of intermittent exotropia in both operated and unoperated patients. This study also indicates that the Office Control Score can be used in a private practice setting.
Several studies have found that vision therapy is useful in the treatment of intermittent exotropia. Previous research, on the other hand, typically included many criteria to assess the success of vision therapy. These criteria vary a lot between research, making it impossible to make meaningful comparisons. It’s worth noting that there’s just one study of vision therapy in the literature that uses a stand-alone control ability outcome measure. Based on the frequency with which exodeviation was decompensated, the control capacity was graded as good, moderate, or poor in that study. They established that their treatment group, which received fusion exercises, improved in distance stereopsis, fusional vergence, and distant deviation control. However, it should be noted that their control ability assessment and grouping approach was not validated.
In conclusion, in a private practice setting, office-based vergence/accommodative therapy with home reinforcement significantly improved exodeviation control in both operated and un-operated intermittent exotropia patients. When treating intermittent exotropia, eye care professionals should consider vision therapy. Our preliminary findings call for more research into the efficacy of vision treatment on intermittent exotropia, such as randomized controlled clinical trials. The effect of postoperative vision therapy on the prognosis of intermittent exotropia (i.e., lowering the risk of recurrence and requiring re-operation) should also be investigated further.
Ma, M. M. L., Kang, Y., Chen, C., Su, C., Tian, Z., & Le, M. (2020). Vision therapy for intermittent exotropia: A case series. Journal of Optometry. Published. https://doi.org/10.1016/j.optom.2020.05.006
