Investigating the Outcomes of Adult Strabismus Surgery Undertaken for Psychosocial Reasons

Introduction: Strabismus surgery undertaken for psychosocial reasons in adults aims to improve eye alignment and health related quality of life (HRQoL). Additionally, patients can gain a larger visual field, unexpected binocular single vision (BSV), and improved binocular summation, eye movements and task performance from surgery. Despite these improvements, NHS funding for strabismus surgery, without expected visual benefit, has been withdrawn in some areas of England due to concern that not enough patient benefit from surgery is proven. Methods: A mixed methods feasibility study was undertaken to investigate the outcomes of adult strabismus surgery undertaken specifically for psychosocial reasons. In the qualitative phase semi-structured interviews were conducted postoperatively and the findings informed the quantitative phase design. The quantitative phase prospectively recruited surgery and control group participants to undergo standard clinical measurements and additional study measurements. Results: In the qualitative interviews participants (n=13) reported a range of improvements in their vision, task performance, physical symptoms and confidence and emotions postoperatively. Compared to the control group (n=15), the surgery group (n=12) had postoperative quantitative improvements in binocular summation at 100% contrast, coarse stereotest (CST) performance, the time to perform a touchscreen spatial localisation (TSL) task and the time to perform the clinical kinematic assessment tool (CKAT) aiming task. Improvements were also reported in vision, task performance, physical symptoms, confidence and emotions, and health related quality of life (HRQoL) using patient reported outcome measures (PROMs). Most measures were unchanged and some worsening of task performance (bead threading and grooved pegboard) was measured postoperatively. Conclusion: Strabismus surgery undertaken for psychosocial reasons can lead to objective improvements in vision and task performance and subjective improvements in vision, task performance, physical symptoms and confidence and emotions. These improvements were in addition to the typically expected outcomes of improved eye alignment and improved HRQoL.